/**
* Callers of this method are not thread safe, and sometimes on application threads. Most often,
* this method will be called to send a buffer worth of data to the peer.
*
* <p>Writes are subject to the write window of the stream and the connection. Until there is a
* window sufficient to send {@code byteCount}, the caller will block. For example, a user of
* {@code HttpURLConnection} who flushes more bytes to the output stream than the connection's
* write window will block.
*
* <p>Zero {@code byteCount} writes are not subject to flow control and will not block. The only
* use case for zero {@code byteCount} is closing a flushed output stream.
*/
public void writeData(int streamId, boolean outFinished, Buffer buffer, long byteCount)
throws IOException {
if (byteCount == 0) { // Empty data frames are not flow-controlled.
frameWriter.data(outFinished, streamId, buffer, 0);
return;
}
while (byteCount > 0) {
int toWrite;
synchronized (FramedConnection.this) {
try {
while (bytesLeftInWriteWindow <= 0) {
// Before blocking, confirm that the stream we're writing is still open. It's possible
// that the stream has since been closed (such as if this write timed out.)
if (!streams.containsKey(streamId)) {
throw new IOException("stream closed");
}
FramedConnection.this.wait(); // Wait until we receive a WINDOW_UPDATE.
}
} catch (InterruptedException e) {
throw new InterruptedIOException();
}
toWrite = (int) Math.min(byteCount, bytesLeftInWriteWindow);
toWrite = Math.min(toWrite, frameWriter.maxDataLength());
bytesLeftInWriteWindow -= toWrite;
}
byteCount -= toWrite;
frameWriter.data(outFinished && byteCount == 0, streamId, buffer, toWrite);
}
}
