github.com/insionng/yougam@v0.0.0-20170714101924-2bc18d833463/libraries/pingcap/tidb/perfschema/perfschema.go (about)

     1  // Copyright 2016 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package perfschema
    15  
    16  import (
    17  	"reflect"
    18  
    19  	"github.com/insionng/yougam/libraries/juju/errors"
    20  	"github.com/insionng/yougam/libraries/pingcap/tidb/kv"
    21  	"github.com/insionng/yougam/libraries/pingcap/tidb/model"
    22  	"github.com/insionng/yougam/libraries/pingcap/tidb/table"
    23  	"github.com/insionng/yougam/libraries/pingcap/tidb/terror"
    24  )
    25  
    26  var (
    27  	errInvalidPerfSchemaTable = terror.ClassPerfSchema.New(codeInvalidPerfSchemaTable, "invalid perfschema table")
    28  	errInvalidTimerFlag       = terror.ClassPerfSchema.New(codeInvalidTimerFlag, "invalid timer flag")
    29  )
    30  
    31  // StatementInstrument defines the methods for statement instrumentation points
    32  type StatementInstrument interface {
    33  	RegisterStatement(category, name string, elem interface{})
    34  
    35  	StartStatement(sql string, connID uint64, callerName EnumCallerName, elem interface{}) *StatementState
    36  
    37  	EndStatement(state *StatementState)
    38  }
    39  
    40  // PerfSchema defines the methods to be invoked by the executor
    41  type PerfSchema interface {
    42  
    43  	// For statement instrumentation only.
    44  	StatementInstrument
    45  
    46  	// GetDBMeta returns db info for PerformanceSchema.
    47  	GetDBMeta() *model.DBInfo
    48  	// GetTable returns table instance for name.
    49  	GetTable(name string) (table.Table, bool)
    50  }
    51  
    52  type perfSchema struct {
    53  	store       kv.Storage
    54  	dbInfo      *model.DBInfo
    55  	tables      map[string]*model.TableInfo
    56  	mTables     map[string]table.Table // Memory tables for perfSchema
    57  	stmtHandles []int64
    58  	stmtInfos   map[reflect.Type]*statementInfo
    59  }
    60  
    61  var _ PerfSchema = (*perfSchema)(nil)
    62  
    63  // NewPerfHandle creates a new perfSchema on store.
    64  func NewPerfHandle() (PerfSchema, error) {
    65  	schema := &perfSchema{}
    66  	err := schema.initialize()
    67  	if err != nil {
    68  		return nil, errors.Trace(err)
    69  	}
    70  	schema.registerStatements()
    71  	return schema, nil
    72  }
    73  
    74  // perfschema error codes.
    75  const (
    76  	codeInvalidPerfSchemaTable terror.ErrCode = 1
    77  	codeInvalidTimerFlag                      = 2
    78  )