80 lines
1.4 KiB
Go
80 lines
1.4 KiB
Go
package testsupport
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import (
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"context"
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"errors"
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"io"
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"log"
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)
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type ChannelReadWriter struct {
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ctx context.Context
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receiver <-chan []byte
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// bytes that were read and that did not fit
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readBuf []byte
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sender chan<- []byte
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closed bool
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}
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func NewChannelReadWriter(ctx context.Context, receiver <-chan []byte,
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sender chan<- []byte) *ChannelReadWriter {
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return &ChannelReadWriter{
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ctx: ctx,
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receiver: receiver,
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sender: sender,
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closed: false,
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}
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}
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func (rw *ChannelReadWriter) Read(p []byte) (n int, err error) {
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nread := copy(p, rw.readBuf)
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if nread > 0 {
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log.Printf("Read %v bytes", nread)
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rw.readBuf = rw.readBuf[nread:]
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return nread, nil
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}
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select {
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case <-rw.ctx.Done():
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return 0, io.ErrClosedPipe
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case data, ok := <-rw.receiver:
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if !ok {
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return 0, io.EOF
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}
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nread = copy(p, data)
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rw.readBuf = data[nread:]
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return nread, nil
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}
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}
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func (rw *ChannelReadWriter) Write(p []byte) (n int, err error) {
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if rw.closed {
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return 0, errors.New("Write on closed channel")
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}
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// if context is canceled it should never write
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select {
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case <-rw.ctx.Done():
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rw.Close()
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return 0, io.ErrClosedPipe
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default:
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}
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select {
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// deal with closing duirng the write
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case <-rw.ctx.Done():
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rw.Close()
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return 0, io.ErrClosedPipe
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case rw.sender <- p:
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}
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return len(p), nil
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}
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func (rw *ChannelReadWriter) Close() error {
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if !rw.closed {
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close(rw.sender)
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rw.closed = true
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}
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return nil
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}
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