Class StreamOutputBuffer

java/org/apache/coyote/http2/Stream.java:978–1191

    class StreamOutputBuffer implements HttpOutputBuffer, WriteBuffer.Sink {

        private final Lock writeLock = new ReentrantLock();
        private final ByteBuffer buffer = ByteBuffer.allocate(8 * 1024);
        private final WriteBuffer writeBuffer = new WriteBuffer(32 * 1024);
        // Flag that indicates that data was left over on a previous
        // non-blocking write. Once set, this flag stays set until all the data
        // has been written.
        private boolean dataLeft;
        private volatile long written = 0;
        private int streamReservation = 0;
        private volatile boolean closed = false;
        private volatile StreamException reset = null;
        private volatile boolean endOfStreamSent = false;

        /*
         * The write methods share a common lock to ensure that only one thread at a time is able to access the buffer.
         * Without this protection, a client that performed concurrent writes could corrupt the buffer.
         */

        @Override
        public final int doWrite(ByteBuffer chunk) throws IOException {
            writeLock.lock();
            try {
                if (closed) {
                    throw new IOException(sm.getString("stream.closed", getConnectionId(), getIdAsString()));
                }
                // chunk is always fully written
                int result = chunk.remaining();
                if (writeBuffer.isEmpty()) {
                    int chunkLimit = chunk.limit();
                    while (chunk.remaining() > 0) {
                        int thisTime = Math.min(buffer.remaining(), chunk.remaining());
                        chunk.limit(chunk.position() + thisTime);
                        buffer.put(chunk);
                        chunk.limit(chunkLimit);
                        if (chunk.remaining() > 0 && !buffer.hasRemaining()) {
                            // Only flush if we have more data to write and the buffer
                            // is full
                            if (flush(true, coyoteResponse.getWriteListener() == null)) {
                                writeBuffer.add(chunk);
                                dataLeft = true;
                                break;
                            }
                        }
                    }
                } else {
                    writeBuffer.add(chunk);
                }
                written += result;
                return result;
            } finally {
                writeLock.unlock();
            }
        }

        final boolean flush(boolean block) throws IOException {
            writeLock.lock();