-
Notifications
You must be signed in to change notification settings - Fork 0
/
distinctopt.go
executable file
·201 lines (157 loc) · 4.69 KB
/
distinctopt.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
package distinctopt
import (
"reflect"
"time"
"github.com/Vincent20101/mongo-go-driver/core/option"
"github.com/Vincent20101/mongo-go-driver/mongo/mongoopt"
)
var distinctBundle = new(DistinctBundle)
// Distinct is options for the distinct command.
type Distinct interface {
distinct()
ConvertDistinctOption() option.DistinctOptioner
}
// DistinctBundle is a bundle of Distinct options.
type DistinctBundle struct {
option Distinct
next *DistinctBundle
}
func (db *DistinctBundle) distinct() {}
// ConvertDistinctOption implements the Distinct interface
func (db *DistinctBundle) ConvertDistinctOption() option.DistinctOptioner { return nil }
// BundleDistinct bundles Distinct options.
func BundleDistinct(opts ...Distinct) *DistinctBundle {
head := distinctBundle
for _, opt := range opts {
newBundle := DistinctBundle{
option: opt,
next: head,
}
head = &newBundle
}
return head
}
// Collation adds an option to specify a collation.
func (db *DistinctBundle) Collation(collation *mongoopt.Collation) *DistinctBundle {
bundle := &DistinctBundle{
option: Collation(collation),
next: db,
}
return bundle
}
// MaxTime adds an option to specify the maximum amount of time to allow the query to run.
func (db *DistinctBundle) MaxTime(d time.Duration) *DistinctBundle {
bundle := &DistinctBundle{
option: MaxTime(d),
next: db,
}
return bundle
}
// Unbundle transofrms a bundle into a slice of DistinctOptioner, optionally deduplicating.
func (db *DistinctBundle) Unbundle(deduplicate bool) ([]option.DistinctOptioner, error) {
options, err := db.unbundle()
if err != nil {
return nil, err
}
if !deduplicate {
return options, nil
}
// iterate backwards and make dedup slice
optionsSet := make(map[reflect.Type]struct{})
for i := len(options) - 1; i >= 0; i-- {
currOption := options[i]
optionType := reflect.TypeOf(currOption)
if _, ok := optionsSet[optionType]; ok {
// option already found
options = append(options[:i], options[i+1:]...)
continue
}
optionsSet[optionType] = struct{}{}
}
return options, nil
}
// Calculates the total length of a bundle, accounting for nested bundles.
func (db *DistinctBundle) bundleLength() int {
if db == nil {
return 0
}
bundleLen := 0
for ; db != nil && db.option != nil; db = db.next {
if converted, ok := db.option.(*DistinctBundle); ok {
// nested bundle
bundleLen += converted.bundleLength()
continue
}
bundleLen++
}
return bundleLen
}
// Helper that recursively unwraps bundle into slice of options
func (db *DistinctBundle) unbundle() ([]option.DistinctOptioner, error) {
if db == nil {
return nil, nil
}
listLen := db.bundleLength()
options := make([]option.DistinctOptioner, listLen)
index := listLen - 1
for listHead := db; listHead != nil && listHead.option != nil; listHead = listHead.next {
// if the current option is a nested bundle, Unbundle it and add its options to the current array
if converted, ok := listHead.option.(*DistinctBundle); ok {
nestedOptions, err := converted.unbundle()
if err != nil {
return nil, err
}
// where to start inserting nested options
startIndex := index - len(nestedOptions) + 1
// add nested options in order
for _, nestedOp := range nestedOptions {
options[startIndex] = nestedOp
startIndex++
}
index -= len(nestedOptions)
continue
}
options[index] = listHead.option.ConvertDistinctOption()
index--
}
return options, nil
}
// String implements the Stringer interface
func (db *DistinctBundle) String() string {
if db == nil {
return ""
}
str := ""
for head := db; head != nil && head.option != nil; head = head.next {
if converted, ok := head.option.(*DistinctBundle); ok {
str += converted.String()
continue
}
str += head.option.ConvertDistinctOption().String() + "\n"
}
return str
}
// Collation specifies a collation.
func Collation(collation *mongoopt.Collation) OptCollation {
return OptCollation{
Collation: collation.Convert(),
}
}
// MaxTime adds an optin to specify the maximum amount of time to allow the query to run.
func MaxTime(d time.Duration) OptMaxTime {
return OptMaxTime(d)
}
// OptCollation specifies a collation
type OptCollation option.OptCollation
func (OptCollation) distinct() {}
// ConvertDistinctOption implements the Distinct interface.
func (opt OptCollation) ConvertDistinctOption() option.DistinctOptioner {
return option.OptCollation(opt)
}
// OptMaxTime specifies the maximum amount of time to allow the query to run.
type OptMaxTime option.OptMaxTime
func (OptMaxTime) distinct() {}
// ConvertDistinctOption implements the Distinct interface.
func (opt OptMaxTime) ConvertDistinctOption() option.DistinctOptioner {
return option.OptMaxTime(opt)
}