forked from mercari/datastore
/
ops.go
197 lines (167 loc) · 4.83 KB
/
ops.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
package shared
import (
"context"
"errors"
"fmt"
"reflect"
"go.mercari.io/datastore"
)
var typeOfPropertyLoadSaver = reflect.TypeOf((*datastore.PropertyLoadSaver)(nil)).Elem()
var typeOfPropertyList = reflect.TypeOf(datastore.PropertyList(nil))
type getOps func(keys []datastore.Key, dst []datastore.PropertyList) error
type putOps func(keys []datastore.Key, src []datastore.PropertyList) ([]datastore.Key, []datastore.PendingKey, error)
type deleteOps func(keys []datastore.Key) error
type nextOps func(dst *datastore.PropertyList) (datastore.Key, error)
type getAllOps func(dst *[]datastore.PropertyList) ([]datastore.Key, error)
func GetMultiOps(ctx context.Context, keys []datastore.Key, dst interface{}, ops getOps) error {
v := reflect.ValueOf(dst)
if v.Kind() != reflect.Slice {
return errors.New("datastore: dst has invalid type")
}
if len(keys) != v.Len() {
return errors.New("datastore: keys and dst slices have different length")
}
if len(keys) == 0 {
return nil
}
pss := make([]datastore.PropertyList, len(keys))
err := ops(keys, pss)
foundError := false
merr, catchMerr := err.(datastore.MultiError)
if catchMerr {
// ok
if len(merr) != len(keys) {
panic(fmt.Sprintf("unexpected merr length: %d, expected: %d", len(merr), len(keys)))
}
} else if err == nil {
merr = make([]error, len(keys))
} else if err != nil {
return err
}
elemType := v.Type().Elem()
for idx := range keys {
if catchMerr {
err := merr[idx]
if err != nil {
foundError = true
continue
}
}
elem := v.Index(idx)
if reflect.PtrTo(elemType).Implements(typeOfPropertyLoadSaver) {
elem = elem.Addr()
} else if elemType.Kind() == reflect.Struct {
elem = elem.Addr()
} else if elemType.Kind() == reflect.Ptr && elemType.Elem().Kind() == reflect.Struct {
if elem.IsNil() {
elem.Set(reflect.New(elem.Type().Elem()))
}
}
if err = datastore.LoadEntity(ctx, elem.Interface(), &datastore.Entity{Key: keys[idx], Properties: pss[idx]}); err != nil {
merr[idx] = err
foundError = true
}
}
if foundError {
return datastore.MultiError(merr)
}
return nil
}
func PutMultiOps(ctx context.Context, keys []datastore.Key, src interface{}, ops putOps) ([]datastore.Key, []datastore.PendingKey, error) {
v := reflect.ValueOf(src)
if v.Kind() != reflect.Slice {
return nil, nil, errors.New("datastore: src has invalid type")
}
if len(keys) != v.Len() {
return nil, nil, errors.New("datastore: key and src slices have different length")
}
if len(keys) == 0 {
return nil, nil, nil
}
var pss []datastore.PropertyList
for idx, key := range keys {
elem := v.Index(idx)
if reflect.PtrTo(elem.Type()).Implements(typeOfPropertyLoadSaver) || elem.Type().Kind() == reflect.Struct {
elem = elem.Addr()
}
src := elem.Interface()
e, err := datastore.SaveEntity(ctx, key, src)
if err != nil {
return nil, nil, err
}
pss = append(pss, e.Properties)
}
keys, pKeys, err := ops(keys, pss)
if err != nil {
return nil, nil, err
}
return keys, pKeys, nil
}
func DeleteMultiOps(ctx context.Context, keys []datastore.Key, ops deleteOps) error {
return ops(keys)
}
func NextOps(ctx context.Context, qDump *datastore.QueryDump, dst interface{}, ops nextOps) (datastore.Key, error) {
// don't pass nil to ops.
// the true query may not be KeysOnly.
var ps datastore.PropertyList
key, err := ops(&ps)
if err != nil {
return nil, err
}
if !qDump.KeysOnly {
if err = datastore.LoadEntity(ctx, dst, &datastore.Entity{Key: key, Properties: ps}); err != nil {
return key, err
}
}
return key, nil
}
func GetAllOps(ctx context.Context, qDump *datastore.QueryDump, dst interface{}, ops getAllOps) ([]datastore.Key, error) {
var dv reflect.Value
var elemType reflect.Type
var isPtrStruct bool
if !qDump.KeysOnly {
dv = reflect.ValueOf(dst)
if dv.Kind() != reflect.Ptr || dv.IsNil() {
return nil, datastore.ErrInvalidEntityType
}
dv = dv.Elem()
if dv.Kind() != reflect.Slice {
return nil, datastore.ErrInvalidEntityType
}
if dv.Type() == typeOfPropertyList {
return nil, datastore.ErrInvalidEntityType
}
elemType = dv.Type().Elem()
if reflect.PtrTo(elemType).Implements(typeOfPropertyLoadSaver) {
// ok
} else {
switch elemType.Kind() {
case reflect.Ptr:
isPtrStruct = true
elemType = elemType.Elem()
if elemType.Kind() != reflect.Struct {
return nil, datastore.ErrInvalidEntityType
}
}
}
}
// TODO add reflect.Map support
var pss []datastore.PropertyList
keys, err := ops(&pss)
if err != nil {
return nil, err
}
if !qDump.KeysOnly {
for idx, ps := range pss {
elem := reflect.New(elemType)
if err = datastore.LoadEntity(ctx, elem.Interface(), &datastore.Entity{Key: keys[idx], Properties: ps}); err != nil {
return nil, err
}
if !isPtrStruct {
elem = elem.Elem()
}
dv.Set(reflect.Append(dv, elem))
}
}
return keys, nil
}