2e3ecdca37
We are change the the rpc call for WriteStream to not require the size argument, opting to drive the process with io.Reader. The main issue was that io.Reader may return io.EOF before reaching size, making the error handling around this condition for callers more complex. To complement this, WriteStream now returns the number of successfully written bytes. The method no longer requires an io.ReadCloser, opting to require just an io.Reader. This keeps the reader under the control of the caller, which provides more flexibility. This also begins to address some of the problems described in #791.
