mirror of
https://github.com/go-gitea/gitea.git
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678 lines
13 KiB
Go
678 lines
13 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 plan
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import (
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"fmt"
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"github.com/pingcap/tidb/ast"
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"github.com/pingcap/tidb/model"
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"github.com/pingcap/tidb/util/types"
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)
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// TableRange represents a range of row handle.
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type TableRange struct {
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LowVal int64
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HighVal int64
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}
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// TableScan represents a table scan plan.
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type TableScan struct {
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basePlan
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Table *model.TableInfo
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Desc bool
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Ranges []TableRange
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// RefAccess indicates it references a previous joined table, used in explain.
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RefAccess bool
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// AccessConditions can be used to build index range.
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AccessConditions []ast.ExprNode
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// FilterConditions can be used to filter result.
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FilterConditions []ast.ExprNode
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}
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// Accept implements Plan Accept interface.
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func (p *TableScan) Accept(v Visitor) (Plan, bool) {
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np, _ := v.Enter(p)
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return v.Leave(np)
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}
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// ShowDDL is for showing DDL information.
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type ShowDDL struct {
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basePlan
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}
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// Accept implements Plan Accept interface.
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func (p *ShowDDL) Accept(v Visitor) (Plan, bool) {
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np, _ := v.Enter(p)
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return v.Leave(np)
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}
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// CheckTable is for checking table data.
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type CheckTable struct {
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basePlan
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Tables []*ast.TableName
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}
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// Accept implements Plan Accept interface.
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func (p *CheckTable) Accept(v Visitor) (Plan, bool) {
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np, _ := v.Enter(p)
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return v.Leave(np)
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}
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// IndexRange represents an index range to be scanned.
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type IndexRange struct {
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LowVal []types.Datum
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LowExclude bool
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HighVal []types.Datum
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HighExclude bool
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}
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// IsPoint returns if the index range is a point.
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func (ir *IndexRange) IsPoint() bool {
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if len(ir.LowVal) != len(ir.HighVal) {
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return false
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}
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for i := range ir.LowVal {
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a := ir.LowVal[i]
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b := ir.HighVal[i]
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if a.Kind() == types.KindMinNotNull || b.Kind() == types.KindMaxValue {
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return false
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}
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cmp, err := a.CompareDatum(b)
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if err != nil {
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return false
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}
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if cmp != 0 {
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return false
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}
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}
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return !ir.LowExclude && !ir.HighExclude
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}
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// IndexScan represents an index scan plan.
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type IndexScan struct {
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basePlan
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// The index used.
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Index *model.IndexInfo
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// The table to lookup.
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Table *model.TableInfo
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// Ordered and non-overlapping ranges to be scanned.
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Ranges []*IndexRange
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// Desc indicates whether the index should be scanned in descending order.
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Desc bool
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// RefAccess indicates it references a previous joined table, used in explain.
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RefAccess bool
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// AccessConditions can be used to build index range.
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AccessConditions []ast.ExprNode
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// Number of leading equal access condition.
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// The offset of each equal condition correspond to the offset of index column.
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// For example, an index has column (a, b, c), condition is 'a = 0 and b = 0 and c > 0'
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// AccessEqualCount would be 2.
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AccessEqualCount int
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// FilterConditions can be used to filter result.
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FilterConditions []ast.ExprNode
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}
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// Accept implements Plan Accept interface.
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func (p *IndexScan) Accept(v Visitor) (Plan, bool) {
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np, _ := v.Enter(p)
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return v.Leave(np)
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}
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// JoinOuter represents outer join plan.
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type JoinOuter struct {
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basePlan
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Outer Plan
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Inner Plan
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}
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// Accept implements Plan interface.
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func (p *JoinOuter) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*JoinOuter)
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var ok bool
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p.Outer, ok = p.Outer.Accept(v)
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if !ok {
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return p, false
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}
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p.Inner, ok = p.Inner.Accept(v)
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if !ok {
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return p, false
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}
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return v.Leave(p)
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}
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// JoinInner represents inner join plan.
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type JoinInner struct {
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basePlan
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Inners []Plan
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Conditions []ast.ExprNode
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}
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func (p *JoinInner) String() string {
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return fmt.Sprintf("JoinInner()")
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}
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// Accept implements Plan interface.
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func (p *JoinInner) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*JoinInner)
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for i, in := range p.Inners {
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x, ok := in.Accept(v)
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if !ok {
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return p, false
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}
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p.Inners[i] = x
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}
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return v.Leave(p)
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}
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// SelectLock represents a select lock plan.
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type SelectLock struct {
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planWithSrc
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Lock ast.SelectLockType
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}
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// Accept implements Plan Accept interface.
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func (p *SelectLock) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*SelectLock)
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var ok bool
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p.src, ok = p.src.Accept(v)
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if !ok {
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return p, false
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}
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return v.Leave(p)
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}
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// SetLimit implements Plan SetLimit interface.
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func (p *SelectLock) SetLimit(limit float64) {
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p.limit = limit
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p.src.SetLimit(p.limit)
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}
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// SelectFields represents a select fields plan.
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type SelectFields struct {
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planWithSrc
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}
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// Accept implements Plan Accept interface.
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func (p *SelectFields) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*SelectFields)
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if p.src != nil {
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var ok bool
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p.src, ok = p.src.Accept(v)
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if !ok {
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return p, false
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}
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}
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return v.Leave(p)
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}
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// SetLimit implements Plan SetLimit interface.
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func (p *SelectFields) SetLimit(limit float64) {
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p.limit = limit
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if p.src != nil {
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p.src.SetLimit(limit)
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}
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}
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// Sort represents a sorting plan.
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type Sort struct {
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planWithSrc
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ByItems []*ast.ByItem
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}
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// Accept implements Plan Accept interface.
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func (p *Sort) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*Sort)
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var ok bool
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p.src, ok = p.src.Accept(v)
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if !ok {
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return p, false
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}
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return v.Leave(p)
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}
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// SetLimit implements Plan SetLimit interface.
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// It set the Src limit only if it is bypassed.
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// Bypass has to be determined before this get called.
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func (p *Sort) SetLimit(limit float64) {
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p.limit = limit
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}
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// Limit represents offset and limit plan.
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type Limit struct {
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planWithSrc
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Offset uint64
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Count uint64
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}
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// Accept implements Plan Accept interface.
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func (p *Limit) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*Limit)
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var ok bool
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p.src, ok = p.src.Accept(v)
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if !ok {
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return p, false
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}
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return v.Leave(p)
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}
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// SetLimit implements Plan SetLimit interface.
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// As Limit itself determine the real limit,
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// We just ignore the input, and set the real limit.
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func (p *Limit) SetLimit(limit float64) {
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p.limit = float64(p.Offset + p.Count)
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p.src.SetLimit(p.limit)
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}
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// Union represents Union plan.
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type Union struct {
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basePlan
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Selects []Plan
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}
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// Accept implements Plan Accept interface.
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func (p *Union) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(p)
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}
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p = np.(*Union)
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for i, sel := range p.Selects {
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var ok bool
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p.Selects[i], ok = sel.Accept(v)
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if !ok {
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return p, false
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}
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}
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return v.Leave(p)
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}
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// Distinct represents Distinct plan.
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type Distinct struct {
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planWithSrc
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}
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// Accept implements Plan Accept interface.
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func (p *Distinct) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(p)
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}
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p = np.(*Distinct)
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var ok bool
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p.src, ok = p.src.Accept(v)
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if !ok {
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return p, false
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}
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return v.Leave(p)
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}
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// SetLimit implements Plan SetLimit interface.
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func (p *Distinct) SetLimit(limit float64) {
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p.limit = limit
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if p.src != nil {
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p.src.SetLimit(limit)
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}
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}
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// Prepare represents prepare plan.
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type Prepare struct {
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basePlan
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Name string
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SQLText string
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}
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// Accept implements Plan Accept interface.
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func (p *Prepare) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*Prepare)
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return v.Leave(p)
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}
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// Execute represents prepare plan.
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type Execute struct {
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basePlan
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Name string
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UsingVars []ast.ExprNode
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ID uint32
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}
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// Accept implements Plan Accept interface.
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func (p *Execute) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*Execute)
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return v.Leave(p)
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}
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// Deallocate represents deallocate plan.
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type Deallocate struct {
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basePlan
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Name string
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}
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// Accept implements Plan Accept interface.
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func (p *Deallocate) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*Deallocate)
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return v.Leave(p)
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}
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// Aggregate represents a select fields plan.
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type Aggregate struct {
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planWithSrc
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AggFuncs []*ast.AggregateFuncExpr
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GroupByItems []*ast.ByItem
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}
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// Accept implements Plan Accept interface.
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func (p *Aggregate) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*Aggregate)
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if p.src != nil {
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var ok bool
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p.src, ok = p.src.Accept(v)
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if !ok {
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return p, false
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}
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}
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return v.Leave(p)
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}
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// SetLimit implements Plan SetLimit interface.
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func (p *Aggregate) SetLimit(limit float64) {
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p.limit = limit
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if p.src != nil {
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p.src.SetLimit(limit)
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}
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}
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// Having represents a having plan.
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// The having plan should after aggregate plan.
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type Having struct {
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planWithSrc
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// Originally the WHERE or ON condition is parsed into a single expression,
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// but after we converted to CNF(Conjunctive normal form), it can be
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// split into a list of AND conditions.
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Conditions []ast.ExprNode
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}
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// Accept implements Plan Accept interface.
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func (p *Having) Accept(v Visitor) (Plan, bool) {
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np, skip := v.Enter(p)
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if skip {
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return v.Leave(np)
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}
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p = np.(*Having)
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var ok bool
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p.src, ok = p.src.Accept(v)
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if !ok {
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return p, false
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}
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return v.Leave(p)
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}
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// SetLimit implements Plan SetLimit interface.
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func (p *Having) SetLimit(limit float64) {
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p.limit = limit
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// We assume 50% of the src row is filtered out.
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p.src.SetLimit(limit * 2)
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}
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// Update represents an update plan.
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type Update struct {
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basePlan
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OrderedList []*ast.Assignment // OrderedList has the same offset as TablePlan's result fields.
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SelectPlan Plan
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}
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||
|
// Accept implements Plan Accept interface.
|
||
|
func (p *Update) Accept(v Visitor) (Plan, bool) {
|
||
|
np, skip := v.Enter(p)
|
||
|
if skip {
|
||
|
return v.Leave(np)
|
||
|
}
|
||
|
p = np.(*Update)
|
||
|
var ok bool
|
||
|
p.SelectPlan, ok = p.SelectPlan.Accept(v)
|
||
|
if !ok {
|
||
|
return p, false
|
||
|
}
|
||
|
return v.Leave(p)
|
||
|
}
|
||
|
|
||
|
// Delete represents a delete plan.
|
||
|
type Delete struct {
|
||
|
basePlan
|
||
|
|
||
|
SelectPlan Plan
|
||
|
Tables []*ast.TableName
|
||
|
IsMultiTable bool
|
||
|
}
|
||
|
|
||
|
// Accept implements Plan Accept interface.
|
||
|
func (p *Delete) Accept(v Visitor) (Plan, bool) {
|
||
|
np, skip := v.Enter(p)
|
||
|
if skip {
|
||
|
return v.Leave(np)
|
||
|
}
|
||
|
p = np.(*Delete)
|
||
|
var ok bool
|
||
|
p.SelectPlan, ok = p.SelectPlan.Accept(v)
|
||
|
if !ok {
|
||
|
return p, false
|
||
|
}
|
||
|
return v.Leave(p)
|
||
|
}
|
||
|
|
||
|
// Filter represents a plan that filter srcplan result.
|
||
|
type Filter struct {
|
||
|
planWithSrc
|
||
|
|
||
|
// Originally the WHERE or ON condition is parsed into a single expression,
|
||
|
// but after we converted to CNF(Conjunctive normal form), it can be
|
||
|
// split into a list of AND conditions.
|
||
|
Conditions []ast.ExprNode
|
||
|
}
|
||
|
|
||
|
// Accept implements Plan Accept interface.
|
||
|
func (p *Filter) Accept(v Visitor) (Plan, bool) {
|
||
|
np, skip := v.Enter(p)
|
||
|
if skip {
|
||
|
return v.Leave(np)
|
||
|
}
|
||
|
p = np.(*Filter)
|
||
|
var ok bool
|
||
|
p.src, ok = p.src.Accept(v)
|
||
|
if !ok {
|
||
|
return p, false
|
||
|
}
|
||
|
return v.Leave(p)
|
||
|
}
|
||
|
|
||
|
// SetLimit implements Plan SetLimit interface.
|
||
|
func (p *Filter) SetLimit(limit float64) {
|
||
|
p.limit = limit
|
||
|
// We assume 50% of the src row is filtered out.
|
||
|
p.src.SetLimit(limit * 2)
|
||
|
}
|
||
|
|
||
|
// Show represents a show plan.
|
||
|
type Show struct {
|
||
|
basePlan
|
||
|
|
||
|
Tp ast.ShowStmtType // Databases/Tables/Columns/....
|
||
|
DBName string
|
||
|
Table *ast.TableName // Used for showing columns.
|
||
|
Column *ast.ColumnName // Used for `desc table column`.
|
||
|
Flag int // Some flag parsed from sql, such as FULL.
|
||
|
Full bool
|
||
|
User string // Used for show grants.
|
||
|
|
||
|
// Used by show variables
|
||
|
GlobalScope bool
|
||
|
}
|
||
|
|
||
|
// Accept implements Plan Accept interface.
|
||
|
func (p *Show) Accept(v Visitor) (Plan, bool) {
|
||
|
np, skip := v.Enter(p)
|
||
|
if skip {
|
||
|
return v.Leave(np)
|
||
|
}
|
||
|
p = np.(*Show)
|
||
|
return v.Leave(p)
|
||
|
}
|
||
|
|
||
|
// Simple represents a simple statement plan which doesn't need any optimization.
|
||
|
type Simple struct {
|
||
|
basePlan
|
||
|
|
||
|
Statement ast.StmtNode
|
||
|
}
|
||
|
|
||
|
// Accept implements Plan Accept interface.
|
||
|
func (p *Simple) Accept(v Visitor) (Plan, bool) {
|
||
|
np, skip := v.Enter(p)
|
||
|
if skip {
|
||
|
return v.Leave(np)
|
||
|
}
|
||
|
p = np.(*Simple)
|
||
|
return v.Leave(p)
|
||
|
}
|
||
|
|
||
|
// Insert represents an insert plan.
|
||
|
type Insert struct {
|
||
|
basePlan
|
||
|
|
||
|
Table *ast.TableRefsClause
|
||
|
Columns []*ast.ColumnName
|
||
|
Lists [][]ast.ExprNode
|
||
|
Setlist []*ast.Assignment
|
||
|
OnDuplicate []*ast.Assignment
|
||
|
SelectPlan Plan
|
||
|
|
||
|
IsReplace bool
|
||
|
Priority int
|
||
|
}
|
||
|
|
||
|
// Accept implements Plan Accept interface.
|
||
|
func (p *Insert) Accept(v Visitor) (Plan, bool) {
|
||
|
np, skip := v.Enter(p)
|
||
|
if skip {
|
||
|
return v.Leave(np)
|
||
|
}
|
||
|
p = np.(*Insert)
|
||
|
if p.SelectPlan != nil {
|
||
|
var ok bool
|
||
|
p.SelectPlan, ok = p.SelectPlan.Accept(v)
|
||
|
if !ok {
|
||
|
return p, false
|
||
|
}
|
||
|
}
|
||
|
return v.Leave(p)
|
||
|
}
|
||
|
|
||
|
// DDL represents a DDL statement plan.
|
||
|
type DDL struct {
|
||
|
basePlan
|
||
|
|
||
|
Statement ast.DDLNode
|
||
|
}
|
||
|
|
||
|
// Accept implements Plan Accept interface.
|
||
|
func (p *DDL) Accept(v Visitor) (Plan, bool) {
|
||
|
np, skip := v.Enter(p)
|
||
|
if skip {
|
||
|
return v.Leave(np)
|
||
|
}
|
||
|
p = np.(*DDL)
|
||
|
return v.Leave(p)
|
||
|
}
|
||
|
|
||
|
// Explain represents a explain plan.
|
||
|
type Explain struct {
|
||
|
basePlan
|
||
|
|
||
|
StmtPlan Plan
|
||
|
}
|
||
|
|
||
|
// Accept implements Plan Accept interface.
|
||
|
func (p *Explain) Accept(v Visitor) (Plan, bool) {
|
||
|
np, skip := v.Enter(p)
|
||
|
if skip {
|
||
|
v.Leave(np)
|
||
|
}
|
||
|
p = np.(*Explain)
|
||
|
return v.Leave(p)
|
||
|
}
|