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Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus')
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diff --git a/vendor/github.com/prometheus/client_golang/prometheus/README.md b/vendor/github.com/prometheus/client_golang/prometheus/README.md new file mode 100644 index 0000000..44986bf --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/README.md @@ -0,0 +1 @@ +See [](https://godoc.org/github.com/prometheus/client_golang/prometheus). diff --git a/vendor/github.com/prometheus/client_golang/prometheus/collector.go b/vendor/github.com/prometheus/client_golang/prometheus/collector.go new file mode 100644 index 0000000..623d3d8 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/collector.go @@ -0,0 +1,75 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +// Collector is the interface implemented by anything that can be used by +// Prometheus to collect metrics. A Collector has to be registered for +// collection. See Registerer.Register. +// +// The stock metrics provided by this package (Gauge, Counter, Summary, +// Histogram, Untyped) are also Collectors (which only ever collect one metric, +// namely itself). An implementer of Collector may, however, collect multiple +// metrics in a coordinated fashion and/or create metrics on the fly. Examples +// for collectors already implemented in this library are the metric vectors +// (i.e. collection of multiple instances of the same Metric but with different +// label values) like GaugeVec or SummaryVec, and the ExpvarCollector. +type Collector interface { + // Describe sends the super-set of all possible descriptors of metrics + // collected by this Collector to the provided channel and returns once + // the last descriptor has been sent. The sent descriptors fulfill the + // consistency and uniqueness requirements described in the Desc + // documentation. (It is valid if one and the same Collector sends + // duplicate descriptors. Those duplicates are simply ignored. However, + // two different Collectors must not send duplicate descriptors.) This + // method idempotently sends the same descriptors throughout the + // lifetime of the Collector. If a Collector encounters an error while + // executing this method, it must send an invalid descriptor (created + // with NewInvalidDesc) to signal the error to the registry. + Describe(chan<- *Desc) + // Collect is called by the Prometheus registry when collecting + // metrics. The implementation sends each collected metric via the + // provided channel and returns once the last metric has been sent. The + // descriptor of each sent metric is one of those returned by + // Describe. Returned metrics that share the same descriptor must differ + // in their variable label values. This method may be called + // concurrently and must therefore be implemented in a concurrency safe + // way. Blocking occurs at the expense of total performance of rendering + // all registered metrics. Ideally, Collector implementations support + // concurrent readers. + Collect(chan<- Metric) +} + +// selfCollector implements Collector for a single Metric so that the Metric +// collects itself. Add it as an anonymous field to a struct that implements +// Metric, and call init with the Metric itself as an argument. +type selfCollector struct { + self Metric +} + +// init provides the selfCollector with a reference to the metric it is supposed +// to collect. It is usually called within the factory function to create a +// metric. See example. +func (c *selfCollector) init(self Metric) { + c.self = self +} + +// Describe implements Collector. +func (c *selfCollector) Describe(ch chan<- *Desc) { + ch <- c.self.Desc() +} + +// Collect implements Collector. +func (c *selfCollector) Collect(ch chan<- Metric) { + ch <- c.self +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/counter.go b/vendor/github.com/prometheus/client_golang/prometheus/counter.go new file mode 100644 index 0000000..72d5256 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/counter.go @@ -0,0 +1,164 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "errors" +) + +// Counter is a Metric that represents a single numerical value that only ever +// goes up. That implies that it cannot be used to count items whose number can +// also go down, e.g. the number of currently running goroutines. Those +// "counters" are represented by Gauges. +// +// A Counter is typically used to count requests served, tasks completed, errors +// occurred, etc. +// +// To create Counter instances, use NewCounter. +type Counter interface { + Metric + Collector + + // Inc increments the counter by 1. Use Add to increment it by arbitrary + // non-negative values. + Inc() + // Add adds the given value to the counter. It panics if the value is < + // 0. + Add(float64) +} + +// CounterOpts is an alias for Opts. See there for doc comments. +type CounterOpts Opts + +// NewCounter creates a new Counter based on the provided CounterOpts. +func NewCounter(opts CounterOpts) Counter { + desc := NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + nil, + opts.ConstLabels, + ) + result := &counter{value: value{desc: desc, valType: CounterValue, labelPairs: desc.constLabelPairs}} + result.init(result) // Init self-collection. + return result +} + +type counter struct { + value +} + +func (c *counter) Add(v float64) { + if v < 0 { + panic(errors.New("counter cannot decrease in value")) + } + c.value.Add(v) +} + +// CounterVec is a Collector that bundles a set of Counters that all share the +// same Desc, but have different values for their variable labels. This is used +// if you want to count the same thing partitioned by various dimensions +// (e.g. number of HTTP requests, partitioned by response code and +// method). Create instances with NewCounterVec. +// +// CounterVec embeds MetricVec. See there for a full list of methods with +// detailed documentation. +type CounterVec struct { + *MetricVec +} + +// NewCounterVec creates a new CounterVec based on the provided CounterOpts and +// partitioned by the given label names. At least one label name must be +// provided. +func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec { + desc := NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + labelNames, + opts.ConstLabels, + ) + return &CounterVec{ + MetricVec: newMetricVec(desc, func(lvs ...string) Metric { + result := &counter{value: value{ + desc: desc, + valType: CounterValue, + labelPairs: makeLabelPairs(desc, lvs), + }} + result.init(result) // Init self-collection. + return result + }), + } +} + +// GetMetricWithLabelValues replaces the method of the same name in +// MetricVec. The difference is that this method returns a Counter and not a +// Metric so that no type conversion is required. +func (m *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) { + metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...) + if metric != nil { + return metric.(Counter), err + } + return nil, err +} + +// GetMetricWith replaces the method of the same name in MetricVec. The +// difference is that this method returns a Counter and not a Metric so that no +// type conversion is required. +func (m *CounterVec) GetMetricWith(labels Labels) (Counter, error) { + metric, err := m.MetricVec.GetMetricWith(labels) + if metric != nil { + return metric.(Counter), err + } + return nil, err +} + +// WithLabelValues works as GetMetricWithLabelValues, but panics where +// GetMetricWithLabelValues would have returned an error. By not returning an +// error, WithLabelValues allows shortcuts like +// myVec.WithLabelValues("404", "GET").Add(42) +func (m *CounterVec) WithLabelValues(lvs ...string) Counter { + return m.MetricVec.WithLabelValues(lvs...).(Counter) +} + +// With works as GetMetricWith, but panics where GetMetricWithLabels would have +// returned an error. By not returning an error, With allows shortcuts like +// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42) +func (m *CounterVec) With(labels Labels) Counter { + return m.MetricVec.With(labels).(Counter) +} + +// CounterFunc is a Counter whose value is determined at collect time by calling a +// provided function. +// +// To create CounterFunc instances, use NewCounterFunc. +type CounterFunc interface { + Metric + Collector +} + +// NewCounterFunc creates a new CounterFunc based on the provided +// CounterOpts. The value reported is determined by calling the given function +// from within the Write method. Take into account that metric collection may +// happen concurrently. If that results in concurrent calls to Write, like in +// the case where a CounterFunc is directly registered with Prometheus, the +// provided function must be concurrency-safe. The function should also honor +// the contract for a Counter (values only go up, not down), but compliance will +// not be checked. +func NewCounterFunc(opts CounterOpts, function func() float64) CounterFunc { + return newValueFunc(NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + nil, + opts.ConstLabels, + ), CounterValue, function) +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/desc.go b/vendor/github.com/prometheus/client_golang/prometheus/desc.go new file mode 100644 index 0000000..1835b16 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/desc.go @@ -0,0 +1,200 @@ +// Copyright 2016 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "errors" + "fmt" + "sort" + "strings" + + "github.com/golang/protobuf/proto" + "github.com/prometheus/common/model" + + dto "github.com/prometheus/client_model/go" +) + +// reservedLabelPrefix is a prefix which is not legal in user-supplied +// label names. +const reservedLabelPrefix = "__" + +// Labels represents a collection of label name -> value mappings. This type is +// commonly used with the With(Labels) and GetMetricWith(Labels) methods of +// metric vector Collectors, e.g.: +// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42) +// +// The other use-case is the specification of constant label pairs in Opts or to +// create a Desc. +type Labels map[string]string + +// Desc is the descriptor used by every Prometheus Metric. It is essentially +// the immutable meta-data of a Metric. The normal Metric implementations +// included in this package manage their Desc under the hood. Users only have to +// deal with Desc if they use advanced features like the ExpvarCollector or +// custom Collectors and Metrics. +// +// Descriptors registered with the same registry have to fulfill certain +// consistency and uniqueness criteria if they share the same fully-qualified +// name: They must have the same help string and the same label names (aka label +// dimensions) in each, constLabels and variableLabels, but they must differ in +// the values of the constLabels. +// +// Descriptors that share the same fully-qualified names and the same label +// values of their constLabels are considered equal. +// +// Use NewDesc to create new Desc instances. +type Desc struct { + // fqName has been built from Namespace, Subsystem, and Name. + fqName string + // help provides some helpful information about this metric. + help string + // constLabelPairs contains precalculated DTO label pairs based on + // the constant labels. + constLabelPairs []*dto.LabelPair + // VariableLabels contains names of labels for which the metric + // maintains variable values. + variableLabels []string + // id is a hash of the values of the ConstLabels and fqName. This + // must be unique among all registered descriptors and can therefore be + // used as an identifier of the descriptor. + id uint64 + // dimHash is a hash of the label names (preset and variable) and the + // Help string. Each Desc with the same fqName must have the same + // dimHash. + dimHash uint64 + // err is an error that occurred during construction. It is reported on + // registration time. + err error +} + +// NewDesc allocates and initializes a new Desc. Errors are recorded in the Desc +// and will be reported on registration time. variableLabels and constLabels can +// be nil if no such labels should be set. fqName and help must not be empty. +// +// variableLabels only contain the label names. Their label values are variable +// and therefore not part of the Desc. (They are managed within the Metric.) +// +// For constLabels, the label values are constant. Therefore, they are fully +// specified in the Desc. See the Opts documentation for the implications of +// constant labels. +func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc { + d := &Desc{ + fqName: fqName, + help: help, + variableLabels: variableLabels, + } + if help == "" { + d.err = errors.New("empty help string") + return d + } + if !model.IsValidMetricName(model.LabelValue(fqName)) { + d.err = fmt.Errorf("%q is not a valid metric name", fqName) + return d + } + // labelValues contains the label values of const labels (in order of + // their sorted label names) plus the fqName (at position 0). + labelValues := make([]string, 1, len(constLabels)+1) + labelValues[0] = fqName + labelNames := make([]string, 0, len(constLabels)+len(variableLabels)) + labelNameSet := map[string]struct{}{} + // First add only the const label names and sort them... + for labelName := range constLabels { + if !checkLabelName(labelName) { + d.err = fmt.Errorf("%q is not a valid label name", labelName) + return d + } + labelNames = append(labelNames, labelName) + labelNameSet[labelName] = struct{}{} + } + sort.Strings(labelNames) + // ... so that we can now add const label values in the order of their names. + for _, labelName := range labelNames { + labelValues = append(labelValues, constLabels[labelName]) + } + // Now add the variable label names, but prefix them with something that + // cannot be in a regular label name. That prevents matching the label + // dimension with a different mix between preset and variable labels. + for _, labelName := range variableLabels { + if !checkLabelName(labelName) { + d.err = fmt.Errorf("%q is not a valid label name", labelName) + return d + } + labelNames = append(labelNames, "$"+labelName) + labelNameSet[labelName] = struct{}{} + } + if len(labelNames) != len(labelNameSet) { + d.err = errors.New("duplicate label names") + return d + } + vh := hashNew() + for _, val := range labelValues { + vh = hashAdd(vh, val) + vh = hashAddByte(vh, separatorByte) + } + d.id = vh + // Sort labelNames so that order doesn't matter for the hash. + sort.Strings(labelNames) + // Now hash together (in this order) the help string and the sorted + // label names. + lh := hashNew() + lh = hashAdd(lh, help) + lh = hashAddByte(lh, separatorByte) + for _, labelName := range labelNames { + lh = hashAdd(lh, labelName) + lh = hashAddByte(lh, separatorByte) + } + d.dimHash = lh + + d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels)) + for n, v := range constLabels { + d.constLabelPairs = append(d.constLabelPairs, &dto.LabelPair{ + Name: proto.String(n), + Value: proto.String(v), + }) + } + sort.Sort(LabelPairSorter(d.constLabelPairs)) + return d +} + +// NewInvalidDesc returns an invalid descriptor, i.e. a descriptor with the +// provided error set. If a collector returning such a descriptor is registered, +// registration will fail with the provided error. NewInvalidDesc can be used by +// a Collector to signal inability to describe itself. +func NewInvalidDesc(err error) *Desc { + return &Desc{ + err: err, + } +} + +func (d *Desc) String() string { + lpStrings := make([]string, 0, len(d.constLabelPairs)) + for _, lp := range d.constLabelPairs { + lpStrings = append( + lpStrings, + fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()), + ) + } + return fmt.Sprintf( + "Desc{fqName: %q, help: %q, constLabels: {%s}, variableLabels: %v}", + d.fqName, + d.help, + strings.Join(lpStrings, ","), + d.variableLabels, + ) +} + +func checkLabelName(l string) bool { + return model.LabelName(l).IsValid() && + !strings.HasPrefix(l, reservedLabelPrefix) +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/doc.go b/vendor/github.com/prometheus/client_golang/prometheus/doc.go new file mode 100644 index 0000000..618c4de --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/doc.go @@ -0,0 +1,181 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Package prometheus provides metrics primitives to instrument code for +// monitoring. It also offers a registry for metrics. Sub-packages allow to +// expose the registered metrics via HTTP (package promhttp) or push them to a +// Pushgateway (package push). +// +// All exported functions and methods are safe to be used concurrently unless +//specified otherwise. +// +// A Basic Example +// +// As a starting point, a very basic usage example: +// +// package main +// +// import ( +// "net/http" +// +// "github.com/prometheus/client_golang/prometheus" +// "github.com/prometheus/client_golang/prometheus/promhttp" +// ) +// +// var ( +// cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts{ +// Name: "cpu_temperature_celsius", +// Help: "Current temperature of the CPU.", +// }) +// hdFailures = prometheus.NewCounterVec( +// prometheus.CounterOpts{ +// Name: "hd_errors_total", +// Help: "Number of hard-disk errors.", +// }, +// []string{"device"}, +// ) +// ) +// +// func init() { +// // Metrics have to be registered to be exposed: +// prometheus.MustRegister(cpuTemp) +// prometheus.MustRegister(hdFailures) +// } +// +// func main() { +// cpuTemp.Set(65.3) +// hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc() +// +// // The Handler function provides a default handler to expose metrics +// // via an HTTP server. "/metrics" is the usual endpoint for that. +// http.Handle("/metrics", promhttp.Handler()) +// log.Fatal(http.ListenAndServe(":8080", nil)) +// } +// +// +// This is a complete program that exports two metrics, a Gauge and a Counter, +// the latter with a label attached to turn it into a (one-dimensional) vector. +// +// Metrics +// +// The number of exported identifiers in this package might appear a bit +// overwhelming. Hovever, in addition to the basic plumbing shown in the example +// above, you only need to understand the different metric types and their +// vector versions for basic usage. +// +// Above, you have already touched the Counter and the Gauge. There are two more +// advanced metric types: the Summary and Histogram. A more thorough description +// of those four metric types can be found in the Prometheus docs: +// https://prometheus.io/docs/concepts/metric_types/ +// +// A fifth "type" of metric is Untyped. It behaves like a Gauge, but signals the +// Prometheus server not to assume anything about its type. +// +// In addition to the fundamental metric types Gauge, Counter, Summary, +// Histogram, and Untyped, a very important part of the Prometheus data model is +// the partitioning of samples along dimensions called labels, which results in +// metric vectors. The fundamental types are GaugeVec, CounterVec, SummaryVec, +// HistogramVec, and UntypedVec. +// +// While only the fundamental metric types implement the Metric interface, both +// the metrics and their vector versions implement the Collector interface. A +// Collector manages the collection of a number of Metrics, but for convenience, +// a Metric can also “collect itself”. Note that Gauge, Counter, Summary, +// Histogram, and Untyped are interfaces themselves while GaugeVec, CounterVec, +// SummaryVec, HistogramVec, and UntypedVec are not. +// +// To create instances of Metrics and their vector versions, you need a suitable +// …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, +// HistogramOpts, or UntypedOpts. +// +// Custom Collectors and constant Metrics +// +// While you could create your own implementations of Metric, most likely you +// will only ever implement the Collector interface on your own. At a first +// glance, a custom Collector seems handy to bundle Metrics for common +// registration (with the prime example of the different metric vectors above, +// which bundle all the metrics of the same name but with different labels). +// +// There is a more involved use case, too: If you already have metrics +// available, created outside of the Prometheus context, you don't need the +// interface of the various Metric types. You essentially want to mirror the +// existing numbers into Prometheus Metrics during collection. An own +// implementation of the Collector interface is perfect for that. You can create +// Metric instances “on the fly” using NewConstMetric, NewConstHistogram, and +// NewConstSummary (and their respective Must… versions). That will happen in +// the Collect method. The Describe method has to return separate Desc +// instances, representative of the “throw-away” metrics to be created +// later. NewDesc comes in handy to create those Desc instances. +// +// The Collector example illustrates the use case. You can also look at the +// source code of the processCollector (mirroring process metrics), the +// goCollector (mirroring Go metrics), or the expvarCollector (mirroring expvar +// metrics) as examples that are used in this package itself. +// +// If you just need to call a function to get a single float value to collect as +// a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting +// shortcuts. +// +// Advanced Uses of the Registry +// +// While MustRegister is the by far most common way of registering a Collector, +// sometimes you might want to handle the errors the registration might +// cause. As suggested by the name, MustRegister panics if an error occurs. With +// the Register function, the error is returned and can be handled. +// +// An error is returned if the registered Collector is incompatible or +// inconsistent with already registered metrics. The registry aims for +// consistency of the collected metrics according to the Prometheus data +// model. Inconsistencies are ideally detected at registration time, not at +// collect time. The former will usually be detected at start-up time of a +// program, while the latter will only happen at scrape time, possibly not even +// on the first scrape if the inconsistency only becomes relevant later. That is +// the main reason why a Collector and a Metric have to describe themselves to +// the registry. +// +// So far, everything we did operated on the so-called default registry, as it +// can be found in the global DefaultRegistry variable. With NewRegistry, you +// can create a custom registry, or you can even implement the Registerer or +// Gatherer interfaces yourself. The methods Register and Unregister work in +// the same way on a custom registry as the global functions Register and +// Unregister on the default registry. +// +// There are a number of uses for custom registries: You can use registries +// with special properties, see NewPedanticRegistry. You can avoid global state, +// as it is imposed by the DefaultRegistry. You can use multiple registries at +// the same time to expose different metrics in different ways. You can use +// separate registries for testing purposes. +// +// Also note that the DefaultRegistry comes registered with a Collector for Go +// runtime metrics (via NewGoCollector) and a Collector for process metrics (via +// NewProcessCollector). With a custom registry, you are in control and decide +// yourself about the Collectors to register. +// +// HTTP Exposition +// +// The Registry implements the Gatherer interface. The caller of the Gather +// method can then expose the gathered metrics in some way. Usually, the metrics +// are served via HTTP on the /metrics endpoint. That's happening in the example +// above. The tools to expose metrics via HTTP are in the promhttp +// sub-package. (The top-level functions in the prometheus package are +// deprecated.) +// +// Pushing to the Pushgateway +// +// Function for pushing to the Pushgateway can be found in the push sub-package. +// +// Other Means of Exposition +// +// More ways of exposing metrics can easily be added. Sending metrics to +// Graphite would be an example that will soon be implemented. +package prometheus diff --git a/vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go b/vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go new file mode 100644 index 0000000..18a99d5 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/expvar_collector.go @@ -0,0 +1,119 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "encoding/json" + "expvar" +) + +type expvarCollector struct { + exports map[string]*Desc +} + +// NewExpvarCollector returns a newly allocated expvar Collector that still has +// to be registered with a Prometheus registry. +// +// An expvar Collector collects metrics from the expvar interface. It provides a +// quick way to expose numeric values that are already exported via expvar as +// Prometheus metrics. Note that the data models of expvar and Prometheus are +// fundamentally different, and that the expvar Collector is inherently slower +// than native Prometheus metrics. Thus, the expvar Collector is probably great +// for experiments and prototying, but you should seriously consider a more +// direct implementation of Prometheus metrics for monitoring production +// systems. +// +// The exports map has the following meaning: +// +// The keys in the map correspond to expvar keys, i.e. for every expvar key you +// want to export as Prometheus metric, you need an entry in the exports +// map. The descriptor mapped to each key describes how to export the expvar +// value. It defines the name and the help string of the Prometheus metric +// proxying the expvar value. The type will always be Untyped. +// +// For descriptors without variable labels, the expvar value must be a number or +// a bool. The number is then directly exported as the Prometheus sample +// value. (For a bool, 'false' translates to 0 and 'true' to 1). Expvar values +// that are not numbers or bools are silently ignored. +// +// If the descriptor has one variable label, the expvar value must be an expvar +// map. The keys in the expvar map become the various values of the one +// Prometheus label. The values in the expvar map must be numbers or bools again +// as above. +// +// For descriptors with more than one variable label, the expvar must be a +// nested expvar map, i.e. where the values of the topmost map are maps again +// etc. until a depth is reached that corresponds to the number of labels. The +// leaves of that structure must be numbers or bools as above to serve as the +// sample values. +// +// Anything that does not fit into the scheme above is silently ignored. +func NewExpvarCollector(exports map[string]*Desc) Collector { + return &expvarCollector{ + exports: exports, + } +} + +// Describe implements Collector. +func (e *expvarCollector) Describe(ch chan<- *Desc) { + for _, desc := range e.exports { + ch <- desc + } +} + +// Collect implements Collector. +func (e *expvarCollector) Collect(ch chan<- Metric) { + for name, desc := range e.exports { + var m Metric + expVar := expvar.Get(name) + if expVar == nil { + continue + } + var v interface{} + labels := make([]string, len(desc.variableLabels)) + if err := json.Unmarshal([]byte(expVar.String()), &v); err != nil { + ch <- NewInvalidMetric(desc, err) + continue + } + var processValue func(v interface{}, i int) + processValue = func(v interface{}, i int) { + if i >= len(labels) { + copiedLabels := append(make([]string, 0, len(labels)), labels...) + switch v := v.(type) { + case float64: + m = MustNewConstMetric(desc, UntypedValue, v, copiedLabels...) + case bool: + if v { + m = MustNewConstMetric(desc, UntypedValue, 1, copiedLabels...) + } else { + m = MustNewConstMetric(desc, UntypedValue, 0, copiedLabels...) + } + default: + return + } + ch <- m + return + } + vm, ok := v.(map[string]interface{}) + if !ok { + return + } + for lv, val := range vm { + labels[i] = lv + processValue(val, i+1) + } + } + processValue(v, 0) + } +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/fnv.go b/vendor/github.com/prometheus/client_golang/prometheus/fnv.go new file mode 100644 index 0000000..e3b67df --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/fnv.go @@ -0,0 +1,29 @@ +package prometheus + +// Inline and byte-free variant of hash/fnv's fnv64a. + +const ( + offset64 = 14695981039346656037 + prime64 = 1099511628211 +) + +// hashNew initializies a new fnv64a hash value. +func hashNew() uint64 { + return offset64 +} + +// hashAdd adds a string to a fnv64a hash value, returning the updated hash. +func hashAdd(h uint64, s string) uint64 { + for i := 0; i < len(s); i++ { + h ^= uint64(s[i]) + h *= prime64 + } + return h +} + +// hashAddByte adds a byte to a fnv64a hash value, returning the updated hash. +func hashAddByte(h uint64, b byte) uint64 { + h ^= uint64(b) + h *= prime64 + return h +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/gauge.go b/vendor/github.com/prometheus/client_golang/prometheus/gauge.go new file mode 100644 index 0000000..9ab5a3d --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/gauge.go @@ -0,0 +1,145 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +// Gauge is a Metric that represents a single numerical value that can +// arbitrarily go up and down. +// +// A Gauge is typically used for measured values like temperatures or current +// memory usage, but also "counts" that can go up and down, like the number of +// running goroutines. +// +// To create Gauge instances, use NewGauge. +type Gauge interface { + Metric + Collector + + // Set sets the Gauge to an arbitrary value. + Set(float64) + // Inc increments the Gauge by 1. Use Add to increment it by arbitrary + // values. + Inc() + // Dec decrements the Gauge by 1. Use Sub to decrement it by arbitrary + // values. + Dec() + // Add adds the given value to the Gauge. (The value can be negative, + // resulting in a decrease of the Gauge.) + Add(float64) + // Sub subtracts the given value from the Gauge. (The value can be + // negative, resulting in an increase of the Gauge.) + Sub(float64) + + // SetToCurrentTime sets the Gauge to the current Unix time in seconds. + SetToCurrentTime() +} + +// GaugeOpts is an alias for Opts. See there for doc comments. +type GaugeOpts Opts + +// NewGauge creates a new Gauge based on the provided GaugeOpts. +func NewGauge(opts GaugeOpts) Gauge { + return newValue(NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + nil, + opts.ConstLabels, + ), GaugeValue, 0) +} + +// GaugeVec is a Collector that bundles a set of Gauges that all share the same +// Desc, but have different values for their variable labels. This is used if +// you want to count the same thing partitioned by various dimensions +// (e.g. number of operations queued, partitioned by user and operation +// type). Create instances with NewGaugeVec. +type GaugeVec struct { + *MetricVec +} + +// NewGaugeVec creates a new GaugeVec based on the provided GaugeOpts and +// partitioned by the given label names. At least one label name must be +// provided. +func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec { + desc := NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + labelNames, + opts.ConstLabels, + ) + return &GaugeVec{ + MetricVec: newMetricVec(desc, func(lvs ...string) Metric { + return newValue(desc, GaugeValue, 0, lvs...) + }), + } +} + +// GetMetricWithLabelValues replaces the method of the same name in +// MetricVec. The difference is that this method returns a Gauge and not a +// Metric so that no type conversion is required. +func (m *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) { + metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...) + if metric != nil { + return metric.(Gauge), err + } + return nil, err +} + +// GetMetricWith replaces the method of the same name in MetricVec. The +// difference is that this method returns a Gauge and not a Metric so that no +// type conversion is required. +func (m *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) { + metric, err := m.MetricVec.GetMetricWith(labels) + if metric != nil { + return metric.(Gauge), err + } + return nil, err +} + +// WithLabelValues works as GetMetricWithLabelValues, but panics where +// GetMetricWithLabelValues would have returned an error. By not returning an +// error, WithLabelValues allows shortcuts like +// myVec.WithLabelValues("404", "GET").Add(42) +func (m *GaugeVec) WithLabelValues(lvs ...string) Gauge { + return m.MetricVec.WithLabelValues(lvs...).(Gauge) +} + +// With works as GetMetricWith, but panics where GetMetricWithLabels would have +// returned an error. By not returning an error, With allows shortcuts like +// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42) +func (m *GaugeVec) With(labels Labels) Gauge { + return m.MetricVec.With(labels).(Gauge) +} + +// GaugeFunc is a Gauge whose value is determined at collect time by calling a +// provided function. +// +// To create GaugeFunc instances, use NewGaugeFunc. +type GaugeFunc interface { + Metric + Collector +} + +// NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The +// value reported is determined by calling the given function from within the +// Write method. Take into account that metric collection may happen +// concurrently. If that results in concurrent calls to Write, like in the case +// where a GaugeFunc is directly registered with Prometheus, the provided +// function must be concurrency-safe. +func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc { + return newValueFunc(NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + nil, + opts.ConstLabels, + ), GaugeValue, function) +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go b/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go new file mode 100644 index 0000000..6dea674 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/go_collector.go @@ -0,0 +1,263 @@ +package prometheus + +import ( + "fmt" + "runtime" + "runtime/debug" + "time" +) + +type goCollector struct { + goroutines Gauge + gcDesc *Desc + + // metrics to describe and collect + metrics memStatsMetrics +} + +// NewGoCollector returns a collector which exports metrics about the current +// go process. +func NewGoCollector() Collector { + return &goCollector{ + goroutines: NewGauge(GaugeOpts{ + Namespace: "go", + Name: "goroutines", + Help: "Number of goroutines that currently exist.", + }), + gcDesc: NewDesc( + "go_gc_duration_seconds", + "A summary of the GC invocation durations.", + nil, nil), + metrics: memStatsMetrics{ + { + desc: NewDesc( + memstatNamespace("alloc_bytes"), + "Number of bytes allocated and still in use.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("alloc_bytes_total"), + "Total number of bytes allocated, even if freed.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) }, + valType: CounterValue, + }, { + desc: NewDesc( + memstatNamespace("sys_bytes"), + "Number of bytes obtained from system.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.Sys) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("lookups_total"), + "Total number of pointer lookups.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) }, + valType: CounterValue, + }, { + desc: NewDesc( + memstatNamespace("mallocs_total"), + "Total number of mallocs.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) }, + valType: CounterValue, + }, { + desc: NewDesc( + memstatNamespace("frees_total"), + "Total number of frees.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.Frees) }, + valType: CounterValue, + }, { + desc: NewDesc( + memstatNamespace("heap_alloc_bytes"), + "Number of heap bytes allocated and still in use.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("heap_sys_bytes"), + "Number of heap bytes obtained from system.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("heap_idle_bytes"), + "Number of heap bytes waiting to be used.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("heap_inuse_bytes"), + "Number of heap bytes that are in use.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("heap_released_bytes"), + "Number of heap bytes released to OS.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("heap_objects"), + "Number of allocated objects.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("stack_inuse_bytes"), + "Number of bytes in use by the stack allocator.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("stack_sys_bytes"), + "Number of bytes obtained from system for stack allocator.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("mspan_inuse_bytes"), + "Number of bytes in use by mspan structures.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("mspan_sys_bytes"), + "Number of bytes used for mspan structures obtained from system.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("mcache_inuse_bytes"), + "Number of bytes in use by mcache structures.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("mcache_sys_bytes"), + "Number of bytes used for mcache structures obtained from system.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("buck_hash_sys_bytes"), + "Number of bytes used by the profiling bucket hash table.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("gc_sys_bytes"), + "Number of bytes used for garbage collection system metadata.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("other_sys_bytes"), + "Number of bytes used for other system allocations.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("next_gc_bytes"), + "Number of heap bytes when next garbage collection will take place.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) }, + valType: GaugeValue, + }, { + desc: NewDesc( + memstatNamespace("last_gc_time_seconds"), + "Number of seconds since 1970 of last garbage collection.", + nil, nil, + ), + eval: func(ms *runtime.MemStats) float64 { return float64(ms.LastGC) / 1e9 }, + valType: GaugeValue, + }, + }, + } +} + +func memstatNamespace(s string) string { + return fmt.Sprintf("go_memstats_%s", s) +} + +// Describe returns all descriptions of the collector. +func (c *goCollector) Describe(ch chan<- *Desc) { + ch <- c.goroutines.Desc() + ch <- c.gcDesc + + for _, i := range c.metrics { + ch <- i.desc + } +} + +// Collect returns the current state of all metrics of the collector. +func (c *goCollector) Collect(ch chan<- Metric) { + c.goroutines.Set(float64(runtime.NumGoroutine())) + ch <- c.goroutines + + var stats debug.GCStats + stats.PauseQuantiles = make([]time.Duration, 5) + debug.ReadGCStats(&stats) + + quantiles := make(map[float64]float64) + for idx, pq := range stats.PauseQuantiles[1:] { + quantiles[float64(idx+1)/float64(len(stats.PauseQuantiles)-1)] = pq.Seconds() + } + quantiles[0.0] = stats.PauseQuantiles[0].Seconds() + ch <- MustNewConstSummary(c.gcDesc, uint64(stats.NumGC), float64(stats.PauseTotal.Seconds()), quantiles) + + ms := &runtime.MemStats{} + runtime.ReadMemStats(ms) + for _, i := range c.metrics { + ch <- MustNewConstMetric(i.desc, i.valType, i.eval(ms)) + } +} + +// memStatsMetrics provide description, value, and value type for memstat metrics. +type memStatsMetrics []struct { + desc *Desc + eval func(*runtime.MemStats) float64 + valType ValueType +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/histogram.go b/vendor/github.com/prometheus/client_golang/prometheus/histogram.go new file mode 100644 index 0000000..9719e8f --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/histogram.go @@ -0,0 +1,444 @@ +// Copyright 2015 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "fmt" + "math" + "sort" + "sync/atomic" + + "github.com/golang/protobuf/proto" + + dto "github.com/prometheus/client_model/go" +) + +// A Histogram counts individual observations from an event or sample stream in +// configurable buckets. Similar to a summary, it also provides a sum of +// observations and an observation count. +// +// On the Prometheus server, quantiles can be calculated from a Histogram using +// the histogram_quantile function in the query language. +// +// Note that Histograms, in contrast to Summaries, can be aggregated with the +// Prometheus query language (see the documentation for detailed +// procedures). However, Histograms require the user to pre-define suitable +// buckets, and they are in general less accurate. The Observe method of a +// Histogram has a very low performance overhead in comparison with the Observe +// method of a Summary. +// +// To create Histogram instances, use NewHistogram. +type Histogram interface { + Metric + Collector + + // Observe adds a single observation to the histogram. + Observe(float64) +} + +// bucketLabel is used for the label that defines the upper bound of a +// bucket of a histogram ("le" -> "less or equal"). +const bucketLabel = "le" + +// DefBuckets are the default Histogram buckets. The default buckets are +// tailored to broadly measure the response time (in seconds) of a network +// service. Most likely, however, you will be required to define buckets +// customized to your use case. +var ( + DefBuckets = []float64{.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10} + + errBucketLabelNotAllowed = fmt.Errorf( + "%q is not allowed as label name in histograms", bucketLabel, + ) +) + +// LinearBuckets creates 'count' buckets, each 'width' wide, where the lowest +// bucket has an upper bound of 'start'. The final +Inf bucket is not counted +// and not included in the returned slice. The returned slice is meant to be +// used for the Buckets field of HistogramOpts. +// +// The function panics if 'count' is zero or negative. +func LinearBuckets(start, width float64, count int) []float64 { + if count < 1 { + panic("LinearBuckets needs a positive count") + } + buckets := make([]float64, count) + for i := range buckets { + buckets[i] = start + start += width + } + return buckets +} + +// ExponentialBuckets creates 'count' buckets, where the lowest bucket has an +// upper bound of 'start' and each following bucket's upper bound is 'factor' +// times the previous bucket's upper bound. The final +Inf bucket is not counted +// and not included in the returned slice. The returned slice is meant to be +// used for the Buckets field of HistogramOpts. +// +// The function panics if 'count' is 0 or negative, if 'start' is 0 or negative, +// or if 'factor' is less than or equal 1. +func ExponentialBuckets(start, factor float64, count int) []float64 { + if count < 1 { + panic("ExponentialBuckets needs a positive count") + } + if start <= 0 { + panic("ExponentialBuckets needs a positive start value") + } + if factor <= 1 { + panic("ExponentialBuckets needs a factor greater than 1") + } + buckets := make([]float64, count) + for i := range buckets { + buckets[i] = start + start *= factor + } + return buckets +} + +// HistogramOpts bundles the options for creating a Histogram metric. It is +// mandatory to set Name and Help to a non-empty string. All other fields are +// optional and can safely be left at their zero value. +type HistogramOpts struct { + // Namespace, Subsystem, and Name are components of the fully-qualified + // name of the Histogram (created by joining these components with + // "_"). Only Name is mandatory, the others merely help structuring the + // name. Note that the fully-qualified name of the Histogram must be a + // valid Prometheus metric name. + Namespace string + Subsystem string + Name string + + // Help provides information about this Histogram. Mandatory! + // + // Metrics with the same fully-qualified name must have the same Help + // string. + Help string + + // ConstLabels are used to attach fixed labels to this + // Histogram. Histograms with the same fully-qualified name must have the + // same label names in their ConstLabels. + // + // Note that in most cases, labels have a value that varies during the + // lifetime of a process. Those labels are usually managed with a + // HistogramVec. ConstLabels serve only special purposes. One is for the + // special case where the value of a label does not change during the + // lifetime of a process, e.g. if the revision of the running binary is + // put into a label. Another, more advanced purpose is if more than one + // Collector needs to collect Histograms with the same fully-qualified + // name. In that case, those Summaries must differ in the values of + // their ConstLabels. See the Collector examples. + // + // If the value of a label never changes (not even between binaries), + // that label most likely should not be a label at all (but part of the + // metric name). + ConstLabels Labels + + // Buckets defines the buckets into which observations are counted. Each + // element in the slice is the upper inclusive bound of a bucket. The + // values must be sorted in strictly increasing order. There is no need + // to add a highest bucket with +Inf bound, it will be added + // implicitly. The default value is DefBuckets. + Buckets []float64 +} + +// NewHistogram creates a new Histogram based on the provided HistogramOpts. It +// panics if the buckets in HistogramOpts are not in strictly increasing order. +func NewHistogram(opts HistogramOpts) Histogram { + return newHistogram( + NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + nil, + opts.ConstLabels, + ), + opts, + ) +} + +func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogram { + if len(desc.variableLabels) != len(labelValues) { + panic(errInconsistentCardinality) + } + + for _, n := range desc.variableLabels { + if n == bucketLabel { + panic(errBucketLabelNotAllowed) + } + } + for _, lp := range desc.constLabelPairs { + if lp.GetName() == bucketLabel { + panic(errBucketLabelNotAllowed) + } + } + + if len(opts.Buckets) == 0 { + opts.Buckets = DefBuckets + } + + h := &histogram{ + desc: desc, + upperBounds: opts.Buckets, + labelPairs: makeLabelPairs(desc, labelValues), + } + for i, upperBound := range h.upperBounds { + if i < len(h.upperBounds)-1 { + if upperBound >= h.upperBounds[i+1] { + panic(fmt.Errorf( + "histogram buckets must be in increasing order: %f >= %f", + upperBound, h.upperBounds[i+1], + )) + } + } else { + if math.IsInf(upperBound, +1) { + // The +Inf bucket is implicit. Remove it here. + h.upperBounds = h.upperBounds[:i] + } + } + } + // Finally we know the final length of h.upperBounds and can make counts. + h.counts = make([]uint64, len(h.upperBounds)) + + h.init(h) // Init self-collection. + return h +} + +type histogram struct { + // sumBits contains the bits of the float64 representing the sum of all + // observations. sumBits and count have to go first in the struct to + // guarantee alignment for atomic operations. + // http://golang.org/pkg/sync/atomic/#pkg-note-BUG + sumBits uint64 + count uint64 + + selfCollector + // Note that there is no mutex required. + + desc *Desc + + upperBounds []float64 + counts []uint64 + + labelPairs []*dto.LabelPair +} + +func (h *histogram) Desc() *Desc { + return h.desc +} + +func (h *histogram) Observe(v float64) { + // TODO(beorn7): For small numbers of buckets (<30), a linear search is + // slightly faster than the binary search. If we really care, we could + // switch from one search strategy to the other depending on the number + // of buckets. + // + // Microbenchmarks (BenchmarkHistogramNoLabels): + // 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op + // 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op + // 300 buckets: 154 ns/op linear - binary 61.6 ns/op + i := sort.SearchFloat64s(h.upperBounds, v) + if i < len(h.counts) { + atomic.AddUint64(&h.counts[i], 1) + } + atomic.AddUint64(&h.count, 1) + for { + oldBits := atomic.LoadUint64(&h.sumBits) + newBits := math.Float64bits(math.Float64frombits(oldBits) + v) + if atomic.CompareAndSwapUint64(&h.sumBits, oldBits, newBits) { + break + } + } +} + +func (h *histogram) Write(out *dto.Metric) error { + his := &dto.Histogram{} + buckets := make([]*dto.Bucket, len(h.upperBounds)) + + his.SampleSum = proto.Float64(math.Float64frombits(atomic.LoadUint64(&h.sumBits))) + his.SampleCount = proto.Uint64(atomic.LoadUint64(&h.count)) + var count uint64 + for i, upperBound := range h.upperBounds { + count += atomic.LoadUint64(&h.counts[i]) + buckets[i] = &dto.Bucket{ + CumulativeCount: proto.Uint64(count), + UpperBound: proto.Float64(upperBound), + } + } + his.Bucket = buckets + out.Histogram = his + out.Label = h.labelPairs + return nil +} + +// HistogramVec is a Collector that bundles a set of Histograms that all share the +// same Desc, but have different values for their variable labels. This is used +// if you want to count the same thing partitioned by various dimensions +// (e.g. HTTP request latencies, partitioned by status code and method). Create +// instances with NewHistogramVec. +type HistogramVec struct { + *MetricVec +} + +// NewHistogramVec creates a new HistogramVec based on the provided HistogramOpts and +// partitioned by the given label names. At least one label name must be +// provided. +func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec { + desc := NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + labelNames, + opts.ConstLabels, + ) + return &HistogramVec{ + MetricVec: newMetricVec(desc, func(lvs ...string) Metric { + return newHistogram(desc, opts, lvs...) + }), + } +} + +// GetMetricWithLabelValues replaces the method of the same name in +// MetricVec. The difference is that this method returns a Histogram and not a +// Metric so that no type conversion is required. +func (m *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Histogram, error) { + metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...) + if metric != nil { + return metric.(Histogram), err + } + return nil, err +} + +// GetMetricWith replaces the method of the same name in MetricVec. The +// difference is that this method returns a Histogram and not a Metric so that no +// type conversion is required. +func (m *HistogramVec) GetMetricWith(labels Labels) (Histogram, error) { + metric, err := m.MetricVec.GetMetricWith(labels) + if metric != nil { + return metric.(Histogram), err + } + return nil, err +} + +// WithLabelValues works as GetMetricWithLabelValues, but panics where +// GetMetricWithLabelValues would have returned an error. By not returning an +// error, WithLabelValues allows shortcuts like +// myVec.WithLabelValues("404", "GET").Observe(42.21) +func (m *HistogramVec) WithLabelValues(lvs ...string) Histogram { + return m.MetricVec.WithLabelValues(lvs...).(Histogram) +} + +// With works as GetMetricWith, but panics where GetMetricWithLabels would have +// returned an error. By not returning an error, With allows shortcuts like +// myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21) +func (m *HistogramVec) With(labels Labels) Histogram { + return m.MetricVec.With(labels).(Histogram) +} + +type constHistogram struct { + desc *Desc + count uint64 + sum float64 + buckets map[float64]uint64 + labelPairs []*dto.LabelPair +} + +func (h *constHistogram) Desc() *Desc { + return h.desc +} + +func (h *constHistogram) Write(out *dto.Metric) error { + his := &dto.Histogram{} + buckets := make([]*dto.Bucket, 0, len(h.buckets)) + + his.SampleCount = proto.Uint64(h.count) + his.SampleSum = proto.Float64(h.sum) + + for upperBound, count := range h.buckets { + buckets = append(buckets, &dto.Bucket{ + CumulativeCount: proto.Uint64(count), + UpperBound: proto.Float64(upperBound), + }) + } + + if len(buckets) > 0 { + sort.Sort(buckSort(buckets)) + } + his.Bucket = buckets + + out.Histogram = his + out.Label = h.labelPairs + + return nil +} + +// NewConstHistogram returns a metric representing a Prometheus histogram with +// fixed values for the count, sum, and bucket counts. As those parameters +// cannot be changed, the returned value does not implement the Histogram +// interface (but only the Metric interface). Users of this package will not +// have much use for it in regular operations. However, when implementing custom +// Collectors, it is useful as a throw-away metric that is generated on the fly +// to send it to Prometheus in the Collect method. +// +// buckets is a map of upper bounds to cumulative counts, excluding the +Inf +// bucket. +// +// NewConstHistogram returns an error if the length of labelValues is not +// consistent with the variable labels in Desc. +func NewConstHistogram( + desc *Desc, + count uint64, + sum float64, + buckets map[float64]uint64, + labelValues ...string, +) (Metric, error) { + if len(desc.variableLabels) != len(labelValues) { + return nil, errInconsistentCardinality + } + return &constHistogram{ + desc: desc, + count: count, + sum: sum, + buckets: buckets, + labelPairs: makeLabelPairs(desc, labelValues), + }, nil +} + +// MustNewConstHistogram is a version of NewConstHistogram that panics where +// NewConstMetric would have returned an error. +func MustNewConstHistogram( + desc *Desc, + count uint64, + sum float64, + buckets map[float64]uint64, + labelValues ...string, +) Metric { + m, err := NewConstHistogram(desc, count, sum, buckets, labelValues...) + if err != nil { + panic(err) + } + return m +} + +type buckSort []*dto.Bucket + +func (s buckSort) Len() int { + return len(s) +} + +func (s buckSort) Swap(i, j int) { + s[i], s[j] = s[j], s[i] +} + +func (s buckSort) Less(i, j int) bool { + return s[i].GetUpperBound() < s[j].GetUpperBound() +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/http.go b/vendor/github.com/prometheus/client_golang/prometheus/http.go new file mode 100644 index 0000000..d74fb48 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/http.go @@ -0,0 +1,526 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "bufio" + "bytes" + "compress/gzip" + "fmt" + "io" + "net" + "net/http" + "strconv" + "strings" + "sync" + "time" + + "github.com/prometheus/common/expfmt" +) + +// TODO(beorn7): Remove this whole file. It is a partial mirror of +// promhttp/http.go (to avoid circular import chains) where everything HTTP +// related should live. The functions here are just for avoiding +// breakage. Everything is deprecated. + +const ( + contentTypeHeader = "Content-Type" + contentLengthHeader = "Content-Length" + contentEncodingHeader = "Content-Encoding" + acceptEncodingHeader = "Accept-Encoding" +) + +var bufPool sync.Pool + +func getBuf() *bytes.Buffer { + buf := bufPool.Get() + if buf == nil { + return &bytes.Buffer{} + } + return buf.(*bytes.Buffer) +} + +func giveBuf(buf *bytes.Buffer) { + buf.Reset() + bufPool.Put(buf) +} + +// Handler returns an HTTP handler for the DefaultGatherer. It is +// already instrumented with InstrumentHandler (using "prometheus" as handler +// name). +// +// Deprecated: Please note the issues described in the doc comment of +// InstrumentHandler. You might want to consider using promhttp.Handler instead +// (which is not instrumented). +func Handler() http.Handler { + return InstrumentHandler("prometheus", UninstrumentedHandler()) +} + +// UninstrumentedHandler returns an HTTP handler for the DefaultGatherer. +// +// Deprecated: Use promhttp.Handler instead. See there for further documentation. +func UninstrumentedHandler() http.Handler { + return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) { + mfs, err := DefaultGatherer.Gather() + if err != nil { + http.Error(w, "An error has occurred during metrics collection:\n\n"+err.Error(), http.StatusInternalServerError) + return + } + + contentType := expfmt.Negotiate(req.Header) + buf := getBuf() + defer giveBuf(buf) + writer, encoding := decorateWriter(req, buf) + enc := expfmt.NewEncoder(writer, contentType) + var lastErr error + for _, mf := range mfs { + if err := enc.Encode(mf); err != nil { + lastErr = err + http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError) + return + } + } + if closer, ok := writer.(io.Closer); ok { + closer.Close() + } + if lastErr != nil && buf.Len() == 0 { + http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError) + return + } + header := w.Header() + header.Set(contentTypeHeader, string(contentType)) + header.Set(contentLengthHeader, fmt.Sprint(buf.Len())) + if encoding != "" { + header.Set(contentEncodingHeader, encoding) + } + w.Write(buf.Bytes()) + }) +} + +// decorateWriter wraps a writer to handle gzip compression if requested. It +// returns the decorated writer and the appropriate "Content-Encoding" header +// (which is empty if no compression is enabled). +func decorateWriter(request *http.Request, writer io.Writer) (io.Writer, string) { + header := request.Header.Get(acceptEncodingHeader) + parts := strings.Split(header, ",") + for _, part := range parts { + part := strings.TrimSpace(part) + if part == "gzip" || strings.HasPrefix(part, "gzip;") { + return gzip.NewWriter(writer), "gzip" + } + } + return writer, "" +} + +var instLabels = []string{"method", "code"} + +type nower interface { + Now() time.Time +} + +type nowFunc func() time.Time + +func (n nowFunc) Now() time.Time { + return n() +} + +var now nower = nowFunc(func() time.Time { + return time.Now() +}) + +func nowSeries(t ...time.Time) nower { + return nowFunc(func() time.Time { + defer func() { + t = t[1:] + }() + + return t[0] + }) +} + +// InstrumentHandler wraps the given HTTP handler for instrumentation. It +// registers four metric collectors (if not already done) and reports HTTP +// metrics to the (newly or already) registered collectors: http_requests_total +// (CounterVec), http_request_duration_microseconds (Summary), +// http_request_size_bytes (Summary), http_response_size_bytes (Summary). Each +// has a constant label named "handler" with the provided handlerName as +// value. http_requests_total is a metric vector partitioned by HTTP method +// (label name "method") and HTTP status code (label name "code"). +// +// Deprecated: InstrumentHandler has several issues: +// +// - It uses Summaries rather than Histograms. Summaries are not useful if +// aggregation across multiple instances is required. +// +// - It uses microseconds as unit, which is deprecated and should be replaced by +// seconds. +// +// - The size of the request is calculated in a separate goroutine. Since this +// calculator requires access to the request header, it creates a race with +// any writes to the header performed during request handling. +// httputil.ReverseProxy is a prominent example for a handler +// performing such writes. +// +// - It has additional issues with HTTP/2, cf. +// https://github.com/prometheus/client_golang/issues/272. +// +// Upcoming versions of this package will provide ways of instrumenting HTTP +// handlers that are more flexible and have fewer issues. Please prefer direct +// instrumentation in the meantime. +func InstrumentHandler(handlerName string, handler http.Handler) http.HandlerFunc { + return InstrumentHandlerFunc(handlerName, handler.ServeHTTP) +} + +// InstrumentHandlerFunc wraps the given function for instrumentation. It +// otherwise works in the same way as InstrumentHandler (and shares the same +// issues). +// +// Deprecated: InstrumentHandlerFunc is deprecated for the same reasons as +// InstrumentHandler is. +func InstrumentHandlerFunc(handlerName string, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc { + return InstrumentHandlerFuncWithOpts( + SummaryOpts{ + Subsystem: "http", + ConstLabels: Labels{"handler": handlerName}, + Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001}, + }, + handlerFunc, + ) +} + +// InstrumentHandlerWithOpts works like InstrumentHandler (and shares the same +// issues) but provides more flexibility (at the cost of a more complex call +// syntax). As InstrumentHandler, this function registers four metric +// collectors, but it uses the provided SummaryOpts to create them. However, the +// fields "Name" and "Help" in the SummaryOpts are ignored. "Name" is replaced +// by "requests_total", "request_duration_microseconds", "request_size_bytes", +// and "response_size_bytes", respectively. "Help" is replaced by an appropriate +// help string. The names of the variable labels of the http_requests_total +// CounterVec are "method" (get, post, etc.), and "code" (HTTP status code). +// +// If InstrumentHandlerWithOpts is called as follows, it mimics exactly the +// behavior of InstrumentHandler: +// +// prometheus.InstrumentHandlerWithOpts( +// prometheus.SummaryOpts{ +// Subsystem: "http", +// ConstLabels: prometheus.Labels{"handler": handlerName}, +// }, +// handler, +// ) +// +// Technical detail: "requests_total" is a CounterVec, not a SummaryVec, so it +// cannot use SummaryOpts. Instead, a CounterOpts struct is created internally, +// and all its fields are set to the equally named fields in the provided +// SummaryOpts. +// +// Deprecated: InstrumentHandlerWithOpts is deprecated for the same reasons as +// InstrumentHandler is. +func InstrumentHandlerWithOpts(opts SummaryOpts, handler http.Handler) http.HandlerFunc { + return InstrumentHandlerFuncWithOpts(opts, handler.ServeHTTP) +} + +// InstrumentHandlerFuncWithOpts works like InstrumentHandlerFunc (and shares +// the same issues) but provides more flexibility (at the cost of a more complex +// call syntax). See InstrumentHandlerWithOpts for details how the provided +// SummaryOpts are used. +// +// Deprecated: InstrumentHandlerFuncWithOpts is deprecated for the same reasons +// as InstrumentHandler is. +func InstrumentHandlerFuncWithOpts(opts SummaryOpts, handlerFunc func(http.ResponseWriter, *http.Request)) http.HandlerFunc { + reqCnt := NewCounterVec( + CounterOpts{ + Namespace: opts.Namespace, + Subsystem: opts.Subsystem, + Name: "requests_total", + Help: "Total number of HTTP requests made.", + ConstLabels: opts.ConstLabels, + }, + instLabels, + ) + if err := Register(reqCnt); err != nil { + if are, ok := err.(AlreadyRegisteredError); ok { + reqCnt = are.ExistingCollector.(*CounterVec) + } else { + panic(err) + } + } + + opts.Name = "request_duration_microseconds" + opts.Help = "The HTTP request latencies in microseconds." + reqDur := NewSummary(opts) + if err := Register(reqDur); err != nil { + if are, ok := err.(AlreadyRegisteredError); ok { + reqDur = are.ExistingCollector.(Summary) + } else { + panic(err) + } + } + + opts.Name = "request_size_bytes" + opts.Help = "The HTTP request sizes in bytes." + reqSz := NewSummary(opts) + if err := Register(reqSz); err != nil { + if are, ok := err.(AlreadyRegisteredError); ok { + reqSz = are.ExistingCollector.(Summary) + } else { + panic(err) + } + } + + opts.Name = "response_size_bytes" + opts.Help = "The HTTP response sizes in bytes." + resSz := NewSummary(opts) + if err := Register(resSz); err != nil { + if are, ok := err.(AlreadyRegisteredError); ok { + resSz = are.ExistingCollector.(Summary) + } else { + panic(err) + } + } + + return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { + now := time.Now() + + delegate := &responseWriterDelegator{ResponseWriter: w} + out := computeApproximateRequestSize(r) + + _, cn := w.(http.CloseNotifier) + _, fl := w.(http.Flusher) + _, hj := w.(http.Hijacker) + _, rf := w.(io.ReaderFrom) + var rw http.ResponseWriter + if cn && fl && hj && rf { + rw = &fancyResponseWriterDelegator{delegate} + } else { + rw = delegate + } + handlerFunc(rw, r) + + elapsed := float64(time.Since(now)) / float64(time.Microsecond) + + method := sanitizeMethod(r.Method) + code := sanitizeCode(delegate.status) + reqCnt.WithLabelValues(method, code).Inc() + reqDur.Observe(elapsed) + resSz.Observe(float64(delegate.written)) + reqSz.Observe(float64(<-out)) + }) +} + +func computeApproximateRequestSize(r *http.Request) <-chan int { + // Get URL length in current go routine for avoiding a race condition. + // HandlerFunc that runs in parallel may modify the URL. + s := 0 + if r.URL != nil { + s += len(r.URL.String()) + } + + out := make(chan int, 1) + + go func() { + s += len(r.Method) + s += len(r.Proto) + for name, values := range r.Header { + s += len(name) + for _, value := range values { + s += len(value) + } + } + s += len(r.Host) + + // N.B. r.Form and r.MultipartForm are assumed to be included in r.URL. + + if r.ContentLength != -1 { + s += int(r.ContentLength) + } + out <- s + close(out) + }() + + return out +} + +type responseWriterDelegator struct { + http.ResponseWriter + + handler, method string + status int + written int64 + wroteHeader bool +} + +func (r *responseWriterDelegator) WriteHeader(code int) { + r.status = code + r.wroteHeader = true + r.ResponseWriter.WriteHeader(code) +} + +func (r *responseWriterDelegator) Write(b []byte) (int, error) { + if !r.wroteHeader { + r.WriteHeader(http.StatusOK) + } + n, err := r.ResponseWriter.Write(b) + r.written += int64(n) + return n, err +} + +type fancyResponseWriterDelegator struct { + *responseWriterDelegator +} + +func (f *fancyResponseWriterDelegator) CloseNotify() <-chan bool { + return f.ResponseWriter.(http.CloseNotifier).CloseNotify() +} + +func (f *fancyResponseWriterDelegator) Flush() { + f.ResponseWriter.(http.Flusher).Flush() +} + +func (f *fancyResponseWriterDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) { + return f.ResponseWriter.(http.Hijacker).Hijack() +} + +func (f *fancyResponseWriterDelegator) ReadFrom(r io.Reader) (int64, error) { + if !f.wroteHeader { + f.WriteHeader(http.StatusOK) + } + n, err := f.ResponseWriter.(io.ReaderFrom).ReadFrom(r) + f.written += n + return n, err +} + +func sanitizeMethod(m string) string { + switch m { + case "GET", "get": + return "get" + case "PUT", "put": + return "put" + case "HEAD", "head": + return "head" + case "POST", "post": + return "post" + case "DELETE", "delete": + return "delete" + case "CONNECT", "connect": + return "connect" + case "OPTIONS", "options": + return "options" + case "NOTIFY", "notify": + return "notify" + default: + return strings.ToLower(m) + } +} + +func sanitizeCode(s int) string { + switch s { + case 100: + return "100" + case 101: + return "101" + + case 200: + return "200" + case 201: + return "201" + case 202: + return "202" + case 203: + return "203" + case 204: + return "204" + case 205: + return "205" + case 206: + return "206" + + case 300: + return "300" + case 301: + return "301" + case 302: + return "302" + case 304: + return "304" + case 305: + return "305" + case 307: + return "307" + + case 400: + return "400" + case 401: + return "401" + case 402: + return "402" + case 403: + return "403" + case 404: + return "404" + case 405: + return "405" + case 406: + return "406" + case 407: + return "407" + case 408: + return "408" + case 409: + return "409" + case 410: + return "410" + case 411: + return "411" + case 412: + return "412" + case 413: + return "413" + case 414: + return "414" + case 415: + return "415" + case 416: + return "416" + case 417: + return "417" + case 418: + return "418" + + case 500: + return "500" + case 501: + return "501" + case 502: + return "502" + case 503: + return "503" + case 504: + return "504" + case 505: + return "505" + + case 428: + return "428" + case 429: + return "429" + case 431: + return "431" + case 511: + return "511" + + default: + return strconv.Itoa(s) + } +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/metric.go b/vendor/github.com/prometheus/client_golang/prometheus/metric.go new file mode 100644 index 0000000..d4063d9 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/metric.go @@ -0,0 +1,166 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "strings" + + dto "github.com/prometheus/client_model/go" +) + +const separatorByte byte = 255 + +// A Metric models a single sample value with its meta data being exported to +// Prometheus. Implementations of Metric in this package are Gauge, Counter, +// Histogram, Summary, and Untyped. +type Metric interface { + // Desc returns the descriptor for the Metric. This method idempotently + // returns the same descriptor throughout the lifetime of the + // Metric. The returned descriptor is immutable by contract. A Metric + // unable to describe itself must return an invalid descriptor (created + // with NewInvalidDesc). + Desc() *Desc + // Write encodes the Metric into a "Metric" Protocol Buffer data + // transmission object. + // + // Metric implementations must observe concurrency safety as reads of + // this metric may occur at any time, and any blocking occurs at the + // expense of total performance of rendering all registered + // metrics. Ideally, Metric implementations should support concurrent + // readers. + // + // While populating dto.Metric, it is the responsibility of the + // implementation to ensure validity of the Metric protobuf (like valid + // UTF-8 strings or syntactically valid metric and label names). It is + // recommended to sort labels lexicographically. (Implementers may find + // LabelPairSorter useful for that.) Callers of Write should still make + // sure of sorting if they depend on it. + Write(*dto.Metric) error + // TODO(beorn7): The original rationale of passing in a pre-allocated + // dto.Metric protobuf to save allocations has disappeared. The + // signature of this method should be changed to "Write() (*dto.Metric, + // error)". +} + +// Opts bundles the options for creating most Metric types. Each metric +// implementation XXX has its own XXXOpts type, but in most cases, it is just be +// an alias of this type (which might change when the requirement arises.) +// +// It is mandatory to set Name and Help to a non-empty string. All other fields +// are optional and can safely be left at their zero value. +type Opts struct { + // Namespace, Subsystem, and Name are components of the fully-qualified + // name of the Metric (created by joining these components with + // "_"). Only Name is mandatory, the others merely help structuring the + // name. Note that the fully-qualified name of the metric must be a + // valid Prometheus metric name. + Namespace string + Subsystem string + Name string + + // Help provides information about this metric. Mandatory! + // + // Metrics with the same fully-qualified name must have the same Help + // string. + Help string + + // ConstLabels are used to attach fixed labels to this metric. Metrics + // with the same fully-qualified name must have the same label names in + // their ConstLabels. + // + // Note that in most cases, labels have a value that varies during the + // lifetime of a process. Those labels are usually managed with a metric + // vector collector (like CounterVec, GaugeVec, UntypedVec). ConstLabels + // serve only special purposes. One is for the special case where the + // value of a label does not change during the lifetime of a process, + // e.g. if the revision of the running binary is put into a + // label. Another, more advanced purpose is if more than one Collector + // needs to collect Metrics with the same fully-qualified name. In that + // case, those Metrics must differ in the values of their + // ConstLabels. See the Collector examples. + // + // If the value of a label never changes (not even between binaries), + // that label most likely should not be a label at all (but part of the + // metric name). + ConstLabels Labels +} + +// BuildFQName joins the given three name components by "_". Empty name +// components are ignored. If the name parameter itself is empty, an empty +// string is returned, no matter what. Metric implementations included in this +// library use this function internally to generate the fully-qualified metric +// name from the name component in their Opts. Users of the library will only +// need this function if they implement their own Metric or instantiate a Desc +// (with NewDesc) directly. +func BuildFQName(namespace, subsystem, name string) string { + if name == "" { + return "" + } + switch { + case namespace != "" && subsystem != "": + return strings.Join([]string{namespace, subsystem, name}, "_") + case namespace != "": + return strings.Join([]string{namespace, name}, "_") + case subsystem != "": + return strings.Join([]string{subsystem, name}, "_") + } + return name +} + +// LabelPairSorter implements sort.Interface. It is used to sort a slice of +// dto.LabelPair pointers. This is useful for implementing the Write method of +// custom metrics. +type LabelPairSorter []*dto.LabelPair + +func (s LabelPairSorter) Len() int { + return len(s) +} + +func (s LabelPairSorter) Swap(i, j int) { + s[i], s[j] = s[j], s[i] +} + +func (s LabelPairSorter) Less(i, j int) bool { + return s[i].GetName() < s[j].GetName() +} + +type hashSorter []uint64 + +func (s hashSorter) Len() int { + return len(s) +} + +func (s hashSorter) Swap(i, j int) { + s[i], s[j] = s[j], s[i] +} + +func (s hashSorter) Less(i, j int) bool { + return s[i] < s[j] +} + +type invalidMetric struct { + desc *Desc + err error +} + +// NewInvalidMetric returns a metric whose Write method always returns the +// provided error. It is useful if a Collector finds itself unable to collect +// a metric and wishes to report an error to the registry. +func NewInvalidMetric(desc *Desc, err error) Metric { + return &invalidMetric{desc, err} +} + +func (m *invalidMetric) Desc() *Desc { return m.desc } + +func (m *invalidMetric) Write(*dto.Metric) error { return m.err } diff --git a/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go b/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go new file mode 100644 index 0000000..94b2553 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/process_collector.go @@ -0,0 +1,140 @@ +// Copyright 2015 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import "github.com/prometheus/procfs" + +type processCollector struct { + pid int + collectFn func(chan<- Metric) + pidFn func() (int, error) + cpuTotal *Desc + openFDs, maxFDs *Desc + vsize, rss *Desc + startTime *Desc +} + +// NewProcessCollector returns a collector which exports the current state of +// process metrics including cpu, memory and file descriptor usage as well as +// the process start time for the given process id under the given namespace. +func NewProcessCollector(pid int, namespace string) Collector { + return NewProcessCollectorPIDFn( + func() (int, error) { return pid, nil }, + namespace, + ) +} + +// NewProcessCollectorPIDFn returns a collector which exports the current state +// of process metrics including cpu, memory and file descriptor usage as well +// as the process start time under the given namespace. The given pidFn is +// called on each collect and is used to determine the process to export +// metrics for. +func NewProcessCollectorPIDFn( + pidFn func() (int, error), + namespace string, +) Collector { + ns := "" + if len(namespace) > 0 { + ns = namespace + "_" + } + + c := processCollector{ + pidFn: pidFn, + collectFn: func(chan<- Metric) {}, + + cpuTotal: NewDesc( + ns+"process_cpu_seconds_total", + "Total user and system CPU time spent in seconds.", + nil, nil, + ), + openFDs: NewDesc( + ns+"process_open_fds", + "Number of open file descriptors.", + nil, nil, + ), + maxFDs: NewDesc( + ns+"process_max_fds", + "Maximum number of open file descriptors.", + nil, nil, + ), + vsize: NewDesc( + ns+"process_virtual_memory_bytes", + "Virtual memory size in bytes.", + nil, nil, + ), + rss: NewDesc( + ns+"process_resident_memory_bytes", + "Resident memory size in bytes.", + nil, nil, + ), + startTime: NewDesc( + ns+"process_start_time_seconds", + "Start time of the process since unix epoch in seconds.", + nil, nil, + ), + } + + // Set up process metric collection if supported by the runtime. + if _, err := procfs.NewStat(); err == nil { + c.collectFn = c.processCollect + } + + return &c +} + +// Describe returns all descriptions of the collector. +func (c *processCollector) Describe(ch chan<- *Desc) { + ch <- c.cpuTotal + ch <- c.openFDs + ch <- c.maxFDs + ch <- c.vsize + ch <- c.rss + ch <- c.startTime +} + +// Collect returns the current state of all metrics of the collector. +func (c *processCollector) Collect(ch chan<- Metric) { + c.collectFn(ch) +} + +// TODO(ts): Bring back error reporting by reverting 7faf9e7 as soon as the +// client allows users to configure the error behavior. +func (c *processCollector) processCollect(ch chan<- Metric) { + pid, err := c.pidFn() + if err != nil { + return + } + + p, err := procfs.NewProc(pid) + if err != nil { + return + } + + if stat, err := p.NewStat(); err == nil { + ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime()) + ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory())) + ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory())) + if startTime, err := stat.StartTime(); err == nil { + ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime) + } + } + + if fds, err := p.FileDescriptorsLen(); err == nil { + ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds)) + } + + if limits, err := p.NewLimits(); err == nil { + ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles)) + } +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go new file mode 100644 index 0000000..b6dd5a2 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go @@ -0,0 +1,201 @@ +// Copyright 2016 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Copyright (c) 2013, The Prometheus Authors +// All rights reserved. +// +// Use of this source code is governed by a BSD-style license that can be found +// in the LICENSE file. + +// Package promhttp contains functions to create http.Handler instances to +// expose Prometheus metrics via HTTP. In later versions of this package, it +// will also contain tooling to instrument instances of http.Handler and +// http.RoundTripper. +// +// promhttp.Handler acts on the prometheus.DefaultGatherer. With HandlerFor, +// you can create a handler for a custom registry or anything that implements +// the Gatherer interface. It also allows to create handlers that act +// differently on errors or allow to log errors. +package promhttp + +import ( + "bytes" + "compress/gzip" + "fmt" + "io" + "net/http" + "strings" + "sync" + + "github.com/prometheus/common/expfmt" + + "github.com/prometheus/client_golang/prometheus" +) + +const ( + contentTypeHeader = "Content-Type" + contentLengthHeader = "Content-Length" + contentEncodingHeader = "Content-Encoding" + acceptEncodingHeader = "Accept-Encoding" +) + +var bufPool sync.Pool + +func getBuf() *bytes.Buffer { + buf := bufPool.Get() + if buf == nil { + return &bytes.Buffer{} + } + return buf.(*bytes.Buffer) +} + +func giveBuf(buf *bytes.Buffer) { + buf.Reset() + bufPool.Put(buf) +} + +// Handler returns an HTTP handler for the prometheus.DefaultGatherer. The +// Handler uses the default HandlerOpts, i.e. report the first error as an HTTP +// error, no error logging, and compression if requested by the client. +// +// If you want to create a Handler for the DefaultGatherer with different +// HandlerOpts, create it with HandlerFor with prometheus.DefaultGatherer and +// your desired HandlerOpts. +func Handler() http.Handler { + return HandlerFor(prometheus.DefaultGatherer, HandlerOpts{}) +} + +// HandlerFor returns an http.Handler for the provided Gatherer. The behavior +// of the Handler is defined by the provided HandlerOpts. +func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler { + return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) { + mfs, err := reg.Gather() + if err != nil { + if opts.ErrorLog != nil { + opts.ErrorLog.Println("error gathering metrics:", err) + } + switch opts.ErrorHandling { + case PanicOnError: + panic(err) + case ContinueOnError: + if len(mfs) == 0 { + http.Error(w, "No metrics gathered, last error:\n\n"+err.Error(), http.StatusInternalServerError) + return + } + case HTTPErrorOnError: + http.Error(w, "An error has occurred during metrics gathering:\n\n"+err.Error(), http.StatusInternalServerError) + return + } + } + + contentType := expfmt.Negotiate(req.Header) + buf := getBuf() + defer giveBuf(buf) + writer, encoding := decorateWriter(req, buf, opts.DisableCompression) + enc := expfmt.NewEncoder(writer, contentType) + var lastErr error + for _, mf := range mfs { + if err := enc.Encode(mf); err != nil { + lastErr = err + if opts.ErrorLog != nil { + opts.ErrorLog.Println("error encoding metric family:", err) + } + switch opts.ErrorHandling { + case PanicOnError: + panic(err) + case ContinueOnError: + // Handled later. + case HTTPErrorOnError: + http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError) + return + } + } + } + if closer, ok := writer.(io.Closer); ok { + closer.Close() + } + if lastErr != nil && buf.Len() == 0 { + http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError) + return + } + header := w.Header() + header.Set(contentTypeHeader, string(contentType)) + header.Set(contentLengthHeader, fmt.Sprint(buf.Len())) + if encoding != "" { + header.Set(contentEncodingHeader, encoding) + } + w.Write(buf.Bytes()) + // TODO(beorn7): Consider streaming serving of metrics. + }) +} + +// HandlerErrorHandling defines how a Handler serving metrics will handle +// errors. +type HandlerErrorHandling int + +// These constants cause handlers serving metrics to behave as described if +// errors are encountered. +const ( + // Serve an HTTP status code 500 upon the first error + // encountered. Report the error message in the body. + HTTPErrorOnError HandlerErrorHandling = iota + // Ignore errors and try to serve as many metrics as possible. However, + // if no metrics can be served, serve an HTTP status code 500 and the + // last error message in the body. Only use this in deliberate "best + // effort" metrics collection scenarios. It is recommended to at least + // log errors (by providing an ErrorLog in HandlerOpts) to not mask + // errors completely. + ContinueOnError + // Panic upon the first error encountered (useful for "crash only" apps). + PanicOnError +) + +// Logger is the minimal interface HandlerOpts needs for logging. Note that +// log.Logger from the standard library implements this interface, and it is +// easy to implement by custom loggers, if they don't do so already anyway. +type Logger interface { + Println(v ...interface{}) +} + +// HandlerOpts specifies options how to serve metrics via an http.Handler. The +// zero value of HandlerOpts is a reasonable default. +type HandlerOpts struct { + // ErrorLog specifies an optional logger for errors collecting and + // serving metrics. If nil, errors are not logged at all. + ErrorLog Logger + // ErrorHandling defines how errors are handled. Note that errors are + // logged regardless of the configured ErrorHandling provided ErrorLog + // is not nil. + ErrorHandling HandlerErrorHandling + // If DisableCompression is true, the handler will never compress the + // response, even if requested by the client. + DisableCompression bool +} + +// decorateWriter wraps a writer to handle gzip compression if requested. It +// returns the decorated writer and the appropriate "Content-Encoding" header +// (which is empty if no compression is enabled). +func decorateWriter(request *http.Request, writer io.Writer, compressionDisabled bool) (io.Writer, string) { + if compressionDisabled { + return writer, "" + } + header := request.Header.Get(acceptEncodingHeader) + parts := strings.Split(header, ",") + for _, part := range parts { + part := strings.TrimSpace(part) + if part == "gzip" || strings.HasPrefix(part, "gzip;") { + return gzip.NewWriter(writer), "gzip" + } + } + return writer, "" +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/registry.go b/vendor/github.com/prometheus/client_golang/prometheus/registry.go new file mode 100644 index 0000000..78d5f19 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/registry.go @@ -0,0 +1,755 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "bytes" + "errors" + "fmt" + "os" + "sort" + "sync" + + "github.com/golang/protobuf/proto" + + dto "github.com/prometheus/client_model/go" +) + +const ( + // Capacity for the channel to collect metrics and descriptors. + capMetricChan = 1000 + capDescChan = 10 +) + +// DefaultRegisterer and DefaultGatherer are the implementations of the +// Registerer and Gatherer interface a number of convenience functions in this +// package act on. Initially, both variables point to the same Registry, which +// has a process collector (see NewProcessCollector) and a Go collector (see +// NewGoCollector) already registered. This approach to keep default instances +// as global state mirrors the approach of other packages in the Go standard +// library. Note that there are caveats. Change the variables with caution and +// only if you understand the consequences. Users who want to avoid global state +// altogether should not use the convenience function and act on custom +// instances instead. +var ( + defaultRegistry = NewRegistry() + DefaultRegisterer Registerer = defaultRegistry + DefaultGatherer Gatherer = defaultRegistry +) + +func init() { + MustRegister(NewProcessCollector(os.Getpid(), "")) + MustRegister(NewGoCollector()) +} + +// NewRegistry creates a new vanilla Registry without any Collectors +// pre-registered. +func NewRegistry() *Registry { + return &Registry{ + collectorsByID: map[uint64]Collector{}, + descIDs: map[uint64]struct{}{}, + dimHashesByName: map[string]uint64{}, + } +} + +// NewPedanticRegistry returns a registry that checks during collection if each +// collected Metric is consistent with its reported Desc, and if the Desc has +// actually been registered with the registry. +// +// Usually, a Registry will be happy as long as the union of all collected +// Metrics is consistent and valid even if some metrics are not consistent with +// their own Desc or a Desc provided by their registered Collector. Well-behaved +// Collectors and Metrics will only provide consistent Descs. This Registry is +// useful to test the implementation of Collectors and Metrics. +func NewPedanticRegistry() *Registry { + r := NewRegistry() + r.pedanticChecksEnabled = true + return r +} + +// Registerer is the interface for the part of a registry in charge of +// registering and unregistering. Users of custom registries should use +// Registerer as type for registration purposes (rather then the Registry type +// directly). In that way, they are free to use custom Registerer implementation +// (e.g. for testing purposes). +type Registerer interface { + // Register registers a new Collector to be included in metrics + // collection. It returns an error if the descriptors provided by the + // Collector are invalid or if they — in combination with descriptors of + // already registered Collectors — do not fulfill the consistency and + // uniqueness criteria described in the documentation of metric.Desc. + // + // If the provided Collector is equal to a Collector already registered + // (which includes the case of re-registering the same Collector), the + // returned error is an instance of AlreadyRegisteredError, which + // contains the previously registered Collector. + // + // It is in general not safe to register the same Collector multiple + // times concurrently. + Register(Collector) error + // MustRegister works like Register but registers any number of + // Collectors and panics upon the first registration that causes an + // error. + MustRegister(...Collector) + // Unregister unregisters the Collector that equals the Collector passed + // in as an argument. (Two Collectors are considered equal if their + // Describe method yields the same set of descriptors.) The function + // returns whether a Collector was unregistered. + // + // Note that even after unregistering, it will not be possible to + // register a new Collector that is inconsistent with the unregistered + // Collector, e.g. a Collector collecting metrics with the same name but + // a different help string. The rationale here is that the same registry + // instance must only collect consistent metrics throughout its + // lifetime. + Unregister(Collector) bool +} + +// Gatherer is the interface for the part of a registry in charge of gathering +// the collected metrics into a number of MetricFamilies. The Gatherer interface +// comes with the same general implication as described for the Registerer +// interface. +type Gatherer interface { + // Gather calls the Collect method of the registered Collectors and then + // gathers the collected metrics into a lexicographically sorted slice + // of MetricFamily protobufs. Even if an error occurs, Gather attempts + // to gather as many metrics as possible. Hence, if a non-nil error is + // returned, the returned MetricFamily slice could be nil (in case of a + // fatal error that prevented any meaningful metric collection) or + // contain a number of MetricFamily protobufs, some of which might be + // incomplete, and some might be missing altogether. The returned error + // (which might be a MultiError) explains the details. In scenarios + // where complete collection is critical, the returned MetricFamily + // protobufs should be disregarded if the returned error is non-nil. + Gather() ([]*dto.MetricFamily, error) +} + +// Register registers the provided Collector with the DefaultRegisterer. +// +// Register is a shortcut for DefaultRegisterer.Register(c). See there for more +// details. +func Register(c Collector) error { + return DefaultRegisterer.Register(c) +} + +// MustRegister registers the provided Collectors with the DefaultRegisterer and +// panics if any error occurs. +// +// MustRegister is a shortcut for DefaultRegisterer.MustRegister(cs...). See +// there for more details. +func MustRegister(cs ...Collector) { + DefaultRegisterer.MustRegister(cs...) +} + +// Unregister removes the registration of the provided Collector from the +// DefaultRegisterer. +// +// Unregister is a shortcut for DefaultRegisterer.Unregister(c). See there for +// more details. +func Unregister(c Collector) bool { + return DefaultRegisterer.Unregister(c) +} + +// GathererFunc turns a function into a Gatherer. +type GathererFunc func() ([]*dto.MetricFamily, error) + +// Gather implements Gatherer. +func (gf GathererFunc) Gather() ([]*dto.MetricFamily, error) { + return gf() +} + +// AlreadyRegisteredError is returned by the Register method if the Collector to +// be registered has already been registered before, or a different Collector +// that collects the same metrics has been registered before. Registration fails +// in that case, but you can detect from the kind of error what has +// happened. The error contains fields for the existing Collector and the +// (rejected) new Collector that equals the existing one. This can be used to +// find out if an equal Collector has been registered before and switch over to +// using the old one, as demonstrated in the example. +type AlreadyRegisteredError struct { + ExistingCollector, NewCollector Collector +} + +func (err AlreadyRegisteredError) Error() string { + return "duplicate metrics collector registration attempted" +} + +// MultiError is a slice of errors implementing the error interface. It is used +// by a Gatherer to report multiple errors during MetricFamily gathering. +type MultiError []error + +func (errs MultiError) Error() string { + if len(errs) == 0 { + return "" + } + buf := &bytes.Buffer{} + fmt.Fprintf(buf, "%d error(s) occurred:", len(errs)) + for _, err := range errs { + fmt.Fprintf(buf, "\n* %s", err) + } + return buf.String() +} + +// MaybeUnwrap returns nil if len(errs) is 0. It returns the first and only +// contained error as error if len(errs is 1). In all other cases, it returns +// the MultiError directly. This is helpful for returning a MultiError in a way +// that only uses the MultiError if needed. +func (errs MultiError) MaybeUnwrap() error { + switch len(errs) { + case 0: + return nil + case 1: + return errs[0] + default: + return errs + } +} + +// Registry registers Prometheus collectors, collects their metrics, and gathers +// them into MetricFamilies for exposition. It implements both Registerer and +// Gatherer. The zero value is not usable. Create instances with NewRegistry or +// NewPedanticRegistry. +type Registry struct { + mtx sync.RWMutex + collectorsByID map[uint64]Collector // ID is a hash of the descIDs. + descIDs map[uint64]struct{} + dimHashesByName map[string]uint64 + pedanticChecksEnabled bool +} + +// Register implements Registerer. +func (r *Registry) Register(c Collector) error { + var ( + descChan = make(chan *Desc, capDescChan) + newDescIDs = map[uint64]struct{}{} + newDimHashesByName = map[string]uint64{} + collectorID uint64 // Just a sum of all desc IDs. + duplicateDescErr error + ) + go func() { + c.Describe(descChan) + close(descChan) + }() + r.mtx.Lock() + defer r.mtx.Unlock() + // Coduct various tests... + for desc := range descChan { + + // Is the descriptor valid at all? + if desc.err != nil { + return fmt.Errorf("descriptor %s is invalid: %s", desc, desc.err) + } + + // Is the descID unique? + // (In other words: Is the fqName + constLabel combination unique?) + if _, exists := r.descIDs[desc.id]; exists { + duplicateDescErr = fmt.Errorf("descriptor %s already exists with the same fully-qualified name and const label values", desc) + } + // If it is not a duplicate desc in this collector, add it to + // the collectorID. (We allow duplicate descs within the same + // collector, but their existence must be a no-op.) + if _, exists := newDescIDs[desc.id]; !exists { + newDescIDs[desc.id] = struct{}{} + collectorID += desc.id + } + + // Are all the label names and the help string consistent with + // previous descriptors of the same name? + // First check existing descriptors... + if dimHash, exists := r.dimHashesByName[desc.fqName]; exists { + if dimHash != desc.dimHash { + return fmt.Errorf("a previously registered descriptor with the same fully-qualified name as %s has different label names or a different help string", desc) + } + } else { + // ...then check the new descriptors already seen. + if dimHash, exists := newDimHashesByName[desc.fqName]; exists { + if dimHash != desc.dimHash { + return fmt.Errorf("descriptors reported by collector have inconsistent label names or help strings for the same fully-qualified name, offender is %s", desc) + } + } else { + newDimHashesByName[desc.fqName] = desc.dimHash + } + } + } + // Did anything happen at all? + if len(newDescIDs) == 0 { + return errors.New("collector has no descriptors") + } + if existing, exists := r.collectorsByID[collectorID]; exists { + return AlreadyRegisteredError{ + ExistingCollector: existing, + NewCollector: c, + } + } + // If the collectorID is new, but at least one of the descs existed + // before, we are in trouble. + if duplicateDescErr != nil { + return duplicateDescErr + } + + // Only after all tests have passed, actually register. + r.collectorsByID[collectorID] = c + for hash := range newDescIDs { + r.descIDs[hash] = struct{}{} + } + for name, dimHash := range newDimHashesByName { + r.dimHashesByName[name] = dimHash + } + return nil +} + +// Unregister implements Registerer. +func (r *Registry) Unregister(c Collector) bool { + var ( + descChan = make(chan *Desc, capDescChan) + descIDs = map[uint64]struct{}{} + collectorID uint64 // Just a sum of the desc IDs. + ) + go func() { + c.Describe(descChan) + close(descChan) + }() + for desc := range descChan { + if _, exists := descIDs[desc.id]; !exists { + collectorID += desc.id + descIDs[desc.id] = struct{}{} + } + } + + r.mtx.RLock() + if _, exists := r.collectorsByID[collectorID]; !exists { + r.mtx.RUnlock() + return false + } + r.mtx.RUnlock() + + r.mtx.Lock() + defer r.mtx.Unlock() + + delete(r.collectorsByID, collectorID) + for id := range descIDs { + delete(r.descIDs, id) + } + // dimHashesByName is left untouched as those must be consistent + // throughout the lifetime of a program. + return true +} + +// MustRegister implements Registerer. +func (r *Registry) MustRegister(cs ...Collector) { + for _, c := range cs { + if err := r.Register(c); err != nil { + panic(err) + } + } +} + +// Gather implements Gatherer. +func (r *Registry) Gather() ([]*dto.MetricFamily, error) { + var ( + metricChan = make(chan Metric, capMetricChan) + metricHashes = map[uint64]struct{}{} + dimHashes = map[string]uint64{} + wg sync.WaitGroup + errs MultiError // The collected errors to return in the end. + registeredDescIDs map[uint64]struct{} // Only used for pedantic checks + ) + + r.mtx.RLock() + metricFamiliesByName := make(map[string]*dto.MetricFamily, len(r.dimHashesByName)) + + // Scatter. + // (Collectors could be complex and slow, so we call them all at once.) + wg.Add(len(r.collectorsByID)) + go func() { + wg.Wait() + close(metricChan) + }() + for _, collector := range r.collectorsByID { + go func(collector Collector) { + defer wg.Done() + collector.Collect(metricChan) + }(collector) + } + + // In case pedantic checks are enabled, we have to copy the map before + // giving up the RLock. + if r.pedanticChecksEnabled { + registeredDescIDs = make(map[uint64]struct{}, len(r.descIDs)) + for id := range r.descIDs { + registeredDescIDs[id] = struct{}{} + } + } + + r.mtx.RUnlock() + + // Drain metricChan in case of premature return. + defer func() { + for range metricChan { + } + }() + + // Gather. + for metric := range metricChan { + // This could be done concurrently, too, but it required locking + // of metricFamiliesByName (and of metricHashes if checks are + // enabled). Most likely not worth it. + desc := metric.Desc() + dtoMetric := &dto.Metric{} + if err := metric.Write(dtoMetric); err != nil { + errs = append(errs, fmt.Errorf( + "error collecting metric %v: %s", desc, err, + )) + continue + } + metricFamily, ok := metricFamiliesByName[desc.fqName] + if ok { + if metricFamily.GetHelp() != desc.help { + errs = append(errs, fmt.Errorf( + "collected metric %s %s has help %q but should have %q", + desc.fqName, dtoMetric, desc.help, metricFamily.GetHelp(), + )) + continue + } + // TODO(beorn7): Simplify switch once Desc has type. + switch metricFamily.GetType() { + case dto.MetricType_COUNTER: + if dtoMetric.Counter == nil { + errs = append(errs, fmt.Errorf( + "collected metric %s %s should be a Counter", + desc.fqName, dtoMetric, + )) + continue + } + case dto.MetricType_GAUGE: + if dtoMetric.Gauge == nil { + errs = append(errs, fmt.Errorf( + "collected metric %s %s should be a Gauge", + desc.fqName, dtoMetric, + )) + continue + } + case dto.MetricType_SUMMARY: + if dtoMetric.Summary == nil { + errs = append(errs, fmt.Errorf( + "collected metric %s %s should be a Summary", + desc.fqName, dtoMetric, + )) + continue + } + case dto.MetricType_UNTYPED: + if dtoMetric.Untyped == nil { + errs = append(errs, fmt.Errorf( + "collected metric %s %s should be Untyped", + desc.fqName, dtoMetric, + )) + continue + } + case dto.MetricType_HISTOGRAM: + if dtoMetric.Histogram == nil { + errs = append(errs, fmt.Errorf( + "collected metric %s %s should be a Histogram", + desc.fqName, dtoMetric, + )) + continue + } + default: + panic("encountered MetricFamily with invalid type") + } + } else { + metricFamily = &dto.MetricFamily{} + metricFamily.Name = proto.String(desc.fqName) + metricFamily.Help = proto.String(desc.help) + // TODO(beorn7): Simplify switch once Desc has type. + switch { + case dtoMetric.Gauge != nil: + metricFamily.Type = dto.MetricType_GAUGE.Enum() + case dtoMetric.Counter != nil: + metricFamily.Type = dto.MetricType_COUNTER.Enum() + case dtoMetric.Summary != nil: + metricFamily.Type = dto.MetricType_SUMMARY.Enum() + case dtoMetric.Untyped != nil: + metricFamily.Type = dto.MetricType_UNTYPED.Enum() + case dtoMetric.Histogram != nil: + metricFamily.Type = dto.MetricType_HISTOGRAM.Enum() + default: + errs = append(errs, fmt.Errorf( + "empty metric collected: %s", dtoMetric, + )) + continue + } + metricFamiliesByName[desc.fqName] = metricFamily + } + if err := checkMetricConsistency(metricFamily, dtoMetric, metricHashes, dimHashes); err != nil { + errs = append(errs, err) + continue + } + if r.pedanticChecksEnabled { + // Is the desc registered at all? + if _, exist := registeredDescIDs[desc.id]; !exist { + errs = append(errs, fmt.Errorf( + "collected metric %s %s with unregistered descriptor %s", + metricFamily.GetName(), dtoMetric, desc, + )) + continue + } + if err := checkDescConsistency(metricFamily, dtoMetric, desc); err != nil { + errs = append(errs, err) + continue + } + } + metricFamily.Metric = append(metricFamily.Metric, dtoMetric) + } + return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap() +} + +// Gatherers is a slice of Gatherer instances that implements the Gatherer +// interface itself. Its Gather method calls Gather on all Gatherers in the +// slice in order and returns the merged results. Errors returned from the +// Gather calles are all returned in a flattened MultiError. Duplicate and +// inconsistent Metrics are skipped (first occurrence in slice order wins) and +// reported in the returned error. +// +// Gatherers can be used to merge the Gather results from multiple +// Registries. It also provides a way to directly inject existing MetricFamily +// protobufs into the gathering by creating a custom Gatherer with a Gather +// method that simply returns the existing MetricFamily protobufs. Note that no +// registration is involved (in contrast to Collector registration), so +// obviously registration-time checks cannot happen. Any inconsistencies between +// the gathered MetricFamilies are reported as errors by the Gather method, and +// inconsistent Metrics are dropped. Invalid parts of the MetricFamilies +// (e.g. syntactically invalid metric or label names) will go undetected. +type Gatherers []Gatherer + +// Gather implements Gatherer. +func (gs Gatherers) Gather() ([]*dto.MetricFamily, error) { + var ( + metricFamiliesByName = map[string]*dto.MetricFamily{} + metricHashes = map[uint64]struct{}{} + dimHashes = map[string]uint64{} + errs MultiError // The collected errors to return in the end. + ) + + for i, g := range gs { + mfs, err := g.Gather() + if err != nil { + if multiErr, ok := err.(MultiError); ok { + for _, err := range multiErr { + errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err)) + } + } else { + errs = append(errs, fmt.Errorf("[from Gatherer #%d] %s", i+1, err)) + } + } + for _, mf := range mfs { + existingMF, exists := metricFamiliesByName[mf.GetName()] + if exists { + if existingMF.GetHelp() != mf.GetHelp() { + errs = append(errs, fmt.Errorf( + "gathered metric family %s has help %q but should have %q", + mf.GetName(), mf.GetHelp(), existingMF.GetHelp(), + )) + continue + } + if existingMF.GetType() != mf.GetType() { + errs = append(errs, fmt.Errorf( + "gathered metric family %s has type %s but should have %s", + mf.GetName(), mf.GetType(), existingMF.GetType(), + )) + continue + } + } else { + existingMF = &dto.MetricFamily{} + existingMF.Name = mf.Name + existingMF.Help = mf.Help + existingMF.Type = mf.Type + metricFamiliesByName[mf.GetName()] = existingMF + } + for _, m := range mf.Metric { + if err := checkMetricConsistency(existingMF, m, metricHashes, dimHashes); err != nil { + errs = append(errs, err) + continue + } + existingMF.Metric = append(existingMF.Metric, m) + } + } + } + return normalizeMetricFamilies(metricFamiliesByName), errs.MaybeUnwrap() +} + +// metricSorter is a sortable slice of *dto.Metric. +type metricSorter []*dto.Metric + +func (s metricSorter) Len() int { + return len(s) +} + +func (s metricSorter) Swap(i, j int) { + s[i], s[j] = s[j], s[i] +} + +func (s metricSorter) Less(i, j int) bool { + if len(s[i].Label) != len(s[j].Label) { + // This should not happen. The metrics are + // inconsistent. However, we have to deal with the fact, as + // people might use custom collectors or metric family injection + // to create inconsistent metrics. So let's simply compare the + // number of labels in this case. That will still yield + // reproducible sorting. + return len(s[i].Label) < len(s[j].Label) + } + for n, lp := range s[i].Label { + vi := lp.GetValue() + vj := s[j].Label[n].GetValue() + if vi != vj { + return vi < vj + } + } + + // We should never arrive here. Multiple metrics with the same + // label set in the same scrape will lead to undefined ingestion + // behavior. However, as above, we have to provide stable sorting + // here, even for inconsistent metrics. So sort equal metrics + // by their timestamp, with missing timestamps (implying "now") + // coming last. + if s[i].TimestampMs == nil { + return false + } + if s[j].TimestampMs == nil { + return true + } + return s[i].GetTimestampMs() < s[j].GetTimestampMs() +} + +// normalizeMetricFamilies returns a MetricFamily slice with empty +// MetricFamilies pruned and the remaining MetricFamilies sorted by name within +// the slice, with the contained Metrics sorted within each MetricFamily. +func normalizeMetricFamilies(metricFamiliesByName map[string]*dto.MetricFamily) []*dto.MetricFamily { + for _, mf := range metricFamiliesByName { + sort.Sort(metricSorter(mf.Metric)) + } + names := make([]string, 0, len(metricFamiliesByName)) + for name, mf := range metricFamiliesByName { + if len(mf.Metric) > 0 { + names = append(names, name) + } + } + sort.Strings(names) + result := make([]*dto.MetricFamily, 0, len(names)) + for _, name := range names { + result = append(result, metricFamiliesByName[name]) + } + return result +} + +// checkMetricConsistency checks if the provided Metric is consistent with the +// provided MetricFamily. It also hashed the Metric labels and the MetricFamily +// name. If the resulting hash is alread in the provided metricHashes, an error +// is returned. If not, it is added to metricHashes. The provided dimHashes maps +// MetricFamily names to their dimHash (hashed sorted label names). If dimHashes +// doesn't yet contain a hash for the provided MetricFamily, it is +// added. Otherwise, an error is returned if the existing dimHashes in not equal +// the calculated dimHash. +func checkMetricConsistency( + metricFamily *dto.MetricFamily, + dtoMetric *dto.Metric, + metricHashes map[uint64]struct{}, + dimHashes map[string]uint64, +) error { + // Type consistency with metric family. + if metricFamily.GetType() == dto.MetricType_GAUGE && dtoMetric.Gauge == nil || + metricFamily.GetType() == dto.MetricType_COUNTER && dtoMetric.Counter == nil || + metricFamily.GetType() == dto.MetricType_SUMMARY && dtoMetric.Summary == nil || + metricFamily.GetType() == dto.MetricType_HISTOGRAM && dtoMetric.Histogram == nil || + metricFamily.GetType() == dto.MetricType_UNTYPED && dtoMetric.Untyped == nil { + return fmt.Errorf( + "collected metric %s %s is not a %s", + metricFamily.GetName(), dtoMetric, metricFamily.GetType(), + ) + } + + // Is the metric unique (i.e. no other metric with the same name and the same label values)? + h := hashNew() + h = hashAdd(h, metricFamily.GetName()) + h = hashAddByte(h, separatorByte) + dh := hashNew() + // Make sure label pairs are sorted. We depend on it for the consistency + // check. + sort.Sort(LabelPairSorter(dtoMetric.Label)) + for _, lp := range dtoMetric.Label { + h = hashAdd(h, lp.GetValue()) + h = hashAddByte(h, separatorByte) + dh = hashAdd(dh, lp.GetName()) + dh = hashAddByte(dh, separatorByte) + } + if _, exists := metricHashes[h]; exists { + return fmt.Errorf( + "collected metric %s %s was collected before with the same name and label values", + metricFamily.GetName(), dtoMetric, + ) + } + if dimHash, ok := dimHashes[metricFamily.GetName()]; ok { + if dimHash != dh { + return fmt.Errorf( + "collected metric %s %s has label dimensions inconsistent with previously collected metrics in the same metric family", + metricFamily.GetName(), dtoMetric, + ) + } + } else { + dimHashes[metricFamily.GetName()] = dh + } + metricHashes[h] = struct{}{} + return nil +} + +func checkDescConsistency( + metricFamily *dto.MetricFamily, + dtoMetric *dto.Metric, + desc *Desc, +) error { + // Desc help consistency with metric family help. + if metricFamily.GetHelp() != desc.help { + return fmt.Errorf( + "collected metric %s %s has help %q but should have %q", + metricFamily.GetName(), dtoMetric, metricFamily.GetHelp(), desc.help, + ) + } + + // Is the desc consistent with the content of the metric? + lpsFromDesc := make([]*dto.LabelPair, 0, len(dtoMetric.Label)) + lpsFromDesc = append(lpsFromDesc, desc.constLabelPairs...) + for _, l := range desc.variableLabels { + lpsFromDesc = append(lpsFromDesc, &dto.LabelPair{ + Name: proto.String(l), + }) + } + if len(lpsFromDesc) != len(dtoMetric.Label) { + return fmt.Errorf( + "labels in collected metric %s %s are inconsistent with descriptor %s", + metricFamily.GetName(), dtoMetric, desc, + ) + } + sort.Sort(LabelPairSorter(lpsFromDesc)) + for i, lpFromDesc := range lpsFromDesc { + lpFromMetric := dtoMetric.Label[i] + if lpFromDesc.GetName() != lpFromMetric.GetName() || + lpFromDesc.Value != nil && lpFromDesc.GetValue() != lpFromMetric.GetValue() { + return fmt.Errorf( + "labels in collected metric %s %s are inconsistent with descriptor %s", + metricFamily.GetName(), dtoMetric, desc, + ) + } + } + return nil +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/summary.go b/vendor/github.com/prometheus/client_golang/prometheus/summary.go new file mode 100644 index 0000000..82b8850 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/summary.go @@ -0,0 +1,543 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "fmt" + "math" + "sort" + "sync" + "time" + + "github.com/beorn7/perks/quantile" + "github.com/golang/protobuf/proto" + + dto "github.com/prometheus/client_model/go" +) + +// quantileLabel is used for the label that defines the quantile in a +// summary. +const quantileLabel = "quantile" + +// A Summary captures individual observations from an event or sample stream and +// summarizes them in a manner similar to traditional summary statistics: 1. sum +// of observations, 2. observation count, 3. rank estimations. +// +// A typical use-case is the observation of request latencies. By default, a +// Summary provides the median, the 90th and the 99th percentile of the latency +// as rank estimations. +// +// Note that the rank estimations cannot be aggregated in a meaningful way with +// the Prometheus query language (i.e. you cannot average or add them). If you +// need aggregatable quantiles (e.g. you want the 99th percentile latency of all +// queries served across all instances of a service), consider the Histogram +// metric type. See the Prometheus documentation for more details. +// +// To create Summary instances, use NewSummary. +type Summary interface { + Metric + Collector + + // Observe adds a single observation to the summary. + Observe(float64) +} + +// DefObjectives are the default Summary quantile values. +// +// Deprecated: DefObjectives will not be used as the default objectives in +// v0.10 of the library. The default Summary will have no quantiles then. +var ( + DefObjectives = map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001} + + errQuantileLabelNotAllowed = fmt.Errorf( + "%q is not allowed as label name in summaries", quantileLabel, + ) +) + +// Default values for SummaryOpts. +const ( + // DefMaxAge is the default duration for which observations stay + // relevant. + DefMaxAge time.Duration = 10 * time.Minute + // DefAgeBuckets is the default number of buckets used to calculate the + // age of observations. + DefAgeBuckets = 5 + // DefBufCap is the standard buffer size for collecting Summary observations. + DefBufCap = 500 +) + +// SummaryOpts bundles the options for creating a Summary metric. It is +// mandatory to set Name and Help to a non-empty string. All other fields are +// optional and can safely be left at their zero value. +type SummaryOpts struct { + // Namespace, Subsystem, and Name are components of the fully-qualified + // name of the Summary (created by joining these components with + // "_"). Only Name is mandatory, the others merely help structuring the + // name. Note that the fully-qualified name of the Summary must be a + // valid Prometheus metric name. + Namespace string + Subsystem string + Name string + + // Help provides information about this Summary. Mandatory! + // + // Metrics with the same fully-qualified name must have the same Help + // string. + Help string + + // ConstLabels are used to attach fixed labels to this + // Summary. Summaries with the same fully-qualified name must have the + // same label names in their ConstLabels. + // + // Note that in most cases, labels have a value that varies during the + // lifetime of a process. Those labels are usually managed with a + // SummaryVec. ConstLabels serve only special purposes. One is for the + // special case where the value of a label does not change during the + // lifetime of a process, e.g. if the revision of the running binary is + // put into a label. Another, more advanced purpose is if more than one + // Collector needs to collect Summaries with the same fully-qualified + // name. In that case, those Summaries must differ in the values of + // their ConstLabels. See the Collector examples. + // + // If the value of a label never changes (not even between binaries), + // that label most likely should not be a label at all (but part of the + // metric name). + ConstLabels Labels + + // Objectives defines the quantile rank estimates with their respective + // absolute error. If Objectives[q] = e, then the value reported for q + // will be the φ-quantile value for some φ between q-e and q+e. The + // default value is DefObjectives. It is used if Objectives is left at + // its zero value (i.e. nil). To create a Summary without Objectives, + // set it to an empty map (i.e. map[float64]float64{}). + // + // Deprecated: Note that the current value of DefObjectives is + // deprecated. It will be replaced by an empty map in v0.10 of the + // library. Please explicitly set Objectives to the desired value. + Objectives map[float64]float64 + + // MaxAge defines the duration for which an observation stays relevant + // for the summary. Must be positive. The default value is DefMaxAge. + MaxAge time.Duration + + // AgeBuckets is the number of buckets used to exclude observations that + // are older than MaxAge from the summary. A higher number has a + // resource penalty, so only increase it if the higher resolution is + // really required. For very high observation rates, you might want to + // reduce the number of age buckets. With only one age bucket, you will + // effectively see a complete reset of the summary each time MaxAge has + // passed. The default value is DefAgeBuckets. + AgeBuckets uint32 + + // BufCap defines the default sample stream buffer size. The default + // value of DefBufCap should suffice for most uses. If there is a need + // to increase the value, a multiple of 500 is recommended (because that + // is the internal buffer size of the underlying package + // "github.com/bmizerany/perks/quantile"). + BufCap uint32 +} + +// Great fuck-up with the sliding-window decay algorithm... The Merge method of +// perk/quantile is actually not working as advertised - and it might be +// unfixable, as the underlying algorithm is apparently not capable of merging +// summaries in the first place. To avoid using Merge, we are currently adding +// observations to _each_ age bucket, i.e. the effort to add a sample is +// essentially multiplied by the number of age buckets. When rotating age +// buckets, we empty the previous head stream. On scrape time, we simply take +// the quantiles from the head stream (no merging required). Result: More effort +// on observation time, less effort on scrape time, which is exactly the +// opposite of what we try to accomplish, but at least the results are correct. +// +// The quite elegant previous contraption to merge the age buckets efficiently +// on scrape time (see code up commit 6b9530d72ea715f0ba612c0120e6e09fbf1d49d0) +// can't be used anymore. + +// NewSummary creates a new Summary based on the provided SummaryOpts. +func NewSummary(opts SummaryOpts) Summary { + return newSummary( + NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + nil, + opts.ConstLabels, + ), + opts, + ) +} + +func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary { + if len(desc.variableLabels) != len(labelValues) { + panic(errInconsistentCardinality) + } + + for _, n := range desc.variableLabels { + if n == quantileLabel { + panic(errQuantileLabelNotAllowed) + } + } + for _, lp := range desc.constLabelPairs { + if lp.GetName() == quantileLabel { + panic(errQuantileLabelNotAllowed) + } + } + + if opts.Objectives == nil { + opts.Objectives = DefObjectives + } + + if opts.MaxAge < 0 { + panic(fmt.Errorf("illegal max age MaxAge=%v", opts.MaxAge)) + } + if opts.MaxAge == 0 { + opts.MaxAge = DefMaxAge + } + + if opts.AgeBuckets == 0 { + opts.AgeBuckets = DefAgeBuckets + } + + if opts.BufCap == 0 { + opts.BufCap = DefBufCap + } + + s := &summary{ + desc: desc, + + objectives: opts.Objectives, + sortedObjectives: make([]float64, 0, len(opts.Objectives)), + + labelPairs: makeLabelPairs(desc, labelValues), + + hotBuf: make([]float64, 0, opts.BufCap), + coldBuf: make([]float64, 0, opts.BufCap), + streamDuration: opts.MaxAge / time.Duration(opts.AgeBuckets), + } + s.headStreamExpTime = time.Now().Add(s.streamDuration) + s.hotBufExpTime = s.headStreamExpTime + + for i := uint32(0); i < opts.AgeBuckets; i++ { + s.streams = append(s.streams, s.newStream()) + } + s.headStream = s.streams[0] + + for qu := range s.objectives { + s.sortedObjectives = append(s.sortedObjectives, qu) + } + sort.Float64s(s.sortedObjectives) + + s.init(s) // Init self-collection. + return s +} + +type summary struct { + selfCollector + + bufMtx sync.Mutex // Protects hotBuf and hotBufExpTime. + mtx sync.Mutex // Protects every other moving part. + // Lock bufMtx before mtx if both are needed. + + desc *Desc + + objectives map[float64]float64 + sortedObjectives []float64 + + labelPairs []*dto.LabelPair + + sum float64 + cnt uint64 + + hotBuf, coldBuf []float64 + + streams []*quantile.Stream + streamDuration time.Duration + headStream *quantile.Stream + headStreamIdx int + headStreamExpTime, hotBufExpTime time.Time +} + +func (s *summary) Desc() *Desc { + return s.desc +} + +func (s *summary) Observe(v float64) { + s.bufMtx.Lock() + defer s.bufMtx.Unlock() + + now := time.Now() + if now.After(s.hotBufExpTime) { + s.asyncFlush(now) + } + s.hotBuf = append(s.hotBuf, v) + if len(s.hotBuf) == cap(s.hotBuf) { + s.asyncFlush(now) + } +} + +func (s *summary) Write(out *dto.Metric) error { + sum := &dto.Summary{} + qs := make([]*dto.Quantile, 0, len(s.objectives)) + + s.bufMtx.Lock() + s.mtx.Lock() + // Swap bufs even if hotBuf is empty to set new hotBufExpTime. + s.swapBufs(time.Now()) + s.bufMtx.Unlock() + + s.flushColdBuf() + sum.SampleCount = proto.Uint64(s.cnt) + sum.SampleSum = proto.Float64(s.sum) + + for _, rank := range s.sortedObjectives { + var q float64 + if s.headStream.Count() == 0 { + q = math.NaN() + } else { + q = s.headStream.Query(rank) + } + qs = append(qs, &dto.Quantile{ + Quantile: proto.Float64(rank), + Value: proto.Float64(q), + }) + } + + s.mtx.Unlock() + + if len(qs) > 0 { + sort.Sort(quantSort(qs)) + } + sum.Quantile = qs + + out.Summary = sum + out.Label = s.labelPairs + return nil +} + +func (s *summary) newStream() *quantile.Stream { + return quantile.NewTargeted(s.objectives) +} + +// asyncFlush needs bufMtx locked. +func (s *summary) asyncFlush(now time.Time) { + s.mtx.Lock() + s.swapBufs(now) + + // Unblock the original goroutine that was responsible for the mutation + // that triggered the compaction. But hold onto the global non-buffer + // state mutex until the operation finishes. + go func() { + s.flushColdBuf() + s.mtx.Unlock() + }() +} + +// rotateStreams needs mtx AND bufMtx locked. +func (s *summary) maybeRotateStreams() { + for !s.hotBufExpTime.Equal(s.headStreamExpTime) { + s.headStream.Reset() + s.headStreamIdx++ + if s.headStreamIdx >= len(s.streams) { + s.headStreamIdx = 0 + } + s.headStream = s.streams[s.headStreamIdx] + s.headStreamExpTime = s.headStreamExpTime.Add(s.streamDuration) + } +} + +// flushColdBuf needs mtx locked. +func (s *summary) flushColdBuf() { + for _, v := range s.coldBuf { + for _, stream := range s.streams { + stream.Insert(v) + } + s.cnt++ + s.sum += v + } + s.coldBuf = s.coldBuf[0:0] + s.maybeRotateStreams() +} + +// swapBufs needs mtx AND bufMtx locked, coldBuf must be empty. +func (s *summary) swapBufs(now time.Time) { + if len(s.coldBuf) != 0 { + panic("coldBuf is not empty") + } + s.hotBuf, s.coldBuf = s.coldBuf, s.hotBuf + // hotBuf is now empty and gets new expiration set. + for now.After(s.hotBufExpTime) { + s.hotBufExpTime = s.hotBufExpTime.Add(s.streamDuration) + } +} + +type quantSort []*dto.Quantile + +func (s quantSort) Len() int { + return len(s) +} + +func (s quantSort) Swap(i, j int) { + s[i], s[j] = s[j], s[i] +} + +func (s quantSort) Less(i, j int) bool { + return s[i].GetQuantile() < s[j].GetQuantile() +} + +// SummaryVec is a Collector that bundles a set of Summaries that all share the +// same Desc, but have different values for their variable labels. This is used +// if you want to count the same thing partitioned by various dimensions +// (e.g. HTTP request latencies, partitioned by status code and method). Create +// instances with NewSummaryVec. +type SummaryVec struct { + *MetricVec +} + +// NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and +// partitioned by the given label names. At least one label name must be +// provided. +func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec { + desc := NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + labelNames, + opts.ConstLabels, + ) + return &SummaryVec{ + MetricVec: newMetricVec(desc, func(lvs ...string) Metric { + return newSummary(desc, opts, lvs...) + }), + } +} + +// GetMetricWithLabelValues replaces the method of the same name in +// MetricVec. The difference is that this method returns a Summary and not a +// Metric so that no type conversion is required. +func (m *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Summary, error) { + metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...) + if metric != nil { + return metric.(Summary), err + } + return nil, err +} + +// GetMetricWith replaces the method of the same name in MetricVec. The +// difference is that this method returns a Summary and not a Metric so that no +// type conversion is required. +func (m *SummaryVec) GetMetricWith(labels Labels) (Summary, error) { + metric, err := m.MetricVec.GetMetricWith(labels) + if metric != nil { + return metric.(Summary), err + } + return nil, err +} + +// WithLabelValues works as GetMetricWithLabelValues, but panics where +// GetMetricWithLabelValues would have returned an error. By not returning an +// error, WithLabelValues allows shortcuts like +// myVec.WithLabelValues("404", "GET").Observe(42.21) +func (m *SummaryVec) WithLabelValues(lvs ...string) Summary { + return m.MetricVec.WithLabelValues(lvs...).(Summary) +} + +// With works as GetMetricWith, but panics where GetMetricWithLabels would have +// returned an error. By not returning an error, With allows shortcuts like +// myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21) +func (m *SummaryVec) With(labels Labels) Summary { + return m.MetricVec.With(labels).(Summary) +} + +type constSummary struct { + desc *Desc + count uint64 + sum float64 + quantiles map[float64]float64 + labelPairs []*dto.LabelPair +} + +func (s *constSummary) Desc() *Desc { + return s.desc +} + +func (s *constSummary) Write(out *dto.Metric) error { + sum := &dto.Summary{} + qs := make([]*dto.Quantile, 0, len(s.quantiles)) + + sum.SampleCount = proto.Uint64(s.count) + sum.SampleSum = proto.Float64(s.sum) + + for rank, q := range s.quantiles { + qs = append(qs, &dto.Quantile{ + Quantile: proto.Float64(rank), + Value: proto.Float64(q), + }) + } + + if len(qs) > 0 { + sort.Sort(quantSort(qs)) + } + sum.Quantile = qs + + out.Summary = sum + out.Label = s.labelPairs + + return nil +} + +// NewConstSummary returns a metric representing a Prometheus summary with fixed +// values for the count, sum, and quantiles. As those parameters cannot be +// changed, the returned value does not implement the Summary interface (but +// only the Metric interface). Users of this package will not have much use for +// it in regular operations. However, when implementing custom Collectors, it is +// useful as a throw-away metric that is generated on the fly to send it to +// Prometheus in the Collect method. +// +// quantiles maps ranks to quantile values. For example, a median latency of +// 0.23s and a 99th percentile latency of 0.56s would be expressed as: +// map[float64]float64{0.5: 0.23, 0.99: 0.56} +// +// NewConstSummary returns an error if the length of labelValues is not +// consistent with the variable labels in Desc. +func NewConstSummary( + desc *Desc, + count uint64, + sum float64, + quantiles map[float64]float64, + labelValues ...string, +) (Metric, error) { + if len(desc.variableLabels) != len(labelValues) { + return nil, errInconsistentCardinality + } + return &constSummary{ + desc: desc, + count: count, + sum: sum, + quantiles: quantiles, + labelPairs: makeLabelPairs(desc, labelValues), + }, nil +} + +// MustNewConstSummary is a version of NewConstSummary that panics where +// NewConstMetric would have returned an error. +func MustNewConstSummary( + desc *Desc, + count uint64, + sum float64, + quantiles map[float64]float64, + labelValues ...string, +) Metric { + m, err := NewConstSummary(desc, count, sum, quantiles, labelValues...) + if err != nil { + panic(err) + } + return m +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/timer.go b/vendor/github.com/prometheus/client_golang/prometheus/timer.go new file mode 100644 index 0000000..f4cac5a --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/timer.go @@ -0,0 +1,74 @@ +// Copyright 2016 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import "time" + +// Observer is the interface that wraps the Observe method, which is used by +// Histogram and Summary to add observations. +type Observer interface { + Observe(float64) +} + +// The ObserverFunc type is an adapter to allow the use of ordinary +// functions as Observers. If f is a function with the appropriate +// signature, ObserverFunc(f) is an Observer that calls f. +// +// This adapter is usually used in connection with the Timer type, and there are +// two general use cases: +// +// The most common one is to use a Gauge as the Observer for a Timer. +// See the "Gauge" Timer example. +// +// The more advanced use case is to create a function that dynamically decides +// which Observer to use for observing the duration. See the "Complex" Timer +// example. +type ObserverFunc func(float64) + +// Observe calls f(value). It implements Observer. +func (f ObserverFunc) Observe(value float64) { + f(value) +} + +// Timer is a helper type to time functions. Use NewTimer to create new +// instances. +type Timer struct { + begin time.Time + observer Observer +} + +// NewTimer creates a new Timer. The provided Observer is used to observe a +// duration in seconds. Timer is usually used to time a function call in the +// following way: +// func TimeMe() { +// timer := NewTimer(myHistogram) +// defer timer.ObserveDuration() +// // Do actual work. +// } +func NewTimer(o Observer) *Timer { + return &Timer{ + begin: time.Now(), + observer: o, + } +} + +// ObserveDuration records the duration passed since the Timer was created with +// NewTimer. It calls the Observe method of the Observer provided during +// construction with the duration in seconds as an argument. ObserveDuration is +// usually called with a defer statement. +func (t *Timer) ObserveDuration() { + if t.observer != nil { + t.observer.Observe(time.Since(t.begin).Seconds()) + } +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/untyped.go b/vendor/github.com/prometheus/client_golang/prometheus/untyped.go new file mode 100644 index 0000000..065501d --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/untyped.go @@ -0,0 +1,143 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +// Untyped is a Metric that represents a single numerical value that can +// arbitrarily go up and down. +// +// An Untyped metric works the same as a Gauge. The only difference is that to +// no type information is implied. +// +// To create Untyped instances, use NewUntyped. +// +// Deprecated: The Untyped type is deprecated because it doesn't make sense in +// direct instrumentation. If you need to mirror an external metric of unknown +// type (usually while writing exporters), Use MustNewConstMetric to create an +// untyped metric instance on the fly. +type Untyped interface { + Metric + Collector + + // Set sets the Untyped metric to an arbitrary value. + Set(float64) + // Inc increments the Untyped metric by 1. + Inc() + // Dec decrements the Untyped metric by 1. + Dec() + // Add adds the given value to the Untyped metric. (The value can be + // negative, resulting in a decrease.) + Add(float64) + // Sub subtracts the given value from the Untyped metric. (The value can + // be negative, resulting in an increase.) + Sub(float64) +} + +// UntypedOpts is an alias for Opts. See there for doc comments. +type UntypedOpts Opts + +// NewUntyped creates a new Untyped metric from the provided UntypedOpts. +func NewUntyped(opts UntypedOpts) Untyped { + return newValue(NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + nil, + opts.ConstLabels, + ), UntypedValue, 0) +} + +// UntypedVec is a Collector that bundles a set of Untyped metrics that all +// share the same Desc, but have different values for their variable +// labels. This is used if you want to count the same thing partitioned by +// various dimensions. Create instances with NewUntypedVec. +type UntypedVec struct { + *MetricVec +} + +// NewUntypedVec creates a new UntypedVec based on the provided UntypedOpts and +// partitioned by the given label names. At least one label name must be +// provided. +func NewUntypedVec(opts UntypedOpts, labelNames []string) *UntypedVec { + desc := NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + labelNames, + opts.ConstLabels, + ) + return &UntypedVec{ + MetricVec: newMetricVec(desc, func(lvs ...string) Metric { + return newValue(desc, UntypedValue, 0, lvs...) + }), + } +} + +// GetMetricWithLabelValues replaces the method of the same name in +// MetricVec. The difference is that this method returns an Untyped and not a +// Metric so that no type conversion is required. +func (m *UntypedVec) GetMetricWithLabelValues(lvs ...string) (Untyped, error) { + metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...) + if metric != nil { + return metric.(Untyped), err + } + return nil, err +} + +// GetMetricWith replaces the method of the same name in MetricVec. The +// difference is that this method returns an Untyped and not a Metric so that no +// type conversion is required. +func (m *UntypedVec) GetMetricWith(labels Labels) (Untyped, error) { + metric, err := m.MetricVec.GetMetricWith(labels) + if metric != nil { + return metric.(Untyped), err + } + return nil, err +} + +// WithLabelValues works as GetMetricWithLabelValues, but panics where +// GetMetricWithLabelValues would have returned an error. By not returning an +// error, WithLabelValues allows shortcuts like +// myVec.WithLabelValues("404", "GET").Add(42) +func (m *UntypedVec) WithLabelValues(lvs ...string) Untyped { + return m.MetricVec.WithLabelValues(lvs...).(Untyped) +} + +// With works as GetMetricWith, but panics where GetMetricWithLabels would have +// returned an error. By not returning an error, With allows shortcuts like +// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42) +func (m *UntypedVec) With(labels Labels) Untyped { + return m.MetricVec.With(labels).(Untyped) +} + +// UntypedFunc is an Untyped whose value is determined at collect time by +// calling a provided function. +// +// To create UntypedFunc instances, use NewUntypedFunc. +type UntypedFunc interface { + Metric + Collector +} + +// NewUntypedFunc creates a new UntypedFunc based on the provided +// UntypedOpts. The value reported is determined by calling the given function +// from within the Write method. Take into account that metric collection may +// happen concurrently. If that results in concurrent calls to Write, like in +// the case where an UntypedFunc is directly registered with Prometheus, the +// provided function must be concurrency-safe. +func NewUntypedFunc(opts UntypedOpts, function func() float64) UntypedFunc { + return newValueFunc(NewDesc( + BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), + opts.Help, + nil, + opts.ConstLabels, + ), UntypedValue, function) +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/value.go b/vendor/github.com/prometheus/client_golang/prometheus/value.go new file mode 100644 index 0000000..7d3e810 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/value.go @@ -0,0 +1,239 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "errors" + "fmt" + "math" + "sort" + "sync/atomic" + "time" + + dto "github.com/prometheus/client_model/go" + + "github.com/golang/protobuf/proto" +) + +// ValueType is an enumeration of metric types that represent a simple value. +type ValueType int + +// Possible values for the ValueType enum. +const ( + _ ValueType = iota + CounterValue + GaugeValue + UntypedValue +) + +var errInconsistentCardinality = errors.New("inconsistent label cardinality") + +// value is a generic metric for simple values. It implements Metric, Collector, +// Counter, Gauge, and Untyped. Its effective type is determined by +// ValueType. This is a low-level building block used by the library to back the +// implementations of Counter, Gauge, and Untyped. +type value struct { + // valBits containst the bits of the represented float64 value. It has + // to go first in the struct to guarantee alignment for atomic + // operations. http://golang.org/pkg/sync/atomic/#pkg-note-BUG + valBits uint64 + + selfCollector + + desc *Desc + valType ValueType + labelPairs []*dto.LabelPair +} + +// newValue returns a newly allocated value with the given Desc, ValueType, +// sample value and label values. It panics if the number of label +// values is different from the number of variable labels in Desc. +func newValue(desc *Desc, valueType ValueType, val float64, labelValues ...string) *value { + if len(labelValues) != len(desc.variableLabels) { + panic(errInconsistentCardinality) + } + result := &value{ + desc: desc, + valType: valueType, + valBits: math.Float64bits(val), + labelPairs: makeLabelPairs(desc, labelValues), + } + result.init(result) + return result +} + +func (v *value) Desc() *Desc { + return v.desc +} + +func (v *value) Set(val float64) { + atomic.StoreUint64(&v.valBits, math.Float64bits(val)) +} + +func (v *value) SetToCurrentTime() { + v.Set(float64(time.Now().UnixNano()) / 1e9) +} + +func (v *value) Inc() { + v.Add(1) +} + +func (v *value) Dec() { + v.Add(-1) +} + +func (v *value) Add(val float64) { + for { + oldBits := atomic.LoadUint64(&v.valBits) + newBits := math.Float64bits(math.Float64frombits(oldBits) + val) + if atomic.CompareAndSwapUint64(&v.valBits, oldBits, newBits) { + return + } + } +} + +func (v *value) Sub(val float64) { + v.Add(val * -1) +} + +func (v *value) Write(out *dto.Metric) error { + val := math.Float64frombits(atomic.LoadUint64(&v.valBits)) + return populateMetric(v.valType, val, v.labelPairs, out) +} + +// valueFunc is a generic metric for simple values retrieved on collect time +// from a function. It implements Metric and Collector. Its effective type is +// determined by ValueType. This is a low-level building block used by the +// library to back the implementations of CounterFunc, GaugeFunc, and +// UntypedFunc. +type valueFunc struct { + selfCollector + + desc *Desc + valType ValueType + function func() float64 + labelPairs []*dto.LabelPair +} + +// newValueFunc returns a newly allocated valueFunc with the given Desc and +// ValueType. The value reported is determined by calling the given function +// from within the Write method. Take into account that metric collection may +// happen concurrently. If that results in concurrent calls to Write, like in +// the case where a valueFunc is directly registered with Prometheus, the +// provided function must be concurrency-safe. +func newValueFunc(desc *Desc, valueType ValueType, function func() float64) *valueFunc { + result := &valueFunc{ + desc: desc, + valType: valueType, + function: function, + labelPairs: makeLabelPairs(desc, nil), + } + result.init(result) + return result +} + +func (v *valueFunc) Desc() *Desc { + return v.desc +} + +func (v *valueFunc) Write(out *dto.Metric) error { + return populateMetric(v.valType, v.function(), v.labelPairs, out) +} + +// NewConstMetric returns a metric with one fixed value that cannot be +// changed. Users of this package will not have much use for it in regular +// operations. However, when implementing custom Collectors, it is useful as a +// throw-away metric that is generated on the fly to send it to Prometheus in +// the Collect method. NewConstMetric returns an error if the length of +// labelValues is not consistent with the variable labels in Desc. +func NewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) (Metric, error) { + if len(desc.variableLabels) != len(labelValues) { + return nil, errInconsistentCardinality + } + return &constMetric{ + desc: desc, + valType: valueType, + val: value, + labelPairs: makeLabelPairs(desc, labelValues), + }, nil +} + +// MustNewConstMetric is a version of NewConstMetric that panics where +// NewConstMetric would have returned an error. +func MustNewConstMetric(desc *Desc, valueType ValueType, value float64, labelValues ...string) Metric { + m, err := NewConstMetric(desc, valueType, value, labelValues...) + if err != nil { + panic(err) + } + return m +} + +type constMetric struct { + desc *Desc + valType ValueType + val float64 + labelPairs []*dto.LabelPair +} + +func (m *constMetric) Desc() *Desc { + return m.desc +} + +func (m *constMetric) Write(out *dto.Metric) error { + return populateMetric(m.valType, m.val, m.labelPairs, out) +} + +func populateMetric( + t ValueType, + v float64, + labelPairs []*dto.LabelPair, + m *dto.Metric, +) error { + m.Label = labelPairs + switch t { + case CounterValue: + m.Counter = &dto.Counter{Value: proto.Float64(v)} + case GaugeValue: + m.Gauge = &dto.Gauge{Value: proto.Float64(v)} + case UntypedValue: + m.Untyped = &dto.Untyped{Value: proto.Float64(v)} + default: + return fmt.Errorf("encountered unknown type %v", t) + } + return nil +} + +func makeLabelPairs(desc *Desc, labelValues []string) []*dto.LabelPair { + totalLen := len(desc.variableLabels) + len(desc.constLabelPairs) + if totalLen == 0 { + // Super fast path. + return nil + } + if len(desc.variableLabels) == 0 { + // Moderately fast path. + return desc.constLabelPairs + } + labelPairs := make([]*dto.LabelPair, 0, totalLen) + for i, n := range desc.variableLabels { + labelPairs = append(labelPairs, &dto.LabelPair{ + Name: proto.String(n), + Value: proto.String(labelValues[i]), + }) + } + for _, lp := range desc.constLabelPairs { + labelPairs = append(labelPairs, lp) + } + sort.Sort(LabelPairSorter(labelPairs)) + return labelPairs +} diff --git a/vendor/github.com/prometheus/client_golang/prometheus/vec.go b/vendor/github.com/prometheus/client_golang/prometheus/vec.go new file mode 100644 index 0000000..7f3eef9 --- /dev/null +++ b/vendor/github.com/prometheus/client_golang/prometheus/vec.go @@ -0,0 +1,404 @@ +// Copyright 2014 The Prometheus Authors +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package prometheus + +import ( + "fmt" + "sync" + + "github.com/prometheus/common/model" +) + +// MetricVec is a Collector to bundle metrics of the same name that +// differ in their label values. MetricVec is usually not used directly but as a +// building block for implementations of vectors of a given metric +// type. GaugeVec, CounterVec, SummaryVec, and UntypedVec are examples already +// provided in this package. +type MetricVec struct { + mtx sync.RWMutex // Protects the children. + children map[uint64][]metricWithLabelValues + desc *Desc + + newMetric func(labelValues ...string) Metric + hashAdd func(h uint64, s string) uint64 // replace hash function for testing collision handling + hashAddByte func(h uint64, b byte) uint64 +} + +// newMetricVec returns an initialized MetricVec. The concrete value is +// returned for embedding into another struct. +func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *MetricVec { + return &MetricVec{ + children: map[uint64][]metricWithLabelValues{}, + desc: desc, + newMetric: newMetric, + hashAdd: hashAdd, + hashAddByte: hashAddByte, + } +} + +// metricWithLabelValues provides the metric and its label values for +// disambiguation on hash collision. +type metricWithLabelValues struct { + values []string + metric Metric +} + +// Describe implements Collector. The length of the returned slice +// is always one. +func (m *MetricVec) Describe(ch chan<- *Desc) { + ch <- m.desc +} + +// Collect implements Collector. +func (m *MetricVec) Collect(ch chan<- Metric) { + m.mtx.RLock() + defer m.mtx.RUnlock() + + for _, metrics := range m.children { + for _, metric := range metrics { + ch <- metric.metric + } + } +} + +// GetMetricWithLabelValues returns the Metric for the given slice of label +// values (same order as the VariableLabels in Desc). If that combination of +// label values is accessed for the first time, a new Metric is created. +// +// It is possible to call this method without using the returned Metric to only +// create the new Metric but leave it at its start value (e.g. a Summary or +// Histogram without any observations). See also the SummaryVec example. +// +// Keeping the Metric for later use is possible (and should be considered if +// performance is critical), but keep in mind that Reset, DeleteLabelValues and +// Delete can be used to delete the Metric from the MetricVec. In that case, the +// Metric will still exist, but it will not be exported anymore, even if a +// Metric with the same label values is created later. See also the CounterVec +// example. +// +// An error is returned if the number of label values is not the same as the +// number of VariableLabels in Desc. +// +// Note that for more than one label value, this method is prone to mistakes +// caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as +// an alternative to avoid that type of mistake. For higher label numbers, the +// latter has a much more readable (albeit more verbose) syntax, but it comes +// with a performance overhead (for creating and processing the Labels map). +// See also the GaugeVec example. +func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) { + h, err := m.hashLabelValues(lvs) + if err != nil { + return nil, err + } + + return m.getOrCreateMetricWithLabelValues(h, lvs), nil +} + +// GetMetricWith returns the Metric for the given Labels map (the label names +// must match those of the VariableLabels in Desc). If that label map is +// accessed for the first time, a new Metric is created. Implications of +// creating a Metric without using it and keeping the Metric for later use are +// the same as for GetMetricWithLabelValues. +// +// An error is returned if the number and names of the Labels are inconsistent +// with those of the VariableLabels in Desc. +// +// This method is used for the same purpose as +// GetMetricWithLabelValues(...string). See there for pros and cons of the two +// methods. +func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) { + h, err := m.hashLabels(labels) + if err != nil { + return nil, err + } + + return m.getOrCreateMetricWithLabels(h, labels), nil +} + +// WithLabelValues works as GetMetricWithLabelValues, but panics if an error +// occurs. The method allows neat syntax like: +// httpReqs.WithLabelValues("404", "POST").Inc() +func (m *MetricVec) WithLabelValues(lvs ...string) Metric { + metric, err := m.GetMetricWithLabelValues(lvs...) + if err != nil { + panic(err) + } + return metric +} + +// With works as GetMetricWith, but panics if an error occurs. The method allows +// neat syntax like: +// httpReqs.With(Labels{"status":"404", "method":"POST"}).Inc() +func (m *MetricVec) With(labels Labels) Metric { + metric, err := m.GetMetricWith(labels) + if err != nil { + panic(err) + } + return metric +} + +// DeleteLabelValues removes the metric where the variable labels are the same +// as those passed in as labels (same order as the VariableLabels in Desc). It +// returns true if a metric was deleted. +// +// It is not an error if the number of label values is not the same as the +// number of VariableLabels in Desc. However, such inconsistent label count can +// never match an actual Metric, so the method will always return false in that +// case. +// +// Note that for more than one label value, this method is prone to mistakes +// caused by an incorrect order of arguments. Consider Delete(Labels) as an +// alternative to avoid that type of mistake. For higher label numbers, the +// latter has a much more readable (albeit more verbose) syntax, but it comes +// with a performance overhead (for creating and processing the Labels map). +// See also the CounterVec example. +func (m *MetricVec) DeleteLabelValues(lvs ...string) bool { + m.mtx.Lock() + defer m.mtx.Unlock() + + h, err := m.hashLabelValues(lvs) + if err != nil { + return false + } + return m.deleteByHashWithLabelValues(h, lvs) +} + +// Delete deletes the metric where the variable labels are the same as those +// passed in as labels. It returns true if a metric was deleted. +// +// It is not an error if the number and names of the Labels are inconsistent +// with those of the VariableLabels in the Desc of the MetricVec. However, such +// inconsistent Labels can never match an actual Metric, so the method will +// always return false in that case. +// +// This method is used for the same purpose as DeleteLabelValues(...string). See +// there for pros and cons of the two methods. +func (m *MetricVec) Delete(labels Labels) bool { + m.mtx.Lock() + defer m.mtx.Unlock() + + h, err := m.hashLabels(labels) + if err != nil { + return false + } + + return m.deleteByHashWithLabels(h, labels) +} + +// deleteByHashWithLabelValues removes the metric from the hash bucket h. If +// there are multiple matches in the bucket, use lvs to select a metric and +// remove only that metric. +func (m *MetricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool { + metrics, ok := m.children[h] + if !ok { + return false + } + + i := m.findMetricWithLabelValues(metrics, lvs) + if i >= len(metrics) { + return false + } + + if len(metrics) > 1 { + m.children[h] = append(metrics[:i], metrics[i+1:]...) + } else { + delete(m.children, h) + } + return true +} + +// deleteByHashWithLabels removes the metric from the hash bucket h. If there +// are multiple matches in the bucket, use lvs to select a metric and remove +// only that metric. +func (m *MetricVec) deleteByHashWithLabels(h uint64, labels Labels) bool { + metrics, ok := m.children[h] + if !ok { + return false + } + i := m.findMetricWithLabels(metrics, labels) + if i >= len(metrics) { + return false + } + + if len(metrics) > 1 { + m.children[h] = append(metrics[:i], metrics[i+1:]...) + } else { + delete(m.children, h) + } + return true +} + +// Reset deletes all metrics in this vector. +func (m *MetricVec) Reset() { + m.mtx.Lock() + defer m.mtx.Unlock() + + for h := range m.children { + delete(m.children, h) + } +} + +func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) { + if len(vals) != len(m.desc.variableLabels) { + return 0, errInconsistentCardinality + } + h := hashNew() + for _, val := range vals { + h = m.hashAdd(h, val) + h = m.hashAddByte(h, model.SeparatorByte) + } + return h, nil +} + +func (m *MetricVec) hashLabels(labels Labels) (uint64, error) { + if len(labels) != len(m.desc.variableLabels) { + return 0, errInconsistentCardinality + } + h := hashNew() + for _, label := range m.desc.variableLabels { + val, ok := labels[label] + if !ok { + return 0, fmt.Errorf("label name %q missing in label map", label) + } + h = m.hashAdd(h, val) + h = m.hashAddByte(h, model.SeparatorByte) + } + return h, nil +} + +// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value +// or creates it and returns the new one. +// +// This function holds the mutex. +func (m *MetricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) Metric { + m.mtx.RLock() + metric, ok := m.getMetricWithLabelValues(hash, lvs) + m.mtx.RUnlock() + if ok { + return metric + } + + m.mtx.Lock() + defer m.mtx.Unlock() + metric, ok = m.getMetricWithLabelValues(hash, lvs) + if !ok { + // Copy to avoid allocation in case wo don't go down this code path. + copiedLVs := make([]string, len(lvs)) + copy(copiedLVs, lvs) + metric = m.newMetric(copiedLVs...) + m.children[hash] = append(m.children[hash], metricWithLabelValues{values: copiedLVs, metric: metric}) + } + return metric +} + +// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value +// or creates it and returns the new one. +// +// This function holds the mutex. +func (m *MetricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metric { + m.mtx.RLock() + metric, ok := m.getMetricWithLabels(hash, labels) + m.mtx.RUnlock() + if ok { + return metric + } + + m.mtx.Lock() + defer m.mtx.Unlock() + metric, ok = m.getMetricWithLabels(hash, labels) + if !ok { + lvs := m.extractLabelValues(labels) + metric = m.newMetric(lvs...) + m.children[hash] = append(m.children[hash], metricWithLabelValues{values: lvs, metric: metric}) + } + return metric +} + +// getMetricWithLabelValues gets a metric while handling possible collisions in +// the hash space. Must be called while holding read mutex. +func (m *MetricVec) getMetricWithLabelValues(h uint64, lvs []string) (Metric, bool) { + metrics, ok := m.children[h] + if ok { + if i := m.findMetricWithLabelValues(metrics, lvs); i < len(metrics) { + return metrics[i].metric, true + } + } + return nil, false +} + +// getMetricWithLabels gets a metric while handling possible collisions in +// the hash space. Must be called while holding read mutex. +func (m *MetricVec) getMetricWithLabels(h uint64, labels Labels) (Metric, bool) { + metrics, ok := m.children[h] + if ok { + if i := m.findMetricWithLabels(metrics, labels); i < len(metrics) { + return metrics[i].metric, true + } + } + return nil, false +} + +// findMetricWithLabelValues returns the index of the matching metric or +// len(metrics) if not found. +func (m *MetricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, lvs []string) int { + for i, metric := range metrics { + if m.matchLabelValues(metric.values, lvs) { + return i + } + } + return len(metrics) +} + +// findMetricWithLabels returns the index of the matching metric or len(metrics) +// if not found. +func (m *MetricVec) findMetricWithLabels(metrics []metricWithLabelValues, labels Labels) int { + for i, metric := range metrics { + if m.matchLabels(metric.values, labels) { + return i + } + } + return len(metrics) +} + +func (m *MetricVec) matchLabelValues(values []string, lvs []string) bool { + if len(values) != len(lvs) { + return false + } + for i, v := range values { + if v != lvs[i] { + return false + } + } + return true +} + +func (m *MetricVec) matchLabels(values []string, labels Labels) bool { + if len(labels) != len(values) { + return false + } + for i, k := range m.desc.variableLabels { + if values[i] != labels[k] { + return false + } + } + return true +} + +func (m *MetricVec) extractLabelValues(labels Labels) []string { + labelValues := make([]string, len(labels)) + for i, k := range m.desc.variableLabels { + labelValues[i] = labels[k] + } + return labelValues +} |