google protobuf ios開發使用

時間 2019-11-18

標籤 google protobuf ios 開發使用欄目 Google 简体版

原文原文鏈接

簡介：php

protobuf 即 google protocol buffer 是一種數據封裝格式協議；java

好比其餘常常用的xml，json等格式；protobuf的優點是效率高，一樣的一份數據使用protobuf存儲的時候更小，更加方便；python

官網：linux

https://developers.google.com/protocol-buffers/git

https://github.com/google/protobufgithub

在iOS上的使用json

目前最新的版本須要xcode7.0+，以及不支持ARCxcode

1. 從github上面下載所有代碼ruby

2. 在mac上編譯protobuf 可能還須要 autoconf,libtool,automake,網絡

請先在mac上安裝這三個依賴庫；使用brew安裝就行

　　brew install autoconf

brew install libtool

brew install automake

automake的安裝可能會鏈接到被牆的網站，這時從網上找一份谷歌host便可；

3. 解壓下載的 protobuf-master，並打開終端入 /protobuf-master/objectivec/DevTools/ 目錄

執行 sudo sh full_mac_build.sh

等待編譯完成，若是遇到錯誤多是上面3個依賴或是別的依賴沒有安裝，排查一下就好

4. 安裝完成以後，即會在 protobuf-master/src/ 目錄下生成 protoc 可執行程序

之後咱們須要用該生成把 .proto文件生成對應平臺的代碼；

5. 以下安裝protobuf定義的proto3語法生成一份測試用的數據格式，Person.proto文件

syntax = "proto3";

message Person {
  string name = 1;
  int32 age = 2;
  string address = 3;

}

6. 使用 protoc 將 .proto文件生成對應平臺的代碼；這裏生成oc的代碼

以下protoc命令的幫助

Parse PROTO_FILES and generate output based on the options given:
  -IPATH, --proto_path=PATH   Specify the directory in which to search for
                              imports.  May be specified multiple times;
                              directories will be searched in order.  If not
                              given, the current working directory is used.
  --version                   Show version info and exit.
  -h, --help                  Show this text and exit.
  --encode=MESSAGE_TYPE       Read a text-format message of the given type
                              from standard input and write it in binary
                              to standard output.  The message type must
                              be defined in PROTO_FILES or their imports.
  --decode=MESSAGE_TYPE       Read a binary message of the given type from
                              standard input and write it in text format
                              to standard output.  The message type must
                              be defined in PROTO_FILES or their imports.
  --decode_raw                Read an arbitrary protocol message from
                              standard input and write the raw tag/value
                              pairs in text format to standard output.  No
                              PROTO_FILES should be given when using this
                              flag.
  -oFILE,                     Writes a FileDescriptorSet (a protocol buffer,
    --descriptor_set_out=FILE defined in descriptor.proto) containing all of
                              the input files to FILE.
  --include_imports           When using --descriptor_set_out, also include
                              all dependencies of the input files in the
                              set, so that the set is self-contained.
  --include_source_info       When using --descriptor_set_out, do not strip
                              SourceCodeInfo from the FileDescriptorProto.
                              This results in vastly larger descriptors that
                              include information about the original
                              location of each decl in the source file as
                              well as surrounding comments.
  --dependency_out=FILE       Write a dependency output file in the format
                              expected by make. This writes the transitive
                              set of input file paths to FILE
  --error_format=FORMAT       Set the format in which to print errors.
                              FORMAT may be 'gcc' (the default) or 'msvs'
                              (Microsoft Visual Studio format).
  --print_free_field_numbers  Print the free field numbers of the messages
                              defined in the given proto files. Groups share
                              the same field number space with the parent 
                              message. Extension ranges are counted as 
                              occupied fields numbers.

  --plugin=EXECUTABLE         Specifies a plugin executable to use.
                              Normally, protoc searches the PATH for
                              plugins, but you may specify additional
                              executables not in the path using this flag.
                              Additionally, EXECUTABLE may be of the form
                              NAME=PATH, in which case the given plugin name
                              is mapped to the given executable even if
                              the executable's own name differs.
  --cpp_out=OUT_DIR           Generate C++ header and source.
  --csharp_out=OUT_DIR        Generate C# source file.
  --java_out=OUT_DIR          Generate Java source file.
  --javanano_out=OUT_DIR      Generate Java Nano source file.
  --js_out=OUT_DIR            Generate JavaScript source.
  --objc_out=OUT_DIR          Generate Objective C header and source.
  --php_out=OUT_DIR           Generate PHP source file.
  --python_out=OUT_DIR        Generate Python source file.
  --ruby_out=OUT_DIR          Generate Ruby source file.

View Code

生成OC代碼格式命令

D/protoc --proto_path=A --objc_out=B C/Person.proto

D: 表示 protoc 可執行程序的目錄

A:表示處理proto文件須要的目錄，和生成目錄同樣就行

B:表示生成代碼的文件，oc會成生.h和.m 這裏就是指生成文件須要放的目錄

C：表示須要的.proto文件，即protoc會根據此文件裏面定義的格式生成相應平臺代碼文件

生成以後的oc，.h 和 .m 就能夠放到xcode工程裏面使用了，不支持ARC，ARC的工程對此.m添加 -fno-objc-arc

7. 這裏使用xcode7.3建立了DEMO工程，GPBDemo,並設置工程爲 mrc

把第6步生成的Person.pbobjc.h,Person.pbobjc.m 導入工程

把 protobuf-master/objectivec/ 目錄下面全部的 .h 和.m 手動導入工程，把該目錄下的google文件也會部導入工程

在工程設置 header search path 添加 $(PROJECT_DIR)/GBPDemo , 否則導入上面的google文件夾以後編譯會出頭文件鏈接錯誤；

把GPBProtocolBuffers.m 從工程裏面刪除掉(這裏是官網說的https://github.com/google/protobuf/tree/master/objectivec)

導入以後的工程結構以下

以上配置完成以後，編譯就正常經過了

8. 測試使用protobuf

在工程ViewController.m 裏面導入

#import "GPBProtocolBuffers.h"
#import "Person.pbobjc.h"

以下代碼

    Person *pe = [[Person alloc]init];
    pe.name = @"jobs";
    pe.age = 86;
    pe.address = @"Beijing";
    
    //如下是效率對比
    //protocbufer
    NSLog(@"protocbufer: %@",pe);
    NSLog(@"%lu",[pe data].length);
    
    
    //json
    NSDictionary *pj = @{@"name":@"jobs",
                           @"age":@86,
                           @"address":@"Beijing"};
    NSData *jsd = [NSJSONSerialization dataWithJSONObject:pj options:0 error:nil];
    NSLog(@"JSON: %@",pj);
    NSLog(@"%lu", jsd.length);
    
    
    //xml
    NSString *xml = @"<name>jobs</name><age>86</age><address>Beijing</address>";
    NSData *xmlData = [xml dataUsingEncoding:NSUTF8StringEncoding];
    NSLog(@"XML: %@",xml);
    NSLog(@"%lu",xmlData.length);
    
    [pe release];