/usr/share/gocode/src/github.com/lunny/nodb/scan.go is in golang-github-lunny-nodb-dev 0.0~git20160621.0.fc1ef06-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | package nodb
import (
"bytes"
"errors"
"regexp"
"github.com/lunny/nodb/store"
)
var errDataType = errors.New("error data type")
var errMetaKey = errors.New("error meta key")
// Seek search the prefix key
func (db *DB) Seek(key []byte) (*store.Iterator, error) {
return db.seek(KVType, key)
}
func (db *DB) seek(dataType byte, key []byte) (*store.Iterator, error) {
var minKey []byte
var err error
if len(key) > 0 {
if err = checkKeySize(key); err != nil {
return nil, err
}
if minKey, err = db.encodeMetaKey(dataType, key); err != nil {
return nil, err
}
} else {
if minKey, err = db.encodeMinKey(dataType); err != nil {
return nil, err
}
}
it := db.bucket.NewIterator()
it.Seek(minKey)
return it, nil
}
func (db *DB) MaxKey() ([]byte, error) {
return db.encodeMaxKey(KVType)
}
func (db *DB) Key(it *store.Iterator) ([]byte, error) {
return db.decodeMetaKey(KVType, it.Key())
}
func (db *DB) scan(dataType byte, key []byte, count int, inclusive bool, match string) ([][]byte, error) {
var minKey, maxKey []byte
var err error
var r *regexp.Regexp
if len(match) > 0 {
if r, err = regexp.Compile(match); err != nil {
return nil, err
}
}
if len(key) > 0 {
if err = checkKeySize(key); err != nil {
return nil, err
}
if minKey, err = db.encodeMetaKey(dataType, key); err != nil {
return nil, err
}
} else {
if minKey, err = db.encodeMinKey(dataType); err != nil {
return nil, err
}
}
if maxKey, err = db.encodeMaxKey(dataType); err != nil {
return nil, err
}
if count <= 0 {
count = defaultScanCount
}
v := make([][]byte, 0, count)
it := db.bucket.NewIterator()
it.Seek(minKey)
if !inclusive {
if it.Valid() && bytes.Equal(it.RawKey(), minKey) {
it.Next()
}
}
for i := 0; it.Valid() && i < count && bytes.Compare(it.RawKey(), maxKey) < 0; it.Next() {
if k, err := db.decodeMetaKey(dataType, it.Key()); err != nil {
continue
} else if r != nil && !r.Match(k) {
continue
} else {
v = append(v, k)
i++
}
}
it.Close()
return v, nil
}
func (db *DB) encodeMinKey(dataType byte) ([]byte, error) {
return db.encodeMetaKey(dataType, nil)
}
func (db *DB) encodeMaxKey(dataType byte) ([]byte, error) {
k, err := db.encodeMetaKey(dataType, nil)
if err != nil {
return nil, err
}
k[len(k)-1] = dataType + 1
return k, nil
}
func (db *DB) encodeMetaKey(dataType byte, key []byte) ([]byte, error) {
switch dataType {
case KVType:
return db.encodeKVKey(key), nil
case LMetaType:
return db.lEncodeMetaKey(key), nil
case HSizeType:
return db.hEncodeSizeKey(key), nil
case ZSizeType:
return db.zEncodeSizeKey(key), nil
case BitMetaType:
return db.bEncodeMetaKey(key), nil
case SSizeType:
return db.sEncodeSizeKey(key), nil
default:
return nil, errDataType
}
}
func (db *DB) decodeMetaKey(dataType byte, ek []byte) ([]byte, error) {
if len(ek) < 2 || ek[0] != db.index || ek[1] != dataType {
return nil, errMetaKey
}
return ek[2:], nil
}
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