forked from pingcap/tidb
-
Notifications
You must be signed in to change notification settings - Fork 0
/
trace.go
131 lines (113 loc) · 3.7 KB
/
trace.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
120
121
122
123
124
125
126
127
128
129
130
131
// Copyright 2018 PingCAP, Inc.
//
// 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,
// See the License for the specific language governing permissions and
// limitations under the License.
package executor
import (
"time"
"github.com/opentracing/basictracer-go"
opentracing "github.com/opentracing/opentracing-go"
"github.com/pingcap/tidb/ast"
plannercore "github.com/pingcap/tidb/planner/core"
"github.com/pingcap/tidb/util/chunk"
"github.com/pingcap/tidb/util/tracing"
"github.com/pkg/errors"
"golang.org/x/net/context"
)
// TraceExec represents a root executor of trace query.
type TraceExec struct {
baseExecutor
// CollectedSpans collects all span during execution. Span is appended via
// callback method which passes into tracer implementation.
CollectedSpans []basictracer.RawSpan
// exhausted being true means there is no more result.
exhausted bool
// stmtNode is the real query ast tree and it is used for building real query's plan.
stmtNode ast.StmtNode
// rootTrace represents root span which is father of all other span.
rootTrace opentracing.Span
builder *executorBuilder
}
// Next executes real query and collects span later.
func (e *TraceExec) Next(ctx context.Context, chk *chunk.Chunk) error {
chk.Reset()
if e.exhausted {
return nil
}
// record how much time was spent for optimizeing plan
optimizeSp := e.rootTrace.Tracer().StartSpan("plan_optimize", opentracing.FollowsFrom(e.rootTrace.Context()))
stmtPlan, err := plannercore.Optimize(e.builder.ctx, e.stmtNode, e.builder.is)
if err != nil {
return err
}
optimizeSp.Finish()
pp, ok := stmtPlan.(plannercore.PhysicalPlan)
if !ok {
return errors.New("cannot cast logical plan to physical plan")
}
// append select executor to trace executor
stmtExec := e.builder.build(pp)
e.rootTrace = tracing.NewRecordedTrace("trace_exec", func(sp basictracer.RawSpan) {
e.CollectedSpans = append(e.CollectedSpans, sp)
})
err = stmtExec.Open(ctx)
if err != nil {
return errors.Trace(err)
}
stmtExecChk := stmtExec.newFirstChunk()
// store span into context
ctx = opentracing.ContextWithSpan(ctx, e.rootTrace)
for {
if err := stmtExec.Next(ctx, stmtExecChk); err != nil {
return errors.Trace(err)
}
if stmtExecChk.NumRows() == 0 {
break
}
}
e.rootTrace.LogKV("event", "tracing completed")
e.rootTrace.Finish()
var rootSpan basictracer.RawSpan
treeSpans := make(map[uint64][]basictracer.RawSpan)
for _, sp := range e.CollectedSpans {
treeSpans[sp.ParentSpanID] = append(treeSpans[sp.ParentSpanID], sp)
// if a span's parentSpanID is 0, then it is root span
// this is by design
if sp.ParentSpanID == 0 {
rootSpan = sp
}
}
dfsTree(rootSpan, treeSpans, "", false, chk)
e.exhausted = true
return nil
}
func dfsTree(span basictracer.RawSpan, tree map[uint64][]basictracer.RawSpan, prefix string, isLast bool, chk *chunk.Chunk) {
suffix := ""
spans := tree[span.Context.SpanID]
var newPrefix string
if span.ParentSpanID == 0 {
newPrefix = prefix
} else {
if len(tree[span.ParentSpanID]) > 0 && !isLast {
suffix = "├─"
newPrefix = prefix + "│ "
} else {
suffix = "└─"
newPrefix = prefix + " "
}
}
chk.AppendString(0, prefix+suffix+span.Operation)
chk.AppendString(1, span.Start.Format(time.StampNano))
chk.AppendString(2, span.Duration.String())
for i, sp := range spans {
dfsTree(sp, tree, newPrefix, i == (len(spans))-1 /*last element of array*/, chk)
}
}