forked from cockroachdb/cockroach
-
Notifications
You must be signed in to change notification settings - Fork 0
/
filter.go
119 lines (101 loc) · 3.5 KB
/
filter.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
// Copyright 2016 The Cockroach Authors.
//
// Licensed 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.
//
// Author: Raphael 'kena' Poss (knz@cockroachlabs.com)
package sql
import (
"bytes"
"fmt"
"golang.org/x/net/context"
"github.com/cockroachdb/cockroach/pkg/roachpb"
"github.com/cockroachdb/cockroach/pkg/sql/parser"
"github.com/cockroachdb/cockroach/pkg/sql/sqlbase"
)
// filterNode implements a filtering stage. It is intended to be used
// during plan optimizations in order to avoid instantiating a fully
// blown selectTopNode/renderNode pair.
type filterNode struct {
p *planner
source planDataSource
filter parser.TypedExpr
ivarHelper parser.IndexedVarHelper
// support attributes for EXPLAIN(DEBUG)
explain explainMode
debugVals debugValues
}
// IndexedVarEval implements the parser.IndexedVarContainer interface.
func (f *filterNode) IndexedVarEval(idx int, ctx *parser.EvalContext) (parser.Datum, error) {
return f.source.plan.Values()[idx].Eval(ctx)
}
// IndexedVarResolvedType implements the parser.IndexedVarContainer interface.
func (f *filterNode) IndexedVarResolvedType(idx int) parser.Type {
return f.source.info.sourceColumns[idx].Typ
}
// IndexedVarFormat implements the parser.IndexedVarContainer interface.
func (f *filterNode) IndexedVarFormat(buf *bytes.Buffer, fl parser.FmtFlags, idx int) {
f.source.info.FormatVar(buf, fl, idx)
}
// Start implements the planNode interface.
func (f *filterNode) Start(ctx context.Context) error {
return f.source.plan.Start(ctx)
}
// Next implements the planNode interface.
func (f *filterNode) Next(ctx context.Context) (bool, error) {
for {
if next, err := f.source.plan.Next(ctx); !next {
return false, err
}
if f.explain == explainDebug {
f.debugVals = f.source.plan.DebugValues()
if f.debugVals.output != debugValueRow {
// Let the debug values pass through.
return true, nil
}
}
passesFilter, err := sqlbase.RunFilter(f.filter, &f.p.evalCtx)
if err != nil {
return false, err
}
if passesFilter {
return true, nil
} else if f.explain == explainDebug {
// Mark the row as filtered out.
f.debugVals.output = debugValueFiltered
return true, nil
}
// Row was filtered out; grab the next row.
}
}
func (f *filterNode) MarkDebug(mode explainMode) {
if mode != explainDebug {
panic(fmt.Sprintf("unknown debug mode %d", mode))
}
f.explain = mode
f.source.plan.MarkDebug(mode)
}
func (f *filterNode) DebugValues() debugValues {
if f.explain != explainDebug {
panic(fmt.Sprintf("node not in debug mode (mode %d)", f.explain))
}
return f.debugVals
}
func (f *filterNode) Close(ctx context.Context) {
f.source.plan.Close(ctx)
}
func (f *filterNode) Values() parser.Datums { return f.source.plan.Values() }
func (f *filterNode) Columns() sqlbase.ResultColumns { return f.source.plan.Columns() }
func (f *filterNode) Ordering() orderingInfo { return f.source.plan.Ordering() }
func (f *filterNode) Spans(ctx context.Context) (_, _ roachpb.Spans, _ error) {
return f.source.plan.Spans(ctx)
}