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| 1 | +// Copyright 2018 The Redix Authors. All rights reserved. |
| 2 | +// Use of this source code is governed by a Apache 2.0 |
| 3 | +// license that can be found in the LICENSE file. |
| 4 | +// |
| 5 | +// leveldb is a db engine based on leveldb |
| 6 | +package leveldb |
| 7 | + |
| 8 | +import ( |
| 9 | + "bytes" |
| 10 | + "errors" |
| 11 | + "fmt" |
| 12 | + "strconv" |
| 13 | + "strings" |
| 14 | + "sync" |
| 15 | + "time" |
| 16 | + |
| 17 | + "github.com/alash3al/redix/kvstore" |
| 18 | + "github.com/syndtr/goleveldb/leveldb" |
| 19 | + "github.com/syndtr/goleveldb/leveldb/iterator" |
| 20 | + "github.com/syndtr/goleveldb/leveldb/util" |
| 21 | +) |
| 22 | + |
| 23 | +// LevelDB - represents a leveldb db implementation |
| 24 | +type LevelDB struct { |
| 25 | + db *leveldb.DB |
| 26 | + sync.RWMutex |
| 27 | +} |
| 28 | + |
| 29 | +// OpenLevelDB - Opens the specified path |
| 30 | +func OpenLevelDB(path string) (*LevelDB, error) { |
| 31 | + db, err := leveldb.OpenFile(path, nil) |
| 32 | + |
| 33 | + if err != nil { |
| 34 | + return nil, err |
| 35 | + } |
| 36 | + |
| 37 | + ldb := new(LevelDB) |
| 38 | + ldb.db = db |
| 39 | + |
| 40 | + return ldb, nil |
| 41 | +} |
| 42 | + |
| 43 | +// Size - returns the size of the database in bytes |
| 44 | +func (ldb *LevelDB) Size() int64 { |
| 45 | + ldb.RLock() |
| 46 | + defer ldb.RUnlock() |
| 47 | + |
| 48 | + // TODO need to find efficiency method stat dbsize |
| 49 | + return int64(0) |
| 50 | +} |
| 51 | + |
| 52 | +// GC - runs the garbage collector |
| 53 | +func (ldb *LevelDB) GC() error { |
| 54 | + return nil |
| 55 | +} |
| 56 | + |
| 57 | +// Incr - increment the key by the specified value |
| 58 | +func (ldb *LevelDB) Incr(k string, by int64) (int64, error) { |
| 59 | + ldb.Lock() |
| 60 | + defer ldb.Unlock() |
| 61 | + |
| 62 | + val, err := ldb.get(k) |
| 63 | + if err != nil { |
| 64 | + val = "" |
| 65 | + } |
| 66 | + |
| 67 | + valFloat, _ := strconv.ParseInt(val, 10, 64) |
| 68 | + valFloat += by |
| 69 | + |
| 70 | + err = ldb.set(k, fmt.Sprintf("%d", valFloat), -1) |
| 71 | + if err != nil { |
| 72 | + return 0, err |
| 73 | + } |
| 74 | + |
| 75 | + return valFloat, nil |
| 76 | +} |
| 77 | + |
| 78 | +func (ldb *LevelDB) set(k, v string, ttl int) error { |
| 79 | + var expires int64 |
| 80 | + if ttl > 0 { |
| 81 | + expires = time.Now().Add(time.Duration(ttl) * time.Millisecond).Unix() |
| 82 | + } |
| 83 | + v = strconv.Itoa(int(expires)) + ";" + v |
| 84 | + return ldb.db.Put([]byte(k), []byte(v), nil) |
| 85 | +} |
| 86 | + |
| 87 | +// Set - sets a key with the specified value and optional ttl |
| 88 | +func (ldb *LevelDB) Set(k, v string, ttl int) error { |
| 89 | + ldb.Lock() |
| 90 | + defer ldb.Unlock() |
| 91 | + |
| 92 | + return ldb.set(k, v, ttl) |
| 93 | +} |
| 94 | + |
| 95 | +// MSet - sets multiple key-value pairs |
| 96 | +func (ldb *LevelDB) MSet(data map[string]string) error { |
| 97 | + ldb.Lock() |
| 98 | + defer ldb.Unlock() |
| 99 | + |
| 100 | + batch := new(leveldb.Batch) |
| 101 | + for k, v := range data { |
| 102 | + v = "0;" + v |
| 103 | + batch.Put([]byte(k), []byte(v)) |
| 104 | + } |
| 105 | + |
| 106 | + return ldb.db.Write(batch, nil) |
| 107 | +} |
| 108 | + |
| 109 | +func (ldb *LevelDB) get(k string) (string, error) { |
| 110 | + var data string |
| 111 | + var err error |
| 112 | + |
| 113 | + delete := false |
| 114 | + |
| 115 | + item, err := ldb.db.Get([]byte(k), nil) |
| 116 | + if err != nil { |
| 117 | + return "", err |
| 118 | + } |
| 119 | + |
| 120 | + parts := strings.SplitN(string(item), ";", 2) |
| 121 | + expires, actual := parts[0], parts[1] |
| 122 | + |
| 123 | + if exp, _ := strconv.Atoi(expires); exp > 0 && int(time.Now().Unix()) >= exp { |
| 124 | + delete = true |
| 125 | + err = errors.New("key not found") |
| 126 | + } else { |
| 127 | + data = actual |
| 128 | + } |
| 129 | + |
| 130 | + if delete { |
| 131 | + ldb.db.Delete([]byte(k), nil) |
| 132 | + return data, errors.New("key not found") |
| 133 | + } |
| 134 | + |
| 135 | + return data, nil |
| 136 | +} |
| 137 | + |
| 138 | +// Get - fetches the value of the specified k |
| 139 | +func (ldb *LevelDB) Get(k string) (string, error) { |
| 140 | + ldb.RLock() |
| 141 | + defer ldb.RUnlock() |
| 142 | + |
| 143 | + return ldb.get(k) |
| 144 | +} |
| 145 | + |
| 146 | +// MGet - fetch multiple values of the specified keys |
| 147 | +func (ldb *LevelDB) MGet(keys []string) (data []string) { |
| 148 | + ldb.RLock() |
| 149 | + defer ldb.RUnlock() |
| 150 | + |
| 151 | + for _, key := range keys { |
| 152 | + val, err := ldb.get(key) |
| 153 | + if err != nil { |
| 154 | + data = append(data, "") |
| 155 | + continue |
| 156 | + } |
| 157 | + data = append(data, val) |
| 158 | + } |
| 159 | + return data |
| 160 | +} |
| 161 | + |
| 162 | +// TTL - returns the time to live of the specified key's value |
| 163 | +func (ldb *LevelDB) TTL(key string) int64 { |
| 164 | + ldb.RLock() |
| 165 | + defer ldb.RUnlock() |
| 166 | + |
| 167 | + item, err := ldb.db.Get([]byte(key), nil) |
| 168 | + if err != nil { |
| 169 | + return -2 |
| 170 | + } |
| 171 | + |
| 172 | + parts := strings.SplitN(string(item), ";", 2) |
| 173 | + exp, _ := strconv.Atoi(parts[0]) |
| 174 | + if exp == 0 { |
| 175 | + return -1 |
| 176 | + } |
| 177 | + |
| 178 | + if int(time.Now().Unix()) >= exp { |
| 179 | + return -2 |
| 180 | + } |
| 181 | + |
| 182 | + return int64(exp) |
| 183 | +} |
| 184 | + |
| 185 | +// Del - removes key(s) from the store |
| 186 | +func (ldb *LevelDB) Del(keys []string) error { |
| 187 | + ldb.Lock() |
| 188 | + defer ldb.Unlock() |
| 189 | + |
| 190 | + batch := new(leveldb.Batch) |
| 191 | + for _, key := range keys { |
| 192 | + batch.Delete([]byte(key)) |
| 193 | + } |
| 194 | + |
| 195 | + return ldb.db.Write(batch, nil) |
| 196 | +} |
| 197 | + |
| 198 | +// Scan - iterate over the whole store using the handler function |
| 199 | +func (ldb *LevelDB) Scan(scannerOpt kvstore.ScannerOptions) error { |
| 200 | + ldb.RLock() |
| 201 | + defer ldb.RUnlock() |
| 202 | + |
| 203 | + var iter iterator.Iterator |
| 204 | + |
| 205 | + if scannerOpt.Offset == "" { |
| 206 | + iter = ldb.db.NewIterator(nil, nil) |
| 207 | + } else { |
| 208 | + iter = ldb.db.NewIterator(&util.Range{Start: []byte(scannerOpt.Offset)}, nil) |
| 209 | + if !scannerOpt.IncludeOffset { |
| 210 | + iter.Next() |
| 211 | + } |
| 212 | + } |
| 213 | + |
| 214 | + valid := func(k []byte) bool { |
| 215 | + if k == nil { |
| 216 | + return false |
| 217 | + } |
| 218 | + |
| 219 | + if scannerOpt.Prefix != "" && !bytes.HasPrefix(k, []byte(scannerOpt.Prefix)) { |
| 220 | + return false |
| 221 | + } |
| 222 | + |
| 223 | + return true |
| 224 | + } |
| 225 | + |
| 226 | + for iter.Next() { |
| 227 | + key := iter.Key() |
| 228 | + val := strings.SplitN(string(iter.Value()), ";", 2)[1] |
| 229 | + if valid(key) && !scannerOpt.Handler(string(key), string(val)) { |
| 230 | + break |
| 231 | + } |
| 232 | + } |
| 233 | + iter.Release() |
| 234 | + |
| 235 | + return iter.Error() |
| 236 | +} |
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