67 lines
2.3 KiB
Go
67 lines
2.3 KiB
Go
package minio
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import "io"
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// ReadSeekCloser wraps an io.Reader returning a ReaderSeekerCloser
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func ReadSeekCloser(r io.Reader) ReaderSeekerCloser {
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return ReaderSeekerCloser{r}
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}
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// ReaderSeekerCloser represents a reader that can also delegate io.Seeker and
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// io.Closer interfaces to the underlying object if available.
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type ReaderSeekerCloser struct {
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r io.Reader
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}
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// Read reads up to len(p) bytes into p. It returns the number of bytes
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// read (0 <= n <= len(p)) and any error encountered. Even if Read
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// returns n < len(p), it may use all of p as scratch space during the call.
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// If some data is available but not len(p) bytes, Read conventionally
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// returns what is available instead of waiting for more.
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//
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// When Read encounters an error or end-of-file condition after
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// successfully reading n > 0 bytes, it returns the number of
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// bytes read. It may return the (non-nil) error from the same call
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// or return the error (and n == 0) from a subsequent call.
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// An instance of this general case is that a Reader returning
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// a non-zero number of bytes at the end of the input stream may
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// return either err == EOF or err == nil. The next Read should
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// return 0, EOF.
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func (r ReaderSeekerCloser) Read(p []byte) (int, error) {
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switch t := r.r.(type) {
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case io.Reader:
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return t.Read(p)
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}
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return 0, nil
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}
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// Seek sets the offset for the next Read or Write to offset,
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// interpreted according to whence: 0 means relative to the start of
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// the file, 1 means relative to the current offset, and 2 means
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// relative to the end. Seek returns the new offset relative to the
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// start of the file and an error, if any.
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//
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// Seeking to an offset before the start of the file is an error.
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//
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// If the ReaderSeekerCloser is not an io.Seeker nothing will be done.
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func (r ReaderSeekerCloser) Seek(offset int64, whence int) (int64, error) {
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switch t := r.r.(type) {
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case io.Seeker:
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return t.Seek(offset, whence)
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}
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return int64(0), nil
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}
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// Close closes the ReaderSeekerCloser.
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//
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// The behavior of Close after the first call is undefined.
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// Specific implementations may document their own behavior.
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//
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// If the ReaderSeekerCloser is not an io.Closer nothing will be done.
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func (r ReaderSeekerCloser) Close() error {
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switch t := r.r.(type) {
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case io.Closer:
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return t.Close()
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}
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return nil
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}
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