diff --git a/leveldb/cache/cache.go b/leveldb/cache/cache.go
index baced77..c9670de 100644
--- a/leveldb/cache/cache.go
+++ b/leveldb/cache/cache.go
@@ -8,152 +8,669 @@
 package cache
 
 import (
+	"sync"
 	"sync/atomic"
+	"unsafe"
+
+	"github.com/syndtr/goleveldb/leveldb/util"
 )
 
-// SetFunc is the function that will be called by Namespace.Get to create
-// a cache object, if charge is less than one than the cache object will
-// not be registered to cache tree, if value is nil then the cache object
-// will not be created.
-type SetFunc func() (charge int, value interface{})
-
-// DelFin is the function that will be called as the result of a delete operation.
-// Exist == true is indication that the object is exist, and pending == true is
-// indication of deletion already happen but haven't done yet (wait for all handles
-// to be released). And exist == false means the object doesn't exist.
-type DelFin func(exist, pending bool)
-
-// PurgeFin is the function that will be called as the result of a purge operation.
-type PurgeFin func(ns, key uint64)
-
-// Cache is a cache tree. A cache instance must be goroutine-safe.
-type Cache interface {
-	// SetCapacity sets cache tree capacity.
-	SetCapacity(capacity int)
-
-	// Capacity returns cache tree capacity.
+// Cacher provides interface to implements a caching functionality.
+// An implementation must be goroutine-safe.
+type Cacher interface {
+	// Capacity returns cache capacity.
 	Capacity() int
 
-	// Used returns used cache tree capacity.
-	Used() int
+	// SetCapacity sets cache capacity.
+	SetCapacity(capacity int)
 
-	// Size returns entire alive cache objects size.
-	Size() int
+	// Promote promotes the 'cache node'.
+	Promote(n *Node)
 
-	// NumObjects returns number of alive objects.
-	NumObjects() int
+	// Ban evicts the 'cache node' and prevent subsequent 'promote'.
+	Ban(n *Node)
 
-	// GetNamespace gets cache namespace with the given id.
-	// GetNamespace is never return nil.
-	GetNamespace(id uint64) Namespace
+	// Evict evicts the 'cache node'.
+	Evict(n *Node)
 
-	// PurgeNamespace purges cache namespace with the given id from this cache tree.
-	// Also read Namespace.Purge.
-	PurgeNamespace(id uint64, fin PurgeFin)
+	// EvictNS evicts 'cache node' with the given namespace.
+	EvictNS(ns uint64)
 
-	// ZapNamespace detaches cache namespace with the given id from this cache tree.
-	// Also read Namespace.Zap.
-	ZapNamespace(id uint64)
+	// EvictAll evicts all 'cache node'.
+	EvictAll()
 
-	// Purge purges all cache namespace from this cache tree.
-	// This is behave the same as calling Namespace.Purge method on all cache namespace.
-	Purge(fin PurgeFin)
-
-	// Zap detaches all cache namespace from this cache tree.
-	// This is behave the same as calling Namespace.Zap method on all cache namespace.
-	Zap()
+	// Close closes the 'cache tree'
+	Close() error
 }
 
-// Namespace is a cache namespace. A namespace instance must be goroutine-safe.
-type Namespace interface {
-	// Get gets cache object with the given key.
-	// If cache object is not found and setf is not nil, Get will atomically creates
-	// the cache object by calling setf. Otherwise Get will returns nil.
-	//
-	// The returned cache handle should be released after use by calling Release
-	// method.
-	Get(key uint64, setf SetFunc) Handle
+// Value is a 'cacheable object'. It may implements util.Releaser, if
+// so the the Release method will be called once object is released.
+type Value interface{}
 
-	// Delete removes cache object with the given key from cache tree.
-	// A deleted cache object will be released as soon as all of its handles have
-	// been released.
-	// Delete only happen once, subsequent delete will consider cache object doesn't
-	// exist, even if the cache object ins't released yet.
-	//
-	// If not nil, fin will be called if the cache object doesn't exist or when
-	// finally be released.
-	//
-	// Delete returns true if such cache object exist and never been deleted.
-	Delete(key uint64, fin DelFin) bool
-
-	// Purge removes all cache objects within this namespace from cache tree.
-	// This is the same as doing delete on all cache objects.
-	//
-	// If not nil, fin will be called on all cache objects when its finally be
-	// released.
-	Purge(fin PurgeFin)
-
-	// Zap detaches namespace from cache tree and release all its cache objects.
-	// A zapped namespace can never be filled again.
-	// Calling Get on zapped namespace will always return nil.
-	Zap()
+type CacheGetter struct {
+	Cache *Cache
+	NS    uint64
 }
 
-// Handle is a cache handle.
-type Handle interface {
-	// Release releases this cache handle. This method can be safely called mutiple
-	// times.
-	Release()
-
-	// Value returns value of this cache handle.
-	// Value will returns nil after this cache handle have be released.
-	Value() interface{}
+func (g *CacheGetter) Get(key uint64, setFunc func() (size int, value Value)) *Handle {
+	return g.Cache.Get(g.NS, key, setFunc)
 }
 
+// The hash tables implementation is based on:
+// "Dynamic-Sized Nonblocking Hash Tables", by Yujie Liu, Kunlong Zhang, and Michael Spear. ACM Symposium on Principles of Distributed Computing, Jul 2014.
+
 const (
-	DelNotExist = iota
-	DelExist
-	DelPendig
+	mInitialSize           = 1 << 4
+	mOverflowThreshold     = 1 << 5
+	mOverflowGrowThreshold = 1 << 7
 )
 
-// Namespace state.
-type nsState int
-
-const (
-	nsEffective nsState = iota
-	nsZapped
-)
-
-// Node state.
-type nodeState int
-
-const (
-	nodeZero nodeState = iota
-	nodeEffective
-	nodeEvicted
-	nodeDeleted
-)
-
-// Fake handle.
-type fakeHandle struct {
-	value interface{}
-	fin   func()
-	once  uint32
+type mBucket struct {
+	mu     sync.Mutex
+	node   []*Node
+	frozen bool
 }
 
-func (h *fakeHandle) Value() interface{} {
-	if atomic.LoadUint32(&h.once) == 0 {
-		return h.value
+func (b *mBucket) freeze() []*Node {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	if !b.frozen {
+		b.frozen = true
+	}
+	return b.node
+}
+
+func (b *mBucket) get(r *Cache, h *mNode, hash uint32, ns, key uint64, noset bool) (done, added bool, n *Node) {
+	b.mu.Lock()
+
+	if b.frozen {
+		b.mu.Unlock()
+		return
+	}
+
+	// Scan the node.
+	for _, n := range b.node {
+		if n.hash == hash && n.ns == ns && n.key == key {
+			atomic.AddInt32(&n.ref, 1)
+			b.mu.Unlock()
+			return true, false, n
+		}
+	}
+
+	// Get only.
+	if noset {
+		b.mu.Unlock()
+		return true, false, nil
+	}
+
+	// Create node.
+	n = &Node{
+		r:    r,
+		hash: hash,
+		ns:   ns,
+		key:  key,
+		ref:  1,
+	}
+	// Add node to bucket.
+	b.node = append(b.node, n)
+	bLen := len(b.node)
+	b.mu.Unlock()
+
+	// Update counter.
+	grow := atomic.AddInt32(&r.nodes, 1) >= h.growThreshold
+	if bLen > mOverflowThreshold {
+		grow = grow || atomic.AddInt32(&h.overflow, 1) >= mOverflowGrowThreshold
+	}
+
+	// Grow.
+	if grow && atomic.CompareAndSwapInt32(&h.resizeInProgess, 0, 1) {
+		nhLen := len(h.buckets) << 1
+		nh := &mNode{
+			buckets:         make([]unsafe.Pointer, nhLen),
+			mask:            uint32(nhLen) - 1,
+			pred:            unsafe.Pointer(h),
+			growThreshold:   int32(nhLen * mOverflowThreshold),
+			shrinkThreshold: int32(nhLen >> 1),
+		}
+		ok := atomic.CompareAndSwapPointer(&r.mHead, unsafe.Pointer(h), unsafe.Pointer(nh))
+		if !ok {
+			panic("BUG: failed swapping head")
+		}
+		go nh.initBuckets()
+	}
+
+	return true, true, n
+}
+
+func (b *mBucket) delete(r *Cache, h *mNode, hash uint32, ns, key uint64) (done, deleted bool) {
+	b.mu.Lock()
+
+	if b.frozen {
+		b.mu.Unlock()
+		return
+	}
+
+	// Scan the node.
+	var (
+		n    *Node
+		bLen int
+	)
+	for i := range b.node {
+		n = b.node[i]
+		if n.ns == ns && n.key == key {
+			if atomic.LoadInt32(&n.ref) == 0 {
+				deleted = true
+
+				// Call releaser.
+				if n.value != nil {
+					if r, ok := n.value.(util.Releaser); ok {
+						r.Release()
+					}
+					n.value = nil
+				}
+
+				// Remove node from bucket.
+				b.node = append(b.node[:i], b.node[i+1:]...)
+				bLen = len(b.node)
+			}
+			break
+		}
+	}
+	b.mu.Unlock()
+
+	if deleted {
+		// Call OnDel.
+		for _, f := range n.onDel {
+			f()
+		}
+
+		// Update counter.
+		atomic.AddInt32(&r.size, int32(n.size)*-1)
+		shrink := atomic.AddInt32(&r.nodes, -1) < h.shrinkThreshold
+		if bLen >= mOverflowThreshold {
+			atomic.AddInt32(&h.overflow, -1)
+		}
+
+		// Shrink.
+		if shrink && len(h.buckets) > mInitialSize && atomic.CompareAndSwapInt32(&h.resizeInProgess, 0, 1) {
+			nhLen := len(h.buckets) >> 1
+			nh := &mNode{
+				buckets:         make([]unsafe.Pointer, nhLen),
+				mask:            uint32(nhLen) - 1,
+				pred:            unsafe.Pointer(h),
+				growThreshold:   int32(nhLen * mOverflowThreshold),
+				shrinkThreshold: int32(nhLen >> 1),
+			}
+			ok := atomic.CompareAndSwapPointer(&r.mHead, unsafe.Pointer(h), unsafe.Pointer(nh))
+			if !ok {
+				panic("BUG: failed swapping head")
+			}
+			go nh.initBuckets()
+		}
+	}
+
+	return true, deleted
+}
+
+type mNode struct {
+	buckets         []unsafe.Pointer // []*mBucket
+	mask            uint32
+	pred            unsafe.Pointer // *mNode
+	resizeInProgess int32
+
+	overflow        int32
+	growThreshold   int32
+	shrinkThreshold int32
+}
+
+func (n *mNode) initBucket(i uint32) *mBucket {
+	if b := (*mBucket)(atomic.LoadPointer(&n.buckets[i])); b != nil {
+		return b
+	}
+
+	p := (*mNode)(atomic.LoadPointer(&n.pred))
+	if p != nil {
+		var node []*Node
+		if n.mask > p.mask {
+			// Grow.
+			pb := (*mBucket)(atomic.LoadPointer(&p.buckets[i&p.mask]))
+			if pb == nil {
+				pb = p.initBucket(i & p.mask)
+			}
+			m := pb.freeze()
+			// Split nodes.
+			for _, x := range m {
+				if x.hash&n.mask == i {
+					node = append(node, x)
+				}
+			}
+		} else {
+			// Shrink.
+			pb0 := (*mBucket)(atomic.LoadPointer(&p.buckets[i]))
+			if pb0 == nil {
+				pb0 = p.initBucket(i)
+			}
+			pb1 := (*mBucket)(atomic.LoadPointer(&p.buckets[i+uint32(len(n.buckets))]))
+			if pb1 == nil {
+				pb1 = p.initBucket(i + uint32(len(n.buckets)))
+			}
+			m0 := pb0.freeze()
+			m1 := pb1.freeze()
+			// Merge nodes.
+			node = make([]*Node, 0, len(m0)+len(m1))
+			node = append(node, m0...)
+			node = append(node, m1...)
+		}
+		b := &mBucket{node: node}
+		if atomic.CompareAndSwapPointer(&n.buckets[i], nil, unsafe.Pointer(b)) {
+			if len(node) > mOverflowThreshold {
+				atomic.AddInt32(&n.overflow, int32(len(node)-mOverflowThreshold))
+			}
+			return b
+		}
+	}
+
+	return (*mBucket)(atomic.LoadPointer(&n.buckets[i]))
+}
+
+func (n *mNode) initBuckets() {
+	for i := range n.buckets {
+		n.initBucket(uint32(i))
+	}
+	atomic.StorePointer(&n.pred, nil)
+}
+
+// Cache is a 'cache map'.
+type Cache struct {
+	mu     sync.RWMutex
+	mHead  unsafe.Pointer // *mNode
+	nodes  int32
+	size   int32
+	cacher Cacher
+	closed bool
+}
+
+// NewCache creates a new 'cache map'. The cacher is optional and
+// may be nil.
+func NewCache(cacher Cacher) *Cache {
+	h := &mNode{
+		buckets:         make([]unsafe.Pointer, mInitialSize),
+		mask:            mInitialSize - 1,
+		growThreshold:   int32(mInitialSize * mOverflowThreshold),
+		shrinkThreshold: 0,
+	}
+	for i := range h.buckets {
+		h.buckets[i] = unsafe.Pointer(&mBucket{})
+	}
+	r := &Cache{
+		mHead:  unsafe.Pointer(h),
+		cacher: cacher,
+	}
+	return r
+}
+
+func (r *Cache) getBucket(hash uint32) (*mNode, *mBucket) {
+	h := (*mNode)(atomic.LoadPointer(&r.mHead))
+	i := hash & h.mask
+	b := (*mBucket)(atomic.LoadPointer(&h.buckets[i]))
+	if b == nil {
+		b = h.initBucket(i)
+	}
+	return h, b
+}
+
+func (r *Cache) delete(n *Node) bool {
+	for {
+		h, b := r.getBucket(n.hash)
+		done, deleted := b.delete(r, h, n.hash, n.ns, n.key)
+		if done {
+			return deleted
+		}
+	}
+	return false
+}
+
+// Nodes returns number of 'cache node' in the map.
+func (r *Cache) Nodes() int {
+	return int(atomic.LoadInt32(&r.nodes))
+}
+
+// Size returns sums of 'cache node' size in the map.
+func (r *Cache) Size() int {
+	return int(atomic.LoadInt32(&r.size))
+}
+
+// Capacity returns cache capacity.
+func (r *Cache) Capacity() int {
+	if r.cacher == nil {
+		return 0
+	}
+	return r.cacher.Capacity()
+}
+
+// SetCapacity sets cache capacity.
+func (r *Cache) SetCapacity(capacity int) {
+	if r.cacher != nil {
+		r.cacher.SetCapacity(capacity)
+	}
+}
+
+// Get gets 'cache node' with the given namespace and key.
+// If cache node is not found and setFunc is not nil, Get will atomically creates
+// the 'cache node' by calling setFunc. Otherwise Get will returns nil.
+//
+// The returned 'cache handle' should be released after use by calling Release
+// method.
+func (r *Cache) Get(ns, key uint64, setFunc func() (size int, value Value)) *Handle {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	if r.closed {
+		return nil
+	}
+
+	hash := murmur32(ns, key, 0xf00)
+	for {
+		h, b := r.getBucket(hash)
+		done, _, n := b.get(r, h, hash, ns, key, setFunc == nil)
+		if done {
+			if n != nil {
+				n.mu.Lock()
+				if n.value == nil {
+					if setFunc == nil {
+						n.mu.Unlock()
+						n.unref()
+						return nil
+					}
+
+					n.size, n.value = setFunc()
+					if n.value == nil {
+						n.size = 0
+						n.mu.Unlock()
+						n.unref()
+						return nil
+					}
+					atomic.AddInt32(&r.size, int32(n.size))
+				}
+				n.mu.Unlock()
+				if r.cacher != nil {
+					r.cacher.Promote(n)
+				}
+				return &Handle{unsafe.Pointer(n)}
+			}
+
+			break
+		}
 	}
 	return nil
 }
 
-func (h *fakeHandle) Release() {
-	if !atomic.CompareAndSwapUint32(&h.once, 0, 1) {
+// Delete removes and ban 'cache node' with the given namespace and key.
+// A banned 'cache node' will never inserted into the 'cache tree'. Ban
+// only attributed to the particular 'cache node', so when a 'cache node'
+// is recreated it will not be banned.
+//
+// If onDel is not nil, then it will be executed if such 'cache node'
+// doesn't exist or once the 'cache node' is released.
+//
+// Delete return true is such 'cache node' exist.
+func (r *Cache) Delete(ns, key uint64, onDel func()) bool {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	if r.closed {
+		return false
+	}
+
+	hash := murmur32(ns, key, 0xf00)
+	for {
+		h, b := r.getBucket(hash)
+		done, _, n := b.get(r, h, hash, ns, key, true)
+		if done {
+			if n != nil {
+				if onDel != nil {
+					n.mu.Lock()
+					n.onDel = append(n.onDel, onDel)
+					n.mu.Unlock()
+				}
+				if r.cacher != nil {
+					r.cacher.Ban(n)
+				}
+				n.unref()
+				return true
+			}
+
+			break
+		}
+	}
+
+	if onDel != nil {
+		onDel()
+	}
+
+	return false
+}
+
+// Evict evicts 'cache node' with the given namespace and key. This will
+// simply call Cacher.Evict.
+//
+// Evict return true is such 'cache node' exist.
+func (r *Cache) Evict(ns, key uint64) bool {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	if r.closed {
+		return false
+	}
+
+	hash := murmur32(ns, key, 0xf00)
+	for {
+		h, b := r.getBucket(hash)
+		done, _, n := b.get(r, h, hash, ns, key, true)
+		if done {
+			if n != nil {
+				if r.cacher != nil {
+					r.cacher.Evict(n)
+				}
+				n.unref()
+				return true
+			}
+
+			break
+		}
+	}
+
+	return false
+}
+
+// EvictNS evicts 'cache node' with the given namespace. This will
+// simply call Cacher.EvictNS.
+func (r *Cache) EvictNS(ns uint64) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	if r.closed {
 		return
 	}
-	if h.fin != nil {
-		h.fin()
-		h.fin = nil
+
+	if r.cacher != nil {
+		r.cacher.EvictNS(ns)
 	}
 }
+
+// EvictAll evicts all 'cache node'. This will simply call Cacher.EvictAll.
+func (r *Cache) EvictAll() {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	if r.closed {
+		return
+	}
+
+	if r.cacher != nil {
+		r.cacher.EvictAll()
+	}
+}
+
+// Close closes the 'cache map' and releases all 'cache node'.
+func (r *Cache) Close() error {
+	r.mu.Lock()
+	if !r.closed {
+		r.closed = true
+
+		if r.cacher != nil {
+			if err := r.cacher.Close(); err != nil {
+				return err
+			}
+		}
+
+		h := (*mNode)(r.mHead)
+		h.initBuckets()
+
+		for i := range h.buckets {
+			b := (*mBucket)(h.buckets[i])
+			for _, n := range b.node {
+				// Call releaser.
+				if n.value != nil {
+					if r, ok := n.value.(util.Releaser); ok {
+						r.Release()
+					}
+					n.value = nil
+				}
+
+				// Call OnDel.
+				for _, f := range n.onDel {
+					f()
+				}
+			}
+		}
+	}
+	r.mu.Unlock()
+	return nil
+}
+
+// Node is a 'cache node'.
+type Node struct {
+	r *Cache
+
+	hash    uint32
+	ns, key uint64
+
+	mu    sync.Mutex
+	size  int
+	value Value
+
+	ref   int32
+	onDel []func()
+
+	CacheData unsafe.Pointer
+}
+
+// NS returns this 'cache node' namespace.
+func (n *Node) NS() uint64 {
+	return n.ns
+}
+
+// Key returns this 'cache node' key.
+func (n *Node) Key() uint64 {
+	return n.key
+}
+
+// Size returns this 'cache node' size.
+func (n *Node) Size() int {
+	return n.size
+}
+
+// Value returns this 'cache node' value.
+func (n *Node) Value() Value {
+	return n.value
+}
+
+// Ref returns this 'cache node' ref counter.
+func (n *Node) Ref() int32 {
+	return atomic.LoadInt32(&n.ref)
+}
+
+// GetHandle returns an handle for this 'cache node'.
+func (n *Node) GetHandle() *Handle {
+	if atomic.AddInt32(&n.ref, 1) <= 1 {
+		panic("BUG: Node.GetHandle on zero ref")
+	}
+	return &Handle{unsafe.Pointer(n)}
+}
+
+func (n *Node) unref() {
+	if atomic.AddInt32(&n.ref, -1) == 0 {
+		n.r.delete(n)
+	}
+}
+
+func (n *Node) unrefLocked() {
+	if atomic.AddInt32(&n.ref, -1) == 0 {
+		n.r.mu.RLock()
+		if !n.r.closed {
+			n.r.delete(n)
+		}
+		n.r.mu.RUnlock()
+	}
+}
+
+type Handle struct {
+	n unsafe.Pointer // *Node
+}
+
+func (h *Handle) Value() Value {
+	n := (*Node)(atomic.LoadPointer(&h.n))
+	if n != nil {
+		return n.value
+	}
+	return nil
+}
+
+func (h *Handle) Release() {
+	nPtr := atomic.LoadPointer(&h.n)
+	if nPtr != nil && atomic.CompareAndSwapPointer(&h.n, nPtr, nil) {
+		n := (*Node)(nPtr)
+		n.unrefLocked()
+	}
+}
+
+func murmur32(ns, key uint64, seed uint32) uint32 {
+	const (
+		m = uint32(0x5bd1e995)
+		r = 24
+	)
+
+	k1 := uint32(ns >> 32)
+	k2 := uint32(ns)
+	k3 := uint32(key >> 32)
+	k4 := uint32(key)
+
+	k1 *= m
+	k1 ^= k1 >> r
+	k1 *= m
+
+	k2 *= m
+	k2 ^= k2 >> r
+	k2 *= m
+
+	k3 *= m
+	k3 ^= k3 >> r
+	k3 *= m
+
+	k4 *= m
+	k4 ^= k4 >> r
+	k4 *= m
+
+	h := seed
+
+	h *= m
+	h ^= k1
+	h *= m
+	h ^= k2
+	h *= m
+	h ^= k3
+	h *= m
+	h ^= k4
+
+	h ^= h >> 13
+	h *= m
+	h ^= h >> 15
+
+	return h
+}
diff --git a/leveldb/cache/cache_test.go b/leveldb/cache/cache_test.go
index 865bc57..5575583 100644
--- a/leveldb/cache/cache_test.go
+++ b/leveldb/cache/cache_test.go
@@ -13,11 +13,26 @@
 	"sync/atomic"
 	"testing"
 	"time"
+	"unsafe"
 )
 
+type int32o int32
+
+func (o *int32o) acquire() {
+	if atomic.AddInt32((*int32)(o), 1) != 1 {
+		panic("BUG: invalid ref")
+	}
+}
+
+func (o *int32o) Release() {
+	if atomic.AddInt32((*int32)(o), -1) != 0 {
+		panic("BUG: invalid ref")
+	}
+}
+
 type releaserFunc struct {
 	fn    func()
-	value interface{}
+	value Value
 }
 
 func (r releaserFunc) Release() {
@@ -26,8 +41,8 @@
 	}
 }
 
-func set(ns Namespace, key uint64, value interface{}, charge int, relf func()) Handle {
-	return ns.Get(key, func() (int, interface{}) {
+func set(c *Cache, ns, key uint64, value Value, charge int, relf func()) *Handle {
+	return c.Get(ns, key, func() (int, Value) {
 		if relf != nil {
 			return charge, releaserFunc{relf, value}
 		} else {
@@ -36,7 +51,246 @@
 	})
 }
 
-func TestCache_HitMiss(t *testing.T) {
+func TestCacheMap(t *testing.T) {
+	runtime.GOMAXPROCS(runtime.NumCPU())
+
+	nsx := []struct {
+		nobjects, nhandles, concurrent, repeat int
+	}{
+		{10000, 400, 50, 3},
+		{100000, 1000, 100, 10},
+	}
+
+	var (
+		objects [][]int32o
+		handles [][]unsafe.Pointer
+	)
+
+	for _, x := range nsx {
+		objects = append(objects, make([]int32o, x.nobjects))
+		handles = append(handles, make([]unsafe.Pointer, x.nhandles))
+	}
+
+	c := NewCache(nil)
+
+	wg := new(sync.WaitGroup)
+	var done int32
+
+	for ns, x := range nsx {
+		for i := 0; i < x.concurrent; i++ {
+			wg.Add(1)
+			go func(ns, i, repeat int, objects []int32o, handles []unsafe.Pointer) {
+				defer wg.Done()
+				r := rand.New(rand.NewSource(time.Now().UnixNano()))
+
+				for j := len(objects) * repeat; j >= 0; j-- {
+					key := uint64(r.Intn(len(objects)))
+					h := c.Get(uint64(ns), key, func() (int, Value) {
+						o := &objects[key]
+						o.acquire()
+						return 1, o
+					})
+					if v := h.Value().(*int32o); v != &objects[key] {
+						t.Fatalf("#%d invalid value: want=%p got=%p", ns, &objects[key], v)
+					}
+					if objects[key] != 1 {
+						t.Fatalf("#%d invalid object %d: %d", ns, key, objects[key])
+					}
+					if !atomic.CompareAndSwapPointer(&handles[r.Intn(len(handles))], nil, unsafe.Pointer(h)) {
+						h.Release()
+					}
+				}
+			}(ns, i, x.repeat, objects[ns], handles[ns])
+		}
+
+		go func(handles []unsafe.Pointer) {
+			r := rand.New(rand.NewSource(time.Now().UnixNano()))
+
+			for atomic.LoadInt32(&done) == 0 {
+				i := r.Intn(len(handles))
+				h := (*Handle)(atomic.LoadPointer(&handles[i]))
+				if h != nil && atomic.CompareAndSwapPointer(&handles[i], unsafe.Pointer(h), nil) {
+					h.Release()
+				}
+				time.Sleep(time.Millisecond)
+			}
+		}(handles[ns])
+	}
+
+	go func() {
+		handles := make([]*Handle, 100000)
+		for atomic.LoadInt32(&done) == 0 {
+			for i := range handles {
+				handles[i] = c.Get(999999999, uint64(i), func() (int, Value) {
+					return 1, 1
+				})
+			}
+			for _, h := range handles {
+				h.Release()
+			}
+		}
+	}()
+
+	wg.Wait()
+
+	atomic.StoreInt32(&done, 1)
+
+	for _, handles0 := range handles {
+		for i := range handles0 {
+			h := (*Handle)(atomic.LoadPointer(&handles0[i]))
+			if h != nil && atomic.CompareAndSwapPointer(&handles0[i], unsafe.Pointer(h), nil) {
+				h.Release()
+			}
+		}
+	}
+
+	for ns, objects0 := range objects {
+		for i, o := range objects0 {
+			if o != 0 {
+				t.Fatalf("invalid object #%d.%d: ref=%d", ns, i, o)
+			}
+		}
+	}
+}
+
+func TestCacheMap_NodesAndSize(t *testing.T) {
+	c := NewCache(nil)
+	if c.Nodes() != 0 {
+		t.Errorf("invalid nodes counter: want=%d got=%d", 0, c.Nodes())
+	}
+	if c.Size() != 0 {
+		t.Errorf("invalid size counter: want=%d got=%d", 0, c.Size())
+	}
+	set(c, 0, 1, 1, 1, nil)
+	set(c, 0, 2, 2, 2, nil)
+	set(c, 1, 1, 3, 3, nil)
+	set(c, 2, 1, 4, 1, nil)
+	if c.Nodes() != 4 {
+		t.Errorf("invalid nodes counter: want=%d got=%d", 4, c.Nodes())
+	}
+	if c.Size() != 7 {
+		t.Errorf("invalid size counter: want=%d got=%d", 4, c.Size())
+	}
+}
+
+func TestLRUCache_Capacity(t *testing.T) {
+	c := NewCache(NewLRU(10))
+	if c.Capacity() != 10 {
+		t.Errorf("invalid capacity: want=%d got=%d", 10, c.Capacity())
+	}
+	set(c, 0, 1, 1, 1, nil).Release()
+	set(c, 0, 2, 2, 2, nil).Release()
+	set(c, 1, 1, 3, 3, nil).Release()
+	set(c, 2, 1, 4, 1, nil).Release()
+	set(c, 2, 2, 5, 1, nil).Release()
+	set(c, 2, 3, 6, 1, nil).Release()
+	set(c, 2, 4, 7, 1, nil).Release()
+	set(c, 2, 5, 8, 1, nil).Release()
+	if c.Nodes() != 7 {
+		t.Errorf("invalid nodes counter: want=%d got=%d", 7, c.Nodes())
+	}
+	if c.Size() != 10 {
+		t.Errorf("invalid size counter: want=%d got=%d", 10, c.Size())
+	}
+	c.SetCapacity(9)
+	if c.Capacity() != 9 {
+		t.Errorf("invalid capacity: want=%d got=%d", 9, c.Capacity())
+	}
+	if c.Nodes() != 6 {
+		t.Errorf("invalid nodes counter: want=%d got=%d", 6, c.Nodes())
+	}
+	if c.Size() != 8 {
+		t.Errorf("invalid size counter: want=%d got=%d", 8, c.Size())
+	}
+}
+
+func TestCacheMap_NilValue(t *testing.T) {
+	c := NewCache(NewLRU(10))
+	h := c.Get(0, 0, func() (size int, value Value) {
+		return 1, nil
+	})
+	if h != nil {
+		t.Error("cache handle is non-nil")
+	}
+	if c.Nodes() != 0 {
+		t.Errorf("invalid nodes counter: want=%d got=%d", 0, c.Nodes())
+	}
+	if c.Size() != 0 {
+		t.Errorf("invalid size counter: want=%d got=%d", 0, c.Size())
+	}
+}
+
+func TestLRUCache_GetLatency(t *testing.T) {
+	runtime.GOMAXPROCS(runtime.NumCPU())
+
+	const (
+		concurrentSet = 30
+		concurrentGet = 3
+		duration      = 3 * time.Second
+		delay         = 3 * time.Millisecond
+		maxkey        = 100000
+	)
+
+	var (
+		set, getHit, getAll        int32
+		getMaxLatency, getDuration int64
+	)
+
+	c := NewCache(NewLRU(5000))
+	wg := &sync.WaitGroup{}
+	until := time.Now().Add(duration)
+	for i := 0; i < concurrentSet; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			r := rand.New(rand.NewSource(time.Now().UnixNano()))
+			for time.Now().Before(until) {
+				c.Get(0, uint64(r.Intn(maxkey)), func() (int, Value) {
+					time.Sleep(delay)
+					atomic.AddInt32(&set, 1)
+					return 1, 1
+				}).Release()
+			}
+		}(i)
+	}
+	for i := 0; i < concurrentGet; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			r := rand.New(rand.NewSource(time.Now().UnixNano()))
+			for {
+				mark := time.Now()
+				if mark.Before(until) {
+					h := c.Get(0, uint64(r.Intn(maxkey)), nil)
+					latency := int64(time.Now().Sub(mark))
+					m := atomic.LoadInt64(&getMaxLatency)
+					if latency > m {
+						atomic.CompareAndSwapInt64(&getMaxLatency, m, latency)
+					}
+					atomic.AddInt64(&getDuration, latency)
+					if h != nil {
+						atomic.AddInt32(&getHit, 1)
+						h.Release()
+					}
+					atomic.AddInt32(&getAll, 1)
+				} else {
+					break
+				}
+			}
+		}(i)
+	}
+
+	wg.Wait()
+	getAvglatency := time.Duration(getDuration) / time.Duration(getAll)
+	t.Logf("set=%d getHit=%d getAll=%d getMaxLatency=%v getAvgLatency=%v",
+		set, getHit, getAll, time.Duration(getMaxLatency), getAvglatency)
+
+	if getAvglatency > delay/3 {
+		t.Errorf("get avg latency > %v: got=%v", delay/3, getAvglatency)
+	}
+}
+
+func TestLRUCache_HitMiss(t *testing.T) {
 	cases := []struct {
 		key   uint64
 		value string
@@ -54,14 +308,13 @@
 	}
 
 	setfin := 0
-	c := NewLRUCache(1000)
-	ns := c.GetNamespace(0)
+	c := NewCache(NewLRU(1000))
 	for i, x := range cases {
-		set(ns, x.key, x.value, len(x.value), func() {
+		set(c, 0, x.key, x.value, len(x.value), func() {
 			setfin++
 		}).Release()
 		for j, y := range cases {
-			h := ns.Get(y.key, nil)
+			h := c.Get(0, y.key, nil)
 			if j <= i {
 				// should hit
 				if h == nil {
@@ -85,7 +338,7 @@
 
 	for i, x := range cases {
 		finalizerOk := false
-		ns.Delete(x.key, func(exist, pending bool) {
+		c.Delete(0, x.key, func() {
 			finalizerOk = true
 		})
 
@@ -94,7 +347,7 @@
 		}
 
 		for j, y := range cases {
-			h := ns.Get(y.key, nil)
+			h := c.Get(0, y.key, nil)
 			if j > i {
 				// should hit
 				if h == nil {
@@ -122,20 +375,19 @@
 }
 
 func TestLRUCache_Eviction(t *testing.T) {
-	c := NewLRUCache(12)
-	ns := c.GetNamespace(0)
-	o1 := set(ns, 1, 1, 1, nil)
-	set(ns, 2, 2, 1, nil).Release()
-	set(ns, 3, 3, 1, nil).Release()
-	set(ns, 4, 4, 1, nil).Release()
-	set(ns, 5, 5, 1, nil).Release()
-	if h := ns.Get(2, nil); h != nil { // 1,3,4,5,2
+	c := NewCache(NewLRU(12))
+	o1 := set(c, 0, 1, 1, 1, nil)
+	set(c, 0, 2, 2, 1, nil).Release()
+	set(c, 0, 3, 3, 1, nil).Release()
+	set(c, 0, 4, 4, 1, nil).Release()
+	set(c, 0, 5, 5, 1, nil).Release()
+	if h := c.Get(0, 2, nil); h != nil { // 1,3,4,5,2
 		h.Release()
 	}
-	set(ns, 9, 9, 10, nil).Release() // 5,2,9
+	set(c, 0, 9, 9, 10, nil).Release() // 5,2,9
 
 	for _, key := range []uint64{9, 2, 5, 1} {
-		h := ns.Get(key, nil)
+		h := c.Get(0, key, nil)
 		if h == nil {
 			t.Errorf("miss for key '%d'", key)
 		} else {
@@ -147,7 +399,7 @@
 	}
 	o1.Release()
 	for _, key := range []uint64{1, 2, 5} {
-		h := ns.Get(key, nil)
+		h := c.Get(0, key, nil)
 		if h == nil {
 			t.Errorf("miss for key '%d'", key)
 		} else {
@@ -158,7 +410,7 @@
 		}
 	}
 	for _, key := range []uint64{3, 4, 9} {
-		h := ns.Get(key, nil)
+		h := c.Get(0, key, nil)
 		if h != nil {
 			t.Errorf("hit for key '%d'", key)
 			if x := h.Value().(int); x != int(key) {
@@ -169,487 +421,150 @@
 	}
 }
 
-func TestLRUCache_SetGet(t *testing.T) {
-	c := NewLRUCache(13)
-	ns := c.GetNamespace(0)
-	for i := 0; i < 200; i++ {
-		n := uint64(rand.Intn(99999) % 20)
-		set(ns, n, n, 1, nil).Release()
-		if h := ns.Get(n, nil); h != nil {
-			if h.Value() == nil {
-				t.Errorf("key '%d' contains nil value", n)
+func TestLRUCache_Evict(t *testing.T) {
+	c := NewCache(NewLRU(6))
+	set(c, 0, 1, 1, 1, nil).Release()
+	set(c, 0, 2, 2, 1, nil).Release()
+	set(c, 1, 1, 4, 1, nil).Release()
+	set(c, 1, 2, 5, 1, nil).Release()
+	set(c, 2, 1, 6, 1, nil).Release()
+	set(c, 2, 2, 7, 1, nil).Release()
+
+	for ns := 0; ns < 3; ns++ {
+		for key := 1; key < 3; key++ {
+			if h := c.Get(uint64(ns), uint64(key), nil); h != nil {
+				h.Release()
 			} else {
-				if x := h.Value().(uint64); x != n {
-					t.Errorf("invalid value for key '%d' want '%d', got '%d'", n, n, x)
-				}
+				t.Errorf("Cache.Get on #%d.%d return nil", ns, key)
 			}
+		}
+	}
+
+	if ok := c.Evict(0, 1); !ok {
+		t.Error("first Cache.Evict on #0.1 return false")
+	}
+	if ok := c.Evict(0, 1); ok {
+		t.Error("second Cache.Evict on #0.1 return true")
+	}
+	if h := c.Get(0, 1, nil); h != nil {
+		t.Errorf("Cache.Get on #0.1 return non-nil: %v", h.Value())
+	}
+
+	c.EvictNS(1)
+	if h := c.Get(1, 1, nil); h != nil {
+		t.Errorf("Cache.Get on #1.1 return non-nil: %v", h.Value())
+	}
+	if h := c.Get(1, 2, nil); h != nil {
+		t.Errorf("Cache.Get on #1.2 return non-nil: %v", h.Value())
+	}
+
+	c.EvictAll()
+	for ns := 0; ns < 3; ns++ {
+		for key := 1; key < 3; key++ {
+			if h := c.Get(uint64(ns), uint64(key), nil); h != nil {
+				t.Errorf("Cache.Get on #%d.%d return non-nil: %v", ns, key, h.Value())
+			}
+		}
+	}
+}
+
+func TestLRUCache_Delete(t *testing.T) {
+	delFuncCalled := 0
+	delFunc := func() {
+		delFuncCalled++
+	}
+
+	c := NewCache(NewLRU(2))
+	set(c, 0, 1, 1, 1, nil).Release()
+	set(c, 0, 2, 2, 1, nil).Release()
+
+	if ok := c.Delete(0, 1, delFunc); !ok {
+		t.Error("Cache.Delete on #1 return false")
+	}
+	if h := c.Get(0, 1, nil); h != nil {
+		t.Errorf("Cache.Get on #1 return non-nil: %v", h.Value())
+	}
+	if ok := c.Delete(0, 1, delFunc); ok {
+		t.Error("Cache.Delete on #1 return true")
+	}
+
+	h2 := c.Get(0, 2, nil)
+	if h2 == nil {
+		t.Error("Cache.Get on #2 return nil")
+	}
+	if ok := c.Delete(0, 2, delFunc); !ok {
+		t.Error("(1) Cache.Delete on #2 return false")
+	}
+	if ok := c.Delete(0, 2, delFunc); !ok {
+		t.Error("(2) Cache.Delete on #2 return false")
+	}
+
+	set(c, 0, 3, 3, 1, nil).Release()
+	set(c, 0, 4, 4, 1, nil).Release()
+	c.Get(0, 2, nil).Release()
+
+	for key := 2; key <= 4; key++ {
+		if h := c.Get(0, uint64(key), nil); h != nil {
 			h.Release()
 		} else {
-			t.Errorf("key '%d' doesn't exist", n)
-		}
-	}
-}
-
-func TestLRUCache_Purge(t *testing.T) {
-	c := NewLRUCache(3)
-	ns1 := c.GetNamespace(0)
-	o1 := set(ns1, 1, 1, 1, nil)
-	o2 := set(ns1, 2, 2, 1, nil)
-	ns1.Purge(nil)
-	set(ns1, 3, 3, 1, nil).Release()
-	for _, key := range []uint64{1, 2, 3} {
-		h := ns1.Get(key, nil)
-		if h == nil {
-			t.Errorf("miss for key '%d'", key)
-		} else {
-			if x := h.Value().(int); x != int(key) {
-				t.Errorf("invalid value for key '%d' want '%d', got '%d'", key, key, x)
-			}
-			h.Release()
-		}
-	}
-	o1.Release()
-	o2.Release()
-	for _, key := range []uint64{1, 2} {
-		h := ns1.Get(key, nil)
-		if h != nil {
-			t.Errorf("hit for key '%d'", key)
-			if x := h.Value().(int); x != int(key) {
-				t.Errorf("invalid value for key '%d' want '%d', got '%d'", key, key, x)
-			}
-			h.Release()
-		}
-	}
-}
-
-type testingCacheObjectCounter struct {
-	created  uint
-	released uint
-}
-
-func (c *testingCacheObjectCounter) createOne() {
-	c.created++
-}
-
-func (c *testingCacheObjectCounter) releaseOne() {
-	c.released++
-}
-
-type testingCacheObject struct {
-	t   *testing.T
-	cnt *testingCacheObjectCounter
-
-	ns, key uint64
-
-	releaseCalled bool
-}
-
-func (x *testingCacheObject) Release() {
-	if !x.releaseCalled {
-		x.releaseCalled = true
-		x.cnt.releaseOne()
-	} else {
-		x.t.Errorf("duplicate setfin NS#%d KEY#%d", x.ns, x.key)
-	}
-}
-
-func TestLRUCache_ConcurrentSetGet(t *testing.T) {
-	runtime.GOMAXPROCS(runtime.NumCPU())
-
-	seed := time.Now().UnixNano()
-	t.Logf("seed=%d", seed)
-
-	const (
-		N = 2000000
-		M = 4000
-		C = 3
-	)
-
-	var set, get uint32
-
-	wg := &sync.WaitGroup{}
-	c := NewLRUCache(M / 4)
-	for ni := uint64(0); ni < C; ni++ {
-		r0 := rand.New(rand.NewSource(seed + int64(ni)))
-		r1 := rand.New(rand.NewSource(seed + int64(ni) + 1))
-		ns := c.GetNamespace(ni)
-
-		wg.Add(2)
-		go func(ns Namespace, r *rand.Rand) {
-			for i := 0; i < N; i++ {
-				x := uint64(r.Int63n(M))
-				o := ns.Get(x, func() (int, interface{}) {
-					atomic.AddUint32(&set, 1)
-					return 1, x
-				})
-				if v := o.Value().(uint64); v != x {
-					t.Errorf("#%d invalid value, got=%d", x, v)
-				}
-				o.Release()
-			}
-			wg.Done()
-		}(ns, r0)
-		go func(ns Namespace, r *rand.Rand) {
-			for i := 0; i < N; i++ {
-				x := uint64(r.Int63n(M))
-				o := ns.Get(x, nil)
-				if o != nil {
-					atomic.AddUint32(&get, 1)
-					if v := o.Value().(uint64); v != x {
-						t.Errorf("#%d invalid value, got=%d", x, v)
-					}
-					o.Release()
-				}
-			}
-			wg.Done()
-		}(ns, r1)
-	}
-
-	wg.Wait()
-
-	t.Logf("set=%d get=%d", set, get)
-}
-
-func TestLRUCache_Finalizer(t *testing.T) {
-	const (
-		capacity   = 100
-		goroutines = 100
-		iterations = 10000
-		keymax     = 8000
-	)
-
-	cnt := &testingCacheObjectCounter{}
-
-	c := NewLRUCache(capacity)
-
-	type instance struct {
-		seed       int64
-		rnd        *rand.Rand
-		nsid       uint64
-		ns         Namespace
-		effective  int
-		handles    []Handle
-		handlesMap map[uint64]int
-
-		delete          bool
-		purge           bool
-		zap             bool
-		wantDel         int
-		delfinCalled    int
-		delfinCalledAll int
-		delfinCalledEff int
-		purgefinCalled  int
-	}
-
-	instanceGet := func(p *instance, key uint64) {
-		h := p.ns.Get(key, func() (charge int, value interface{}) {
-			to := &testingCacheObject{
-				t: t, cnt: cnt,
-				ns:  p.nsid,
-				key: key,
-			}
-			p.effective++
-			cnt.createOne()
-			return 1, releaserFunc{func() {
-				to.Release()
-				p.effective--
-			}, to}
-		})
-		p.handles = append(p.handles, h)
-		p.handlesMap[key] = p.handlesMap[key] + 1
-	}
-	instanceRelease := func(p *instance, i int) {
-		h := p.handles[i]
-		key := h.Value().(releaserFunc).value.(*testingCacheObject).key
-		if n := p.handlesMap[key]; n == 0 {
-			t.Fatal("key ref == 0")
-		} else if n > 1 {
-			p.handlesMap[key] = n - 1
-		} else {
-			delete(p.handlesMap, key)
-		}
-		h.Release()
-		p.handles = append(p.handles[:i], p.handles[i+1:]...)
-		p.handles[len(p.handles) : len(p.handles)+1][0] = nil
-	}
-
-	seed := time.Now().UnixNano()
-	t.Logf("seed=%d", seed)
-
-	instances := make([]*instance, goroutines)
-	for i := range instances {
-		p := &instance{}
-		p.handlesMap = make(map[uint64]int)
-		p.seed = seed + int64(i)
-		p.rnd = rand.New(rand.NewSource(p.seed))
-		p.nsid = uint64(i)
-		p.ns = c.GetNamespace(p.nsid)
-		p.delete = i%6 == 0
-		p.purge = i%8 == 0
-		p.zap = i%12 == 0 || i%3 == 0
-		instances[i] = p
-	}
-
-	runr := rand.New(rand.NewSource(seed - 1))
-	run := func(rnd *rand.Rand, x []*instance, init func(p *instance) bool, fn func(p *instance, i int) bool) {
-		var (
-			rx []*instance
-			rn []int
-		)
-		if init == nil {
-			rx = append([]*instance{}, x...)
-			rn = make([]int, len(x))
-		} else {
-			for _, p := range x {
-				if init(p) {
-					rx = append(rx, p)
-					rn = append(rn, 0)
-				}
-			}
-		}
-		for len(rx) > 0 {
-			i := rand.Intn(len(rx))
-			if fn(rx[i], rn[i]) {
-				rn[i]++
-			} else {
-				rx = append(rx[:i], rx[i+1:]...)
-				rn = append(rn[:i], rn[i+1:]...)
-			}
+			t.Errorf("Cache.Get on #%d return nil", key)
 		}
 	}
 
-	// Get and release.
-	run(runr, instances, nil, func(p *instance, i int) bool {
-		if i < iterations {
-			if len(p.handles) == 0 || p.rnd.Int()%2 == 0 {
-				instanceGet(p, uint64(p.rnd.Intn(keymax)))
-			} else {
-				instanceRelease(p, p.rnd.Intn(len(p.handles)))
-			}
-			return true
-		} else {
-			return false
+	h2.Release()
+	if h := c.Get(0, 2, nil); h != nil {
+		t.Errorf("Cache.Get on #2 return non-nil: %v", h.Value())
+	}
+
+	if delFuncCalled != 4 {
+		t.Errorf("delFunc isn't called 4 times: got=%d", delFuncCalled)
+	}
+}
+
+func TestLRUCache_Close(t *testing.T) {
+	relFuncCalled := 0
+	relFunc := func() {
+		relFuncCalled++
+	}
+	delFuncCalled := 0
+	delFunc := func() {
+		delFuncCalled++
+	}
+
+	c := NewCache(NewLRU(2))
+	set(c, 0, 1, 1, 1, relFunc).Release()
+	set(c, 0, 2, 2, 1, relFunc).Release()
+
+	h3 := set(c, 0, 3, 3, 1, relFunc)
+	if h3 == nil {
+		t.Error("Cache.Get on #3 return nil")
+	}
+	if ok := c.Delete(0, 3, delFunc); !ok {
+		t.Error("Cache.Delete on #3 return false")
+	}
+
+	c.Close()
+
+	if relFuncCalled != 3 {
+		t.Errorf("relFunc isn't called 3 times: got=%d", relFuncCalled)
+	}
+	if delFuncCalled != 1 {
+		t.Errorf("delFunc isn't called 1 times: got=%d", delFuncCalled)
+	}
+}
+
+func BenchmarkLRUCache(b *testing.B) {
+	c := NewCache(NewLRU(10000))
+
+	b.SetParallelism(10)
+	b.RunParallel(func(pb *testing.PB) {
+		r := rand.New(rand.NewSource(time.Now().UnixNano()))
+
+		for pb.Next() {
+			key := uint64(r.Intn(1000000))
+			c.Get(0, key, func() (int, Value) {
+				return 1, key
+			}).Release()
 		}
 	})
-
-	if used, cap := c.Used(), c.Capacity(); used > cap {
-		t.Errorf("Used > capacity, used=%d cap=%d", used, cap)
-	}
-
-	// Check effective objects.
-	for i, p := range instances {
-		if int(p.effective) < len(p.handlesMap) {
-			t.Errorf("#%d effective objects < acquired handle, eo=%d ah=%d", i, p.effective, len(p.handlesMap))
-		}
-	}
-
-	if want := int(cnt.created - cnt.released); c.Size() != want {
-		t.Errorf("Invalid cache size, want=%d got=%d", want, c.Size())
-	}
-
-	// First delete.
-	run(runr, instances, func(p *instance) bool {
-		p.wantDel = p.effective
-		return p.delete
-	}, func(p *instance, i int) bool {
-		key := uint64(i)
-		if key < keymax {
-			_, wantExist := p.handlesMap[key]
-			gotExist := p.ns.Delete(key, func(exist, pending bool) {
-				p.delfinCalledAll++
-				if exist {
-					p.delfinCalledEff++
-				}
-			})
-			if !gotExist && wantExist {
-				t.Errorf("delete on NS#%d KEY#%d not found", p.nsid, key)
-			}
-			return true
-		} else {
-			return false
-		}
-	})
-
-	// Second delete.
-	run(runr, instances, func(p *instance) bool {
-		p.delfinCalled = 0
-		return p.delete
-	}, func(p *instance, i int) bool {
-		key := uint64(i)
-		if key < keymax {
-			gotExist := p.ns.Delete(key, func(exist, pending bool) {
-				if exist && !pending {
-					t.Errorf("delete fin on NS#%d KEY#%d exist and not pending for deletion", p.nsid, key)
-				}
-				p.delfinCalled++
-			})
-			if gotExist {
-				t.Errorf("delete on NS#%d KEY#%d found", p.nsid, key)
-			}
-			return true
-		} else {
-			if p.delfinCalled != keymax {
-				t.Errorf("(2) NS#%d not all delete fin called, diff=%d", p.nsid, keymax-p.delfinCalled)
-			}
-			return false
-		}
-	})
-
-	// Purge.
-	run(runr, instances, func(p *instance) bool {
-		return p.purge
-	}, func(p *instance, i int) bool {
-		p.ns.Purge(func(ns, key uint64) {
-			p.purgefinCalled++
-		})
-		return false
-	})
-
-	if want := int(cnt.created - cnt.released); c.Size() != want {
-		t.Errorf("Invalid cache size, want=%d got=%d", want, c.Size())
-	}
-
-	// Release.
-	run(runr, instances, func(p *instance) bool {
-		return !p.zap
-	}, func(p *instance, i int) bool {
-		if len(p.handles) > 0 {
-			instanceRelease(p, len(p.handles)-1)
-			return true
-		} else {
-			return false
-		}
-	})
-
-	if want := int(cnt.created - cnt.released); c.Size() != want {
-		t.Errorf("Invalid cache size, want=%d got=%d", want, c.Size())
-	}
-
-	// Zap.
-	run(runr, instances, func(p *instance) bool {
-		return p.zap
-	}, func(p *instance, i int) bool {
-		p.ns.Zap()
-		p.handles = nil
-		p.handlesMap = nil
-		return false
-	})
-
-	if want := int(cnt.created - cnt.released); c.Size() != want {
-		t.Errorf("Invalid cache size, want=%d got=%d", want, c.Size())
-	}
-
-	if notrel, used := int(cnt.created-cnt.released), c.Used(); notrel != used {
-		t.Errorf("Invalid used value, want=%d got=%d", notrel, used)
-	}
-
-	c.Purge(nil)
-
-	for _, p := range instances {
-		if p.delete {
-			if p.delfinCalledAll != keymax {
-				t.Errorf("#%d not all delete fin called, purge=%v zap=%v diff=%d", p.nsid, p.purge, p.zap, keymax-p.delfinCalledAll)
-			}
-			if p.delfinCalledEff != p.wantDel {
-				t.Errorf("#%d not all effective delete fin called, diff=%d", p.nsid, p.wantDel-p.delfinCalledEff)
-			}
-			if p.purge && p.purgefinCalled > 0 {
-				t.Errorf("#%d some purge fin called, delete=%v zap=%v n=%d", p.nsid, p.delete, p.zap, p.purgefinCalled)
-			}
-		} else {
-			if p.purge {
-				if p.purgefinCalled != p.wantDel {
-					t.Errorf("#%d not all purge fin called, delete=%v zap=%v diff=%d", p.nsid, p.delete, p.zap, p.wantDel-p.purgefinCalled)
-				}
-			}
-		}
-	}
-
-	if cnt.created != cnt.released {
-		t.Errorf("Some cache object weren't released, created=%d released=%d", cnt.created, cnt.released)
-	}
-}
-
-func BenchmarkLRUCache_Set(b *testing.B) {
-	c := NewLRUCache(0)
-	ns := c.GetNamespace(0)
-	b.ResetTimer()
-	for i := uint64(0); i < uint64(b.N); i++ {
-		set(ns, i, "", 1, nil)
-	}
-}
-
-func BenchmarkLRUCache_Get(b *testing.B) {
-	c := NewLRUCache(0)
-	ns := c.GetNamespace(0)
-	b.ResetTimer()
-	for i := uint64(0); i < uint64(b.N); i++ {
-		set(ns, i, "", 1, nil)
-	}
-	b.ResetTimer()
-	for i := uint64(0); i < uint64(b.N); i++ {
-		ns.Get(i, nil)
-	}
-}
-
-func BenchmarkLRUCache_Get2(b *testing.B) {
-	c := NewLRUCache(0)
-	ns := c.GetNamespace(0)
-	b.ResetTimer()
-	for i := uint64(0); i < uint64(b.N); i++ {
-		set(ns, i, "", 1, nil)
-	}
-	b.ResetTimer()
-	for i := uint64(0); i < uint64(b.N); i++ {
-		ns.Get(i, func() (charge int, value interface{}) {
-			return 0, nil
-		})
-	}
-}
-
-func BenchmarkLRUCache_Release(b *testing.B) {
-	c := NewLRUCache(0)
-	ns := c.GetNamespace(0)
-	handles := make([]Handle, b.N)
-	for i := uint64(0); i < uint64(b.N); i++ {
-		handles[i] = set(ns, i, "", 1, nil)
-	}
-	b.ResetTimer()
-	for _, h := range handles {
-		h.Release()
-	}
-}
-
-func BenchmarkLRUCache_SetRelease(b *testing.B) {
-	capacity := b.N / 100
-	if capacity <= 0 {
-		capacity = 10
-	}
-	c := NewLRUCache(capacity)
-	ns := c.GetNamespace(0)
-	b.ResetTimer()
-	for i := uint64(0); i < uint64(b.N); i++ {
-		set(ns, i, "", 1, nil).Release()
-	}
-}
-
-func BenchmarkLRUCache_SetReleaseTwice(b *testing.B) {
-	capacity := b.N / 100
-	if capacity <= 0 {
-		capacity = 10
-	}
-	c := NewLRUCache(capacity)
-	ns := c.GetNamespace(0)
-	b.ResetTimer()
-
-	na := b.N / 2
-	nb := b.N - na
-
-	for i := uint64(0); i < uint64(na); i++ {
-		set(ns, i, "", 1, nil).Release()
-	}
-
-	for i := uint64(0); i < uint64(nb); i++ {
-		set(ns, i, "", 1, nil).Release()
-	}
 }
diff --git a/leveldb/cache/lru.go b/leveldb/cache/lru.go
new file mode 100644
index 0000000..d9a84cd
--- /dev/null
+++ b/leveldb/cache/lru.go
@@ -0,0 +1,195 @@
+// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
+// All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package cache
+
+import (
+	"sync"
+	"unsafe"
+)
+
+type lruNode struct {
+	n   *Node
+	h   *Handle
+	ban bool
+
+	next, prev *lruNode
+}
+
+func (n *lruNode) insert(at *lruNode) {
+	x := at.next
+	at.next = n
+	n.prev = at
+	n.next = x
+	x.prev = n
+}
+
+func (n *lruNode) remove() {
+	if n.prev != nil {
+		n.prev.next = n.next
+		n.next.prev = n.prev
+		n.prev = nil
+		n.next = nil
+	} else {
+		panic("BUG: removing removed node")
+	}
+}
+
+type lru struct {
+	mu       sync.Mutex
+	capacity int
+	used     int
+	recent   lruNode
+}
+
+func (r *lru) reset() {
+	r.recent.next = &r.recent
+	r.recent.prev = &r.recent
+	r.used = 0
+}
+
+func (r *lru) Capacity() int {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	return r.capacity
+}
+
+func (r *lru) SetCapacity(capacity int) {
+	var evicted []*lruNode
+
+	r.mu.Lock()
+	r.capacity = capacity
+	for r.used > r.capacity {
+		rn := r.recent.prev
+		if rn == nil {
+			panic("BUG: invalid LRU used or capacity counter")
+		}
+		rn.remove()
+		rn.n.CacheData = nil
+		r.used -= rn.n.Size()
+		evicted = append(evicted, rn)
+	}
+	r.mu.Unlock()
+
+	for _, rn := range evicted {
+		rn.h.Release()
+	}
+}
+
+func (r *lru) Promote(n *Node) {
+	var evicted []*lruNode
+
+	r.mu.Lock()
+	if n.CacheData == nil {
+		if n.Size() <= r.capacity {
+			rn := &lruNode{n: n, h: n.GetHandle()}
+			rn.insert(&r.recent)
+			n.CacheData = unsafe.Pointer(rn)
+			r.used += n.Size()
+
+			for r.used > r.capacity {
+				rn := r.recent.prev
+				if rn == nil {
+					panic("BUG: invalid LRU used or capacity counter")
+				}
+				rn.remove()
+				rn.n.CacheData = nil
+				r.used -= rn.n.Size()
+				evicted = append(evicted, rn)
+			}
+		}
+	} else {
+		rn := (*lruNode)(n.CacheData)
+		if !rn.ban {
+			rn.remove()
+			rn.insert(&r.recent)
+		}
+	}
+	r.mu.Unlock()
+
+	for _, rn := range evicted {
+		rn.h.Release()
+	}
+}
+
+func (r *lru) Ban(n *Node) {
+	r.mu.Lock()
+	if n.CacheData == nil {
+		n.CacheData = unsafe.Pointer(&lruNode{n: n, ban: true})
+	} else {
+		rn := (*lruNode)(n.CacheData)
+		if !rn.ban {
+			rn.remove()
+			rn.ban = true
+			r.used -= rn.n.Size()
+			r.mu.Unlock()
+
+			rn.h.Release()
+			rn.h = nil
+			return
+		}
+	}
+	r.mu.Unlock()
+}
+
+func (r *lru) Evict(n *Node) {
+	r.mu.Lock()
+	rn := (*lruNode)(n.CacheData)
+	if rn == nil || rn.ban {
+		r.mu.Unlock()
+		return
+	}
+	n.CacheData = nil
+	r.mu.Unlock()
+
+	rn.h.Release()
+}
+
+func (r *lru) EvictNS(ns uint64) {
+	var evicted []*lruNode
+
+	r.mu.Lock()
+	for e := r.recent.prev; e != &r.recent; {
+		rn := e
+		e = e.prev
+		if rn.n.NS() == ns {
+			rn.remove()
+			rn.n.CacheData = nil
+			r.used -= rn.n.Size()
+			evicted = append(evicted, rn)
+		}
+	}
+	r.mu.Unlock()
+
+	for _, rn := range evicted {
+		rn.h.Release()
+	}
+}
+
+func (r *lru) EvictAll() {
+	r.mu.Lock()
+	back := r.recent.prev
+	for rn := back; rn != &r.recent; rn = rn.prev {
+		rn.n.CacheData = nil
+	}
+	r.reset()
+	r.mu.Unlock()
+
+	for rn := back; rn != &r.recent; rn = rn.prev {
+		rn.h.Release()
+	}
+}
+
+func (r *lru) Close() error {
+	return nil
+}
+
+// NewLRU create a new LRU-cache.
+func NewLRU(capacity int) Cacher {
+	r := &lru{capacity: capacity}
+	r.reset()
+	return r
+}
diff --git a/leveldb/cache/lru_cache.go b/leveldb/cache/lru_cache.go
deleted file mode 100644
index d56c6ea..0000000
--- a/leveldb/cache/lru_cache.go
+++ /dev/null
@@ -1,622 +0,0 @@
-// Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com>
-// All rights reserved.
-//
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package cache
-
-import (
-	"sync"
-	"sync/atomic"
-
-	"github.com/syndtr/goleveldb/leveldb/util"
-)
-
-// The LLRB implementation were taken from https://github.com/petar/GoLLRB.
-// Which contains the following header:
-//
-// Copyright 2010 Petar Maymounkov. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// lruCache represent a LRU cache state.
-type lruCache struct {
-	mu                sync.Mutex
-	recent            lruNode
-	table             map[uint64]*lruNs
-	capacity          int
-	used, size, alive int
-}
-
-// NewLRUCache creates a new initialized LRU cache with the given capacity.
-func NewLRUCache(capacity int) Cache {
-	c := &lruCache{
-		table:    make(map[uint64]*lruNs),
-		capacity: capacity,
-	}
-	c.recent.rNext = &c.recent
-	c.recent.rPrev = &c.recent
-	return c
-}
-
-func (c *lruCache) Capacity() int {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.capacity
-}
-
-func (c *lruCache) Used() int {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.used
-}
-
-func (c *lruCache) Size() int {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.size
-}
-
-func (c *lruCache) NumObjects() int {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.alive
-}
-
-// SetCapacity set cache capacity.
-func (c *lruCache) SetCapacity(capacity int) {
-	c.mu.Lock()
-	c.capacity = capacity
-	c.evict()
-	c.mu.Unlock()
-}
-
-// GetNamespace return namespace object for given id.
-func (c *lruCache) GetNamespace(id uint64) Namespace {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	if ns, ok := c.table[id]; ok {
-		return ns
-	}
-
-	ns := &lruNs{lru: c, id: id}
-	c.table[id] = ns
-	return ns
-}
-
-func (c *lruCache) ZapNamespace(id uint64) {
-	c.mu.Lock()
-	if ns, exist := c.table[id]; exist {
-		ns.zapNB()
-		delete(c.table, id)
-	}
-	c.mu.Unlock()
-}
-
-func (c *lruCache) PurgeNamespace(id uint64, fin PurgeFin) {
-	c.mu.Lock()
-	if ns, exist := c.table[id]; exist {
-		ns.purgeNB(fin)
-	}
-	c.mu.Unlock()
-}
-
-// Purge purge entire cache.
-func (c *lruCache) Purge(fin PurgeFin) {
-	c.mu.Lock()
-	for _, ns := range c.table {
-		ns.purgeNB(fin)
-	}
-	c.mu.Unlock()
-}
-
-func (c *lruCache) Zap() {
-	c.mu.Lock()
-	for _, ns := range c.table {
-		ns.zapNB()
-	}
-	c.table = make(map[uint64]*lruNs)
-	c.mu.Unlock()
-}
-
-func (c *lruCache) evict() {
-	top := &c.recent
-	for n := c.recent.rPrev; c.used > c.capacity && n != top; {
-		if n.state != nodeEffective {
-			panic("evicting non effective node")
-		}
-		n.state = nodeEvicted
-		n.rRemove()
-		n.derefNB()
-		c.used -= n.charge
-		n = c.recent.rPrev
-	}
-}
-
-type lruNs struct {
-	lru    *lruCache
-	id     uint64
-	rbRoot *lruNode
-	state  nsState
-}
-
-func (ns *lruNs) rbGetOrCreateNode(h *lruNode, key uint64) (hn, n *lruNode) {
-	if h == nil {
-		n = &lruNode{ns: ns, key: key}
-		return n, n
-	}
-
-	if key < h.key {
-		hn, n = ns.rbGetOrCreateNode(h.rbLeft, key)
-		if hn != nil {
-			h.rbLeft = hn
-		} else {
-			return nil, n
-		}
-	} else if key > h.key {
-		hn, n = ns.rbGetOrCreateNode(h.rbRight, key)
-		if hn != nil {
-			h.rbRight = hn
-		} else {
-			return nil, n
-		}
-	} else {
-		return nil, h
-	}
-
-	if rbIsRed(h.rbRight) && !rbIsRed(h.rbLeft) {
-		h = rbRotLeft(h)
-	}
-	if rbIsRed(h.rbLeft) && rbIsRed(h.rbLeft.rbLeft) {
-		h = rbRotRight(h)
-	}
-	if rbIsRed(h.rbLeft) && rbIsRed(h.rbRight) {
-		rbFlip(h)
-	}
-	return h, n
-}
-
-func (ns *lruNs) getOrCreateNode(key uint64) *lruNode {
-	hn, n := ns.rbGetOrCreateNode(ns.rbRoot, key)
-	if hn != nil {
-		ns.rbRoot = hn
-		ns.rbRoot.rbBlack = true
-	}
-	return n
-}
-
-func (ns *lruNs) rbGetNode(key uint64) *lruNode {
-	h := ns.rbRoot
-	for h != nil {
-		switch {
-		case key < h.key:
-			h = h.rbLeft
-		case key > h.key:
-			h = h.rbRight
-		default:
-			return h
-		}
-	}
-	return nil
-}
-
-func (ns *lruNs) getNode(key uint64) *lruNode {
-	return ns.rbGetNode(key)
-}
-
-func (ns *lruNs) rbDeleteNode(h *lruNode, key uint64) *lruNode {
-	if h == nil {
-		return nil
-	}
-
-	if key < h.key {
-		if h.rbLeft == nil { // key not present. Nothing to delete
-			return h
-		}
-		if !rbIsRed(h.rbLeft) && !rbIsRed(h.rbLeft.rbLeft) {
-			h = rbMoveLeft(h)
-		}
-		h.rbLeft = ns.rbDeleteNode(h.rbLeft, key)
-	} else {
-		if rbIsRed(h.rbLeft) {
-			h = rbRotRight(h)
-		}
-		// If @key equals @h.key and no right children at @h
-		if h.key == key && h.rbRight == nil {
-			return nil
-		}
-		if h.rbRight != nil && !rbIsRed(h.rbRight) && !rbIsRed(h.rbRight.rbLeft) {
-			h = rbMoveRight(h)
-		}
-		// If @key equals @h.key, and (from above) 'h.Right != nil'
-		if h.key == key {
-			var x *lruNode
-			h.rbRight, x = rbDeleteMin(h.rbRight)
-			if x == nil {
-				panic("logic")
-			}
-			x.rbLeft, h.rbLeft = h.rbLeft, nil
-			x.rbRight, h.rbRight = h.rbRight, nil
-			x.rbBlack = h.rbBlack
-			h = x
-		} else { // Else, @key is bigger than @h.key
-			h.rbRight = ns.rbDeleteNode(h.rbRight, key)
-		}
-	}
-
-	return rbFixup(h)
-}
-
-func (ns *lruNs) deleteNode(key uint64) {
-	ns.rbRoot = ns.rbDeleteNode(ns.rbRoot, key)
-	if ns.rbRoot != nil {
-		ns.rbRoot.rbBlack = true
-	}
-}
-
-func (ns *lruNs) rbIterateNodes(h *lruNode, pivot uint64, iter func(n *lruNode) bool) bool {
-	if h == nil {
-		return true
-	}
-	if h.key >= pivot {
-		if !ns.rbIterateNodes(h.rbLeft, pivot, iter) {
-			return false
-		}
-		if !iter(h) {
-			return false
-		}
-	}
-	return ns.rbIterateNodes(h.rbRight, pivot, iter)
-}
-
-func (ns *lruNs) iterateNodes(iter func(n *lruNode) bool) {
-	ns.rbIterateNodes(ns.rbRoot, 0, iter)
-}
-
-func (ns *lruNs) Get(key uint64, setf SetFunc) Handle {
-	ns.lru.mu.Lock()
-	defer ns.lru.mu.Unlock()
-
-	if ns.state != nsEffective {
-		return nil
-	}
-
-	var n *lruNode
-	if setf == nil {
-		n = ns.getNode(key)
-		if n == nil {
-			return nil
-		}
-	} else {
-		n = ns.getOrCreateNode(key)
-	}
-	switch n.state {
-	case nodeZero:
-		charge, value := setf()
-		if value == nil {
-			ns.deleteNode(key)
-			return nil
-		}
-		if charge < 0 {
-			charge = 0
-		}
-
-		n.value = value
-		n.charge = charge
-		n.state = nodeEvicted
-
-		ns.lru.size += charge
-		ns.lru.alive++
-
-		fallthrough
-	case nodeEvicted:
-		if n.charge == 0 {
-			break
-		}
-
-		// Insert to recent list.
-		n.state = nodeEffective
-		n.ref++
-		ns.lru.used += n.charge
-		ns.lru.evict()
-
-		fallthrough
-	case nodeEffective:
-		// Bump to front.
-		n.rRemove()
-		n.rInsert(&ns.lru.recent)
-	case nodeDeleted:
-		// Do nothing.
-	default:
-		panic("invalid state")
-	}
-	n.ref++
-
-	return &lruHandle{node: n}
-}
-
-func (ns *lruNs) Delete(key uint64, fin DelFin) bool {
-	ns.lru.mu.Lock()
-	defer ns.lru.mu.Unlock()
-
-	if ns.state != nsEffective {
-		if fin != nil {
-			fin(false, false)
-		}
-		return false
-	}
-
-	n := ns.getNode(key)
-	if n == nil {
-		if fin != nil {
-			fin(false, false)
-		}
-		return false
-
-	}
-
-	switch n.state {
-	case nodeEffective:
-		ns.lru.used -= n.charge
-		n.state = nodeDeleted
-		n.delfin = fin
-		n.rRemove()
-		n.derefNB()
-	case nodeEvicted:
-		n.state = nodeDeleted
-		n.delfin = fin
-	case nodeDeleted:
-		if fin != nil {
-			fin(true, true)
-		}
-		return false
-	default:
-		panic("invalid state")
-	}
-
-	return true
-}
-
-func (ns *lruNs) purgeNB(fin PurgeFin) {
-	if ns.state == nsEffective {
-		var nodes []*lruNode
-		ns.iterateNodes(func(n *lruNode) bool {
-			nodes = append(nodes, n)
-			return true
-		})
-		for _, n := range nodes {
-			switch n.state {
-			case nodeEffective:
-				ns.lru.used -= n.charge
-				n.state = nodeDeleted
-				n.purgefin = fin
-				n.rRemove()
-				n.derefNB()
-			case nodeEvicted:
-				n.state = nodeDeleted
-				n.purgefin = fin
-			case nodeDeleted:
-			default:
-				panic("invalid state")
-			}
-		}
-	}
-}
-
-func (ns *lruNs) Purge(fin PurgeFin) {
-	ns.lru.mu.Lock()
-	ns.purgeNB(fin)
-	ns.lru.mu.Unlock()
-}
-
-func (ns *lruNs) zapNB() {
-	if ns.state == nsEffective {
-		ns.state = nsZapped
-
-		ns.iterateNodes(func(n *lruNode) bool {
-			if n.state == nodeEffective {
-				ns.lru.used -= n.charge
-				n.rRemove()
-			}
-			ns.lru.size -= n.charge
-			n.state = nodeDeleted
-			n.fin()
-
-			return true
-		})
-		ns.rbRoot = nil
-	}
-}
-
-func (ns *lruNs) Zap() {
-	ns.lru.mu.Lock()
-	ns.zapNB()
-	delete(ns.lru.table, ns.id)
-	ns.lru.mu.Unlock()
-}
-
-type lruNode struct {
-	ns *lruNs
-
-	rNext, rPrev    *lruNode
-	rbLeft, rbRight *lruNode
-	rbBlack         bool
-
-	key      uint64
-	value    interface{}
-	charge   int
-	ref      int
-	state    nodeState
-	delfin   DelFin
-	purgefin PurgeFin
-}
-
-func (n *lruNode) rInsert(at *lruNode) {
-	x := at.rNext
-	at.rNext = n
-	n.rPrev = at
-	n.rNext = x
-	x.rPrev = n
-}
-
-func (n *lruNode) rRemove() bool {
-	if n.rPrev == nil {
-		return false
-	}
-
-	n.rPrev.rNext = n.rNext
-	n.rNext.rPrev = n.rPrev
-	n.rPrev = nil
-	n.rNext = nil
-
-	return true
-}
-
-func (n *lruNode) fin() {
-	if r, ok := n.value.(util.Releaser); ok {
-		r.Release()
-	}
-	if n.purgefin != nil {
-		if n.delfin != nil {
-			panic("conflicting delete and purge fin")
-		}
-		n.purgefin(n.ns.id, n.key)
-		n.purgefin = nil
-	} else if n.delfin != nil {
-		n.delfin(true, false)
-		n.delfin = nil
-	}
-}
-
-func (n *lruNode) derefNB() {
-	n.ref--
-	if n.ref == 0 {
-		if n.ns.state == nsEffective {
-			// Remove elemement.
-			n.ns.deleteNode(n.key)
-			n.ns.lru.size -= n.charge
-			n.ns.lru.alive--
-			n.fin()
-		}
-		n.value = nil
-	} else if n.ref < 0 {
-		panic("leveldb/cache: lruCache: negative node reference")
-	}
-}
-
-func (n *lruNode) deref() {
-	n.ns.lru.mu.Lock()
-	n.derefNB()
-	n.ns.lru.mu.Unlock()
-}
-
-type lruHandle struct {
-	node *lruNode
-	once uint32
-}
-
-func (h *lruHandle) Value() interface{} {
-	if atomic.LoadUint32(&h.once) == 0 {
-		return h.node.value
-	}
-	return nil
-}
-
-func (h *lruHandle) Release() {
-	if !atomic.CompareAndSwapUint32(&h.once, 0, 1) {
-		return
-	}
-	h.node.deref()
-	h.node = nil
-}
-
-func rbIsRed(h *lruNode) bool {
-	if h == nil {
-		return false
-	}
-	return !h.rbBlack
-}
-
-func rbRotLeft(h *lruNode) *lruNode {
-	x := h.rbRight
-	if x.rbBlack {
-		panic("rotating a black link")
-	}
-	h.rbRight = x.rbLeft
-	x.rbLeft = h
-	x.rbBlack = h.rbBlack
-	h.rbBlack = false
-	return x
-}
-
-func rbRotRight(h *lruNode) *lruNode {
-	x := h.rbLeft
-	if x.rbBlack {
-		panic("rotating a black link")
-	}
-	h.rbLeft = x.rbRight
-	x.rbRight = h
-	x.rbBlack = h.rbBlack
-	h.rbBlack = false
-	return x
-}
-
-func rbFlip(h *lruNode) {
-	h.rbBlack = !h.rbBlack
-	h.rbLeft.rbBlack = !h.rbLeft.rbBlack
-	h.rbRight.rbBlack = !h.rbRight.rbBlack
-}
-
-func rbMoveLeft(h *lruNode) *lruNode {
-	rbFlip(h)
-	if rbIsRed(h.rbRight.rbLeft) {
-		h.rbRight = rbRotRight(h.rbRight)
-		h = rbRotLeft(h)
-		rbFlip(h)
-	}
-	return h
-}
-
-func rbMoveRight(h *lruNode) *lruNode {
-	rbFlip(h)
-	if rbIsRed(h.rbLeft.rbLeft) {
-		h = rbRotRight(h)
-		rbFlip(h)
-	}
-	return h
-}
-
-func rbFixup(h *lruNode) *lruNode {
-	if rbIsRed(h.rbRight) {
-		h = rbRotLeft(h)
-	}
-
-	if rbIsRed(h.rbLeft) && rbIsRed(h.rbLeft.rbLeft) {
-		h = rbRotRight(h)
-	}
-
-	if rbIsRed(h.rbLeft) && rbIsRed(h.rbRight) {
-		rbFlip(h)
-	}
-
-	return h
-}
-
-func rbDeleteMin(h *lruNode) (hn, n *lruNode) {
-	if h == nil {
-		return nil, nil
-	}
-	if h.rbLeft == nil {
-		return nil, h
-	}
-
-	if !rbIsRed(h.rbLeft) && !rbIsRed(h.rbLeft.rbLeft) {
-		h = rbMoveLeft(h)
-	}
-
-	h.rbLeft, n = rbDeleteMin(h.rbLeft)
-
-	return rbFixup(h), n
-}
diff --git a/leveldb/corrupt_test.go b/leveldb/corrupt_test.go
index 427d722..a351874 100644
--- a/leveldb/corrupt_test.go
+++ b/leveldb/corrupt_test.go
@@ -9,14 +9,12 @@
 import (
 	"bytes"
 	"fmt"
-	"io"
-	"math/rand"
-	"testing"
-
-	"github.com/syndtr/goleveldb/leveldb/cache"
 	"github.com/syndtr/goleveldb/leveldb/filter"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 	"github.com/syndtr/goleveldb/leveldb/storage"
+	"io"
+	"math/rand"
+	"testing"
 )
 
 const ctValSize = 1000
@@ -33,8 +31,8 @@
 
 func newDbCorruptHarness(t *testing.T) *dbCorruptHarness {
 	return newDbCorruptHarnessWopt(t, &opt.Options{
-		BlockCache: cache.NewLRUCache(100),
-		Strict:     opt.StrictJournalChecksum,
+		BlockCacheCapacity: 100,
+		Strict:             opt.StrictJournalChecksum,
 	})
 }
 
@@ -269,9 +267,9 @@
 func TestCorruptDB_MissingManifest(t *testing.T) {
 	rnd := rand.New(rand.NewSource(0x0badda7a))
 	h := newDbCorruptHarnessWopt(t, &opt.Options{
-		BlockCache:  cache.NewLRUCache(100),
-		Strict:      opt.StrictJournalChecksum,
-		WriteBuffer: 1000 * 60,
+		BlockCacheCapacity: 100,
+		Strict:             opt.StrictJournalChecksum,
+		WriteBuffer:        1000 * 60,
 	})
 
 	h.build(1000)
diff --git a/leveldb/db.go b/leveldb/db.go
index 70c847f..d50a008 100644
--- a/leveldb/db.go
+++ b/leveldb/db.go
@@ -823,8 +823,8 @@
 	case p == "blockpool":
 		value = fmt.Sprintf("%v", db.s.tops.bpool)
 	case p == "cachedblock":
-		if bc := db.s.o.GetBlockCache(); bc != nil {
-			value = fmt.Sprintf("%d", bc.Size())
+		if db.s.tops.bcache != nil {
+			value = fmt.Sprintf("%d", db.s.tops.bcache.Size())
 		} else {
 			value = "<nil>"
 		}
diff --git a/leveldb/db_test.go b/leveldb/db_test.go
index 0d51534..0acb567 100644
--- a/leveldb/db_test.go
+++ b/leveldb/db_test.go
@@ -1271,7 +1271,7 @@
 }
 
 func TestDB_CompactionTableOpenError(t *testing.T) {
-	h := newDbHarnessWopt(t, &opt.Options{CachedOpenFiles: -1})
+	h := newDbHarnessWopt(t, &opt.Options{OpenFilesCacheCapacity: -1})
 	defer h.close()
 
 	im := 10
@@ -1629,8 +1629,8 @@
 
 func TestDB_BloomFilter(t *testing.T) {
 	h := newDbHarnessWopt(t, &opt.Options{
-		BlockCache: opt.NoCache,
-		Filter:     filter.NewBloomFilter(10),
+		DisableBlockCache: true,
+		Filter:            filter.NewBloomFilter(10),
 	})
 	defer h.close()
 
@@ -2066,8 +2066,8 @@
 
 func TestDB_GoleveldbIssue72and83(t *testing.T) {
 	h := newDbHarnessWopt(t, &opt.Options{
-		WriteBuffer:     1 * opt.MiB,
-		CachedOpenFiles: 3,
+		WriteBuffer:            1 * opt.MiB,
+		OpenFilesCacheCapacity: 3,
 	})
 	defer h.close()
 
@@ -2200,7 +2200,7 @@
 func TestDB_TransientError(t *testing.T) {
 	h := newDbHarnessWopt(t, &opt.Options{
 		WriteBuffer:              128 * opt.KiB,
-		CachedOpenFiles:          3,
+		OpenFilesCacheCapacity:   3,
 		DisableCompactionBackoff: true,
 	})
 	defer h.close()
@@ -2410,7 +2410,7 @@
 		CompactionTableSize:         43 * opt.KiB,
 		CompactionExpandLimitFactor: 1,
 		CompactionGPOverlapsFactor:  1,
-		BlockCache:                  opt.NoCache,
+		DisableBlockCache:           true,
 	}
 	s, err := newSession(stor, o)
 	if err != nil {
diff --git a/leveldb/external_test.go b/leveldb/external_test.go
index 1ae304e..b328ece 100644
--- a/leveldb/external_test.go
+++ b/leveldb/external_test.go
@@ -17,14 +17,14 @@
 var _ = testutil.Defer(func() {
 	Describe("Leveldb external", func() {
 		o := &opt.Options{
-			BlockCache:           opt.NoCache,
-			BlockRestartInterval: 5,
-			BlockSize:            80,
-			Compression:          opt.NoCompression,
-			CachedOpenFiles:      -1,
-			Strict:               opt.StrictAll,
-			WriteBuffer:          1000,
-			CompactionTableSize:  2000,
+			DisableBlockCache:      true,
+			BlockRestartInterval:   5,
+			BlockSize:              80,
+			Compression:            opt.NoCompression,
+			OpenFilesCacheCapacity: -1,
+			Strict:                 opt.StrictAll,
+			WriteBuffer:            1000,
+			CompactionTableSize:    2000,
 		}
 
 		Describe("write test", func() {
diff --git a/leveldb/opt/options.go b/leveldb/opt/options.go
index 0798b87..86828f4 100644
--- a/leveldb/opt/options.go
+++ b/leveldb/opt/options.go
@@ -20,8 +20,9 @@
 	GiB = MiB * 1024
 )
 
-const (
-	DefaultBlockCacheSize                = 8 * MiB
+var (
+	DefaultBlockCacher                   = LRUCacher
+	DefaultBlockCacheCapacity            = 8 * MiB
 	DefaultBlockRestartInterval          = 16
 	DefaultBlockSize                     = 4 * KiB
 	DefaultCompactionExpandLimitFactor   = 25
@@ -33,7 +34,8 @@
 	DefaultCompactionTotalSize           = 10 * MiB
 	DefaultCompactionTotalSizeMultiplier = 10.0
 	DefaultCompressionType               = SnappyCompression
-	DefaultCachedOpenFiles               = 500
+	DefaultOpenFilesCacher               = LRUCacher
+	DefaultOpenFilesCacheCapacity        = 500
 	DefaultMaxMemCompationLevel          = 2
 	DefaultNumLevel                      = 7
 	DefaultWriteBuffer                   = 4 * MiB
@@ -41,22 +43,33 @@
 	DefaultWriteL0SlowdownTrigger        = 8
 )
 
-type noCache struct{}
+// Cacher is a caching algorithm.
+type Cacher interface {
+	New(capacity int) cache.Cacher
+}
 
-func (noCache) SetCapacity(capacity int)                     {}
-func (noCache) Capacity() int                                { return 0 }
-func (noCache) Used() int                                    { return 0 }
-func (noCache) Size() int                                    { return 0 }
-func (noCache) NumObjects() int                              { return 0 }
-func (noCache) GetNamespace(id uint64) cache.Namespace       { return nil }
-func (noCache) PurgeNamespace(id uint64, fin cache.PurgeFin) {}
-func (noCache) ZapNamespace(id uint64)                       {}
-func (noCache) Purge(fin cache.PurgeFin)                     {}
-func (noCache) Zap()                                         {}
+type CacherFunc struct {
+	NewFunc func(capacity int) cache.Cacher
+}
 
-var NoCache cache.Cache = noCache{}
+func (f *CacherFunc) New(capacity int) cache.Cacher {
+	if f.NewFunc != nil {
+		return f.NewFunc(capacity)
+	}
+	return nil
+}
 
-// Compression is the per-block compression algorithm to use.
+func noCacher(int) cache.Cacher { return nil }
+
+var (
+	// LRUCacher is the LRU-cache algorithm.
+	LRUCacher = &CacherFunc{cache.NewLRU}
+
+	// NoCacher is the value to disable caching algorithm.
+	NoCacher = &CacherFunc{}
+)
+
+// Compression is the 'sorted table' block compression algorithm to use.
 type Compression uint
 
 func (c Compression) String() string {
@@ -133,16 +146,17 @@
 	// The default value is nil
 	AltFilters []filter.Filter
 
-	// BlockCache provides per-block caching for LevelDB. Specify NoCache to
-	// disable block caching.
+	// BlockCacher provides cache algorithm for LevelDB 'sorted table' block caching.
+	// Specify NoCacher to disable caching algorithm.
 	//
-	// By default LevelDB will create LRU-cache with capacity of BlockCacheSize.
-	BlockCache cache.Cache
+	// The default value is LRUCacher.
+	BlockCacher Cacher
 
-	// BlockCacheSize defines the capacity of the default 'block cache'.
+	// BlockCacheCapacity defines the capacity of the 'sorted table' block caching.
+	// Use -1 for zero, this has same effect with specifying NoCacher to BlockCacher.
 	//
 	// The default value is 8MiB.
-	BlockCacheSize int
+	BlockCacheCapacity int
 
 	// BlockRestartInterval is the number of keys between restart points for
 	// delta encoding of keys.
@@ -156,13 +170,6 @@
 	// The default value is 4KiB.
 	BlockSize int
 
-	// CachedOpenFiles defines number of open files to kept around when not
-	// in-use, the counting includes still in-use files.
-	// Set this to negative value to disable caching.
-	//
-	// The default value is 500.
-	CachedOpenFiles int
-
 	// CompactionExpandLimitFactor limits compaction size after expanded.
 	// This will be multiplied by table size limit at compaction target level.
 	//
@@ -237,11 +244,17 @@
 	// The default value uses the same ordering as bytes.Compare.
 	Comparer comparer.Comparer
 
-	// Compression defines the per-block compression to use.
+	// Compression defines the 'sorted table' block compression to use.
 	//
 	// The default value (DefaultCompression) uses snappy compression.
 	Compression Compression
 
+	// DisableBlockCache allows disable use of cache.Cache functionality on
+	// 'sorted table' block.
+	//
+	// The default value is false.
+	DisableBlockCache bool
+
 	// DisableCompactionBackoff allows disable compaction retry backoff.
 	//
 	// The default value is false.
@@ -288,6 +301,18 @@
 	// The default is 7.
 	NumLevel int
 
+	// OpenFilesCacher provides cache algorithm for open files caching.
+	// Specify NoCacher to disable caching algorithm.
+	//
+	// The default value is LRUCacher.
+	OpenFilesCacher Cacher
+
+	// OpenFilesCacheCapacity defines the capacity of the open files caching.
+	// Use -1 for zero, this has same effect with specifying NoCacher to OpenFilesCacher.
+	//
+	// The default value is 500.
+	OpenFilesCacheCapacity int
+
 	// Strict defines the DB strict level.
 	Strict Strict
 
@@ -320,18 +345,22 @@
 	return o.AltFilters
 }
 
-func (o *Options) GetBlockCache() cache.Cache {
-	if o == nil {
+func (o *Options) GetBlockCacher() Cacher {
+	if o == nil || o.BlockCacher == nil {
+		return DefaultBlockCacher
+	} else if o.BlockCacher == NoCacher {
 		return nil
 	}
-	return o.BlockCache
+	return o.BlockCacher
 }
 
-func (o *Options) GetBlockCacheSize() int {
-	if o == nil || o.BlockCacheSize <= 0 {
-		return DefaultBlockCacheSize
+func (o *Options) GetBlockCacheCapacity() int {
+	if o == nil || o.BlockCacheCapacity <= 0 {
+		return DefaultBlockCacheCapacity
+	} else if o.BlockCacheCapacity == -1 {
+		return 0
 	}
-	return o.BlockCacheSize
+	return o.BlockCacheCapacity
 }
 
 func (o *Options) GetBlockRestartInterval() int {
@@ -348,15 +377,6 @@
 	return o.BlockSize
 }
 
-func (o *Options) GetCachedOpenFiles() int {
-	if o == nil || o.CachedOpenFiles == 0 {
-		return DefaultCachedOpenFiles
-	} else if o.CachedOpenFiles < 0 {
-		return 0
-	}
-	return o.CachedOpenFiles
-}
-
 func (o *Options) GetCompactionExpandLimit(level int) int {
 	factor := DefaultCompactionExpandLimitFactor
 	if o != nil && o.CompactionExpandLimitFactor > 0 {
@@ -494,6 +514,25 @@
 	return o.NumLevel
 }
 
+func (o *Options) GetOpenFilesCacher() Cacher {
+	if o == nil || o.OpenFilesCacher == nil {
+		return DefaultOpenFilesCacher
+	}
+	if o.OpenFilesCacher == NoCacher {
+		return nil
+	}
+	return o.OpenFilesCacher
+}
+
+func (o *Options) GetOpenFilesCacheCapacity() int {
+	if o == nil || o.OpenFilesCacheCapacity <= 0 {
+		return DefaultOpenFilesCacheCapacity
+	} else if o.OpenFilesCacheCapacity == -1 {
+		return 0
+	}
+	return o.OpenFilesCacheCapacity
+}
+
 func (o *Options) GetStrict(strict Strict) bool {
 	if o == nil || o.Strict == 0 {
 		return DefaultStrict&strict != 0
diff --git a/leveldb/options.go b/leveldb/options.go
index 3928cd1..a3d84ef 100644
--- a/leveldb/options.go
+++ b/leveldb/options.go
@@ -7,7 +7,6 @@
 package leveldb
 
 import (
-	"github.com/syndtr/goleveldb/leveldb/cache"
 	"github.com/syndtr/goleveldb/leveldb/filter"
 	"github.com/syndtr/goleveldb/leveldb/opt"
 )
@@ -32,13 +31,6 @@
 			no.AltFilters[i] = &iFilter{filter}
 		}
 	}
-	// Block cache.
-	switch o.GetBlockCache() {
-	case nil:
-		no.BlockCache = cache.NewLRUCache(o.GetBlockCacheSize())
-	case opt.NoCache:
-		no.BlockCache = nil
-	}
 	// Comparer.
 	s.icmp = &iComparer{o.GetComparer()}
 	no.Comparer = s.icmp
diff --git a/leveldb/session.go b/leveldb/session.go
index 5b251ef..b3906f7 100644
--- a/leveldb/session.go
+++ b/leveldb/session.go
@@ -73,7 +73,7 @@
 		stCompPtrs: make([]iKey, o.GetNumLevel()),
 	}
 	s.setOptions(o)
-	s.tops = newTableOps(s, s.o.GetCachedOpenFiles())
+	s.tops = newTableOps(s)
 	s.setVersion(newVersion(s))
 	s.log("log@legend F·NumFile S·FileSize N·Entry C·BadEntry B·BadBlock Ke·KeyError D·DroppedEntry L·Level Q·SeqNum T·TimeElapsed")
 	return
@@ -82,9 +82,6 @@
 // Close session.
 func (s *session) close() {
 	s.tops.close()
-	if bc := s.o.GetBlockCache(); bc != nil {
-		bc.Purge(nil)
-	}
 	if s.manifest != nil {
 		s.manifest.Close()
 	}
diff --git a/leveldb/table.go b/leveldb/table.go
index c3432fc..3e8df6a 100644
--- a/leveldb/table.go
+++ b/leveldb/table.go
@@ -286,10 +286,10 @@
 
 // Table operations.
 type tOps struct {
-	s       *session
-	cache   cache.Cache
-	cacheNS cache.Namespace
-	bpool   *util.BufferPool
+	s      *session
+	cache  *cache.Cache
+	bcache *cache.Cache
+	bpool  *util.BufferPool
 }
 
 // Creates an empty table and returns table writer.
@@ -338,26 +338,28 @@
 
 // Opens table. It returns a cache handle, which should
 // be released after use.
-func (t *tOps) open(f *tFile) (ch cache.Handle, err error) {
+func (t *tOps) open(f *tFile) (ch *cache.Handle, err error) {
 	num := f.file.Num()
-	ch = t.cacheNS.Get(num, func() (charge int, value interface{}) {
+	ch = t.cache.Get(0, num, func() (size int, value cache.Value) {
 		var r storage.Reader
 		r, err = f.file.Open()
 		if err != nil {
 			return 0, nil
 		}
 
-		var bcacheNS cache.Namespace
-		if bc := t.s.o.GetBlockCache(); bc != nil {
-			bcacheNS = bc.GetNamespace(num)
+		var bcache *cache.CacheGetter
+		if t.bcache != nil {
+			bcache = &cache.CacheGetter{Cache: t.bcache, NS: num}
 		}
+
 		var tr *table.Reader
-		tr, err = table.NewReader(r, int64(f.size), storage.NewFileInfo(f.file), bcacheNS, t.bpool, t.s.o.Options)
+		tr, err = table.NewReader(r, int64(f.size), storage.NewFileInfo(f.file), bcache, t.bpool, t.s.o.Options)
 		if err != nil {
 			r.Close()
 			return 0, nil
 		}
 		return 1, tr
+
 	})
 	if ch == nil && err == nil {
 		err = ErrClosed
@@ -412,16 +414,14 @@
 // no one use the the table.
 func (t *tOps) remove(f *tFile) {
 	num := f.file.Num()
-	t.cacheNS.Delete(num, func(exist, pending bool) {
-		if !pending {
-			if err := f.file.Remove(); err != nil {
-				t.s.logf("table@remove removing @%d %q", num, err)
-			} else {
-				t.s.logf("table@remove removed @%d", num)
-			}
-			if bc := t.s.o.GetBlockCache(); bc != nil {
-				bc.ZapNamespace(num)
-			}
+	t.cache.Delete(0, num, func() {
+		if err := f.file.Remove(); err != nil {
+			t.s.logf("table@remove removing @%d %q", num, err)
+		} else {
+			t.s.logf("table@remove removed @%d", num)
+		}
+		if t.bcache != nil {
+			t.bcache.EvictNS(num)
 		}
 	})
 }
@@ -429,18 +429,34 @@
 // Closes the table ops instance. It will close all tables,
 // regadless still used or not.
 func (t *tOps) close() {
-	t.cache.Zap()
 	t.bpool.Close()
+	t.cache.Close()
+	if t.bcache != nil {
+		t.bcache.Close()
+	}
 }
 
 // Creates new initialized table ops instance.
-func newTableOps(s *session, cacheCap int) *tOps {
-	c := cache.NewLRUCache(cacheCap)
+func newTableOps(s *session) *tOps {
+	var (
+		cacher cache.Cacher
+		bcache *cache.Cache
+	)
+	if s.o.GetOpenFilesCacheCapacity() > 0 {
+		cacher = cache.NewLRU(s.o.GetOpenFilesCacheCapacity())
+	}
+	if !s.o.DisableBlockCache {
+		var bcacher cache.Cacher
+		if s.o.GetBlockCacheCapacity() > 0 {
+			bcacher = cache.NewLRU(s.o.GetBlockCacheCapacity())
+		}
+		bcache = cache.NewCache(bcacher)
+	}
 	return &tOps{
-		s:       s,
-		cache:   c,
-		cacheNS: c.GetNamespace(0),
-		bpool:   util.NewBufferPool(s.o.GetBlockSize() + 5),
+		s:      s,
+		cache:  cache.NewCache(cacher),
+		bcache: bcache,
+		bpool:  util.NewBufferPool(s.o.GetBlockSize() + 5),
 	}
 }
 
diff --git a/leveldb/table/reader.go b/leveldb/table/reader.go
index 3b57446..6f38e84 100644
--- a/leveldb/table/reader.go
+++ b/leveldb/table/reader.go
@@ -509,7 +509,7 @@
 	mu     sync.RWMutex
 	fi     *storage.FileInfo
 	reader io.ReaderAt
-	cache  cache.Namespace
+	cache  *cache.CacheGetter
 	err    error
 	bpool  *util.BufferPool
 	// Options
@@ -613,18 +613,22 @@
 
 func (r *Reader) readBlockCached(bh blockHandle, verifyChecksum, fillCache bool) (*block, util.Releaser, error) {
 	if r.cache != nil {
-		var err error
-		ch := r.cache.Get(bh.offset, func() (charge int, value interface{}) {
-			if !fillCache {
-				return 0, nil
-			}
-			var b *block
-			b, err = r.readBlock(bh, verifyChecksum)
-			if err != nil {
-				return 0, nil
-			}
-			return cap(b.data), b
-		})
+		var (
+			err error
+			ch  *cache.Handle
+		)
+		if fillCache {
+			ch = r.cache.Get(bh.offset, func() (size int, value cache.Value) {
+				var b *block
+				b, err = r.readBlock(bh, verifyChecksum)
+				if err != nil {
+					return 0, nil
+				}
+				return cap(b.data), b
+			})
+		} else {
+			ch = r.cache.Get(bh.offset, nil)
+		}
 		if ch != nil {
 			b, ok := ch.Value().(*block)
 			if !ok {
@@ -667,18 +671,22 @@
 
 func (r *Reader) readFilterBlockCached(bh blockHandle, fillCache bool) (*filterBlock, util.Releaser, error) {
 	if r.cache != nil {
-		var err error
-		ch := r.cache.Get(bh.offset, func() (charge int, value interface{}) {
-			if !fillCache {
-				return 0, nil
-			}
-			var b *filterBlock
-			b, err = r.readFilterBlock(bh)
-			if err != nil {
-				return 0, nil
-			}
-			return cap(b.data), b
-		})
+		var (
+			err error
+			ch  *cache.Handle
+		)
+		if fillCache {
+			ch = r.cache.Get(bh.offset, func() (size int, value cache.Value) {
+				var b *filterBlock
+				b, err = r.readFilterBlock(bh)
+				if err != nil {
+					return 0, nil
+				}
+				return cap(b.data), b
+			})
+		} else {
+			ch = r.cache.Get(bh.offset, nil)
+		}
 		if ch != nil {
 			b, ok := ch.Value().(*filterBlock)
 			if !ok {
@@ -980,7 +988,7 @@
 // The fi, cache and bpool is optional and can be nil.
 //
 // The returned table reader instance is goroutine-safe.
-func NewReader(f io.ReaderAt, size int64, fi *storage.FileInfo, cache cache.Namespace, bpool *util.BufferPool, o *opt.Options) (*Reader, error) {
+func NewReader(f io.ReaderAt, size int64, fi *storage.FileInfo, cache *cache.CacheGetter, bpool *util.BufferPool, o *opt.Options) (*Reader, error) {
 	if f == nil {
 		return nil, errors.New("leveldb/table: nil file")
 	}
diff --git a/manualtest/leveldb/main.go b/manualtest/leveldb/main.go
index 1047a32..de94e3b 100644
--- a/manualtest/leveldb/main.go
+++ b/manualtest/leveldb/main.go
@@ -27,12 +27,12 @@
 )
 
 var (
-	dbPath           = path.Join(os.TempDir(), "goleveldb-testdb")
-	cachedOpenFiles  = 500
-	dataLen          = 63
-	numKeys          = arrayInt{100000, 1332, 531, 1234, 9553, 1024, 35743}
-	httpProf         = "127.0.0.1:5454"
-	enableBlockCache = false
+	dbPath                 = path.Join(os.TempDir(), "goleveldb-testdb")
+	openFilesCacheCapacity = 500
+	dataLen                = 63
+	numKeys                = arrayInt{100000, 1332, 531, 1234, 9553, 1024, 35743}
+	httpProf               = "127.0.0.1:5454"
+	enableBlockCache       = false
 
 	wg         = new(sync.WaitGroup)
 	done, fail uint32
@@ -71,7 +71,7 @@
 
 func init() {
 	flag.StringVar(&dbPath, "db", dbPath, "testdb path")
-	flag.IntVar(&cachedOpenFiles, "cachedopenfile", cachedOpenFiles, "cached open file")
+	flag.IntVar(&openFilesCacheCapacity, "openfilescachecap", openFilesCacheCapacity, "open files cache capacity")
 	flag.IntVar(&dataLen, "datalen", dataLen, "data length")
 	flag.Var(&numKeys, "numkeys", "num keys")
 	flag.StringVar(&httpProf, "httpprof", httpProf, "http prof listen addr")
@@ -346,12 +346,13 @@
 		runtime.Goexit()
 	}
 
-	o := &opt.Options{
-		CachedOpenFiles: cachedOpenFiles,
-		ErrorIfExist:    true,
+	if openFilesCacheCapacity == 0 {
+		openFilesCacheCapacity = -1
 	}
-	if !enableBlockCache {
-		o.BlockCache = opt.NoCache
+	o := &opt.Options{
+		OpenFilesCacheCapacity: openFilesCacheCapacity,
+		DisableBlockCache:      !enableBlockCache,
+		ErrorIfExist:           true,
 	}
 
 	db, err := leveldb.Open(stor, o)
@@ -394,7 +395,7 @@
 			mu.Lock()
 			log.Printf("> GetLatencyMin=%v GetLatencyMax=%v GetLatencyAvg=%v GetRatePerSec=%d",
 				gGetStat.min, gGetStat.max, gGetStat.avg(), gGetStat.ratePerSec())
-			log.Printf("> IterLatencyMin=%v IterLatencyMax=%v IterLatencyAvg=%v WriteRatePerSec=%d",
+			log.Printf("> IterLatencyMin=%v IterLatencyMax=%v IterLatencyAvg=%v IterRatePerSec=%d",
 				gIterStat.min, gIterStat.max, gIterStat.avg(), gIterStat.ratePerSec())
 			log.Printf("> WriteLatencyMin=%v WriteLatencyMax=%v WriteLatencyAvg=%v WriteRatePerSec=%d",
 				gWriteStat.min, gWriteStat.max, gWriteStat.avg(), gWriteStat.ratePerSec())