58 lines
929 B
Go
58 lines
929 B
Go
package main
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import (
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"errors"
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"io"
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"time"
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)
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const MAX_LOG_QLEN = 128
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const QUEUE_SHUTDOWN_TIMEOUT = 500 * time.Millisecond
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type LogWriter struct {
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writer io.Writer
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ch chan []byte
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done chan struct{}
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}
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func (lw *LogWriter) Write(p []byte) (int, error) {
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if p == nil {
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return 0, errors.New("Can't write nil byte slice")
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}
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buf := make([]byte, len(p))
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copy(buf, p)
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select {
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case lw.ch <- buf:
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return len(p), nil
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default:
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return 0, errors.New("Writer queue overflow")
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}
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}
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func NewLogWriter(writer io.Writer) *LogWriter {
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lw := &LogWriter{writer,
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make(chan []byte, MAX_LOG_QLEN),
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make(chan struct{})}
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go lw.loop()
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return lw
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}
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func (lw *LogWriter) loop() {
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for p := range lw.ch {
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if p == nil {
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break
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}
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lw.writer.Write(p)
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}
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lw.done <- struct{}{}
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}
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func (lw *LogWriter) Close() {
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lw.ch <- nil
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timer := time.After(QUEUE_SHUTDOWN_TIMEOUT)
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select {
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case <-timer:
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case <-lw.done:
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}
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}
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