tidb conn_ip_example 代码
文件路径：/plugin/conn_ip_example/conn_ip_example.go
/ Copyright 2019 PingCAP, Inc.
/
/ Licensed under the Apache License, Version 2.0 (the "License");
/ you may not use this file except in compliance with the License.
/ You may obtain a copy of the License at
/
/ http://www.apache.org/licenses/LICENSE-2.0
/
/ Unless required by applicable law or agreed to in writing, software
/ distributed under the License is distributed on an "AS IS" BASIS,
/ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/ See the License for the specific language governing permissions and
/ limitations under the License.
package main
import (
"context"
"fmt"
"strings"
"sync/atomic"
"github.com/pingcap/tidb/plugin"
"github.com/pingcap/tidb/sessionctx/variable"
)
/ Accumulator of connection
/ It can be increased by 1 after each OnConnectionEvent is triggered.
var connection int32
/ Validate implements TiDB plugin's Validate SPI.
/ It is called before OnInit
/ nolint: unused, deadcode
func Validate(ctx context.Context, m *plugin.Manifest) error {
fmt.Println("## conn_ip_example Validate called ##")
fmt.Printf("---- context: %s\n", ctx)
return nil
}
/ OnInit implements TiDB plugin's OnInit SPI.
/ nolint: unused, deadcode
func OnInit(ctx context.Context, manifest *plugin.Manifest) error {
fmt.Println("## conn_ip_example OnInit called ##")
fmt.Printf("---- context: %s\n", ctx)
/ Register an example system variable
/ With the server.
sv := &variable.SysVar{
Name: "conn_ip_example_key",
Scope: variable.ScopeGlobal | variable.ScopeSession,
Value: "v1",
Type: variable.TypeStr, / default.
/ (Optional) specifying a validation function helps to normalize the value before setting it.
/ The "normalizedValue" applies if the value has a Type associated, where some formatting may have already
/ been applied. i.e. TypeBool: ON/oN/1/on -> ON
Validation: func(vars *variable.SessionVars, normalizedValue string, originalValue string, scope variable.ScopeFlag) (string, error) {
fmt.Println("The validation function was called")
return strings.ToLower(normalizedValue), nil
},
/ (Optional) the SetSession function is called when a session scoped variable is changed.
/ *And* when a new session is initialized.
SetSession: func(vars *variable.SessionVars, value string) error {
fmt.Println("The set session function was called")
return nil
},
/ (Optional) the SetGlobal function is called when a global variable is changed.
/ This will only be called on the TiDB server that the change is made on,
/ and not on the tidb-server peers which will also update their global variable eventually.
SetGlobal: func(vars *variable.SessionVars, value string) error {
fmt.Println("The set global function was called")
return nil
},
}
variable.RegisterSysVar(sv)
fmt.Printf("---- read cfg in init [key: conn_ip_example_key, value: %s]\n", variable.GetSysVar("conn_ip_example_key").Value)
atomic.SwapInt32(&connection, 0)
return nil
}
/ OnShutdown implements TiDB plugin's OnShutdown SPI.
/ nolint: unused, deadcode
func OnShutdown(ctx context.Context, manifest *plugin.Manifest) error {
fmt.Println("## conn_ip_example OnShutdown called ##")
fmt.Printf("---- context: %s\n", ctx)
fmt.Printf("---- read cfg in shutdown [key: conn_ip_example_key, value: %s]\n", variable.GetSysVar("conn_ip_example_key").Value)
atomic.SwapInt32(&connection, 0)
return nil
}
/ OnGeneralEvent implements TiDB Audit plugin's OnGeneralEvent SPI.
/ nolint: unused, deadcode
func OnGeneralEvent(ctx context.Context, sctx *variable.SessionVars, event plugin.GeneralEvent, cmd string) {
fmt.Println("## conn_ip_example OnGeneralEvent called ##")
if sctx != nil {
fmt.Printf("---- session status: %d\n", sctx.Status)
digest, _ := sctx.StmtCtx.SQLDigest()
fmt.Printf("---- statement sql: %s, digest: %s\n", sctx.StmtCtx.OriginalSQL, digest)
if len(sctx.StmtCtx.Tables) > 0 {
fmt.Printf("---- statement tables: %#v\n", sctx.StmtCtx.Tables)
}
fmt.Printf("---- executed by user: %#v\n", sctx.User)
}
switch event {
case plugin.Starting:
fmt.Println("---- event: Statement Starting")
case plugin.Completed:
fmt.Println("---- event: Statement Completed")
case plugin.Error:
fmt.Println("---- event: ERROR!")
default:
fmt.Println("---- event: unrecognized")
}
fmt.Printf("---- cmd: %s\n", cmd)
}
/ OnConnectionEvent implements TiDB Audit plugin's OnConnectionEvent SPI.
/ nolint: unused, deadcode
func OnConnectionEvent(ctx context.Context, event plugin.ConnectionEvent, info *variable.ConnectionInfo) error {
var reason string
if r := ctx.Value(plugin.RejectReasonCtxValue{}); r != nil {
reason = r.(string)
}
fmt.Println("## conn_ip_example onConnectionEvent called ##")
fmt.Printf("---- conenct event: %s, reason: [%s]\n", event, reason)
fmt.Printf("---- connection host: %s\n", info.Host)
fmt.Printf("---- connection details: %s@%s/%s type: %s\n", info.User, info.Host, info.DB, info.ConnectionType)
atomic.AddInt32(&connection, 1)
return nil
}