FlatBuffers的使用

下载地址：

https://github.com/google/flatbuffers/releases

Solution(包括示例工程)：

flatbuffers-1.1.0\build\VS2010\FlatBuffers.sln

flatc 

生成器

flatsamplebinary

FlatBufferBuilder的使用示例

引入monster_generated.h头文件，创建Monster对象，并使用flatbuffers::FlatBufferBuilder生成二进制buffer数据

flatsampletext

Parser的使用示例

加载monster.fbs、和monsterdata.json，使用flatbuffers::Parser，将它们的文本转换为二进制buffer数据，再用二进制buffer数据转换回文本

flattests

测试用例

FuzzTest1 使用确定性随机序列来模拟builder中添加不同类型的数据组合，创建Table，然后解析table中对应位置的值，判断是否相等

FuzzTest2 

四个头文件：

flatbuffers-1.1.0\include\flatbuffers\flatbuffers.h

flatbuffers-1.1.0\include\flatbuffers\hash.h

flatbuffers-1.1.0\include\flatbuffers\idl.h

flatbuffers-1.1.0\include\flatbuffers\util.h

idl.h

GenerateText

从 buffer 转 json

schema <-> cpp.h <-> buffer (bin) <-> text (json)

创建schema文件：

TestFlat.fbs

先使用vs2013编译得到： flatc.exe

进入命令行：

f:

cd F:\sonikk\b编程\flatBuffers\flatBuffers_2015-4-28 193412

flatc -c -o ./ ./TestFlat.fbs

生成了：

TestFlat_generated.h

flatsamplebinary工程t的sample_binary.cpp改写：

#include "flatbuffers/flatbuffers.h"
#include "monster_generated.h"

using namespace MyGame::Sample;

// sonikk
#include 

void save_to_file_bin(std::string file_name, unsigned char* data, unsigned int length)
{
	std::ofstream rs(file_name.c_str(), std::ios::binary);
	rs.write((char*)data, length);
	rs.close();
}

// @data OUT
unsigned int read_from_file_bin(std::string file_name, unsigned char*& data)
{
	std::ifstream rs(file_name.c_str(), std::ios::binary);

	//获取文件大小
	rs.seekg(0, std::ios_base::end); // 对输入文件定位
	long long length = rs.tellg();
	
	rs.seekg(0, std::ios_base::beg); // 定位回开头，这样才可以读取

	data = new unsigned char[(int)length];
	rs.read((char*)data, length);
	rs.close();

	return (unsigned int)length;
}


int main(int /*argc*/, const char * /*argv*/[]) 
{
  // Build up a serialized buffer algorithmically:
  flatbuffers::FlatBufferBuilder builder;

  auto vec = Vec3(1, 2, 3);

  auto name = builder.CreateString("MyMonster");

  unsigned char inv_data[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
  auto inventory = builder.CreateVector(inv_data, 10);

  // Shortcut for creating monster with all fields set:
  auto mloc = CreateMonster(builder, &vec, 150, 80, name, inventory,
                            Color_Blue);

  builder.Finish(mloc);
  // We now have a FlatBuffer we can store or send somewhere.

  // ** file/network code goes here :) **
  // access builder.GetBufferPointer() for builder.GetSize() bytes


  // ------------------------------------------------------------------------------------
  // 保存二进制到文件当中 @sonikk 2015-4-28 20:11:16
  save_to_file_bin("test_bin.bin", builder.GetBufferPointer(), builder.GetSize() );
  // -> flatbuffers-1.1.0\flatbuffers-1.1.0\build\VS2010\test_bin.bin

  unsigned char* data = nullptr;
  read_from_file_bin("test_bin.bin", data);

  auto monster1 = GetMonster( (const void*) data);
  auto hp = monster1->hp();
  auto mana = monster1->mana();

  // 成功！！！ @sonikk 2015-4-28 20:52:13
  hp = 1;
  mana = 2;
  // ------------------------------------------------------------------------------------

  // Instead, we're going to access it straight away.
  // Get access to the root:
  auto monster = GetMonster(builder.GetBufferPointer());

  assert(monster->hp() == 80);
  assert(monster->mana() == 150);  // default
  assert(!strcmp(monster->name()->c_str(), "MyMonster"));

  auto pos = monster->pos();
  assert(pos);
  assert(pos->z() == 3);
  (void)pos;

  auto inv = monster->inventory();
  assert(inv);
  assert(inv->Get(9) == 9);
  (void)inv;
}