/
query_impl.go
127 lines (109 loc) · 2.21 KB
/
query_impl.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
package query
func DerivedResults(qr Results, ch <-chan Result) Results {
return &results{
query: qr.Query(),
proc: qr.Process(),
res: ch,
}
}
// NaiveFilter applies a filter to the results.
func NaiveFilter(qr Results, filter Filter) Results {
ch := make(chan Result)
go func() {
defer close(ch)
defer qr.Close()
for e := range qr.Next() {
if e.Error != nil || filter.Filter(e.Entry) {
ch <- e
}
}
}()
return DerivedResults(qr, ch)
}
// NaiveLimit truncates the results to a given int limit
func NaiveLimit(qr Results, limit int) Results {
ch := make(chan Result)
go func() {
defer close(ch)
defer qr.Close()
l := 0
for e := range qr.Next() {
if e.Error != nil {
ch <- e
continue
}
ch <- e
l++
if limit > 0 && l >= limit {
break
}
}
}()
return DerivedResults(qr, ch)
}
// NaiveOffset skips a given number of results
func NaiveOffset(qr Results, offset int) Results {
ch := make(chan Result)
go func() {
defer close(ch)
defer qr.Close()
sent := 0
for e := range qr.Next() {
if e.Error != nil {
ch <- e
}
if sent < offset {
sent++
continue
}
ch <- e
}
}()
return DerivedResults(qr, ch)
}
// NaiveOrder reorders results according to given Order.
// WARNING: this is the only non-stream friendly operation!
func NaiveOrder(qr Results, o Order) Results {
ch := make(chan Result)
var entries []Entry
go func() {
defer close(ch)
defer qr.Close()
for e := range qr.Next() {
if e.Error != nil {
ch <- e
}
entries = append(entries, e.Entry)
}
o.Sort(entries)
for _, e := range entries {
ch <- Result{Entry: e}
}
}()
return DerivedResults(qr, ch)
}
func NaiveQueryApply(q Query, qr Results) Results {
if q.Prefix != "" {
qr = NaiveFilter(qr, FilterKeyPrefix{q.Prefix})
}
for _, f := range q.Filters {
qr = NaiveFilter(qr, f)
}
for _, o := range q.Orders {
qr = NaiveOrder(qr, o)
}
if q.Offset != 0 {
qr = NaiveOffset(qr, q.Offset)
}
if q.Limit != 0 {
qr = NaiveLimit(qr, q.Offset)
}
return qr
}
func ResultEntriesFrom(keys []string, vals []interface{}) []Entry {
re := make([]Entry, len(keys))
for i, k := range keys {
re[i] = Entry{Key: k, Value: vals[i]}
}
return re
}