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Diffstat (limited to 'vendor/go.opencensus.io/stats/measure.go')
-rw-r--r-- | vendor/go.opencensus.io/stats/measure.go | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/vendor/go.opencensus.io/stats/measure.go b/vendor/go.opencensus.io/stats/measure.go new file mode 100644 index 0000000..aa555c2 --- /dev/null +++ b/vendor/go.opencensus.io/stats/measure.go @@ -0,0 +1,96 @@ +// Copyright 2017, OpenCensus 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 stats + +import ( + "sync" + "sync/atomic" +) + +// Measure represents a type of metric to be tracked and recorded. +// For example, latency, request Mb/s, and response Mb/s are measures +// to collect from a server. +// +// Each measure needs to be registered before being used. +// Measure constructors such as Int64 and +// Float64 automatically registers the measure +// by the given name. +// Each registered measure needs to be unique by name. +// Measures also have a description and a unit. +type Measure interface { + Name() string + Description() string + Unit() string +} + +// measureDescriptor is the untyped descriptor associated with each measure. +// Int64Measure and Float64Measure wrap measureDescriptor to provide typed +// recording APIs. +// Two Measures with the same name will have the same measureDescriptor. +type measureDescriptor struct { + subs int32 // access atomically + + name string + description string + unit string +} + +func (m *measureDescriptor) subscribe() { + atomic.StoreInt32(&m.subs, 1) +} + +func (m *measureDescriptor) subscribed() bool { + return atomic.LoadInt32(&m.subs) == 1 +} + +var ( + mu sync.RWMutex + measures = make(map[string]*measureDescriptor) +) + +func registerMeasureHandle(name, desc, unit string) *measureDescriptor { + mu.Lock() + defer mu.Unlock() + + if stored, ok := measures[name]; ok { + return stored + } + m := &measureDescriptor{ + name: name, + description: desc, + unit: unit, + } + measures[name] = m + return m +} + +// Measurement is the numeric value measured when recording stats. Each measure +// provides methods to create measurements of their kind. For example, Int64Measure +// provides M to convert an int64 into a measurement. +type Measurement struct { + v float64 + m Measure +} + +// Value returns the value of the Measurement as a float64. +func (m Measurement) Value() float64 { + return m.v +} + +// Measure returns the Measure from which this Measurement was created. +func (m Measurement) Measure() Measure { + return m.m +} |