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.
shutdownGracefully() provides two optional parameters that give more
control over when an executor has to be shut down.
- Related issue: #1307
- Add shutdownGracefully(..) and isShuttingDown()
- Deprecate shutdown() / shutdownNow()
- Replace lastAccessTime with lastExecutionTime and update it after task
execution for accurate quiet period check
- runAllTasks() and runShutdownTasks() update it automatically.
- Add updateLastExecutionTime() so that subclasses can update it
- Add a constructor parameter that tells not to add an unncessary wakeup
task in execute() if addTask() wakes up the executor thread
automatically. Previously, execute() always called wakeup() after
addTask(), which often caused an extra dummy task in the task queue.
- Use shutdownGracefully() wherever possible / Deprecation javadoc
- Reduce the running time of SingleThreadEventLoopTest from 40s to 15s
using custom graceful shutdown parameters
- Other changes made along with this commit:
- takeTask() does not throw InterruptedException anymore.
- Returns null on interruption or wakeup
- Make sure runShutdownTasks() return true even if an exception was
raised while running the shutdown tasks
- Remove unnecessary isShutdown() checks
- Consistent use of SingleThreadEventExecutor.nanoTime()
Replace isWakeupOverridden with a constructor parameter
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
- Now works without the transport package
- Renamed TransferFuture to ProgressiveFuture and ChannelProgressiveFuture / same for promises
- ProgressiveFutureListener now extends GenericProgressiveFutureListener and GenericFutureListener (add/removeTransferListener*() were removed)
- Renamed DefaultEventListeners to DefaultFutureListeners and only accept GenericFutureListeners
- Various clean-up
- 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.
- Add ChannelHandlerUtil and move the core logic of ChannelInbound/OutboundMessageHandler to ChannelHandlerUtil
- Add ChannelHandlerUtil.SingleInbound/OutboundMessageHandler and make ChannelInbound/OutboundMessageHandlerAdapter implement them. This is a backward incompatible change because it forces all handler methods to be public (was protected previously)
- Fixes: #1119
- Move common methods from ByteBuf to Buf
- Rename ensureWritableBytes() to ensureWritable()
- Rename readable() to isReadable()
- Rename writable() to isWritable()
- Add isReadable(int) and isWritable(int)
- Add AbstractMessageBuf
- Rewrite DefaultMessageBuf and QueueBackedMessageBuf
- based on Josh Bloch's public domain ArrayDeque impl
* 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
This changes the behavior of the ChannelPipeline.remove(..) and ChannelPipeline.replace(..) methods in that way
that after invocation it is not possible anymore to access any data in the inbound or outbound buffer. This is
because it empty it now to prevent side-effects. If a user want to preserve the content and forward it to the
next handler in the pipeline it is adviced to use one of the new methods which where introduced.
- ChannelPipeline.removeAndForward(..)
- ChannelPipeline.replaceAndForward(..)
- 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.
This pull request adds two new handler methods: discardInboundReadBytes(ctx) and discardOutboundReadBytes(ctx) to ChannelInboundByteHandler and ChannelOutboundByteHandler respectively. They are called between every inboundBufferUpdated() and flush() respectively. Their default implementation is to call discardSomeReadBytes() on their buffers and a user can override this behavior easily. For example, ReplayingDecoder.discardInboundReadBytes() looks like the following:
@Override
public void discardInboundReadBytes(ChannelHandlerContext ctx) throws Exception {
ByteBuf in = ctx.inboundByteBuffer();
final int oldReaderIndex = in.readerIndex();
super.discardInboundReadBytes(ctx);
final int newReaderIndex = in.readerIndex();
checkpoint -= oldReaderIndex - newReaderIndex;
}
If a handler, which has its own buffer index variable, extends ReplayingDecoder or ByteToMessageDecoder, the handler can also override discardInboundReadBytes() and adjust its index variable accordingly.
use single static initialization of available metrics monitor registries
* This changes the original implementation to work in a similar way to
how slf4j selects and loads an implementation.
* Uses a single static instance so intialization is done only once.
* Doesn't throw IllegalStateException if multiple implementations are
found on the classpath. It instead selects and uses the first
implementation returned by iterator()
* Class left as an iterable to keep the API the same
add yammer metrics to examples to allow them to publish metrics
publish the number of threads used in an EventLoopGroup see issue #718
* seems like the better place to put this because it sets the default
thread count if the MultithreadEventLoopGroup uses super(0,...)
* It also happens to be the common parent class amongst all the
MultiThreadedEventLoopGroup implementations
* Count is reported for
io.netty.channel.{*,.local,.socket.aio,.socket.nio}
fix cosmetic issues pointed out in pull request and updated notice.txt
see https://github.com/netty/netty/pull/780
count # of channels registered in single threaded event loop
measure how many times Selector.select return before SELECT_TIME
This pull request introduces a new operation called read() that replaces the existing inbound traffic control method. EventLoop now performs socket reads only when the read() operation has been issued. Once the requested read() operation is actually performed, EventLoop triggers an inboundBufferSuspended event that tells the handlers that the requested read() operation has been performed and the inbound traffic has been suspended again. A handler can decide to continue reading or not.
Unlike other outbound operations, read() does not use ChannelFuture at all to avoid GC cost. If there's a good reason to create a new future per read at the GC cost, I'll change this.
This pull request consequently removes the readable property in ChannelHandlerContext, which means how the traffic control works changed significantly.
This pull request also adds a new configuration property ChannelOption.AUTO_READ whose default value is true. If true, Netty will call ctx.read() for you. If you need a close control over when read() is called, you can set it to false.
Another interesting fact is that non-terminal handlers do not really need to call read() at all. Only the last inbound handler will have to call it, and that's just enough. Actually, you don't even need to call it at the last handler in most cases because of the ChannelOption.AUTO_READ mentioned above.
There's no serious backward compatibility issue. If the compiler complains your handler does not implement the read() method, add the following:
public void read(ChannelHandlerContext ctx) throws Exception {
ctx.read();
}
Note that this pull request certainly makes bounded inbound buffer support very easy, but itself does not add the bounded inbound buffer support.
- Remove HttpRequestEncoder after handshaking is complete
- Fix a bug in the WebSocket client example where it sends a frame even before handshake is complete
- Add EventExecutorGroup and EventLoopGroup
- EventExecutor and EventLoop extends EventExecutorGroup and
EventLoopGroup
- They form their own group so that .next() returns itself.
- Rename Bootstrap.eventLoop() to group()
- Rename parameter names such as executor to group
- Rename *EventLoop/Executor to *EventLoop/ExecutorGroup
- Rename *ChildEventLoop/Executor to *EventLoop/Executor
- Rename ZlibEncoder/Decoder to JZlibEncoder/Decoder
- Define a new ZlibEncoder/Decoder class
- Add JdkZlibEncoder
- All JZlib* and JdkZlib* extends ZlibEncoder/Decoder
- Add ZlibCodecFactory and use it everywhere
- ChannelInboundHandler and ChannelOutboundHandler does not have a type
parameter anymore.
- User should implement ChannelInboundMessageHandler or
ChannelOutboundMessageHandler.
- Add MessageBuf which replaces java.util.Queue
- Add ChannelBuf which is common type of ByteBuf and ChannelBuf
- ChannelBuffers was renamed to ByteBufs
- Add MessageBufs
- All these changes are going to replace ChannelBufferHolder.
- ChannelBuffer gives a perception that it's a buffer of a
channel, but channel's buffer is now a byte buffer or a message
buffer. Therefore letting it be as is is going to be confusing.
- Also prohibited a user from overriding
ChannelInbound(Byte|Message)HandlerAdapter. If a user wants to do
that, he or she should extend ChannelInboundHandlerAdapter instead.
- In computing, 'stream' means both byte stream and message stream,
which is confusing.
- Also, we were already mixing stream and byte in some places and
it's better use the terms consistently.
(e.g. inboundByteBuffer & inbound stream)
- SslHandler always begins handshake unless startTls is true
- Removed issueHandshake property
- If a user wants to start handshake later, he/she has to add
SslHandler later.
- Removed enableRenegotiation property
- JDK upgrade fixes the security vulnerability - no need to complicate
our code
- Some property name changes
- getSSLEngineInboundCloseFuture() -> sslCloseFuture()
- Updated securechat example
- Added timeout for handshake and close_notify for better security
- However, it's currently hard-coded. Will make it a property later.
- Extracted some handler methods from ChannelInboundHandler into
ChannelStateHandler
- Extracted some handler methods from ChannelOutboundHandler into
ChannelOperationHandler
- Moved exceptionCaught and userEventTriggered are now in
ChannelHandler
- Channel(Inbound|Outbound)HandlerContext is merged into
ChannelHandlerContext
- ChannelHandlerContext adds direct access methods for inboud and
outbound buffers
- The use of ChannelBufferHolder is minimal now.
- Before: inbound().byteBuffer()
- After: inboundByteBuffer()
- Simpler and better performance
- Bypass buffer types were removed because it just does not work at all
with the thread model.
- All handlers that uses a bypass buffer are broken. Will fix soon.
- CombinedHandlerAdapter does not make sense anymore either because
there are four handler interfaces to consider and often the two
handlers will implement the same handler interface such as
ChannelStateHandler. Thinking of better ways to provide this feature
- The handler you specify with initializer() is actually simply added
to the pipeline and that's all. It's ChannelInitializer which does
additional work. For example, a user can specify just a single
handler with initializer() and it will still work. This is especially
common for Bootstrap, so I renamed initializer to handler, which makes
more sense.
- Removed ones are: IP filer and HTTP multipart codec
- Needs closer code review and polishing
- Sorry. I'll add them back in the next alpha releases
- SSL handler and ChunkedWriteHandler also need more work, but
I really want to make them part of the first alpha because they
are used pretty often by users.
- Add EventExecutor and make EventLoop extend it
- Add SingleThreadEventExecutor and MultithreadEventExecutor
- Add EventExecutor's default implementation
- Fixed an API design problem where there is no way to get non-bypass
buffer of desired type
- Add ChannelHandlerContext.eventLoop() for convenience
- Bootstrap and ServerBootstrap handles channel initialization failure
better
- More strict checks for missing @Sharable annotation
- A handler without @Sharable annotation cannot be added more than
once now.
- Added a new convenience method to ChannelInboundstreamHandlerAdapter
- EchoServerHandler uses the new method
- DefaultChannelPipeline calls inboundByteBuffer.discardReadBytes()
when it is sure there's no memory copy involved
- LocalChannel and LocalServerChannel uses it to close themselves on
shutdown
- LocalEcho example does not call close() anymore because the channels
are closed automatically on shutdown
- Renamed ChannelBootstrap to Bootstrap
- Renamed ServerChannelBootstrap to ServerBootstrap
- Moved bootstrap classes to io.netty.bootstrap as before
- Moved unfoldAndAdd() to a separate utility class
- Fixed a bug in unfoldAndAdd() where it did not handle ChannelBuffer
correctly
- Previous API did not support the pipeline which contains multiple
MessageToStreamEncoders because there was no way to find the closest
outbound byte buffer. Now you always get the correct buffer even if
the handler that provides the buffer is placed distantly.
For example:
Channel -> MsgAEncoder -> MsgBEncoder -> MsgCEncoder
Msg(A|B|C)Encoder will all have access to the channel's outbound
byte buffer. Previously, it was simply impossible.
- Improved ChannelBufferHolder.toString()
- Replaced pipeline factories with initializers
- Ported essential parts related with HTTP to the new API
- Replaced ChannelHandlerAdapter.combine() with CombinedChannelHandler
- Fixed a bug where ReplayingDecoder does not notify the next handler
- Fixed a bug where ReplayingDecoder calls wrong callDecode() method
- Added a destination buffer as an argument to AbstractChannel.doRead()
for easier implementation
- Fixed a bug where NioSocketChannel did not try to increase the inbound
buffer size (moved the logic to AbstractChannel)
- Replaced FrameDecoder and OneToOne(Encoder|Decoder) with:
- (Stream|Message)To(String|Message)(Encoder|Decoder)
- Moved the classes in 'codec.frame' up to 'codec'
- Fixed some bugs found while running unit tests
- It does not build a new Channel but just helps bootstrapping it.
- Added shutdown() method for simpler deinitialization
- ServerChannelBootstrap has shorter method names for the parent channel
- Added ChannelInitializer which is supposed to be used with the
builders
- Echo examples use ChannelBuilder and ServerChannelBuilder now
- Replace ChannelFuture.rethrowIfFailed() with sync*()
- Bug fixes
- Added ChannelBufferHolders.(inbound|outbound)BypassBuffer()
- The holder returned by these methods returns the next handler's
buffer. When a handler's new(Inbound|Outbound)Buffer returns
a bypass holder, your inboundBufferUpdated() and flush()
implementation should check if the buffer is a bypass and should not
modify the content of the buffer.
- Channel(Inbound|Outbound)?HandlerAdapter is now abstract.
- A user has to specify the exact inbound/outbound buffer type
- It's because there's no way to determine the best buffer type
- Implemented LoggingHandler using the new API.
- It doesn't dump received or sent messages yet.
- Fixed a bug where DefaultUnsafe.close() does not trigger deregister()
- Fixed a bug where NioSocketChannel.isActive() does not return false
when closed
- Made sure unnecessary interestOps are not OR'd
- Fixed a bug where DefaultChannelFuture.rethrowIfFailed() returns
silently if the future is not done yet - there's no ways to tell
the differences between failure and incompleteness.
- Optimized AbstractChannelBuffer.discardReadBytes()
- Split ChannelHandlerInvoker into ChannelInboundInvoker and
ChannelOutboundInvoker
- Channel implements ChannelOutboundInvoker
- ChannelOutboundInvoker.nextOut() is now out()
- ChannelOutboundHandlerContext.out() is now prevOut()
- Added the outbound operations without future
parameter to ChannelOutboundInvoker for user convenience
- All async operations which requires a ChannelFuture as a parameter
now returns ChannelFuture for user convenience
- Added ChannelFutureFactory.newVoidFuture() to allow a user specify
a dummy future that is of no use
- I'm unsure if it is actually a good idea to introduce it. It might
go away later.
- Made the contract of AbstractChannel.doXXX() much simpler and moved
all common code up to AbstractChannel.DefaultUnsafe
- Added Channel.isOpen()
- Fixed a bug where MultithreadEventLoop always shut down its child
event loops on construction
- Maybe more changes I don't remember :-)
- Channel now creates a ChannelPipeline by itself
I find no reason to allow a user to use one's own pipeline
implementation since I saw nobody does except for the cases where a
user wants to add a user attribute to a channel, which is now covered
by AttributeMap.
- Removed ChannelEvent and its subtypes because they are replaced by
direct method invocation.
- Replaced ChannelSink with Channel.unsafe()
- Various getter renaming (e.g. Channel.getId() -> Channel.id())
- Added ChannelHandlerInvoker interface
- Implemented AbstractChannel and AbstractServerChannel
- Some other changes I don't remember
