74 lines
1.5 KiB
Go
74 lines
1.5 KiB
Go
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/*
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Copyright (c) 2014 VMware, Inc. All Rights Reserved.
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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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http://www.apache.org/licenses/LICENSE-2.0
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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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*/
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package progress
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import "sync"
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type Aggregator struct {
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downstream Sinker
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upstream chan (<-chan Report)
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done chan struct{}
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w sync.WaitGroup
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}
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func NewAggregator(s Sinker) *Aggregator {
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a := &Aggregator{
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downstream: s,
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upstream: make(chan (<-chan Report)),
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done: make(chan struct{}),
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}
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a.w.Add(1)
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go a.loop()
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return a
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}
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func (a *Aggregator) loop() {
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defer a.w.Done()
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dch := a.downstream.Sink()
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defer close(dch)
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for {
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select {
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case uch := <-a.upstream:
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// Drain upstream channel
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for e := range uch {
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dch <- e
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}
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case <-a.done:
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return
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}
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}
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}
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func (a *Aggregator) Sink() chan<- Report {
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ch := make(chan Report)
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a.upstream <- ch
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return ch
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}
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// Done marks the aggregator as done. No more calls to Sink() may be made and
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// the downstream progress report channel will be closed when Done() returns.
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func (a *Aggregator) Done() {
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close(a.done)
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a.w.Wait()
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}
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