seata-go/pkg/datasource/sql/exec/executor.go

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 exec

import (
	"context"
	"database/sql/driver"

	"github.com/seata/seata-go/pkg/datasource/sql/parser"
	"github.com/seata/seata-go/pkg/datasource/sql/types"
	"github.com/seata/seata-go/pkg/datasource/sql/undo"
	"github.com/seata/seata-go/pkg/datasource/sql/undo/builder"
	"github.com/seata/seata-go/pkg/tm"
	"github.com/seata/seata-go/pkg/util/log"
)

func init() {
	undo.RegisterUndoLogBuilder(types.UpdateExecutor, builder.GetMySQLUpdateUndoLogBuilder)
	undo.RegisterUndoLogBuilder(types.MultiExecutor, builder.GetMySQLMultiUndoLogBuilder)
}

// executorSolts
var (
	executorSoltsAT = make(map[types.DBType]map[types.ExecutorType]func() SQLExecutor)
	executorSoltsXA = make(map[types.DBType]func() SQLExecutor)
)

// RegisterATExecutor
func RegisterATExecutor(dt types.DBType, et types.ExecutorType, builder func() SQLExecutor) {
	if _, ok := executorSoltsAT[dt]; !ok {
		executorSoltsAT[dt] = make(map[types.ExecutorType]func() SQLExecutor)
	}

	val := executorSoltsAT[dt]

	val[et] = func() SQLExecutor {
		return &BaseExecutor{ex: builder()}
	}
}

// RegisterXAExecutor
func RegisterXAExecutor(dt types.DBType, builder func() SQLExecutor) {
	executorSoltsXA[dt] = func() SQLExecutor {
		return &BaseExecutor{ex: builder()}
	}
}

type (
	CallbackWithNamedValue func(ctx context.Context, query string, args []driver.NamedValue) (types.ExecResult, error)

	CallbackWithValue func(ctx context.Context, query string, args []driver.Value) (types.ExecResult, error)

	SQLExecutor interface {
		// Interceptors
		Interceptors(interceptors []SQLHook)
		// Exec
		ExecWithNamedValue(ctx context.Context, execCtx *types.ExecContext, f CallbackWithNamedValue) (types.ExecResult, error)
		// Exec
		ExecWithValue(ctx context.Context, execCtx *types.ExecContext, f CallbackWithValue) (types.ExecResult, error)
	}
)

// BuildExecutor
func BuildExecutor(dbType types.DBType, txType types.TransactionType, query string) (SQLExecutor, error) {
	if txType == types.XAMode {
		hooks := make([]SQLHook, 0, 4)
		hooks = append(hooks, commonHook...)

		e := executorSoltsXA[dbType]()
		e.Interceptors(hooks)
		return e, nil
	}

	parseCtx, err := parser.DoParser(query)
	if err != nil {
		return nil, err
	}

	hooks := make([]SQLHook, 0, 4)
	hooks = append(hooks, commonHook...)
	hooks = append(hooks, hookSolts[parseCtx.SQLType]...)

	factories, ok := executorSoltsAT[dbType]

	if !ok {
		log.Debugf("%s not found executor factories, return default Executor", dbType.String())
		e := &BaseExecutor{}
		e.Interceptors(hooks)
		return e, nil
	}

	supplier, ok := factories[parseCtx.ExecutorType]
	if !ok {
		log.Debugf("%s not found executor for %s, return default Executor",
			dbType.String(), parseCtx.ExecutorType)
		e := &BaseExecutor{}
		e.Interceptors(hooks)
		return e, nil
	}

	executor := supplier()
	executor.Interceptors(hooks)
	return executor, nil
}

type BaseExecutor struct {
	is []SQLHook
	ex SQLExecutor
}

// Interceptors
func (e *BaseExecutor) Interceptors(interceptors []SQLHook) {
	e.is = interceptors
}

// ExecWithNamedValue
func (e *BaseExecutor) ExecWithNamedValue(ctx context.Context, execCtx *types.ExecContext, f CallbackWithNamedValue) (types.ExecResult, error) {
	for i := range e.is {
		_ = e.is[i].Before(ctx, execCtx)
	}

	var (
		beforeImages []*types.RecordImage
		afterImages  []*types.RecordImage
		result       types.ExecResult
		err          error
	)

	beforeImages, err = e.beforeImage(ctx, execCtx)
	if err != nil {
		return nil, err
	}
	if beforeImages != nil {
		execCtx.TxCtx.RoundImages.AppendBeofreImages(beforeImages)
	}

	defer func() {
		for i := range e.is {
			_ = e.is[i].After(ctx, execCtx)
		}
	}()

	if e.ex != nil {
		result, err = e.ex.ExecWithNamedValue(ctx, execCtx, f)
	} else {
		result, err = f(ctx, execCtx.Query, execCtx.NamedValues)
	}

	if err != nil {
		return nil, err
	}

	afterImages, err = e.afterImage(ctx, execCtx, beforeImages)
	if err != nil {
		return nil, err
	}
	if afterImages != nil {
		execCtx.TxCtx.RoundImages.AppendAfterImages(afterImages)
	}

	return result, err
}

// ExecWithValue
func (e *BaseExecutor) ExecWithValue(ctx context.Context, execCtx *types.ExecContext, f CallbackWithValue) (types.ExecResult, error) {
	for i := range e.is {
		e.is[i].Before(ctx, execCtx)
	}

	var (
		beforeImages []*types.RecordImage
		afterImages  []*types.RecordImage
		result       types.ExecResult
		err          error
	)

	beforeImages, err = e.beforeImage(ctx, execCtx)
	if err != nil {
		return nil, err
	}
	if beforeImages != nil {
		execCtx.TxCtx.RoundImages.AppendBeofreImages(beforeImages)
	}

	defer func() {
		for i := range e.is {
			_ = e.is[i].After(ctx, execCtx)
		}
	}()

	if e.ex != nil {
		result, err = e.ex.ExecWithValue(ctx, execCtx, f)
	} else {
		result, err = f(ctx, execCtx.Query, execCtx.Values)
	}
	if err != nil {
		return nil, err
	}

	afterImages, err = e.afterImage(ctx, execCtx, beforeImages)
	if err != nil {
		return nil, err
	}
	if afterImages != nil {
		execCtx.TxCtx.RoundImages.AppendAfterImages(afterImages)
	}

	return result, err
}

func (h *BaseExecutor) beforeImage(ctx context.Context, execCtx *types.ExecContext) ([]*types.RecordImage, error) {
	if !tm.IsTransactionOpened(ctx) {
		return nil, nil
	}

	pc, err := parser.DoParser(execCtx.Query)
	if err != nil {
		return nil, err
	}
	if !pc.HasValidStmt() {
		return nil, nil
	}

	builder := undo.GetUndologBuilder(pc.ExecutorType)
	if builder == nil {
		return nil, nil
	}
	return builder.BeforeImage(ctx, execCtx)
}

// After
func (h *BaseExecutor) afterImage(ctx context.Context, execCtx *types.ExecContext, beforeImages []*types.RecordImage) ([]*types.RecordImage, error) {
	if !tm.IsTransactionOpened(ctx) {
		return nil, nil
	}
	pc, err := parser.DoParser(execCtx.Query)
	if err != nil {
		return nil, err
	}
	if !pc.HasValidStmt() {
		return nil, nil
	}
	builder := undo.GetUndologBuilder(pc.ExecutorType)
	if builder == nil {
		return nil, nil
	}
	return builder.AfterImage(ctx, execCtx, beforeImages)
}