forked from TrueCloudLab/lego
58 lines
1.7 KiB
Go
58 lines
1.7 KiB
Go
// Copyright 2017, OpenCensus Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package view
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import "sync"
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var (
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exportersMu sync.RWMutex // guards exporters
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exporters = make(map[Exporter]struct{})
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)
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// Exporter exports the collected records as view data.
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//
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// The ExportView method should return quickly; if an
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// Exporter takes a significant amount of time to
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// process a Data, that work should be done on another goroutine.
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//
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// It is safe to assume that ExportView will not be called concurrently from
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// multiple goroutines.
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//
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// The Data should not be modified.
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type Exporter interface {
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ExportView(viewData *Data)
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}
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// RegisterExporter registers an exporter.
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// Collected data will be reported via all the
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// registered exporters. Once you no longer
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// want data to be exported, invoke UnregisterExporter
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// with the previously registered exporter.
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//
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// Binaries can register exporters, libraries shouldn't register exporters.
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func RegisterExporter(e Exporter) {
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exportersMu.Lock()
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defer exportersMu.Unlock()
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exporters[e] = struct{}{}
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}
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// UnregisterExporter unregisters an exporter.
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func UnregisterExporter(e Exporter) {
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exportersMu.Lock()
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defer exportersMu.Unlock()
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delete(exporters, e)
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}
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