72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
/*
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*
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* Copyright 2020 gRPC 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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*/
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package testutils
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import (
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"context"
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)
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// DefaultChanBufferSize is the default buffer size of the underlying channel.
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const DefaultChanBufferSize = 1
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// Channel wraps a generic channel and provides a timed receive operation.
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type Channel struct {
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ch chan interface{}
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}
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// Send sends value on the underlying channel.
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func (cwt *Channel) Send(value interface{}) {
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cwt.ch <- value
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}
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// Receive returns the value received on the underlying channel, or the error
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// returned by ctx if it is closed or cancelled.
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func (cwt *Channel) Receive(ctx context.Context) (interface{}, error) {
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select {
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case <-ctx.Done():
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return nil, ctx.Err()
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case got := <-cwt.ch:
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return got, nil
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}
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}
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// Replace clears the value on the underlying channel, and sends the new value.
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//
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// It's expected to be used with a size-1 channel, to only keep the most
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// up-to-date item. This method is inherently racy when invoked concurrently
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// from multiple goroutines.
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func (cwt *Channel) Replace(value interface{}) {
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for {
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select {
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case cwt.ch <- value:
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return
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case <-cwt.ch:
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}
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}
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}
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// NewChannel returns a new Channel.
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func NewChannel() *Channel {
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return NewChannelWithSize(DefaultChanBufferSize)
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}
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// NewChannelWithSize returns a new Channel with a buffer of bufSize.
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func NewChannelWithSize(bufSize int) *Channel {
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return &Channel{ch: make(chan interface{}, bufSize)}
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}
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