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gitea/vendor/github.com/lunny/nodb/t_list.go
2019-02-05 11:52:51 -05:00

493 lines
9.0 KiB
Go
Vendored

package nodb
import (
"encoding/binary"
"errors"
"time"
"github.com/lunny/nodb/store"
)
const (
listHeadSeq int32 = 1
listTailSeq int32 = 2
listMinSeq int32 = 1000
listMaxSeq int32 = 1<<31 - 1000
listInitialSeq int32 = listMinSeq + (listMaxSeq-listMinSeq)/2
)
var errLMetaKey = errors.New("invalid lmeta key")
var errListKey = errors.New("invalid list key")
var errListSeq = errors.New("invalid list sequence, overflow")
func (db *DB) lEncodeMetaKey(key []byte) []byte {
buf := make([]byte, len(key)+2)
buf[0] = db.index
buf[1] = LMetaType
copy(buf[2:], key)
return buf
}
func (db *DB) lDecodeMetaKey(ek []byte) ([]byte, error) {
if len(ek) < 2 || ek[0] != db.index || ek[1] != LMetaType {
return nil, errLMetaKey
}
return ek[2:], nil
}
func (db *DB) lEncodeListKey(key []byte, seq int32) []byte {
buf := make([]byte, len(key)+8)
pos := 0
buf[pos] = db.index
pos++
buf[pos] = ListType
pos++
binary.BigEndian.PutUint16(buf[pos:], uint16(len(key)))
pos += 2
copy(buf[pos:], key)
pos += len(key)
binary.BigEndian.PutUint32(buf[pos:], uint32(seq))
return buf
}
func (db *DB) lDecodeListKey(ek []byte) (key []byte, seq int32, err error) {
if len(ek) < 8 || ek[0] != db.index || ek[1] != ListType {
err = errListKey
return
}
keyLen := int(binary.BigEndian.Uint16(ek[2:]))
if keyLen+8 != len(ek) {
err = errListKey
return
}
key = ek[4 : 4+keyLen]
seq = int32(binary.BigEndian.Uint32(ek[4+keyLen:]))
return
}
func (db *DB) lpush(key []byte, whereSeq int32, args ...[]byte) (int64, error) {
if err := checkKeySize(key); err != nil {
return 0, err
}
var headSeq int32
var tailSeq int32
var size int32
var err error
t := db.listBatch
t.Lock()
defer t.Unlock()
metaKey := db.lEncodeMetaKey(key)
headSeq, tailSeq, size, err = db.lGetMeta(nil, metaKey)
if err != nil {
return 0, err
}
var pushCnt int = len(args)
if pushCnt == 0 {
return int64(size), nil
}
var seq int32 = headSeq
var delta int32 = -1
if whereSeq == listTailSeq {
seq = tailSeq
delta = 1
}
// append elements
if size > 0 {
seq += delta
}
for i := 0; i < pushCnt; i++ {
ek := db.lEncodeListKey(key, seq+int32(i)*delta)
t.Put(ek, args[i])
}
seq += int32(pushCnt-1) * delta
if seq <= listMinSeq || seq >= listMaxSeq {
return 0, errListSeq
}
// set meta info
if whereSeq == listHeadSeq {
headSeq = seq
} else {
tailSeq = seq
}
db.lSetMeta(metaKey, headSeq, tailSeq)
err = t.Commit()
return int64(size) + int64(pushCnt), err
}
func (db *DB) lpop(key []byte, whereSeq int32) ([]byte, error) {
if err := checkKeySize(key); err != nil {
return nil, err
}
t := db.listBatch
t.Lock()
defer t.Unlock()
var headSeq int32
var tailSeq int32
var err error
metaKey := db.lEncodeMetaKey(key)
headSeq, tailSeq, _, err = db.lGetMeta(nil, metaKey)
if err != nil {
return nil, err
}
var value []byte
var seq int32 = headSeq
if whereSeq == listTailSeq {
seq = tailSeq
}
itemKey := db.lEncodeListKey(key, seq)
value, err = db.bucket.Get(itemKey)
if err != nil {
return nil, err
}
if whereSeq == listHeadSeq {
headSeq += 1
} else {
tailSeq -= 1
}
t.Delete(itemKey)
size := db.lSetMeta(metaKey, headSeq, tailSeq)
if size == 0 {
db.rmExpire(t, HashType, key)
}
err = t.Commit()
return value, err
}
// ps : here just focus on deleting the list data,
// any other likes expire is ignore.
func (db *DB) lDelete(t *batch, key []byte) int64 {
mk := db.lEncodeMetaKey(key)
var headSeq int32
var tailSeq int32
var err error
it := db.bucket.NewIterator()
defer it.Close()
headSeq, tailSeq, _, err = db.lGetMeta(it, mk)
if err != nil {
return 0
}
var num int64 = 0
startKey := db.lEncodeListKey(key, headSeq)
stopKey := db.lEncodeListKey(key, tailSeq)
rit := store.NewRangeIterator(it, &store.Range{startKey, stopKey, store.RangeClose})
for ; rit.Valid(); rit.Next() {
t.Delete(rit.RawKey())
num++
}
t.Delete(mk)
return num
}
func (db *DB) lGetMeta(it *store.Iterator, ek []byte) (headSeq int32, tailSeq int32, size int32, err error) {
var v []byte
if it != nil {
v = it.Find(ek)
} else {
v, err = db.bucket.Get(ek)
}
if err != nil {
return
} else if v == nil {
headSeq = listInitialSeq
tailSeq = listInitialSeq
size = 0
return
} else {
headSeq = int32(binary.LittleEndian.Uint32(v[0:4]))
tailSeq = int32(binary.LittleEndian.Uint32(v[4:8]))
size = tailSeq - headSeq + 1
}
return
}
func (db *DB) lSetMeta(ek []byte, headSeq int32, tailSeq int32) int32 {
t := db.listBatch
var size int32 = tailSeq - headSeq + 1
if size < 0 {
// todo : log error + panic
} else if size == 0 {
t.Delete(ek)
} else {
buf := make([]byte, 8)
binary.LittleEndian.PutUint32(buf[0:4], uint32(headSeq))
binary.LittleEndian.PutUint32(buf[4:8], uint32(tailSeq))
t.Put(ek, buf)
}
return size
}
func (db *DB) lExpireAt(key []byte, when int64) (int64, error) {
t := db.listBatch
t.Lock()
defer t.Unlock()
if llen, err := db.LLen(key); err != nil || llen == 0 {
return 0, err
} else {
db.expireAt(t, ListType, key, when)
if err := t.Commit(); err != nil {
return 0, err
}
}
return 1, nil
}
func (db *DB) LIndex(key []byte, index int32) ([]byte, error) {
if err := checkKeySize(key); err != nil {
return nil, err
}
var seq int32
var headSeq int32
var tailSeq int32
var err error
metaKey := db.lEncodeMetaKey(key)
it := db.bucket.NewIterator()
defer it.Close()
headSeq, tailSeq, _, err = db.lGetMeta(it, metaKey)
if err != nil {
return nil, err
}
if index >= 0 {
seq = headSeq + index
} else {
seq = tailSeq + index + 1
}
sk := db.lEncodeListKey(key, seq)
v := it.Find(sk)
return v, nil
}
func (db *DB) LLen(key []byte) (int64, error) {
if err := checkKeySize(key); err != nil {
return 0, err
}
ek := db.lEncodeMetaKey(key)
_, _, size, err := db.lGetMeta(nil, ek)
return int64(size), err
}
func (db *DB) LPop(key []byte) ([]byte, error) {
return db.lpop(key, listHeadSeq)
}
func (db *DB) LPush(key []byte, arg1 []byte, args ...[]byte) (int64, error) {
var argss = [][]byte{arg1}
argss = append(argss, args...)
return db.lpush(key, listHeadSeq, argss...)
}
func (db *DB) LRange(key []byte, start int32, stop int32) ([][]byte, error) {
if err := checkKeySize(key); err != nil {
return nil, err
}
var headSeq int32
var llen int32
var err error
metaKey := db.lEncodeMetaKey(key)
it := db.bucket.NewIterator()
defer it.Close()
if headSeq, _, llen, err = db.lGetMeta(it, metaKey); err != nil {
return nil, err
}
if start < 0 {
start = llen + start
}
if stop < 0 {
stop = llen + stop
}
if start < 0 {
start = 0
}
if start > stop || start >= llen {
return [][]byte{}, nil
}
if stop >= llen {
stop = llen - 1
}
limit := (stop - start) + 1
headSeq += start
v := make([][]byte, 0, limit)
startKey := db.lEncodeListKey(key, headSeq)
rit := store.NewRangeLimitIterator(it,
&store.Range{
Min: startKey,
Max: nil,
Type: store.RangeClose},
&store.Limit{
Offset: 0,
Count: int(limit)})
for ; rit.Valid(); rit.Next() {
v = append(v, rit.Value())
}
return v, nil
}
func (db *DB) RPop(key []byte) ([]byte, error) {
return db.lpop(key, listTailSeq)
}
func (db *DB) RPush(key []byte, arg1 []byte, args ...[]byte) (int64, error) {
var argss = [][]byte{arg1}
argss = append(argss, args...)
return db.lpush(key, listTailSeq, argss...)
}
func (db *DB) LClear(key []byte) (int64, error) {
if err := checkKeySize(key); err != nil {
return 0, err
}
t := db.listBatch
t.Lock()
defer t.Unlock()
num := db.lDelete(t, key)
db.rmExpire(t, ListType, key)
err := t.Commit()
return num, err
}
func (db *DB) LMclear(keys ...[]byte) (int64, error) {
t := db.listBatch
t.Lock()
defer t.Unlock()
for _, key := range keys {
if err := checkKeySize(key); err != nil {
return 0, err
}
db.lDelete(t, key)
db.rmExpire(t, ListType, key)
}
err := t.Commit()
return int64(len(keys)), err
}
func (db *DB) lFlush() (drop int64, err error) {
t := db.listBatch
t.Lock()
defer t.Unlock()
return db.flushType(t, ListType)
}
func (db *DB) LExpire(key []byte, duration int64) (int64, error) {
if duration <= 0 {
return 0, errExpireValue
}
return db.lExpireAt(key, time.Now().Unix()+duration)
}
func (db *DB) LExpireAt(key []byte, when int64) (int64, error) {
if when <= time.Now().Unix() {
return 0, errExpireValue
}
return db.lExpireAt(key, when)
}
func (db *DB) LTTL(key []byte) (int64, error) {
if err := checkKeySize(key); err != nil {
return -1, err
}
return db.ttl(ListType, key)
}
func (db *DB) LPersist(key []byte) (int64, error) {
if err := checkKeySize(key); err != nil {
return 0, err
}
t := db.listBatch
t.Lock()
defer t.Unlock()
n, err := db.rmExpire(t, ListType, key)
if err != nil {
return 0, err
}
err = t.Commit()
return n, err
}
func (db *DB) LScan(key []byte, count int, inclusive bool, match string) ([][]byte, error) {
return db.scan(LMetaType, key, count, inclusive, match)
}
func (db *DB) lEncodeMinKey() []byte {
return db.lEncodeMetaKey(nil)
}
func (db *DB) lEncodeMaxKey() []byte {
ek := db.lEncodeMetaKey(nil)
ek[len(ek)-1] = LMetaType + 1
return ek
}