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