服务器协议一直以来都使用erlang-protobuff，项目地址：https://github.com/ngerakines/erlang_protobuffs，但觉得效率不行，于是想优化一下，思路就是把协议编解码放到底层c去做。正好可以使用云风写的pbc：https://github.com/cloudwu/pbc，于是拿来封装一下nif。虽然看起来很简单，但中间也遇到了一些问题：
1. pbc是非线程安全的，解决办法是初始化时为每个线程创建一个pbc_env环境
2. pbc以字符串key作为消息的字段，但erlang的record结构没有key，只是一个存放term的数组，怎么对应起来
3. c层如何构造一个初始的erlang消息结构，然后解完消息之后，返回给erlang层使用
4. 这个初始的erlang结构都是固定的，怎么把这个erlang结构在c层保存起来一直使用
最终做出来效率提升好几倍，而且可以同时支持record和map结构， 代码已提交到github，https://github.com/616050468/erlang_pbc
erlang_pbc
erlang_pbc is erlang nif of protobuff-c which is developed by cloudwu, want to know protobuff-c more, please see:https://github.com/cloudwu/pbc
erlang_pbc is faster than erlang-protobuff, support record and map. if you use map, you don't need any erlang code.
Quick Example
package msg; message attriMessage { optional int32 index = 1; optional int32 value = 2; } message longMessage { optional int64 dbID = 1; optional int32 sceneID = 2; optional int32 sceneLine = 3; optional int32 x = 4; optional int32 y = 5; optional int32 z = 6; repeated attriMessage attriList = 7; optional string name = 8; optional int32 career = 9; optional bool sex = 10; optional string signature = 11; optional int32 vip_level = 12; optional string telphone = 13; } Eshell V6.1 (abort with ^G)
1> test_msg:init_pbc().
[ok,ok,ok,ok,ok,ok,ok]
2> pbc_nif:get_default("msg.attriMessage").
{{'msg.attriMessage',0,0},#{"index" => 0,"value" => 0}}
3>
3> Bin = pbc_nif:encode("msg.attriMessage", {'msg.attriMessage', 100, 100}).
<<8,100,16,100>>
4>
4> pbc_nif:decode("msg.attriMessage", Bin, 0).
{'msg.attriMessage',100,100}
5>
5> pbc_nif:decode("msg.attriMessage", Bin, 1).
#{"index" => 100,"value" => 100}
Profile
please see test_msg.erl to know more....
test data in personal note-book:
Intel(R) Xeon(R) CPU E3-1231 v3 @3.40GHz RAM: 8.00GB OS TYPE: 64-bit Eshell V6.1 (abort with ^G)
1> test_msg:profile().
begin profile encode
encode_short_erlang (10.0w): 439ms
encode_short_pbc_map (10.0w): 58ms
encode_short_pbc_record (10.0w): 52ms
encode_long_erlang (10.0w): 850ms
encode_long_pbc_map (10.0w): 187ms
encode_long_pbc_record (10.0w): 152ms
encode_big_erlang (10.0w): 13084ms
encode_big_pbc_map (10.0w): 2203ms
encode_big_pbc_record (10.0w): 1739ms
begin profile decode
decode_short_erlang (10.0w): 164ms
decode_short_pbc_map (10.0w): 76ms
decode_short_pbc_record (10.0w): 60ms
decode_long_erlang (10.0w): 1342ms
decode_long_pbc_map (10.0w): 424ms
decode_long_pbc_record (10.0w): 175ms
decode_big_erlang (10.0w): 20312ms
decode_big_pbc_map (10.0w): 6099ms
decode_big_pbc_record (10.0w): 2556ms
ok
compile
Windows: open project use VS and build the project.
Linux: (use premake4 to create makefile)
premake4 gmake