encodeFileRegionContent() — netty Function Reference

Source Code

codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectEncoder.java lines 373–403

    private void encodeFileRegionContent(ChannelHandlerContext ctx, FileRegion msg, List<Object> out) {
        try {
            assert state != ST_INIT;
            switch (state) {
                case ST_CONTENT_NON_CHUNK:
                    if (msg.count() > 0) {
                        out.add(msg.retain());
                        break;
                    }

                    // fall-through!
                case ST_CONTENT_ALWAYS_EMPTY:
                    // Need to produce some output otherwise an
                    // IllegalStateException will be thrown as we did not write anything
                    // Its ok to just write an EMPTY_BUFFER as if there are reference count issues these will be
                    // propagated as the caller of the encode(...) method will release the original
                    // buffer.
                    // Writing an empty buffer will not actually write anything on the wire, so if there is a user
                    // error with msg it will not be visible externally
                    out.add(Unpooled.EMPTY_BUFFER);
                    break;
                case ST_CONTENT_CHUNK:
                    encodedChunkedFileRegionContent(ctx, msg, out);
                    break;
                default:
                    throw new Error("Unexpected http object encoder state: " + state);
            }
        } finally {
            msg.release();
        }
    }