// GetReader returns an io.ReadCloser for the Blob with the given name of
// type t at offset and length. If length is 0, the reader reads until EOF.
func (b *Local) GetReader(t backend.Type, name string, offset, length uint) (io.ReadCloser, error) {
f, err := os.Open(filename(b.p, t, name))
if err != nil {
return nil, err
}
_, err = f.Seek(int64(offset), 0)
if err != nil {
return nil, err
}
if length == 0 {
return f, nil
}
return backend.LimitReadCloser(f, int64(length)), nil
}
// GetReader returns an io.ReadCloser for the Blob with the given name of
// type t at offset and length. If length is 0, the reader reads until EOF.
func (r *SFTP) GetReader(t backend.Type, name string, offset, length uint) (io.ReadCloser, error) {
f, err := r.c.Open(r.filename(t, name))
if err != nil {
return nil, err
}
if offset > 0 {
_, err = f.Seek(int64(offset), 0)
if err != nil {
return nil, err
}
}
if length == 0 {
return f, nil
}
return backend.LimitReadCloser(f, int64(length)), nil
}
// GetReader returns an io.ReadCloser for the Blob with the given name of
// type t at offset and length. If length is 0, the reader reads until EOF.
func (be *S3Backend) GetReader(t backend.Type, name string, offset, length uint) (io.ReadCloser, error) {
rc, err := be.Get(t, name)
if err != nil {
return nil, err
}
n, errc := io.CopyN(ioutil.Discard, rc, int64(offset))
if errc != nil {
return nil, errc
} else if n != int64(offset) {
return nil, fmt.Errorf("less bytes read than expected, read: %d, expected: %d", n, offset)
}
if length == 0 {
return rc, nil
}
return backend.LimitReadCloser(rc, int64(length)), nil
}
// GetReader returns an io.ReadCloser for the Blob with the given name of
// type t at offset and length. If length is 0, the reader reads until EOF.
func (b *Local) GetReader(t backend.Type, name string, offset, length uint) (io.ReadCloser, error) {
f, err := os.Open(filename(b.p, t, name))
if err != nil {
return nil, err
}
b.mu.Lock()
open, _ := b.open[filename(b.p, t, name)]
b.open[filename(b.p, t, name)] = append(open, f)
b.mu.Unlock()
_, err = f.Seek(int64(offset), 0)
if err != nil {
return nil, err
}
if length == 0 {
return f, nil
}
return backend.LimitReadCloser(f, int64(length)), nil
}
// GetReader returns an io.ReadCloser for the Blob with the given name of
// type t at offset and length. If length is 0, the reader reads until EOF.
func (be *S3Backend) GetReader(t backend.Type, name string, offset, length uint) (io.ReadCloser, error) {
debug.Log("s3.GetReader", "%v %v, offset %v len %v", t, name, offset, length)
path := s3path(t, name)
obj, err := be.client.GetObject(be.bucketname, path)
if err != nil {
debug.Log("s3.GetReader", " err %v", err)
return nil, err
}
if offset > 0 {
_, err = obj.Seek(int64(offset), 0)
if err != nil {
return nil, err
}
}
if length == 0 {
return obj, nil
}
return backend.LimitReadCloser(obj, int64(length)), nil
}