| // Copyright 2017 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 |
| |
| // 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) |
| } |
| |
| // ObserverVec is an interface implemented by `HistogramVec` and `SummaryVec`. |
| type ObserverVec interface { |
| GetMetricWith(Labels) (Observer, error) |
| GetMetricWithLabelValues(lvs ...string) (Observer, error) |
| With(Labels) Observer |
| WithLabelValues(...string) Observer |
| CurryWith(Labels) (ObserverVec, error) |
| MustCurryWith(Labels) ObserverVec |
| |
| Collector |
| } |