- Related issues: #1937#1938 and #1946
- Add InterfaceHttpPostRequestDecoder and Make HttpPostRequestDecoder implement it
- HttpPostRequestDecoder actually delegates itself to HttpPostStandardRequestDecoder or HttpPostMultipartRequestDecoder
- Remove IncompatibleDataDecoderException because it's not thrown anywhere now
- Proposed fix for #1824
UniqueName and its subtypes do not allow getting the previously registered instance. For example, let's assume that a user is running his/her application in an OSGi container with Netty bundles and his server bundle. Whenever the server bundle is reloaded, the server will try to create a new AttributeKey instance with the same name. However, Netty bundles were not reloaded at all, so AttributeKey will complain that the name is taken already (by the previously loaded bundle.)
To fix this problem:
- Replaced UniqueName with Constant, AbstractConstant, and ConstantPool. Better name and better design.
- Sctp/Udt/RxtxChannelOption is not a ChannelOption anymore. They are just constant providers and ChannelOption is final now. It's because caching anything that's from outside of netty-transport will lead to ClassCastException on reload, because ChannelOption's constant pool will keep all option objects for reuse.
- Signal implements Constant because we can't ensure its uniqueness anymore by relying on the exception raised by UniqueName's constructor.
- This commit allows a user to write its first web socket frame right after calling WebSocketServerHandshaker.handshake() rather than adding a listener to the future it returns.
- Should fix#1933
This includes the following changes:
* Rewrite HttpObjectDecoder to use ByteToMessageDecoder
* Optimize parsing of the header
* Allow to disable the header validation for performance reason
* Not need to validate kwown header names and values
* Minimize access of ThreadLocals
* Optimize parsing of initial line
encode of chunked content is not the most common pattern so moving it to an extra method makes it possible to inline the rest as it is a smaller method now.
* Minimize allocation of StringBuilder and also minimize char array copy
* Try to detect HttpVersion without calling toUpperCase() for performance reasons
- write() now accepts a ChannelPromise and returns ChannelFuture as most
users expected. It makes the user's life much easier because it is
now much easier to get notified when a specific message has been
written.
- flush() does not create a ChannelPromise nor returns ChannelFuture.
It is now similar to what read() looks like.
DefaultChannelHandlerContext does not trigger exceptionCaught() immediately when ChannelOutboundHandler.write() raises an exception. It just records the exception until flush() is triggered. On invokeFlush(), if there's any exception recorded, DefaultChannelHandlerContext will fail the promise without calling ChannelOutboundHandler.flush(). If more than one exception were raised, only the first exception is used as the cause of the failure and the others will be logged at warn level.
- Remove channelReadSuspended because it's actually same with messageReceivedLast
- Rename messageReceived to channelRead
- Rename messageReceivedLast to channelReadComplete
We renamed messageReceivedLast to channelReadComplete because it
reflects what it really is for. Also, we renamed messageReceived to
channelRead for consistency in method names.
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.
- SimpleChannelInboundHandler now has a constructor parameter to let a
user decide to enable automatic message release. (the default is to
enable), which makes ChannelInboundConsumingHandler of less value.
* This fix the bug which caused an UnsupportedOperationException when renameTo(...) was called and the underlying ByteBuf was backed by multiple ByteBuffers
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#1282 (not perfectly, but to the extent it's possible with the current API)
- Add AddressedEnvelope and DefaultAddressedEnvelope
- Make DatagramPacket extend DefaultAddressedEnvelope<ByteBuf, InetSocketAddress>
- Rename ByteBufHolder.data() to content() so that a message can implement both AddressedEnvelope and ByteBufHolder (DatagramPacket does) without introducing two getter methods for the content
- Datagram channel implementations now understand ByteBuf and ByteBufHolder as a message with unspecified remote address.
- Fixes#1308
freeInboundBuffer() and freeOutboundBuffer() were introduced in the early days of the new API when we did not have reference counting mechanism in the buffer. A user did not want Netty to free the handler buffers had to override these methods.
However, now that we have reference counting mechanism built into the buffer, a user who wants to retain the buffers beyond handler's life cycle can simply return the buffer whose reference count is greater than 1 in newInbound/OutboundBuffer().
This change also introduce a few other changes which was needed:
* ChannelHandler.beforeAdd(...) and ChannelHandler.beforeRemove(...) were removed
* ChannelHandler.afterAdd(...) -> handlerAdded(...)
* ChannelHandler.afterRemoved(...) -> handlerRemoved(...)
* SslHandler.handshake() -> SslHandler.hanshakeFuture() as the handshake is triggered automatically after
the Channel becomes active
