decode() — netty Function Reference

Source Code

codec-stomp/src/main/java/io/netty/handler/codec/stomp/StompSubframeDecoder.java lines 99–192

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        switch (state()) {
            case SKIP_CONTROL_CHARACTERS:
                skipControlCharacters(in);
                checkpoint(State.READ_HEADERS);
                // Fall through.
            case READ_HEADERS:
                StompCommand command = StompCommand.UNKNOWN;
                StompHeadersSubframe frame = null;
                try {
                    command = readCommand(in);
                    frame = new DefaultStompHeadersSubframe(command);
                    checkpoint(readHeaders(in, frame));
                    out.add(frame);
                } catch (Exception e) {
                    if (frame == null) {
                        frame = new DefaultStompHeadersSubframe(command);
                    }
                    frame.setDecoderResult(DecoderResult.failure(e));
                    out.add(frame);
                    checkpoint(State.BAD_FRAME);
                    return;
                }
                break;
            case BAD_FRAME:
                in.skipBytes(actualReadableBytes());
                return;
        }
        try {
            switch (state()) {
                case READ_CONTENT:
                    int toRead = in.readableBytes();
                    if (toRead == 0) {
                        return;
                    }
                    if (toRead > maxChunkSize) {
                        toRead = maxChunkSize;
                    }
                    if (contentLength >= 0) {
                        int remainingLength = (int) (contentLength - alreadyReadChunkSize);
                        if (toRead > remainingLength) {
                            toRead = remainingLength;
                        }
                        ByteBuf chunkBuffer = readBytes(ctx.alloc(), in, toRead);
                        if ((alreadyReadChunkSize += toRead) >= contentLength) {
                            lastContent = new DefaultLastStompContentSubframe(chunkBuffer);
                            checkpoint(State.FINALIZE_FRAME_READ);
                        } else {
                            out.add(new DefaultStompContentSubframe(chunkBuffer));
                            return;
                        }
                    } else {
                        int nulIndex = indexOf(in, in.readerIndex(), in.writerIndex(), StompConstants.NUL);
                        if (nulIndex == in.readerIndex()) {
                            checkpoint(State.FINALIZE_FRAME_READ);
                        } else {
                            if (nulIndex > 0) {
                                toRead = nulIndex - in.readerIndex();
                            } else {
                                toRead = in.writerIndex() - in.readerIndex();
                            }
                            ByteBuf chunkBuffer = readBytes(ctx.alloc(), in, toRead);
                            alreadyReadChunkSize += toRead;
                            if (nulIndex > 0) {
                                lastContent = new DefaultLastStompContentSubframe(chunkBuffer);
                                checkpoint(State.FINALIZE_FRAME_READ);
                            } else {
                                out.add(new DefaultStompContentSubframe(chunkBuffer));
                                return;
                            }
                        }
                    }
                    // Fall through.
                case FINALIZE_FRAME_READ:
                    skipNullCharacter(in);
                    if (lastContent == null) {
                        lastContent = LastStompContentSubframe.EMPTY_LAST_CONTENT;
                    }
                    out.add(lastContent);
                    resetDecoder();