83 lines
1.5 KiB
Go
83 lines
1.5 KiB
Go
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package stream
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import "io"
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// Reader is a concurrent-safe Stream Reader.
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type Reader struct {
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s *Stream
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file File
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}
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// Name returns the name of the underlying File in the FileSystem.
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func (r *Reader) Name() string { return r.file.Name() }
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// ReadAt lets you Read from specific offsets in the Stream.
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// ReadAt blocks while waiting for the requested section of the Stream to be written,
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// unless the Stream is closed in which case it will always return immediately.
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func (r *Reader) ReadAt(p []byte, off int64) (n int, err error) {
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r.s.b.RLock()
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defer r.s.b.RUnlock()
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var m int
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for {
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m, err = r.file.ReadAt(p[n:], off+int64(n))
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n += m
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if r.s.b.IsOpen() {
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switch {
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case n != 0 && err == nil:
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return n, err
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case err == io.EOF:
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r.s.b.Wait()
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case err != nil:
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return n, err
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}
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} else {
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return n, err
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}
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}
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}
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// Read reads from the Stream. If the end of an open Stream is reached, Read
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// blocks until more data is written or the Stream is Closed.
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func (r *Reader) Read(p []byte) (n int, err error) {
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r.s.b.RLock()
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defer r.s.b.RUnlock()
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var m int
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for {
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m, err = r.file.Read(p[n:])
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n += m
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if r.s.b.IsOpen() {
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switch {
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case n != 0 && err == nil:
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return n, err
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case err == io.EOF:
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r.s.b.Wait()
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case err != nil:
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return n, err
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}
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} else {
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return n, err
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}
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}
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}
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// Close closes this Reader on the Stream. This must be called when done with the
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// Reader or else the Stream cannot be Removed.
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func (r *Reader) Close() error {
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defer r.s.dec()
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return r.file.Close()
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}
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