diff options
Diffstat (limited to 'vendor/github.com/aws/aws-sdk-go/aws/request/offset_reader.go')
-rw-r--r-- | vendor/github.com/aws/aws-sdk-go/aws/request/offset_reader.go | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/vendor/github.com/aws/aws-sdk-go/aws/request/offset_reader.go b/vendor/github.com/aws/aws-sdk-go/aws/request/offset_reader.go new file mode 100644 index 00000000..02f07f4a --- /dev/null +++ b/vendor/github.com/aws/aws-sdk-go/aws/request/offset_reader.go @@ -0,0 +1,58 @@ +package request + +import ( + "io" + "sync" +) + +// offsetReader is a thread-safe io.ReadCloser to prevent racing +// with retrying requests +type offsetReader struct { + buf io.ReadSeeker + lock sync.Mutex + closed bool +} + +func newOffsetReader(buf io.ReadSeeker, offset int64) *offsetReader { + reader := &offsetReader{} + buf.Seek(offset, 0) + + reader.buf = buf + return reader +} + +// Close will close the instance of the offset reader's access to +// the underlying io.ReadSeeker. +func (o *offsetReader) Close() error { + o.lock.Lock() + defer o.lock.Unlock() + o.closed = true + return nil +} + +// Read is a thread-safe read of the underlying io.ReadSeeker +func (o *offsetReader) Read(p []byte) (int, error) { + o.lock.Lock() + defer o.lock.Unlock() + + if o.closed { + return 0, io.EOF + } + + return o.buf.Read(p) +} + +// Seek is a thread-safe seeking operation. +func (o *offsetReader) Seek(offset int64, whence int) (int64, error) { + o.lock.Lock() + defer o.lock.Unlock() + + return o.buf.Seek(offset, whence) +} + +// CloseAndCopy will return a new offsetReader with a copy of the old buffer +// and close the old buffer. +func (o *offsetReader) CloseAndCopy(offset int64) *offsetReader { + o.Close() + return newOffsetReader(o.buf, offset) +} |