add expire for the kv type; simplify the listMetaKey format

This commit is contained in:
silentsai 2014-06-03 15:41:17 +08:00
parent 038f9c7000
commit 654a0a4704
2 changed files with 380 additions and 0 deletions

208
ledis/t_ttl.go Normal file
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@ -0,0 +1,208 @@
package ledis
import (
"encoding/binary"
"errors"
"github.com/siddontang/go-leveldb/leveldb"
"time"
)
var mapExpMetaType = map[byte]byte{
kvExpType: kvExpMetaType,
lExpType: lExpMetaType,
hExpType: hExpMetaType,
zExpType: zExpMetaType}
type retireCallback func(*tx, []byte) int64
type Elimination struct {
db *DB
exp2Tx map[byte]*tx
exp2Retire map[byte]retireCallback
}
var errExpType = errors.New("invalid expire type")
func (db *DB) expEncodeTimeKey(expType byte, key []byte, when int64) []byte {
// format : db[8] / expType[8] / when[64] / key[...]
buf := make([]byte, len(key)+10)
buf[0] = db.index
buf[1] = expType
pos := 2
binary.BigEndian.PutUint64(buf[pos:], uint64(when))
pos += 8
copy(buf[pos:], key)
return buf
}
func (db *DB) expEncodeMetaKey(expType byte, key []byte) []byte {
// format : db[8] / expType[8] / key[...]
buf := make([]byte, len(key)+2)
buf[0] = db.index
buf[1] = expType
pos := 2
copy(buf[pos:], key)
return buf
}
// usage : separate out the original key
func (db *DB) expDecodeMetaKey(mk []byte) []byte {
if len(mk) <= 2 {
// check db ? check type ?
return nil
}
return mk[2:]
}
func (db *DB) expire(t *tx, expType byte, key []byte, duration int64) {
db.expireAt(t, expType, key, time.Now().Unix()+duration)
}
func (db *DB) expireAt(t *tx, expType byte, key []byte, when int64) {
mk := db.expEncodeMetaKey(expType+1, key)
tk := db.expEncodeTimeKey(expType, key, when)
t.Put(tk, mk)
t.Put(mk, PutInt64(when))
}
func (db *DB) ttl(expType byte, key []byte) (t int64, err error) {
mk := db.expEncodeMetaKey(expType+1, key)
if t, err = Int64(db.db.Get(mk)); err != nil || t == 0 {
t = -1
} else {
t -= time.Now().Unix()
if t <= 0 {
t = -1
}
// if t == -1 : to remove ????
}
return t, err
}
func (db *DB) rmExpire(t *tx, expType byte, key []byte) {
mk := db.expEncodeMetaKey(expType+1, key)
when, err := Int64(db.db.Get(mk))
if err == nil && when > 0 {
tk := db.expEncodeTimeKey(expType, key, when)
t.Delete(mk)
t.Delete(tk)
}
}
func (db *DB) expFlush(t *tx, expType byte) (err error) {
expMetaType, ok := mapExpMetaType[expType]
if !ok {
return errExpType
}
drop := 0
minKey := make([]byte, 2)
minKey[0] = db.index
minKey[1] = expType
maxKey := make([]byte, 2)
maxKey[0] = db.index
maxKey[1] = expMetaType + 1
it := db.db.Iterator(minKey, maxKey, leveldb.RangeROpen, 0, -1)
for ; it.Valid(); it.Next() {
t.Delete(it.Key())
drop++
if drop&1023 == 0 {
if err = t.Commit(); err != nil {
return
}
}
}
err = t.Commit()
return
}
//////////////////////////////////////////////////////////
//
//////////////////////////////////////////////////////////
func newEliminator(db *DB) *Elimination {
eli := new(Elimination)
eli.db = db
eli.exp2Tx = make(map[byte]*tx)
eli.exp2Retire = make(map[byte]retireCallback)
return eli
}
func (eli *Elimination) regRetireContext(expType byte, t *tx, onRetire retireCallback) {
eli.exp2Tx[expType] = t
eli.exp2Retire[expType] = onRetire
}
// call by outside ... (from *db to another *db)
func (eli *Elimination) active() {
now := time.Now().Unix()
db := eli.db
dbGet := db.db.Get
expKeys := make([][]byte, 0, 1024)
expTypes := [...]byte{kvExpType, lExpType, hExpType, zExpType}
for _, et := range expTypes {
// search those keys' which expire till the moment
minKey := db.expEncodeTimeKey(et, nil, 0)
maxKey := db.expEncodeTimeKey(et, nil, now+1)
expKeys = expKeys[0:0]
t, _ := eli.exp2Tx[et]
onRetire, _ := eli.exp2Retire[et]
if t == nil || onRetire == nil {
// todo : log error
continue
}
it := db.db.Iterator(minKey, maxKey, leveldb.RangeROpen, 0, -1)
for it.Valid() {
for i := 1; i < 512 && it.Valid(); i++ {
expKeys = append(expKeys, it.Key(), it.Value())
it.Next()
}
var cnt int = len(expKeys)
if cnt == 0 {
continue
}
t.Lock()
var mk, ek, k []byte
for i := 0; i < cnt; i += 2 {
ek, mk = expKeys[i], expKeys[i+1]
if exp, err := Int64(dbGet(mk)); err == nil {
// check expire again
if exp > now {
continue
}
// delete keys
k = db.expDecodeMetaKey(mk)
onRetire(t, k)
t.Delete(ek)
t.Delete(mk)
}
}
t.Commit()
t.Unlock()
} // end : it
} // end : expType
return
}

172
ledis/t_ttl_test.go Normal file
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package ledis
import (
"fmt"
"sync"
"testing"
"time"
)
var m sync.Mutex
func TestKvExpire(t *testing.T) {
db := getTestDB()
m.Lock()
defer m.Unlock()
k := []byte("ttl_a")
ek := []byte("ttl_b")
db.Set(k, []byte("1"))
if ok, _ := db.Expire(k, 10); ok != 1 {
t.Fatal(ok)
}
// err - expire on an inexisting key
if ok, _ := db.Expire(ek, 10); ok != 0 {
t.Fatal(ok)
}
// err - duration is zero
if ok, err := db.Expire(k, 0); err == nil || ok != 0 {
t.Fatal(fmt.Sprintf("res = %d, err = %s", ok, err))
}
// err - duration is negative
if ok, err := db.Expire(k, -10); err == nil || ok != 0 {
t.Fatal(fmt.Sprintf("res = %d, err = %s", ok, err))
}
}
func TestKvExpireAt(t *testing.T) {
db := getTestDB()
m.Lock()
defer m.Unlock()
k := []byte("ttl_a")
ek := []byte("ttl_b")
db.Set(k, []byte("1"))
now := time.Now().Unix()
if ok, _ := db.ExpireAt(k, now+5); ok != 1 {
t.Fatal(ok)
}
// err - expire on an inexisting key
if ok, _ := db.ExpireAt(ek, now+5); ok != 0 {
t.Fatal(ok)
}
// err - expire with the current time
if ok, err := db.ExpireAt(k, now); err == nil || ok != 0 {
t.Fatal(fmt.Sprintf("res = %d, err = %s", ok, err))
}
// err - expire with the time before
if ok, err := db.ExpireAt(k, now-5); err == nil || ok != 0 {
t.Fatal(fmt.Sprintf("res = %d, err = %s", ok, err))
}
}
func TestKvTtl(t *testing.T) {
db := getTestDB()
m.Lock()
defer m.Unlock()
k := []byte("ttl_a")
ek := []byte("ttl_b")
db.Set(k, []byte("1"))
db.Expire(k, 2)
if tRemain, _ := db.Ttl(k); tRemain != 2 {
t.Fatal(tRemain)
}
// err - check ttl on an inexisting key
if tRemain, _ := db.Ttl(ek); tRemain != -1 {
t.Fatal(tRemain)
}
db.Del(k)
if tRemain, _ := db.Ttl(k); tRemain != -1 {
t.Fatal(tRemain)
}
}
func TestKvExpCompose(t *testing.T) {
db := getTestDB()
m.Lock()
defer m.Unlock()
k0 := []byte("ttl_a")
k1 := []byte("ttl_b")
k2 := []byte("ttl_c")
db.Set(k0, k0)
db.Set(k1, k1)
db.Set(k2, k2)
db.Expire(k0, 5)
db.Expire(k1, 2)
db.Expire(k2, 60)
if tRemain, _ := db.Ttl(k0); tRemain != 5 {
t.Fatal(tRemain)
}
if tRemain, _ := db.Ttl(k1); tRemain != 2 {
t.Fatal(tRemain)
}
if tRemain, _ := db.Ttl(k2); tRemain != 60 {
t.Fatal(tRemain)
}
// after 1 sec
time.Sleep(1 * time.Second)
if tRemain, _ := db.Ttl(k0); tRemain != 4 {
t.Fatal(tRemain)
}
if tRemain, _ := db.Ttl(k1); tRemain != 1 {
t.Fatal(tRemain)
}
// after 2 sec
time.Sleep(2 * time.Second)
if tRemain, _ := db.Ttl(k1); tRemain != -1 {
t.Fatal(tRemain)
}
if v, _ := db.Get(k1); v != nil {
t.Fatal(v)
}
if tRemain, _ := db.Ttl(k0); tRemain != 2 {
t.Fatal(tRemain)
}
if v, _ := db.Get(k0); v == nil {
t.Fatal(v)
}
// refresh the expiration of key
if tRemain, _ := db.Ttl(k2); !(0 < tRemain && tRemain < 60) {
t.Fatal(tRemain)
}
if ok, _ := db.Expire(k2, 100); ok != 1 {
t.Fatal(false)
}
if tRemain, _ := db.Ttl(k2); tRemain != 100 {
t.Fatal(tRemain)
}
// expire an inexisting key
if ok, _ := db.Expire(k1, 10); ok == 1 {
t.Fatal(false)
}
if tRemain, _ := db.Ttl(k1); tRemain != -1 {
t.Fatal(tRemain)
}
return
}