Motivation:
Some users already use an SSLEngine implementation in finagle-native. It
wraps OpenSSL to get higher SSL performance. However, to take advantage
of it, finagle-native must be compiled manually, and it means we cannot
pull it in as a dependency and thus we cannot test our SslHandler
against the OpenSSL-based SSLEngine. For an instance, we had #2216.
Because the construction procedures of JDK SSLEngine and OpenSslEngine
are very different from each other, we also need to provide a universal
way to enable SSL in a Netty application.
Modifications:
- Pull netty-tcnative in as an optional dependency.
http://netty.io/wiki/forked-tomcat-native.html
- Backport NativeLibraryLoader from 4.0
- Move OpenSSL-based SSLEngine implementation into our code base.
- Copied from finagle-native; originally written by @jpinner et al.
- Overall cleanup by @trustin.
- Run all SslHandler tests with both default SSLEngine and OpenSslEngine
- Add a unified API for creating an SSL context
- SslContext allows you to create a new SSLEngine or a new SslHandler
with your PKCS#8 key and X.509 certificate chain.
- Add JdkSslContext and its subclasses
- Add OpenSslServerContext
- Add ApplicationProtocolSelector to ensure the future support for NPN
(NextProtoNego) and ALPN (Application Layer Protocol Negotiation) on
the client-side.
- Add SimpleTrustManagerFactory to help a user write a
TrustManagerFactory easily, which should be useful for those who need
to write an alternative verification mechanism. For example, we can
use it to implement an unsafe TrustManagerFactory that accepts
self-signed certificates for testing purposes.
- Add InsecureTrustManagerFactory and FingerprintTrustManager for quick
and dirty testing
- Add SelfSignedCertificate class which generates a self-signed X.509
certificate very easily.
- Update all our examples to use SslContext.newClient/ServerContext()
- SslHandler now logs the chosen cipher suite when handshake is
finished.
Result:
- Cleaner unified API for configuring an SSL client and an SSL server
regardless of its internal implementation.
- When native libraries are available, OpenSSL-based SSLEngine
implementation is selected automatically to take advantage of its
performance benefit.
- Examples take advantage of this modification and thus are cleaner.
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.
Split the project into the following modules:
* common
* buffer
* codec
* codec-http
* transport
* transport-*
* handler
* example
* testsuite (integration tests that involve 2+ modules)
* all (does nothing yet, but will make it generate netty.jar)
This commit also fixes the compilation errors with transport-sctp on
non-Linux systems. It will at least compile without complaints.
