forked from Shiloh/githaven
91 lines
3.2 KiB
Go
91 lines
3.2 KiB
Go
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// Copyright 2015 PingCAP, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package optimizer
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import (
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"github.com/juju/errors"
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"github.com/pingcap/tidb/ast"
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"github.com/pingcap/tidb/context"
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"github.com/pingcap/tidb/infoschema"
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"github.com/pingcap/tidb/mysql"
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"github.com/pingcap/tidb/optimizer/plan"
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"github.com/pingcap/tidb/terror"
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)
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// Optimize does optimization and creates a Plan.
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// The node must be prepared first.
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func Optimize(ctx context.Context, node ast.Node, sb plan.SubQueryBuilder) (plan.Plan, error) {
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// We have to infer type again because after parameter is set, the expression type may change.
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if err := InferType(node); err != nil {
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return nil, errors.Trace(err)
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}
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if err := logicOptimize(ctx, node); err != nil {
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return nil, errors.Trace(err)
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}
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p, err := plan.BuildPlan(node, sb)
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if err != nil {
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return nil, errors.Trace(err)
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}
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err = plan.Refine(p)
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if err != nil {
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return nil, errors.Trace(err)
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}
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return p, nil
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}
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// Prepare prepares a raw statement parsed from parser.
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// The statement must be prepared before it can be passed to optimize function.
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// We pass InfoSchema instead of getting from Context in case it is changed after resolving name.
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func Prepare(is infoschema.InfoSchema, ctx context.Context, node ast.Node) error {
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ast.SetFlag(node)
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if err := Preprocess(node, is, ctx); err != nil {
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return errors.Trace(err)
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}
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if err := Validate(node, true); err != nil {
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return errors.Trace(err)
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}
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return nil
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}
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// Optimizer error codes.
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const (
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CodeOneColumn terror.ErrCode = 1
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CodeSameColumns terror.ErrCode = 2
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CodeMultiWildCard terror.ErrCode = 3
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CodeUnsupported terror.ErrCode = 4
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CodeInvalidGroupFuncUse terror.ErrCode = 5
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CodeIllegalReference terror.ErrCode = 6
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)
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// Optimizer base errors.
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var (
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ErrOneColumn = terror.ClassOptimizer.New(CodeOneColumn, "Operand should contain 1 column(s)")
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ErrSameColumns = terror.ClassOptimizer.New(CodeSameColumns, "Operands should contain same columns")
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ErrMultiWildCard = terror.ClassOptimizer.New(CodeMultiWildCard, "wildcard field exist more than once")
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ErrUnSupported = terror.ClassOptimizer.New(CodeUnsupported, "unsupported")
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ErrInvalidGroupFuncUse = terror.ClassOptimizer.New(CodeInvalidGroupFuncUse, "Invalid use of group function")
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ErrIllegalReference = terror.ClassOptimizer.New(CodeIllegalReference, "Illegal reference")
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)
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func init() {
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mySQLErrCodes := map[terror.ErrCode]uint16{
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CodeOneColumn: mysql.ErrOperandColumns,
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CodeSameColumns: mysql.ErrOperandColumns,
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CodeMultiWildCard: mysql.ErrParse,
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CodeInvalidGroupFuncUse: mysql.ErrInvalidGroupFuncUse,
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CodeIllegalReference: mysql.ErrIllegalReference,
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}
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terror.ErrClassToMySQLCodes[terror.ClassOptimizer] = mySQLErrCodes
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}
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