103 lines
2.7 KiB
Go
103 lines
2.7 KiB
Go
// 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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"github.com/juju/errors"
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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/util/format"
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"github.com/pingcap/tidb/util/types"
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)
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var (
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_ plan.Plan = (*SelectFinalPlan)(nil)
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)
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// SelectFinalPlan sets info field for resuilt.
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type SelectFinalPlan struct {
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*SelectList
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Src plan.Plan
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infered bool // If result field info is already infered
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}
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// Explain implements the plan.Plan Explain interface.
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func (r *SelectFinalPlan) Explain(w format.Formatter) {
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r.Src.Explain(w)
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if r.HiddenFieldOffset == len(r.Src.GetFields()) {
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// we have no hidden fields, can return.
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return
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}
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w.Format("┌Evaluate\n└Output field names %v\n", field.RFQNames(r.ResultFields[0:r.HiddenFieldOffset]))
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}
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// GetFields implements the plan.Plan GetFields interface.
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func (r *SelectFinalPlan) GetFields() []*field.ResultField {
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return r.ResultFields[0:r.HiddenFieldOffset]
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}
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// Filter implements the plan.Plan Filter interface.
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func (r *SelectFinalPlan) Filter(ctx context.Context, expr expression.Expression) (p plan.Plan, filtered bool, err 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 *SelectFinalPlan) Next(ctx context.Context) (row *plan.Row, err error) {
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// push a new rowStackItem into RowStack
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pushRowStack(ctx, r.SelectList.ResultFields, r.SelectList.FromFields)
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row, err = r.Src.Next(ctx)
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// pop the rowStackItem
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if errPop := popRowStack(ctx); errPop != nil {
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return nil, errors.Wrap(err, errPop)
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}
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if row == nil || err != nil {
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return nil, errors.Trace(err)
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}
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// we should not output hidden fields to client.
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row.Data = row.Data[:r.HiddenFieldOffset]
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for i, o := range row.Data {
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d := types.RawData(o)
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switch v := d.(type) {
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case bool:
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// Convert bool field to int
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if v {
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row.Data[i] = uint8(1)
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} else {
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row.Data[i] = uint8(0)
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}
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default:
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row.Data[i] = d
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}
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}
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if !r.infered {
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setResultFieldInfo(r.ResultFields[0:r.HiddenFieldOffset], row.Data)
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r.infered = true
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}
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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 *SelectFinalPlan) Close() error {
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r.infered = false
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return r.Src.Close()
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}
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