为什么使用GRPC？
- Google出品，基于HTTP2.0，减少TCP握手次数，客户端快，省电，服务端并发。需要Protobuf3.0配合使用。
iOS 如何使用？
- 在工程目录添加一个后缀名为 .podspec的文件， HelloWorld.podspec文件内容见文档（.podspec 制作私有库时也需要这个文件，主要是和CocoaPods关联）
- CocoaPods
步骤
- CocoaPods: version 1.0 or higher
- Xcode: version 7.2 or higher
- Homebrew
- brew install autoconf
brew install automake brew upgrade automake
brew install libtool
brew install pkg-config brew upgrade pkg-config - 下载示例程序
git clone --recursive -b v1.12.x https://github.com/grpc/grpc.git
- 下载插件和库
git clone 之后默认下载到/User/yourAccountName目录下
cd /Users/“yourAccountName”/grpc/
make
sudo make install
- 安装protoc编译器
brew tap grpc/grpc
brew install protobuf
- Run the server
cd /Users/***/grpc/examples/cpp/helloworld/
make
./greeter_server &
make 之后会报错
protoc -I ../../protos --cpp_out=. ../../protos/helloworld.proto
g++ -std=c++11 `pkg-config --cflags protobuf grpc` -c -o helloworld.pb.o helloworld.pb.cc
In file included from helloworld.pb.cc:5:
./helloworld.pb.h:9:10: fatal error: 'google/protobuf/stubs/common.h' file not found
#include <google/protobuf/stubs/common.h>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
make: *** [helloworld.pb.o] Error 1
看到错误是不是很尴尬，这个原因是当前项目没有引入gRPC相关库。
所以，只要用pod 导入相关库即可。
- 切换到工程目录
cd /Users/***/grpc/examples/objective-c/helloworld
pod init
pod install
... wait install...
Analyzing dependencies
Fetching podspec for `HelloWorld` from `.`
Downloading dependencies
Installing !ProtoCompiler (3.5.0)
Installing !ProtoCompiler-gRPCPlugin (1.9.0)
Installing BoringSSL (9.2)
Installing HelloWorld (0.0.1)
Installing Protobuf (3.5.0)
Installing gRPC (1.9.0)
Installing gRPC-Core (1.9.0)
Installing gRPC-ProtoRPC (1.9.0)
Installing gRPC-RxLibrary (1.9.0)
Installing nanopb (0.3.8)
Generating Pods project
Integrating client project
[!] Please close any current Xcode sessions and use `HelloWorld.xcworkspace` for this project from now on.
Sending stats
Pod installation complete! There is 1 dependency from the Podfile and 10 total pods installed.
GRPC Objective-C Quickstart官方网站
.podspec 文件
# Base directory where the .proto files are. 根据注释可以知道这里是.proto文件的目录，如果就在工程目录的第一级文件夹下，直接写文件夹名字就可以。
src = "protos"
# Run protoc with the Objective-C and gRPC plugins to generate protocol messages and gRPC clients.
# You can run this command manually if you later change your protos and need to regenerate.
s.prepare_command = <<-CMD
#{protoc} \
--plugin=protoc-gen-grpc=#{plugin} \
--objc_out=. \
--grpc_out=. \
-I . \
-I #{protoc_dir} \
google/*/*.proto google/*/*/*/*.proto
最后一行是填写.proto文件的路径，
1. google为存放.proto的文件夹，
2. 如果google文件夹中存在多级文件目录，google/*/*.proto
3. 如果google文件夹中存在N级文件目录，googleN+1个/*.proto
N=3 google/*/*/*/*.proto
两级目录.png
五级目录.png
scrforProto.png
