FlatBuffers使用记录(Golang)

标签：flatbuffers   golang   idl   序列化   go语言   

              试用了下FlatBuffers,把一些东东记录一下。

 FlatBuffers 官网: http://google.github.io/flatbuffers/md__go_usage.html

它支持生成Go语言相关的东西，总的使用步骤如下:

 3. 在Go工程中安装FlatBuffers的Go支持包，就可以在代码直接使用了.        

 再详细说说IDL的一些语法。先上一份.fbs的例子:  

// example IDL file

namespace MyGame;

attribute "priority";

enum Color : byte { Red = 1, Green, Blue }

///union Any { Monster, Weapon, Pickup }
//union Any { Monster}
union Any { Monster, Weapon}

struct Vec3 {
  x:float;
  y:float;
  z:float;
}

/// 注释
table Monster {
  pos:Vec3;
  mana:short = 150;
  hp:short = 100;
  name:string;
  friendly:bool = false (deprecated, priority: 1);
  inventory:[ubyte];
  color:Color = Blue;
  test:Any;
}

table Weapon {
  pos:Vec3;
  mana:short = 150;
}

root_type Monster;
root_type Weapon;

const (
			AnyNONE = 0
			AnyMonster = 1
			AnyWeapon = 2
		)    

/// 加id指定生成顺序
table Monster {
  pos:Vec3  (id: 0);
  mana:short = 150 (id: 3);
  hp:short = 100 (id: 1);
  name:string (id: 2);
  //friendly:bool = false (deprecated, priority: 1);
  friendly:bool = false (deprecated,id: 4);
  //friendly:bool = false (priority: 1);
  inventory:[ubyte] (id: 6);
  color:Color = Blue (id: 5);
  test:Any (id: 8);
}

依此为例,会按id指定顺序生成相关函数.
     注意:
        如有加id,则table中所有字段都要加id才可通过
        对于Any,可以看到id为8,而不是按顺序来的7.原来是它会生成:
        func (rcv *Monster) TestType() byte {}
        func (rcv *Monster) Test(obj *flatbuffers.Table) bool {}
        即隐含一个Type的字段。所以要加1. 即union型的，其id为{}内总个数加1

使用方法:    

    取值:

 buf, err := ioutil.ReadFile("monster.dat")
    offset := 0
    monster := example.GetRootAsMonster(buf, offset)
    got := monster.Hp()

builder := flatbuffers.NewBuilder(0)

	str := builder.CreateString("MyMonster")
	example.MonsterStart(builder)
	example.MonsterAddPos(builder, example.CreateVec3(builder, 1.0, 2.0, 3.0, 3.0, 4, 5, 6))
	example.MonsterAddHp(builder, 80)
	example.MonsterAddName(builder, str)
	example.MonsterAddInventory(builder, inv)
	example.MonsterAddTestType(builder, 1)
	// example.MonsterAddTest(builder, mon2)
	// example.MonsterAddTest4(builder, test4s)
	_ = example.MonsterEnd(builder)

   MAIL: xcl_168@aliyun.com

 BLOG:http://blog.csdn.net/xcl168

FlatBuffers使用记录(Golang)

标签：flatbuffers   golang   idl   序列化   go语言   

原文地址：http://blog.csdn.net/xcl168/article/details/44197161