81 lines
2.2 KiB
Go
81 lines
2.2 KiB
Go
// Copyright 2014 The ql Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSES/QL-LICENSE file.
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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 plans
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import (
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"bytes"
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"strings"
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"github.com/pingcap/tidb/context"
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"github.com/pingcap/tidb/expression"
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"github.com/pingcap/tidb/field"
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"github.com/pingcap/tidb/plan"
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"github.com/pingcap/tidb/stmt"
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"github.com/pingcap/tidb/util/format"
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)
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var _ plan.Plan = (*ExplainDefaultPlan)(nil)
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// ExplainDefaultPlan executes the explain statement, and provides debug
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// infomations.
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type ExplainDefaultPlan struct {
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S stmt.Statement
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lines []string
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cursor int
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}
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// Explain implements the plan.Plan Explain interface.
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func (r *ExplainDefaultPlan) Explain(w format.Formatter) {
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// Do nothing
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}
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// GetFields implements the plan.Plan GetFields interface.
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func (r *ExplainDefaultPlan) GetFields() []*field.ResultField {
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return []*field.ResultField{{Name: ""}}
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}
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// Filter implements the plan.Plan Filter interface.
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func (r *ExplainDefaultPlan) Filter(ctx context.Context, expr expression.Expression) (plan.Plan, bool, error) {
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return r, false, nil
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}
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// Next implements plan.Plan Next interface.
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func (r *ExplainDefaultPlan) Next(ctx context.Context) (row *plan.Row, err error) {
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if r.lines == nil {
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var buf bytes.Buffer
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w := format.IndentFormatter(&buf, "│ ")
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r.S.Explain(ctx, w)
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r.lines = strings.Split(string(buf.Bytes()), "\n")
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}
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if r.cursor == len(r.lines)-1 {
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return
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}
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row = &plan.Row{
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Data: []interface{}{r.lines[r.cursor]},
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}
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r.cursor++
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return
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}
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// Close implements plan.Plan Close interface.
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func (r *ExplainDefaultPlan) Close() error {
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r.lines = nil
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r.cursor = 0
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return nil
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}
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