61 lines
1.7 KiB
Go
61 lines
1.7 KiB
Go
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package service
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import (
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"errors"
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"net"
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"sync"
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)
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// ListenerPipe returns a full-duplex in-memory connection, like net.Pipe.
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// Unlike net.Pipe one end of the connection is returned as an object
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// satisfying the net.Listener interface.
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// The first call to the Accept method of this object will return a net.Conn
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// connected to the other net.Conn returned by ListenerPipe.
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// Any subsequent calls to Accept will block until the listener is closed.
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func ListenerPipe() (net.Listener, net.Conn) {
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conn0, conn1 := net.Pipe()
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return &preconnectedListener{conn: conn0, closech: make(chan struct{})}, conn1
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}
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// preconnectedListener satisfies the net.Listener interface by accepting a
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// single pre-established connection.
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// The first call to Accept will return the conn field, any subsequent call
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// will block until the listener is closed.
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type preconnectedListener struct {
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accepted bool
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conn net.Conn
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closech chan struct{}
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closeMu sync.Mutex
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acceptMu sync.Mutex
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}
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// Accept returns the pre-established connection the first time it's called,
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// it blocks until the listener is closed on every subsequent call.
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func (l *preconnectedListener) Accept() (net.Conn, error) {
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l.acceptMu.Lock()
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defer l.acceptMu.Unlock()
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if !l.accepted {
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l.accepted = true
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return l.conn, nil
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}
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<-l.closech
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return nil, errors.New("accept failed: listener closed")
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}
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// Close closes the listener.
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func (l *preconnectedListener) Close() error {
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l.closeMu.Lock()
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defer l.closeMu.Unlock()
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if l.closech == nil {
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return nil
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}
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close(l.closech)
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l.closech = nil
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return nil
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}
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// Addr returns the listener's network address.
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func (l *preconnectedListener) Addr() net.Addr {
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return l.conn.LocalAddr()
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}
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