* Minimize allocation of StringBuilder and also minimize char array copy
* Try to detect HttpVersion without calling toUpperCase() for performance reasons
I must admit MesageList was pain in the ass. Instead of forcing a
handler always loop over the list of messages, this commit splits
messageReceived(ctx, list) into two event handlers:
- messageReceived(ctx, msg)
- mmessageReceivedLast(ctx)
When Netty reads one or more messages, messageReceived(ctx, msg) event
is triggered for each message. Once the current read operation is
finished, messageReceivedLast() is triggered to tell the handler that
the last messageReceived() was the last message in the current batch.
Similarly, for outbound, write(ctx, list) has been split into two:
- write(ctx, msg)
- flush(ctx, promise)
Instead of writing a list of message with a promise, a user is now
supposed to call write(msg) multiple times and then call flush() to
actually flush the buffered messages.
Please note that write() doesn't have a promise with it. You must call
flush() to get notified on completion. (or you can use writeAndFlush())
Other changes:
- Because MessageList is completely hidden, codec framework uses
List<Object> instead of MessageList as an output parameter.
The API changes made so far turned out to increase the memory footprint
and consumption while our intention was actually decreasing them.
Memory consumption issue:
When there are many connections which does not exchange data frequently,
the old Netty 4 API spent a lot more memory than 3 because it always
allocates per-handler buffer for each connection unless otherwise
explicitly stated by a user. In a usual real world load, a client
doesn't always send requests without pausing, so the idea of having a
buffer whose life cycle if bound to the life cycle of a connection
didn't work as expected.
Memory footprint issue:
The old Netty 4 API decreased overall memory footprint by a great deal
in many cases. It was mainly because the old Netty 4 API did not
allocate a new buffer and event object for each read. Instead, it
created a new buffer for each handler in a pipeline. This works pretty
well as long as the number of handlers in a pipeline is only a few.
However, for a highly modular application with many handlers which
handles connections which lasts for relatively short period, it actually
makes the memory footprint issue much worse.
Changes:
All in all, this is about retaining all the good changes we made in 4 so
far such as better thread model and going back to the way how we dealt
with message events in 3.
To fix the memory consumption/footprint issue mentioned above, we made a
hard decision to break the backward compatibility again with the
following changes:
- Remove MessageBuf
- Merge Buf into ByteBuf
- Merge ChannelInboundByte/MessageHandler and ChannelStateHandler into ChannelInboundHandler
- Similar changes were made to the adapter classes
- Merge ChannelOutboundByte/MessageHandler and ChannelOperationHandler into ChannelOutboundHandler
- Similar changes were made to the adapter classes
- Introduce MessageList which is similar to `MessageEvent` in Netty 3
- Replace inboundBufferUpdated(ctx) with messageReceived(ctx, MessageList)
- Replace flush(ctx, promise) with write(ctx, MessageList, promise)
- Remove ByteToByteEncoder/Decoder/Codec
- Replaced by MessageToByteEncoder<ByteBuf>, ByteToMessageDecoder<ByteBuf>, and ByteMessageCodec<ByteBuf>
- Merge EmbeddedByteChannel and EmbeddedMessageChannel into EmbeddedChannel
- Add SimpleChannelInboundHandler which is sometimes more useful than
ChannelInboundHandlerAdapter
- Bring back Channel.isWritable() from Netty 3
- Add ChannelInboundHandler.channelWritabilityChanges() event
- Add RecvByteBufAllocator configuration property
- Similar to ReceiveBufferSizePredictor in Netty 3
- Some existing configuration properties such as
DatagramChannelConfig.receivePacketSize is gone now.
- Remove suspend/resumeIntermediaryDeallocation() in ByteBuf
This change would have been impossible without @normanmaurer's help. He
fixed, ported, and improved many parts of the changes.
- Fixes#1229
- Primarily written by @normanmaurer and revised by @trustin
This commit removes the notion of unfolding from the codec framework
completely. Unfolding was introduced in Netty 3.x to work around the
shortcoming of the codec framework where encode() and decode() did not
allow generating multiple messages.
Such a shortcoming can be fixed by changing the signature of encode()
and decode() instead of introducing an obscure workaround like
unfolding. Therefore, we changed the signature of them in 4.0.
The change is simple, but backward-incompatible. encode() and decode()
do not return anything. Instead, the codec framework will pass a
MessageBuf<Object> so encode() and decode() can add the generated
messages into the MessageBuf.
* This is done because we noticed that the previous change limit the usage more then it gave us any benefit. Now it is possible
again to rewrite the url on the fly or reuse the objects when writing a proxy and so limit the GC pressure.
* Fixes also #979
- Rename message types for clarity
- HttpMessage -> FullHttpMessage
- HttpHeader -> HttpMessage
- HttpRequest -> FullHttpRequest
- HttpResponse -> FulllHttpResponse
- HttpRequestHeader -> HttpRequest
- HttpResponseHeader -> HttpResponse
- HttpContent now extends ByteBufHolder; no more content() method
- Make HttpHeaders abstract, make its header access methods public, and
add DefaultHttpHeaders
- Header accessor methods in HttpMessage and LastHttpContent are
replaced with HttpMessage.headers() and
LastHttpContent.trailingHeaders(). Both methods return HttpHeaders.
- Remove setters wherever possible and remove 'get' prefix
- Instead of calling setContent(), a user can either specify the content
when constructing a message or write content into the buffer.
(e.g. m.content().writeBytes(...))
- Overall cleanup & fixes
This commit tries to simplify the handling of Http easier and more consistent. This has a effect of many channges. Including:
- HttpMessage was renamed to HttpHeader and the setContent and getContent methods were removed
- HttpChunk was renamed to HttpContent
- HttpChunkTrailer was renamed to LastHttpContent
- HttpCodecUtil was merged into HttpHeaders
Now a "complete" Http message (request or response) contains of the following parts:
- HttpHeader (HttpRequestHeader or HttpResponseHeader)
- 0 - n HttpContent objects which contains parts of the content of the message
- 1 LastHttpContent which marks the end of the message and contains the remaining data of the content
I also changed the sematic of HttpResponse and HttpRequest, these now represent a "complete" message which contains the HttpHeader and the HttpLastContent, and so can be used to eeasily send requests. The HttpMessageAggregator was renamed to HttpObjectAggregator and produce HttpResponse / HttpRequest message.
