ee7027288e
Motivation: ByteToMessageDecoder's default MERGE_CUMULATOR will allocate a new buffer and copy if the refCnt() of the cumulation is > 1. However this is overly conservative because we maybe able to avoid allocate/copy if the current cumulation can accommodate the input buffer without a reallocation. Also when the reallocation and copy does occur the new buffer is sized just large enough to accommodate the current the current amount of data. If some data remains in the cumulation after decode this will require a new allocation/copy when more data arrives. Modifications: - Use maxFastWritableBytes to avoid allocation/copy if the current buffer can accommodate the input data without a reallocation operation. - Use ByteBufAllocator#calculateNewCapacity(..) to get the size of the buffer when a reallocation/copy operation is necessary. Result: ByteToMessageDecoder MERGE_CUMULATOR won't allocate/copy if the cumulation buffer can accommodate data without a reallocation, and when a reallocation occurs we are more likely to leave additional space for future data in an effort to reduce overall reallocations.
Netty Project
Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients.
Links
How to build
For the detailed information about building and developing Netty, please visit the developer guide. This page only gives very basic information.
You require the following to build Netty:
- Latest stable Oracle JDK 7
- Latest stable Apache Maven
- If you are on Linux, you need additional development packages installed on your system, because you'll build the native transport.
Note that this is build-time requirement. JDK 5 (for 3.x) or 6 (for 4.0+) is enough to run your Netty-based application.
Branches to look
Development of all versions takes place in each branch whose name is identical to <majorVersion>.<minorVersion>. For example, the development of 3.9 and 4.0 resides in the branch '3.9' and the branch '4.0' respectively.
Usage with JDK 9
Netty can be used in modular JDK9 applications as a collection of automatic modules. The module names follow the reverse-DNS style, and are derived from subproject names rather than root packages due to historical reasons. They are listed below:
io.netty.allio.netty.bufferio.netty.codecio.netty.codec.dnsio.netty.codec.haproxyio.netty.codec.httpio.netty.codec.http2io.netty.codec.memcacheio.netty.codec.mqttio.netty.codec.redisio.netty.codec.smtpio.netty.codec.socksio.netty.codec.stompio.netty.codec.xmlio.netty.commonio.netty.handlerio.netty.handler.proxyio.netty.resolverio.netty.resolver.dnsio.netty.transportio.netty.transport.epoll(nativeomitted - reserved keyword in Java)io.netty.transport.kqueue(nativeomitted - reserved keyword in Java)io.netty.transport.unix.common(nativeomitted - reserved keyword in Java)io.netty.transport.rxtxio.netty.transport.sctpio.netty.transport.udt
Automatic modules do not provide any means to declare dependencies, so you need to list each used module separately
in your module-info file.