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+// 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
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-25 05:39:20 +0000