forked from vitessio/vitess
-
Notifications
You must be signed in to change notification settings - Fork 6
/
lookup_hash.go
244 lines (212 loc) · 6.92 KB
/
lookup_hash.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
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
// Copyright 2014, Google Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vindexes
import (
"encoding/json"
"fmt"
)
func init() {
Register("lookup_hash", NewLookupHash)
Register("lookup_hash_unique", NewLookupHashUnique)
}
//====================================================================
// LookupHash defines a vindex that uses a lookup table.
// The table is expected to define the id column as unique. It's
// NonUnique and a Lookup.
type LookupHash struct {
name string
lkp lookup
}
// NewLookupHash creates a LookupHash vindex.
func NewLookupHash(name string, m map[string]string) (Vindex, error) {
lhu := &LookupHash{name: name}
lhu.lkp.Init(m)
return lhu, nil
}
// String returns the name of the vindex.
func (vind *LookupHash) String() string {
return vind.name
}
// Cost returns the cost of this vindex as 20.
func (vind *LookupHash) Cost() int {
return 20
}
// Map returns the corresponding KeyspaceId values for the given ids.
func (vind *LookupHash) Map(vcursor VCursor, ids []interface{}) ([][][]byte, error) {
return vind.lkp.Map2(vcursor, ids)
}
// Verify returns true if id maps to ksid.
func (vind *LookupHash) Verify(vcursor VCursor, id interface{}, ksid []byte) (bool, error) {
return vind.lkp.Verify(vcursor, id, ksid)
}
// Create reserves the id by inserting it into the vindex table.
func (vind *LookupHash) Create(vcursor VCursor, id interface{}, ksid []byte) error {
return vind.lkp.Create(vcursor, id, ksid)
}
// Delete deletes the entry from the vindex table.
func (vind *LookupHash) Delete(vcursor VCursor, ids []interface{}, ksid []byte) error {
return vind.lkp.Delete(vcursor, ids, ksid)
}
// MarshalJSON returns a JSON representation of LookupHash.
func (vind *LookupHash) MarshalJSON() ([]byte, error) {
return json.Marshal(vind.lkp)
}
//====================================================================
// LookupHashUnique defines a vindex that uses a lookup table.
// The table is expected to define the id column as unique. It's
// Unique and a Lookup.
type LookupHashUnique struct {
name string
lkp lookup
}
// NewLookupHashUnique creates a LookupHashUnique vindex.
func NewLookupHashUnique(name string, m map[string]string) (Vindex, error) {
lhu := &LookupHashUnique{name: name}
lhu.lkp.Init(m)
return lhu, nil
}
// String returns the name of the vindex.
func (vind *LookupHashUnique) String() string {
return vind.name
}
// Cost returns the cost of this vindex as 10.
func (vind *LookupHashUnique) Cost() int {
return 10
}
// Map returns the corresponding KeyspaceId values for the given ids.
func (vind *LookupHashUnique) Map(vcursor VCursor, ids []interface{}) ([][]byte, error) {
return vind.lkp.Map1(vcursor, ids)
}
// Verify returns true if id maps to ksid.
func (vind *LookupHashUnique) Verify(vcursor VCursor, id interface{}, ksid []byte) (bool, error) {
return vind.lkp.Verify(vcursor, id, ksid)
}
// Create reserves the id by inserting it into the vindex table.
func (vind *LookupHashUnique) Create(vcursor VCursor, id interface{}, ksid []byte) error {
return vind.lkp.Create(vcursor, id, ksid)
}
// Delete deletes the entry from the vindex table.
func (vind *LookupHashUnique) Delete(vcursor VCursor, ids []interface{}, ksid []byte) error {
return vind.lkp.Delete(vcursor, ids, ksid)
}
// MarshalJSON returns a JSON representation of LookupHashUnique.
func (vind *LookupHashUnique) MarshalJSON() ([]byte, error) {
return json.Marshal(vind.lkp)
}
//====================================================================
// lookup implements the functions for the Lookup vindexes.
type lookup struct {
Table string `json:"table"`
From string `json:"from"`
To string `json:"to"`
sel, ver, ins, del string
}
func (lkp *lookup) Init(m map[string]string) {
t := m["table"]
from := m["from"]
to := m["to"]
lkp.Table = t
lkp.From = from
lkp.To = to
lkp.sel = fmt.Sprintf("select %s from %s where %s = :%s", to, t, from, from)
lkp.ver = fmt.Sprintf("select %s from %s where %s = :%s and %s = :%s", from, t, from, from, to, to)
lkp.ins = fmt.Sprintf("insert into %s(%s, %s) values(:%s, :%s)", t, from, to, from, to)
lkp.del = fmt.Sprintf("delete from %s where %s = :%s and %s = :%s", t, from, from, to, to)
}
// Map1 is for a unique vindex.
func (lkp *lookup) Map1(vcursor VCursor, ids []interface{}) ([][]byte, error) {
out := make([][]byte, 0, len(ids))
for _, id := range ids {
result, err := vcursor.Execute(lkp.sel, map[string]interface{}{
lkp.From: id,
})
if err != nil {
return nil, fmt.Errorf("lookup.Map: %v", err)
}
if len(result.Rows) == 0 {
out = append(out, []byte{})
continue
}
if len(result.Rows) != 1 {
return nil, fmt.Errorf("lookup.Map: unexpected multiple results from vindex %s: %v", lkp.Table, id)
}
num, err := getNumber(result.Rows[0][0].ToNative())
if err != nil {
return nil, fmt.Errorf("lookup.Map: %v", err)
}
out = append(out, vhash(num))
}
return out, nil
}
// Map2 is for a non-unique vindex.
func (lkp *lookup) Map2(vcursor VCursor, ids []interface{}) ([][][]byte, error) {
out := make([][][]byte, 0, len(ids))
for _, id := range ids {
result, err := vcursor.Execute(lkp.sel, map[string]interface{}{
lkp.From: id,
})
if err != nil {
return nil, fmt.Errorf("lookup.Map: %v", err)
}
var ksids [][]byte
for _, row := range result.Rows {
num, err := getNumber(row[0].ToNative())
if err != nil {
return nil, fmt.Errorf("lookup.Map: %v", err)
}
ksids = append(ksids, vhash(num))
}
out = append(out, ksids)
}
return out, nil
}
// Verify returns true if id maps to ksid.
func (lkp *lookup) Verify(vcursor VCursor, id interface{}, ksid []byte) (bool, error) {
val, err := vunhash(ksid)
if err != nil {
return false, fmt.Errorf("lookup.Verify: %v", err)
}
result, err := vcursor.Execute(lkp.ver, map[string]interface{}{
lkp.From: id,
lkp.To: val,
})
if err != nil {
return false, fmt.Errorf("lookup.Verify: %v", err)
}
if len(result.Rows) == 0 {
return false, nil
}
return true, nil
}
// Create creates an association between id and ksid by inserting a row in the vindex table.
func (lkp *lookup) Create(vcursor VCursor, id interface{}, ksid []byte) error {
val, err := vunhash(ksid)
if err != nil {
return fmt.Errorf("lookup.Create: %v", err)
}
if _, err := vcursor.Execute(lkp.ins, map[string]interface{}{
lkp.From: id,
lkp.To: val,
}); err != nil {
return fmt.Errorf("lookup.Create: %v", err)
}
return nil
}
// Delete deletes the association between ids and ksid.
func (lkp *lookup) Delete(vcursor VCursor, ids []interface{}, ksid []byte) error {
val, err := vunhash(ksid)
if err != nil {
return fmt.Errorf("lookup.Delete: %v", err)
}
bindvars := map[string]interface{}{
lkp.To: val,
}
for _, id := range ids {
bindvars[lkp.From] = id
if _, err := vcursor.Execute(lkp.del, bindvars); err != nil {
return fmt.Errorf("lookup.Delete: %v", err)
}
}
return nil
}