iterator use range to support close/open interval

This commit is contained in:
siddontang 2014-05-07 13:40:48 +08:00
parent 09923bdf6a
commit da25e2b37f
4 changed files with 164 additions and 237 deletions

View File

@ -115,6 +115,13 @@ func (db *DB) Destroy() {
levigo.DestroyDatabase(db.cfg.Path, opts)
}
func (db *DB) Clear() {
it := db.Iterator(NewRange(nil, nil), 0)
for ; it.Valid(); it.Next() {
db.Delete(it.Key())
}
}
func (db *DB) Put(key, value []byte) error {
return db.db.Put(db.writeOpts, key, value)
}
@ -134,21 +141,14 @@ func (db *DB) NewWriteBatch() *WriteBatch {
return wb
}
//[begin, end] close(inclusive) interval
//if begin is nil, we will seek to first
//if end is nil, we will seek to last
//limit <= 0, no limit
func (db *DB) Iterator(begin []byte, end []byte, limit int) *Iterator {
return newIterator(db, db.iteratorOpts, begin, end, limit, forward)
func (db *DB) Iterator(r *Range, limit int) *Iterator {
return newIterator(db, db.iteratorOpts, r, limit, forward)
}
//[rbegin, rend] close(inclusive) interval
//rbegin should bigger than rend
//if rbegin is nil, we will seek to last
//if end is nil, we will seek to first
//limit <= 0, no limit
func (db *DB) ReverseIterator(rbegin []byte, rend []byte, limit int) *Iterator {
return newIterator(db, db.iteratorOpts, rbegin, rend, limit, backward)
func (db *DB) ReverseIterator(r *Range, limit int) *Iterator {
return newIterator(db, db.iteratorOpts, r, limit, backward)
}
func (db *DB) NewSnapshot() *Snapshot {

View File

@ -8,11 +8,39 @@ import (
const forward uint8 = 0
const backward uint8 = 1
//min must less or equal than max
//MinEx if true, range is left open interval (min, ...
//MaxEx if true, range is right open interval ..., max)
//Default range is close interval
type Range struct {
Min []byte
Max []byte
MinEx bool
MaxEx bool
}
func NewRange(min []byte, max []byte) *Range {
return &Range{min, max, false, false}
}
func NewOpenRange(min []byte, max []byte) *Range {
return &Range{min, max, true, true}
}
func NewLOpenRange(min []byte, max []byte) *Range {
return &Range{min, max, true, false}
}
func NewROpenRange(min []byte, max []byte) *Range {
return &Range{min, max, true, true}
}
type Iterator struct {
it *levigo.Iterator
start []byte
stop []byte
r *Range
limit int
step int
@ -21,31 +49,42 @@ type Iterator struct {
direction uint8
}
func newIterator(db *DB, opts *levigo.ReadOptions, start []byte, stop []byte, limit int, direction uint8) *Iterator {
func newIterator(db *DB, opts *levigo.ReadOptions, r *Range, limit int, direction uint8) *Iterator {
it := new(Iterator)
it.it = db.db.NewIterator(opts)
it.start = start
it.stop = stop
it.r = r
it.limit = limit
it.direction = direction
it.step = 0
if start == nil {
if direction == forward {
if direction == forward {
if r.Min == nil {
it.it.SeekToFirst()
} else {
it.it.SeekToLast()
it.it.Seek(r.Min)
if r.MinEx {
if it.Valid() && bytes.Equal(it.Key(), r.Min) {
it.it.Next()
}
}
}
} else {
it.it.Seek(start)
if it.Valid() && !bytes.Equal(it.Key(), start) {
//for forward, key is the next bigger than start
//for backward, key is the next bigger than start, so must go prev
if direction == backward {
if r.Max == nil {
it.it.SeekToLast()
} else {
it.it.Seek(r.Max)
if it.Valid() && !bytes.Equal(it.Key(), r.Max) {
//key must bigger than max, so we must go prev
it.it.Prev()
}
if r.MaxEx {
if it.Valid() && bytes.Equal(it.Key(), r.Max) {
it.it.Prev()
}
}
}
}
@ -62,12 +101,22 @@ func (it *Iterator) Valid() bool {
}
if it.direction == forward {
if it.stop != nil && bytes.Compare(it.Key(), it.stop) > 0 {
return false
if it.r.Max != nil {
r := bytes.Compare(it.Key(), it.r.Max)
if !it.r.MaxEx {
return !(r > 0)
} else {
return !(r >= 0)
}
}
} else {
if it.stop != nil && bytes.Compare(it.Key(), it.stop) < 0 {
return false
if it.r.Min != nil {
r := bytes.Compare(it.Key(), it.r.Min)
if !it.r.MinEx {
return !(r < 0)
} else {
return !(r <= 0)
}
}
}

View File

@ -107,210 +107,118 @@ func TestBatch(t *testing.T) {
db.Delete(key1)
}
func TestIterator(t *testing.T) {
db := getTestDB()
for it := db.Iterator(nil, nil, 0); it.Valid(); it.Next() {
db.Delete(it.Key())
}
for i := 0; i < 10; i++ {
key := []byte(fmt.Sprintf("key_%d", i))
value := []byte(fmt.Sprintf("value_%d", i))
db.Put(key, value)
}
step := 0
var it *Iterator
for it = db.Iterator(nil, nil, 0); it.Valid(); it.Next() {
key := it.Key()
value := it.Value()
if string(key) != fmt.Sprintf("key_%d", step) {
t.Fatal(string(key), step)
}
if string(value) != fmt.Sprintf("value_%d", step) {
t.Fatal(string(value), step)
}
step++
func checkIterator(it *Iterator, cv ...int) error {
v := make([]string, 0, len(cv))
for ; it.Valid(); it.Next() {
k := it.Key()
v = append(v, string(k))
}
it.Close()
step = 2
for it = db.Iterator([]byte("key_2"), nil, 3); it.Valid(); it.Next() {
key := it.Key()
value := it.Value()
if len(v) != len(cv) {
return fmt.Errorf("len error %d != %d", len(v), len(cv))
}
if string(key) != fmt.Sprintf("key_%d", step) {
t.Fatal(string(key), step)
for k, i := range cv {
if fmt.Sprintf("key_%d", i) != v[k] {
return fmt.Errorf("%s, %d", v[k], i)
}
if string(value) != fmt.Sprintf("value_%d", step) {
t.Fatal(string(value), step)
}
step++
}
it.Close()
if step != 5 {
t.Fatal("invalid step", step)
}
step = 2
for it = db.Iterator([]byte("key_2"), []byte("key_5"), 0); it.Valid(); it.Next() {
key := it.Key()
value := it.Value()
return nil
}
if string(key) != fmt.Sprintf("key_%d", step) {
t.Fatal(string(key), step)
}
if string(value) != fmt.Sprintf("value_%d", step) {
t.Fatal(string(value), step)
}
step++
}
it.Close()
if step != 6 {
t.Fatal("invalid step", step)
}
step = 2
for it = db.Iterator([]byte("key_5"), []byte("key_2"), 0); it.Valid(); it.Next() {
step++
}
it.Close()
if step != 2 {
t.Fatal("must 0")
}
step = 9
for it = db.ReverseIterator(nil, nil, 0); it.Valid(); it.Next() {
key := it.Key()
value := it.Value()
if string(key) != fmt.Sprintf("key_%d", step) {
t.Fatal(string(key), step)
}
if string(value) != fmt.Sprintf("value_%d", step) {
t.Fatal(string(value), step)
}
step--
}
it.Close()
step = 5
for it = db.ReverseIterator([]byte("key_5"), nil, 3); it.Valid(); it.Next() {
key := it.Key()
value := it.Value()
if string(key) != fmt.Sprintf("key_%d", step) {
t.Fatal(string(key), step)
}
if string(value) != fmt.Sprintf("value_%d", step) {
t.Fatal(string(value), step)
}
step--
}
it.Close()
if step != 2 {
t.Fatal("invalid step", step)
}
step = 5
for it = db.ReverseIterator([]byte("key_5"), []byte("key_2"), 0); it.Valid(); it.Next() {
key := it.Key()
value := it.Value()
if string(key) != fmt.Sprintf("key_%d", step) {
t.Fatal(string(key), step)
}
if string(value) != fmt.Sprintf("value_%d", step) {
t.Fatal(string(value), step)
}
step--
}
it.Close()
if step != 1 {
t.Fatal("invalid step", step)
}
step = 5
for it = db.ReverseIterator([]byte("key_2"), []byte("key_5"), 0); it.Valid(); it.Next() {
step--
}
it.Close()
if step != 5 {
t.Fatal("must 5")
func testKeyRange(min int, max int) *Range {
return &Range{
[]byte(fmt.Sprintf("key_%d", min)),
[]byte(fmt.Sprintf("key_%d", max)),
false,
false,
}
}
func TestIterator_2(t *testing.T) {
func testLKeyRange(min int, max int) *Range {
r := testKeyRange(min, max)
r.MinEx = true
return r
}
func testRKeyRange(min int, max int) *Range {
r := testKeyRange(min, max)
r.MaxEx = true
return r
}
func testOpenKeyRange(min int, max int) *Range {
r := testKeyRange(min, max)
r.MinEx = true
r.MaxEx = true
return r
}
func TestIterator(t *testing.T) {
db := getTestDB()
for it := db.Iterator(nil, nil, 0); it.Valid(); it.Next() {
db.Delete(it.Key())
db.Clear()
for i := 0; i < 10; i++ {
key := []byte(fmt.Sprintf("key_%d", i))
value := []byte("")
db.Put(key, value)
}
db.Put([]byte("key_1"), []byte("value_1"))
db.Put([]byte("key_7"), []byte("value_9"))
db.Put([]byte("key_9"), []byte("value_9"))
var it *Iterator
it := db.Iterator([]byte("key_0"), []byte("key_8"), 0)
if !it.Valid() {
t.Fatal("must valid")
it = db.Iterator(testKeyRange(1, 5), 0)
if err := checkIterator(it, 1, 2, 3, 4, 5); err != nil {
t.Fatal(err)
}
if string(it.Key()) != "key_1" {
t.Fatal(string(it.Key()))
it = db.Iterator(testKeyRange(1, 9), 5)
if err := checkIterator(it, 1, 2, 3, 4, 5); err != nil {
t.Fatal(err)
}
it.Close()
it = db.ReverseIterator([]byte("key_8"), []byte("key_0"), 0)
if !it.Valid() {
t.Fatal("must valid")
it = db.Iterator(testLKeyRange(1, 5), 0)
if err := checkIterator(it, 2, 3, 4, 5); err != nil {
t.Fatal(err)
}
if string(it.Key()) != "key_7" {
t.Fatal(string(it.Key()))
it = db.Iterator(testRKeyRange(1, 5), 0)
if err := checkIterator(it, 1, 2, 3, 4); err != nil {
t.Fatal(err)
}
it.Close()
for it = db.Iterator(nil, nil, 0); it.Valid(); it.Next() {
db.Delete(it.Key())
it = db.Iterator(testOpenKeyRange(1, 5), 0)
if err := checkIterator(it, 2, 3, 4); err != nil {
t.Fatal(err)
}
it.Close()
it = db.Iterator([]byte("key_0"), []byte("key_8"), 0)
if it.Valid() {
t.Fatal("must not valid")
it = db.ReverseIterator(testKeyRange(1, 5), 0)
if err := checkIterator(it, 5, 4, 3, 2, 1); err != nil {
t.Fatal(err)
}
it.Close()
it = db.ReverseIterator([]byte("key_8"), []byte("key_0"), 0)
if it.Valid() {
t.Fatal("must not valid")
it = db.ReverseIterator(testKeyRange(1, 9), 5)
if err := checkIterator(it, 9, 8, 7, 6, 5); err != nil {
t.Fatal(err)
}
it.Close()
it = db.ReverseIterator(testLKeyRange(1, 5), 0)
if err := checkIterator(it, 5, 4, 3, 2); err != nil {
t.Fatal(err)
}
it = db.ReverseIterator(testRKeyRange(1, 5), 0)
if err := checkIterator(it, 4, 3, 2, 1); err != nil {
t.Fatal(err)
}
it = db.ReverseIterator(testOpenKeyRange(1, 5), 0)
if err := checkIterator(it, 4, 3, 2); err != nil {
t.Fatal(err)
}
}
func TestSnapshot(t *testing.T) {
@ -331,36 +239,6 @@ func TestSnapshot(t *testing.T) {
} else if string(v) != string(value) {
t.Fatal(string(v))
}
found := false
var it *Iterator
for it = s.Iterator(nil, nil, 0); it.Valid(); it.Next() {
if string(it.Key()) == string(key) {
found = true
break
}
}
it.Close()
if !found {
t.Fatal("must found")
}
found = false
for it = s.ReverseIterator(nil, nil, 0); it.Valid(); it.Next() {
if string(it.Key()) == string(key) {
found = true
break
}
}
it.Close()
if !found {
t.Fatal("must found")
}
}
func TestDestroy(t *testing.T) {

View File

@ -38,12 +38,12 @@ func (s *Snapshot) Get(key []byte) ([]byte, error) {
}
//same as db iterator and reverse iterator
func (s *Snapshot) Iterator(begin []byte, end []byte, limit int) *Iterator {
return newIterator(s.db, s.iteratorOpts, begin, end, limit, forward)
func (s *Snapshot) Iterator(r *Range, limit int) *Iterator {
return newIterator(s.db, s.iteratorOpts, r, limit, forward)
}
func (s *Snapshot) ReverseIterator(rbegin []byte, rend []byte, limit int) *Iterator {
return newIterator(s.db, s.iteratorOpts, rbegin, rend, limit, backward)
func (s *Snapshot) ReverseIterator(r *Range, limit int) *Iterator {
return newIterator(s.db, s.iteratorOpts, r, limit, backward)
}
func (s *Snapshot) GetInt(key []byte) (int64, error) {