decode() — netty Function Reference

Architecture documentation for the decode() function in SpdyHttpDecoder.java from the netty codebase.

Function java Buffer Allocators

Entity Profile

Buffer→ Allocators→ decode() — netty Function Reference

Dependency Diagram

graph TD
  9d3e067f_5ad6_e6e1_a9d7_8d35a6ab74ac["decode()"]
  025fd5f9_dfbe_4042_6d63_96c1c1168bd5["SpdyHttpDecoder"]
  9d3e067f_5ad6_e6e1_a9d7_8d35a6ab74ac -->|defined in| 025fd5f9_dfbe_4042_6d63_96c1c1168bd5
  style 9d3e067f_5ad6_e6e1_a9d7_8d35a6ab74ac fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyHttpDecoder.java lines 164–387

    @Override
    protected void decode(ChannelHandlerContext ctx, SpdyFrame msg, List<Object> out)
            throws Exception {
        if (msg instanceof SpdySynStreamFrame) {

            // HTTP requests/responses are mapped one-to-one to SPDY streams.
            SpdySynStreamFrame spdySynStreamFrame = (SpdySynStreamFrame) msg;
            int streamId = spdySynStreamFrame.streamId();

            if (SpdyCodecUtil.isServerId(streamId)) {
                // SYN_STREAM frames initiated by the server are pushed resources
                int associatedToStreamId = spdySynStreamFrame.associatedStreamId();

                // If a client receives a SYN_STREAM with an Associated-To-Stream-ID of 0
                // it must reply with a RST_STREAM with error code INVALID_STREAM.
                if (associatedToStreamId == 0) {
                    SpdyRstStreamFrame spdyRstStreamFrame =
                        new DefaultSpdyRstStreamFrame(streamId, SpdyStreamStatus.INVALID_STREAM);
                    ctx.writeAndFlush(spdyRstStreamFrame);
                    return;
                }

                // If a client receives a SYN_STREAM with isLast set,
                // reply with a RST_STREAM with error code PROTOCOL_ERROR
                // (we only support pushed resources divided into two header blocks).
                if (spdySynStreamFrame.isLast()) {
                    SpdyRstStreamFrame spdyRstStreamFrame =
                        new DefaultSpdyRstStreamFrame(streamId, SpdyStreamStatus.PROTOCOL_ERROR);
                    ctx.writeAndFlush(spdyRstStreamFrame);
                    return;
                }

                // If a client receives a response with a truncated header block,
                // reply with a RST_STREAM with error code INTERNAL_ERROR.
                if (spdySynStreamFrame.isTruncated()) {
                    SpdyRstStreamFrame spdyRstStreamFrame =
                    new DefaultSpdyRstStreamFrame(streamId, SpdyStreamStatus.INTERNAL_ERROR);
                    ctx.writeAndFlush(spdyRstStreamFrame);
                    return;
                }

                try {
                    FullHttpRequest httpRequestWithEntity = createHttpRequest(spdySynStreamFrame, ctx.alloc());

                    // Set the Stream-ID, Associated-To-Stream-ID, and Priority as headers
                    httpRequestWithEntity.headers().setInt(Names.STREAM_ID, streamId);
                    httpRequestWithEntity.headers().setInt(Names.ASSOCIATED_TO_STREAM_ID, associatedToStreamId);
                    httpRequestWithEntity.headers().setInt(Names.PRIORITY, spdySynStreamFrame.priority());

                    out.add(httpRequestWithEntity);

                } catch (Throwable ignored) {
                    SpdyRstStreamFrame spdyRstStreamFrame =
                        new DefaultSpdyRstStreamFrame(streamId, SpdyStreamStatus.PROTOCOL_ERROR);
                    ctx.writeAndFlush(spdyRstStreamFrame);
                }
            } else {
                // SYN_STREAM frames initiated by the client are HTTP requests

                // If a client sends a request with a truncated header block, the server must
                // reply with an HTTP 431 REQUEST HEADER FIELDS TOO LARGE reply.
                if (spdySynStreamFrame.isTruncated()) {
                    SpdySynReplyFrame spdySynReplyFrame = new DefaultSpdySynReplyFrame(streamId);
                    spdySynReplyFrame.setLast(true);
                    SpdyHeaders frameHeaders = spdySynReplyFrame.headers();
                    frameHeaders.setInt(STATUS, HttpResponseStatus.REQUEST_HEADER_FIELDS_TOO_LARGE.code());
                    frameHeaders.setObject(VERSION, HttpVersion.HTTP_1_0);
                    ctx.writeAndFlush(spdySynReplyFrame);
                    return;
                }

                try {
                    FullHttpRequest httpRequestWithEntity = createHttpRequest(spdySynStreamFrame, ctx.alloc());

                    // Set the Stream-ID as a header
                    httpRequestWithEntity.headers().setInt(Names.STREAM_ID, streamId);

                    if (spdySynStreamFrame.isLast()) {
                        out.add(httpRequestWithEntity);
                    } else {
                        // Request body will follow in a series of Data Frames