/
system_tables.go
134 lines (115 loc) · 4.21 KB
/
system_tables.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
132
133
134
/*
Copyright 2022 The Vitess 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.
*/
package physical
import (
"strings"
"vitess.io/vitess/go/mysql/collations"
"vitess.io/vitess/go/sqltypes"
vtrpcpb "vitess.io/vitess/go/vt/proto/vtrpc"
"vitess.io/vitess/go/vt/sqlparser"
"vitess.io/vitess/go/vt/vterrors"
"vitess.io/vitess/go/vt/vtgate/evalengine"
)
func (rp *Route) findSysInfoRoutingPredicatesGen4(predicates []sqlparser.Expr, reservedVars *sqlparser.ReservedVars) error {
for _, pred := range predicates {
isTableSchema, bvName, out, err := extractInfoSchemaRoutingPredicate(pred, reservedVars)
if err != nil {
return err
}
if out == nil {
// we didn't find a predicate to use for routing, continue to look for next predicate
continue
}
if isTableSchema {
rp.SysTableTableSchema = append(rp.SysTableTableSchema, out)
} else {
if rp.SysTableTableName == nil {
rp.SysTableTableName = map[string]evalengine.Expr{}
}
rp.SysTableTableName[bvName] = out
}
}
return nil
}
func extractInfoSchemaRoutingPredicate(in sqlparser.Expr, reservedVars *sqlparser.ReservedVars) (bool, string, evalengine.Expr, error) {
switch cmp := in.(type) {
case *sqlparser.ComparisonExpr:
if cmp.Operator == sqlparser.EqualOp {
isSchemaName, col, other, replaceOther := findOtherComparator(cmp)
if col != nil && shouldRewrite(other) {
evalExpr, err := evalengine.Translate(other, ¬ImplementedSchemaInfoConverter{})
if err != nil {
if strings.Contains(err.Error(), evalengine.ErrTranslateExprNotSupported) {
// This just means we can't rewrite this particular expression,
// not that we have to exit altogether
return false, "", nil, nil
}
return false, "", nil, err
}
var name string
if isSchemaName {
name = sqltypes.BvSchemaName
} else {
name = reservedVars.ReserveColName(col.(*sqlparser.ColName))
}
replaceOther(sqlparser.NewArgument(name))
return isSchemaName, name, evalExpr, nil
}
}
}
return false, "", nil, nil
}
func findOtherComparator(cmp *sqlparser.ComparisonExpr) (bool, sqlparser.Expr, sqlparser.Expr, func(arg sqlparser.Argument)) {
if schema, table := isTableSchemaOrName(cmp.Left); schema || table {
return schema, cmp.Left, cmp.Right, func(arg sqlparser.Argument) {
cmp.Right = arg
}
}
if schema, table := isTableSchemaOrName(cmp.Right); schema || table {
return schema, cmp.Right, cmp.Left, func(arg sqlparser.Argument) {
cmp.Left = arg
}
}
return false, nil, nil, nil
}
func shouldRewrite(e sqlparser.Expr) bool {
switch node := e.(type) {
case *sqlparser.FuncExpr:
// we should not rewrite database() calls against information_schema
return !(node.Name.EqualString("database") || node.Name.EqualString("schema"))
}
return true
}
func isTableSchemaOrName(e sqlparser.Expr) (isTableSchema bool, isTableName bool) {
col, ok := e.(*sqlparser.ColName)
if !ok {
return false, false
}
return isDbNameCol(col), isTableNameCol(col)
}
func isDbNameCol(col *sqlparser.ColName) bool {
return col.Name.EqualString("table_schema") || col.Name.EqualString("constraint_schema") || col.Name.EqualString("schema_name") || col.Name.EqualString("routine_schema")
}
func isTableNameCol(col *sqlparser.ColName) bool {
return col.Name.EqualString("table_name")
}
type notImplementedSchemaInfoConverter struct{}
func (f *notImplementedSchemaInfoConverter) ColumnLookup(*sqlparser.ColName) (int, error) {
return 0, vterrors.Errorf(vtrpcpb.Code_UNIMPLEMENTED, "Comparing table schema name with a column name not yet supported")
}
func (f *notImplementedSchemaInfoConverter) CollationForExpr(sqlparser.Expr) collations.ID {
return collations.Unknown
}
func (f *notImplementedSchemaInfoConverter) DefaultCollation() collations.ID {
return collations.Default()
}