forked from decred/dcrdata
-
Notifications
You must be signed in to change notification settings - Fork 0
/
arrays.go
131 lines (123 loc) · 2.9 KB
/
arrays.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
// Package internal provides helper functions borrowed from lib/pq's array.go,
// to facilitate the new UInt64Array type.
package internal
import (
"bytes"
"fmt"
"strings"
)
// parseArray extracts the dimensions and elements of an array represented in
// text format. Only representations emitted by the backend are supported.
// Notably, whitespace around brackets and delimiters is significant, and NULL
// is case-sensitive.
//
// See http://www.postgresql.org/docs/current/static/arrays.html#ARRAYS-IO
func parseArray(src, del []byte) (dims []int, elems [][]byte, err error) {
var depth, i int
if len(src) < 1 || src[0] != '{' {
return nil, nil, fmt.Errorf("pq: unable to parse array; expected %q at offset %d", '{', 0)
}
Open:
for i < len(src) {
switch src[i] {
case '{':
depth++
i++
case '}':
elems = make([][]byte, 0)
goto Close
default:
break Open
}
}
dims = make([]int, i)
Element:
for i < len(src) {
switch src[i] {
case '{':
if depth == len(dims) {
break Element
}
depth++
dims[depth-1] = 0
i++
case '"':
var elem = []byte{}
var escape bool
for i++; i < len(src); i++ {
if escape {
elem = append(elem, src[i])
escape = false
} else {
switch src[i] {
default:
elem = append(elem, src[i])
case '\\':
escape = true
case '"':
elems = append(elems, elem)
i++
break Element
}
}
}
default:
for start := i; i < len(src); i++ {
if bytes.HasPrefix(src[i:], del) || src[i] == '}' {
elem := src[start:i]
if len(elem) == 0 {
return nil, nil, fmt.Errorf("pq: unable to parse array; unexpected %q at offset %d", src[i], i)
}
if bytes.Equal(elem, []byte("NULL")) {
elem = nil
}
elems = append(elems, elem)
break Element
}
}
}
}
for i < len(src) {
if bytes.HasPrefix(src[i:], del) && depth > 0 {
dims[depth-1]++
i += len(del)
goto Element
} else if src[i] == '}' && depth > 0 {
dims[depth-1]++
depth--
i++
} else {
return nil, nil, fmt.Errorf("pq: unable to parse array; unexpected %q at offset %d", src[i], i)
}
}
Close:
for i < len(src) {
if src[i] == '}' && depth > 0 {
depth--
i++
} else {
return nil, nil, fmt.Errorf("pq: unable to parse array; unexpected %q at offset %d", src[i], i)
}
}
if depth > 0 {
err = fmt.Errorf("pq: unable to parse array; expected %q at offset %d", '}', i)
}
if err == nil {
for _, d := range dims {
if (len(elems) % d) != 0 {
err = fmt.Errorf("pq: multidimensional arrays must have elements with matching dimensions")
}
}
}
return
}
func ScanLinearArray(src, del []byte, typ string) (elems [][]byte, err error) {
dims, elems, err := parseArray(src, del)
if err != nil {
return nil, err
}
if len(dims) > 1 {
return nil, fmt.Errorf("pq: cannot convert ARRAY%s to %s", strings.Replace(fmt.Sprint(dims), " ", "][", -1), typ)
}
return elems, err
}