forgejo-federation/vendor/github.com/lunny/nodb/t_kv.go

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2019-02-05 22:22:51 +05:30
package nodb
import (
"errors"
"time"
)
type KVPair struct {
Key []byte
Value []byte
}
var errKVKey = errors.New("invalid encode kv key")
func checkKeySize(key []byte) error {
if len(key) > MaxKeySize || len(key) == 0 {
return errKeySize
}
return nil
}
func checkValueSize(value []byte) error {
if len(value) > MaxValueSize {
return errValueSize
}
return nil
}
func (db *DB) encodeKVKey(key []byte) []byte {
ek := make([]byte, len(key)+2)
ek[0] = db.index
ek[1] = KVType
copy(ek[2:], key)
return ek
}
func (db *DB) decodeKVKey(ek []byte) ([]byte, error) {
if len(ek) < 2 || ek[0] != db.index || ek[1] != KVType {
return nil, errKVKey
}
return ek[2:], nil
}
func (db *DB) encodeKVMinKey() []byte {
ek := db.encodeKVKey(nil)
return ek
}
func (db *DB) encodeKVMaxKey() []byte {
ek := db.encodeKVKey(nil)
ek[len(ek)-1] = KVType + 1
return ek
}
func (db *DB) incr(key []byte, delta int64) (int64, error) {
if err := checkKeySize(key); err != nil {
return 0, err
}
var err error
key = db.encodeKVKey(key)
t := db.kvBatch
t.Lock()
defer t.Unlock()
var n int64
n, err = StrInt64(db.bucket.Get(key))
if err != nil {
return 0, err
}
n += delta
t.Put(key, StrPutInt64(n))
//todo binlog
err = t.Commit()
return n, err
}
// ps : here just focus on deleting the key-value data,
// any other likes expire is ignore.
func (db *DB) delete(t *batch, key []byte) int64 {
key = db.encodeKVKey(key)
t.Delete(key)
return 1
}
func (db *DB) setExpireAt(key []byte, when int64) (int64, error) {
t := db.kvBatch
t.Lock()
defer t.Unlock()
if exist, err := db.Exists(key); err != nil || exist == 0 {
return 0, err
} else {
db.expireAt(t, KVType, key, when)
if err := t.Commit(); err != nil {
return 0, err
}
}
return 1, nil
}
func (db *DB) Decr(key []byte) (int64, error) {
return db.incr(key, -1)
}
func (db *DB) DecrBy(key []byte, decrement int64) (int64, error) {
return db.incr(key, -decrement)
}
func (db *DB) Del(keys ...[]byte) (int64, error) {
if len(keys) == 0 {
return 0, nil
}
codedKeys := make([][]byte, len(keys))
for i, k := range keys {
codedKeys[i] = db.encodeKVKey(k)
}
t := db.kvBatch
t.Lock()
defer t.Unlock()
for i, k := range keys {
t.Delete(codedKeys[i])
db.rmExpire(t, KVType, k)
}
err := t.Commit()
return int64(len(keys)), err
}
func (db *DB) Exists(key []byte) (int64, error) {
if err := checkKeySize(key); err != nil {
return 0, err
}
var err error
key = db.encodeKVKey(key)
var v []byte
v, err = db.bucket.Get(key)
if v != nil && err == nil {
return 1, nil
}
return 0, err
}
func (db *DB) Get(key []byte) ([]byte, error) {
if err := checkKeySize(key); err != nil {
return nil, err
}
key = db.encodeKVKey(key)
return db.bucket.Get(key)
}
func (db *DB) GetSet(key []byte, value []byte) ([]byte, error) {
if err := checkKeySize(key); err != nil {
return nil, err
} else if err := checkValueSize(value); err != nil {
return nil, err
}
key = db.encodeKVKey(key)
t := db.kvBatch
t.Lock()
defer t.Unlock()
oldValue, err := db.bucket.Get(key)
if err != nil {
return nil, err
}
t.Put(key, value)
//todo, binlog
err = t.Commit()
return oldValue, err
}
func (db *DB) Incr(key []byte) (int64, error) {
return db.incr(key, 1)
}
func (db *DB) IncrBy(key []byte, increment int64) (int64, error) {
return db.incr(key, increment)
}
func (db *DB) MGet(keys ...[]byte) ([][]byte, error) {
values := make([][]byte, len(keys))
it := db.bucket.NewIterator()
defer it.Close()
for i := range keys {
if err := checkKeySize(keys[i]); err != nil {
return nil, err
}
values[i] = it.Find(db.encodeKVKey(keys[i]))
}
return values, nil
}
func (db *DB) MSet(args ...KVPair) error {
if len(args) == 0 {
return nil
}
t := db.kvBatch
var err error
var key []byte
var value []byte
t.Lock()
defer t.Unlock()
for i := 0; i < len(args); i++ {
if err := checkKeySize(args[i].Key); err != nil {
return err
} else if err := checkValueSize(args[i].Value); err != nil {
return err
}
key = db.encodeKVKey(args[i].Key)
value = args[i].Value
t.Put(key, value)
//todo binlog
}
err = t.Commit()
return err
}
func (db *DB) Set(key []byte, value []byte) error {
if err := checkKeySize(key); err != nil {
return err
} else if err := checkValueSize(value); err != nil {
return err
}
var err error
key = db.encodeKVKey(key)
t := db.kvBatch
t.Lock()
defer t.Unlock()
t.Put(key, value)
err = t.Commit()
return err
}
func (db *DB) SetNX(key []byte, value []byte) (int64, error) {
if err := checkKeySize(key); err != nil {
return 0, err
} else if err := checkValueSize(value); err != nil {
return 0, err
}
var err error
key = db.encodeKVKey(key)
var n int64 = 1
t := db.kvBatch
t.Lock()
defer t.Unlock()
if v, err := db.bucket.Get(key); err != nil {
return 0, err
} else if v != nil {
n = 0
} else {
t.Put(key, value)
//todo binlog
err = t.Commit()
}
return n, err
}
func (db *DB) flush() (drop int64, err error) {
t := db.kvBatch
t.Lock()
defer t.Unlock()
return db.flushType(t, KVType)
}
//if inclusive is true, scan range [key, inf) else (key, inf)
func (db *DB) Scan(key []byte, count int, inclusive bool, match string) ([][]byte, error) {
return db.scan(KVType, key, count, inclusive, match)
}
func (db *DB) Expire(key []byte, duration int64) (int64, error) {
if duration <= 0 {
return 0, errExpireValue
}
return db.setExpireAt(key, time.Now().Unix()+duration)
}
func (db *DB) ExpireAt(key []byte, when int64) (int64, error) {
if when <= time.Now().Unix() {
return 0, errExpireValue
}
return db.setExpireAt(key, when)
}
func (db *DB) TTL(key []byte) (int64, error) {
if err := checkKeySize(key); err != nil {
return -1, err
}
return db.ttl(KVType, key)
}
func (db *DB) Persist(key []byte) (int64, error) {
if err := checkKeySize(key); err != nil {
return 0, err
}
t := db.kvBatch
t.Lock()
defer t.Unlock()
n, err := db.rmExpire(t, KVType, key)
if err != nil {
return 0, err
}
err = t.Commit()
return n, err
}
func (db *DB) Lock() {
t := db.kvBatch
t.Lock()
}
func (db *DB) Remove(key []byte) bool {
if len(key) == 0 {
return false
}
t := db.kvBatch
t.Delete(db.encodeKVKey(key))
_, err := db.rmExpire(t, KVType, key)
if err != nil {
return false
}
return true
}
func (db *DB) Commit() error {
t := db.kvBatch
return t.Commit()
}
func (db *DB) Unlock() {
t := db.kvBatch
t.Unlock()
}