66 lines
1.5 KiB
Go
66 lines
1.5 KiB
Go
package ioutils // import "github.com/docker/docker/pkg/ioutils"
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import "io"
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// NopWriter represents a type which write operation is nop.
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type NopWriter struct{}
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func (*NopWriter) Write(buf []byte) (int, error) {
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return len(buf), nil
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}
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type nopWriteCloser struct {
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io.Writer
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}
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func (w *nopWriteCloser) Close() error { return nil }
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// NopWriteCloser returns a nopWriteCloser.
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func NopWriteCloser(w io.Writer) io.WriteCloser {
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return &nopWriteCloser{w}
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}
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// NopFlusher represents a type which flush operation is nop.
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type NopFlusher struct{}
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// Flush is a nop operation.
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func (f *NopFlusher) Flush() {}
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type writeCloserWrapper struct {
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io.Writer
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closer func() error
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}
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func (r *writeCloserWrapper) Close() error {
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return r.closer()
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}
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// NewWriteCloserWrapper returns a new io.WriteCloser.
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func NewWriteCloserWrapper(r io.Writer, closer func() error) io.WriteCloser {
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return &writeCloserWrapper{
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Writer: r,
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closer: closer,
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}
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}
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// WriteCounter wraps a concrete io.Writer and hold a count of the number
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// of bytes written to the writer during a "session".
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// This can be convenient when write return is masked
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// (e.g., json.Encoder.Encode())
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type WriteCounter struct {
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Count int64
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Writer io.Writer
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}
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// NewWriteCounter returns a new WriteCounter.
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func NewWriteCounter(w io.Writer) *WriteCounter {
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return &WriteCounter{
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Writer: w,
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}
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}
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func (wc *WriteCounter) Write(p []byte) (count int, err error) {
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count, err = wc.Writer.Write(p)
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wc.Count += int64(count)
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return
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}
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