vendor/github.com/fsouza/go-dockerclient/external/github.com/docker/docker/pkg/ioutils/writers.go

   1 package ioutils
   2
   3 import "io"
   4
   5 // NopWriter represents a type which write operation is nop.
   6 type NopWriter struct{}
   7
   8 func (*NopWriter) Write(buf []byte) (int, error) {
   9         return len(buf), nil
  10 }
  11
  12 type nopWriteCloser struct {
  13         io.Writer
  14 }
  15
  16 func (w *nopWriteCloser) Close() error { return nil }
  17
  18 // NopWriteCloser returns a nopWriteCloser.
  19 func NopWriteCloser(w io.Writer) io.WriteCloser {
  20         return &nopWriteCloser{w}
  21 }
  22
  23 // NopFlusher represents a type which flush operation is nop.
  24 type NopFlusher struct{}
  25
  26 // Flush is a nop operation.
  27 func (f *NopFlusher) Flush() {}
  28
  29 type writeCloserWrapper struct {
  30         io.Writer
  31         closer func() error
  32 }
  33
  34 func (r *writeCloserWrapper) Close() error {
  35         return r.closer()
  36 }
  37
  38 // NewWriteCloserWrapper returns a new io.WriteCloser.
  39 func NewWriteCloserWrapper(r io.Writer, closer func() error) io.WriteCloser {
  40         return &writeCloserWrapper{
  41                 Writer: r,
  42                 closer: closer,
  43         }
  44 }
  45
  46 // WriteCounter wraps a concrete io.Writer and hold a count of the number
  47 // of bytes written to the writer during a "session".
  48 // This can be convenient when write return is masked
  49 // (e.g., json.Encoder.Encode())
  50 type WriteCounter struct {
  51         Count  int64
  52         Writer io.Writer
  53 }
  54
  55 // NewWriteCounter returns a new WriteCounter.
  56 func NewWriteCounter(w io.Writer) *WriteCounter {
  57         return &WriteCounter{
  58                 Writer: w,
  59         }
  60 }
  61
  62 func (wc *WriteCounter) Write(p []byte) (count int, err error) {
  63         count, err = wc.Writer.Write(p)
  64         wc.Count += int64(count)
  65         return
  66 }