Fix the issue where the intecepting call fails in start(), does not
call super.start(), and makes the subsequent use of other methods on the
call throw IllegalStateException.

Create ClientInterceptors.CheckedForwardingCall that handles exception
in start logic.

Create Forwarding[Server]Call[Listener] for generic decoration use
cases, with an abstract delegate() for flexibility.

Create SimpleForwarding[Server]Call[Listener] to replace now deprecated
forwarding classes.
10 files changed
tree: c994b3283dfa73101e12fe8b3c8989e3d01f7879
  1. all/
  2. auth/
  3. benchmarks/
  4. buildscripts/
  5. compiler/
  6. core/
  7. examples/
  8. gradle/
  9. integration-testing/
  10. lib/
  11. nano/
  12. netty/
  13. okhttp/
  14. stub/
  15. testing/
  16. .gitignore
  17. .gitmodules
  18. .travis.yml
  19. AUTH-README.md
  20. build.gradle
  21. checkstyle.license
  22. checkstyle.xml
  23. CONTRIBUTING.md
  24. gradlew
  25. gradlew.bat
  26. LICENSE
  27. PATENTS
  28. README.md
  29. run-test-client.sh
  30. run-test-server.sh
  31. settings.gradle
README.md

grpc-java

How to Build

grpc-java requires Netty 4.1, which is still in flux. The version we need can be found in the lib/netty submodule, which requires Maven 3.2 or higher to build:

$ git submodule update --init
$ cd lib/netty
$ mvn install -pl codec-http2 -am -DskipTests=true

The codegen plugin requires protobuf 3.0.0-alpha-2:

$ git clone https://github.com/google/protobuf.git
$ cd protobuf
$ git checkout v3.0.0-alpha-2
$ ./autogen.sh
$ ./configure
$ make
$ make check
$ sudo make install

If you are comfortable with C++ compilation and autotools, you can specify a --prefix for protobuf and use -I in CXXFLAGS, -L in LDFLAGS, LD_LIBRARY_PATH, and PATH to reference it. The environment variables will be used when building grpc-java.

Protobuf installs to /usr/local by default. If /usr/local/lib is not in your library search path, you can add it by running:

$ sudo sh -c 'echo /usr/local/lib >> /etc/ld.so.conf'
$ sudo ldconfig

Now to build grpc-java itself:

$ ./gradlew install

When building on Windows and VC++, you need to specify project properties for Gradle to find protobuf:

.\gradlew install -Pprotobuf.include=C:\path\to\protobuf-3.0.0-alpha-2\src ^
    -Pprotobuf.libs=C:\path\to\protobuf-3.0.0-alpha-2\vsprojects\Release

Since specifying those properties every build is bothersome, you can instead create %HOMEDRIVE%%HOMEPATH%.gradle\gradle.properties with contents like:

protobuf.include=C:\\path\\to\\protobuf-3.0.0-alpha-2\\src
protobuf.libs=C:\\path\\to\\protobuf-3.0.0-alpha-2\\vsprojects\\Release

Navigating Around the Source

Heres a quick readers guide to the code to help folks get started. At a high level there are three distinct layers to the library: stub, channel & transport.

Stub

The 'stub' layer is what is exposed to most developers and provides type-safe bindings to whatever datamodel/IDL/interface you are adapting. An example is provided of a binding to code generated by the protocol-buffers compiler but others should be trivial to add and are welcome.

Key Interfaces

Stream Observer

Channel

The 'channel' layer is an abstraction over transport handling that is suitable for interception/decoration and exposes more behavior to the application than the stub layer. It is intended to be easy for application frameworks to use this layer to address cross-cutting concerns such as logging, monitoring, auth etc. Flow-control is also exposed at this layer to allow more sophisticated applications to interact with it directly.

Common

Client

Server

Transport

The 'transport' layer does the heavy lifting of putting & taking bytes off the wire. The interfaces to it are abstract just enough to allow plugging in of different implementations. Transports are modeled as 'Stream' factories. The variation in interface between a server stream and a client stream exists to codify their differing semantics for cancellation and error reporting.

Common

Client

Server

Examples

Tests showing how these layers are composed to execute calls using protobuf messages can be found here https://github.com/google/grpc-java/tree/master/integration-testing/src/main/java/io/grpc/testing/integration