关于 shazam 代理

关于 shazam

他是基于mysql的一个代理，import了PingCAP基于golang实现的sql parser
代理需要做路由以及sharding，所以需要解析语法，但仅实现ast，不实现语义
更多介绍去看他的官方git就可以了，写的总体还是不错的，性能我没做测试，后续安排此事

他比较重要的一个数据结构resultset

mysql/result.go

// Resultset means mysql results of sql execution, included split table sql
type Resultset struct {
  Fields     []*Field        // 解析协议后的mysql协议内field段
  FieldNames map[string]int  // column information, key: column name value: index in Fields
  Values     [][]interface{} // 解析协议后的mysql协议内的data段

  RowDatas []RowData // 原始mysql协议数据，上面三个字段都是parser，并不返回session中的客户端
  　　　　　　　　　　　// 返回客户端的是这个RowDatas
}

通过golang的调试器dlv调试数据

dlv exec ./shazam-proxy 

b writeResultset 停到这个断点，他返回mysql会话内协议数据

[GIN-debug] GET    /api/proxy/ping           --> github.com/nooncall/shazam/proxy/server.(*AdminServer).ping-fm (2 handlers)
[GIN-debug] PUT    /api/proxy/config/prepare/:name --> github.com/nooncall/shazam/proxy/server.(*AdminServer).prepareConfig-fm (2 handlers)
[GIN-debug] PUT    /api/proxy/config/commit/:name --> github.com/nooncall/shazam/proxy/server.(*AdminServer).commitConfig-fm (2 handlers)
[GIN-debug] PUT    /api/proxy/namespace/delete/:name --> github.com/nooncall/shazam/proxy/server.(*AdminServer).deleteNamespace-fm (2 handlers)
[GIN-debug] GET    /api/proxy/config/fingerprint --> github.com/nooncall/shazam/proxy/server.(*AdminServer).configFingerprint-fm (2 handlers)
[GIN-debug] GET    /api/proxy/stats/sessionsqlfingerprint/:namespace --> github.com/nooncall/shazam/proxy/server.(*AdminServer).getNamespaceSessionSQLFingerprint-fm (2 handlers)
[GIN-debug] GET    /api/proxy/stats/backendsqlfingerprint/:namespace --> github.com/nooncall/shazam/proxy/server.(*AdminServer).getNamespaceBackendSQLFingerprint-fm (2 handlers)
[GIN-debug] GET    /api/metric/metrics       --> github.com/gin-gonic/gin.WrapH.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/             --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/cmdline      --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/profile      --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] POST   /debug/pprof/symbol       --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/symbol       --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/trace        --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/block        --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/goroutine    --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/heap         --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/mutex        --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/threadcreate --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)
[GIN-debug] GET    /debug/pprof/allocs       --> github.com/gin-gonic/gin.WrapF.func1 (2 handlers)

没啥问题的化，已经正常启动了

下面这段是mysql原始协议，这个文档在以下实现描述
https://dev.mysql.com/doc/internals/en/com-query-response.html#packet-ProtocolText::Resultset

(dlv) p r.Fields
[]*github.com/nooncall/shazam/mysql.Field len: 3, cap: 3, [
	*{
		Data: github.com/nooncall/shazam/mysql.FieldData len: 48, cap: 48, [3,100,101,102,4,116,101,115,116,4,98,111,111,107,4,98,111,111,107,7,112,117,98,108,105,115,104,7,112,117,98,108,105,115,104,12,33,0,96,0,0,0,253,0,0,0,0,0],
		Schema: []uint8 len: 4, cap: 43, [116,101,115,116],
		Table: []uint8 len: 4, cap: 38, [98,111,111,107],
		OrgTable: []uint8 len: 4, cap: 33, [98,111,111,107],
		Name: []uint8 len: 7, cap: 28, [112,117,98,108,105,115,104],
		OrgName: []uint8 len: 7, cap: 20, [112,117,98,108,105,115,104],
		Charset: 33,
		ColumnLength: 96,
		Type: 253,
		Flag: 0,
		Decimal: 0,
		DefaultValueLength: 0,
		DefaultValue: []uint8 len: 0, cap: 0, nil,},
	*{
		Data: github.com/nooncall/shazam/mysql.FieldData len: 48, cap: 48, [3,100,101,102,4,116,101,115,116,4,98,111,111,107,4,98,111,111,107,7,97,100,100,114,101,115,115,7,97,100,100,114,101,115,115,12,33,0,96,0,0,0,253,0,0,0,0,0],
		Schema: []uint8 len: 4, cap: 43, [116,101,115,116],
		Table: []uint8 len: 4, cap: 38, [98,111,111,107],
		OrgTable: []uint8 len: 4, cap: 33, [98,111,111,107],
		Name: []uint8 len: 7, cap: 28, [97,100,100,114,101,115,115],
		OrgName: []uint8 len: 7, cap: 20, [97,100,100,114,101,115,115],
		Charset: 33,
		ColumnLength: 96,
		Type: 253,
		Flag: 0,
		Decimal: 0,
		DefaultValueLength: 0,
		DefaultValue: []uint8 len: 0, cap: 0, nil,},
	*{
		Data: github.com/nooncall/shazam/mysql.FieldData len: 44, cap: 44, [3,100,101,102,4,116,101,115,116,4,98,111,111,107,4,98,111,111,107,5,112,104,111,110,101,5,112,104,111,110,101,12,33,0,96,0,0,0,253,0,0,0,0,0],
		Schema: []uint8 len: 4, cap: 39, [116,101,115,116],
		Table: []uint8 len: 4, cap: 34, [98,111,111,107],
		OrgTable: []uint8 len: 4, cap: 29, [98,111,111,107],
		Name: []uint8 len: 5, cap: 24, [112,104,111,110,101],
		OrgName: []uint8 len: 5, cap: 18, [112,104,111,110,101],
		Charset: 33,
		ColumnLength: 96,
		Type: 253,
		Flag: 0,
		Decimal: 0,
		DefaultValueLength: 0,
		DefaultValue: []uint8 len: 0, cap: 0, nil,},
]

足够了