mirror of
https://github.com/etcd-io/etcd.git
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76 lines
1.8 KiB
Go
76 lines
1.8 KiB
Go
// Copyright 2016 The etcd 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 grpcproxy
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import (
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"github.com/coreos/etcd/clientv3"
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"golang.org/x/net/context"
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)
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type watcherSingle struct {
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// ch delievers events received from the etcd server
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ch clientv3.WatchChan
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// cancel is used to cancel the underlying etcd server watcher
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// It should also close the ch.
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cancel context.CancelFunc
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// sws is the stream this watcherSingle attached to
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sws *serverWatchStream
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w watcher
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rev int64 // current revision
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lastSeenRev int64
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donec chan struct{}
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}
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func newWatcherSingle(wch clientv3.WatchChan, c context.CancelFunc, w watcher, sws *serverWatchStream) *watcherSingle {
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return &watcherSingle{
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sws: sws,
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ch: wch,
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cancel: c,
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w: w,
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donec: make(chan struct{}),
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}
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}
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func (ws watcherSingle) run() {
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defer close(ws.donec)
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for wr := range ws.ch {
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ws.rev = wr.Header.Revision
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ws.w.send(wr)
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ws.lastSeenRev = wr.Events[len(wr.Events)-1].Kv.ModRevision
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if ws.sws.maybeCoalesceWatcher(ws) {
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return
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}
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}
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}
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// canPromote returns true if a watcherSingle can promote itself to a watchergroup
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// when it already caught up with the current revision.
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func (ws watcherSingle) canPromote() bool {
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return ws.rev == ws.lastSeenRev
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}
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func (ws watcherSingle) stop() {
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ws.cancel()
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<-ws.donec
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}
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