diff options
author | Kevin Lyda <kevin@ie.suberic.net> | 2017-02-12 14:38:12 +0000 |
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committer | Niall Sheridan <nsheridan@gmail.com> | 2017-02-12 14:38:12 +0000 |
commit | ed8bc523fd0d1a66acf3fa449c453508035efdfc (patch) | |
tree | c05849546e1dd9d771dcc4c4ff52056d249a95fb /vendor/github.com/prometheus/client_golang/prometheus/collector.go | |
parent | 9c344a0a95c44ef9cebade7b8a65ac160d9eb900 (diff) |
Initial pass at prometheus support. (#56)
Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus/collector.go')
-rw-r--r-- | vendor/github.com/prometheus/client_golang/prometheus/collector.go | 75 |
1 files changed, 75 insertions, 0 deletions
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 +} |