// HandleRead handles a read request assuming that data is the entire file content.
// It adjusts the amount returned in resp according to req.Offset and req.Size.
func HandleRead(req *fuse.ReadRequest, resp *fuse.ReadResponse, data []byte) {
if req.Offset >= int64(len(data)) {
data = nil
} else {
data = data[req.Offset:]
}
if len(data) > req.Size {
data = data[:req.Size]
}
n := copy(resp.Data[:req.Size], data)
resp.Data = resp.Data[:n]
}
func (fh *FileHandle) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error {
// We don't actually enforce Offset to match where previous read
// ended. Maybe we should, but that would mean'd we need to track
// it. The kernel *should* do it for us, based on the
// fuse.OpenNonSeekable flag.
//
// One exception to the above is if we fail to fully populate a
// page cache page; a read into page cache is always page aligned.
// Make sure we never serve a partial read, to avoid that.
_, e := fh.r.Seek(req.Offset, 0)
if e != nil {
return e
}
//buf := bytes.NewBuffer(nil)
buf := make([]byte, req.Size)
n, err := fh.r.Read(buf) //io.ReadFull(fh.r, buf)
if err == io.ErrUnexpectedEOF || err == io.EOF {
err = nil
}
resp.Data = buf[:n]
return err
}
func (benchFile) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error {
resp.Data = resp.Data[:cap(resp.Data)]
return nil
}