1bce70dddb
Currently some public API methods are defined in GenreatedMessage.java
and they have a generric return type:
class GeneratedMessage {
class Builder<BuilderType extends Builder<BuilderType>> {
public BuilderType setField(...);
public BuilderType setExtension(...);
}
}
With these definitions, the compiled byte code of a callsite will have
a direct reference to GeneratedMessage. For example:
fooBuilder.setField(...);
becomes:
##: invokevirtual // Method Builder.setField:(...)LGeneratedMessage.Builder
##: checkcast // class Builder
This will prevent us from updating generated classes to subclass a
different versioned GeneratedMessageV3 class in the future (we can't do
it in a binary compatible way).
This change addresses the problem by overriding these methods directly
in the generated class:
class Foo {
class Builder extends GeneratedMessage.Builder<Builder> {
public Builder setField(...) {
return super.setField(...);
}
}
}
After this, fooBuilder.setField(...) will be compiled to:
##: invokevirtual // Method Builder.setField:(...)LFoo.Builder
The callsites will no longer reference GeneratedMessage directly and we
can change Foo to subclass GeneratedMessageV3 without breaking binary
compatiblity.
The downside of this change is:
1. It increases generated code size (though it saves some instructions
on the callsites).
2. We can never stop generating these overrides because doing that
will break binary compatibility.
Change-Id: I879afbbc1325a66324a51565e017143489b06e97
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| benchmarks | ||
| cmake | ||
| conformance | ||
| csharp | ||
| docs | ||
| editors | ||
| examples | ||
| java | ||
| javanano | ||
| jenkins | ||
| js | ||
| m4 | ||
| more_tests | ||
| objectivec | ||
| php | ||
| protoc-artifacts | ||
| python | ||
| ruby | ||
| src | ||
| util/python | ||
| .gitignore | ||
| .travis.yml | ||
| appveyor.bat | ||
| appveyor.yml | ||
| autogen.sh | ||
| BUILD | ||
| CHANGES.txt | ||
| configure.ac | ||
| CONTRIBUTORS.txt | ||
| generate_descriptor_proto.sh | ||
| gmock.BUILD | ||
| LICENSE | ||
| Makefile.am | ||
| post_process_dist.sh | ||
| protobuf-lite.pc.in | ||
| protobuf.bzl | ||
| protobuf.pc.in | ||
| Protobuf.podspec | ||
| README.md | ||
| six.BUILD | ||
| tests.sh | ||
| update_file_lists.sh | ||
| WORKSPACE | ||
Protocol Buffers - Google's data interchange format
Copyright 2008 Google Inc.
https://developers.google.com/protocol-buffers/
Overview
Protocol Buffers (a.k.a., protobuf) are Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data. You can find protobuf's documentation on the Google Developers site.
This README file contains protobuf installation instructions. To install protobuf, you need to install the protocol compiler (used to compile .proto files) and the protobuf runtime for your chosen programming language.
Protocol Compiler Installation
The protocol compiler is written in C++. If you are using C++, please follow the C++ Installation Instructions to install protoc along with the C++ runtime.
For non-C++ users, the simplest way to install the protocol compiler is to download a pre-built binary from our release page:
https://github.com/google/protobuf/releases
In the downloads section of each release, you can find pre-built binaries in zip packages: protoc-$VERSION-$PLATFORM.zip. It contains the protoc binary as well as a set of standard .proto files distributed along with protobuf.
If you are looking for an old version that is not available in the release page, check out the maven repo here:
http://repo1.maven.org/maven2/com/google/protobuf/protoc/
These pre-built binaries are only provided for released versions. If you want to use the github master version at HEAD, or you need to modify protobuf code, or you are using C++, it's recommended to build your own protoc binary from source.
If you would like to build protoc binary from source, see the C++ Installation Instructions.
Protobuf Runtime Installation
Protobuf supports several different programming languages. For each programming language, you can find instructions in the corresponding source directory about how to install protobuf runtime for that specific language:
| Language | Source |
|---|---|
| C++ (include C++ runtime and protoc) | src |
| Java | java |
| Python | python |
| Objective-C | objectivec |
| C# | csharp |
| JavaNano | javanano |
| JavaScript | js |
| Ruby | ruby |
| Go | golang/protobuf |
| PHP | TBD |
Usage
The complete documentation for Protocol Buffers is available via the web at:
https://developers.google.com/protocol-buffers/