Use Go 1.5 vendoring instead of Godeps

Change made by:

- running "gvt fetch" on each of the packages mentioned in
  Godeps/Godeps.json
- `rm -rf Godeps`
- tweaking the build scripts to not mention Godeps
- tweaking the build scripts to test `./lib/...`, `./cmd/...` explicitly
  (to avoid testing vendor)
- tweaking the build scripts to not juggle GOPATH for Godeps and instead
  set GO15VENDOREXPERIMENT.

This also results in some updated packages at the same time I bet.

Building with Go 1.3 and 1.4 still *works* but won't use our vendored
dependencies - the user needs to have the actual packages in their
GOPATH then, which they'll get with a normal "go get". Building with Go
1.6+ will get our vendored dependencies by default even when not using
our build script, which is nice.

By doing this we gain some freedom in that we can pick and choose
manually what to include in vendor, as it's not based on just dependency
analysis of our own code. This is also a risk as we might pick up
dependencies we are unaware of, as the build may work locally with those
packages present in GOPATH. On the other hand the build server will
detect this as it has no packages in it's GOPATH beyond what is included
in the repo.

Recommended tool to manage dependencies is github.com/FiloSottile/gvt.

vendor/github.com/syndtr/goleveldb/leveldb/cache/bench2_test.go

@@ -0,0 +1,30 @@
+// 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.
+
+// +build !go1.2
+
+package cache
+
+import (
+	"math/rand"
+	"testing"
+)
+
+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()
+		}
+	})
+}

vendor/github.com/syndtr/goleveldb/leveldb/cache/cache.go

@@ -0,0 +1,684 @@
+// 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 provides interface and implementation of a cache algorithms.
+package cache
+
+import (
+	"sync"
+	"sync/atomic"
+	"unsafe"
+
+	"github.com/syndtr/goleveldb/leveldb/util"
+)
+
+// Cacher provides interface to implements a caching functionality.
+// An implementation must be goroutine-safe.
+type Cacher interface {
+	// Capacity returns cache capacity.
+	Capacity() int
+
+	// SetCapacity sets cache capacity.
+	SetCapacity(capacity int)
+
+	// Promote promotes the 'cache node'.
+	Promote(n *Node)
+
+	// Ban evicts the 'cache node' and prevent subsequent 'promote'.
+	Ban(n *Node)
+
+	// Evict evicts the 'cache node'.
+	Evict(n *Node)
+
+	// EvictNS evicts 'cache node' with the given namespace.
+	EvictNS(ns uint64)
+
+	// EvictAll evicts all 'cache node'.
+	EvictAll()
+
+	// Close closes the 'cache tree'
+	Close() error
+}
+
+// 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{}
+
+// NamespaceGetter provides convenient wrapper for namespace.
+type NamespaceGetter struct {
+	Cache *Cache
+	NS    uint64
+}
+
+// Get simply calls Cache.Get() method.
+func (g *NamespaceGetter) 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 (
+	mInitialSize           = 1 << 4
+	mOverflowThreshold     = 1 << 5
+	mOverflowGrowThreshold = 1 << 7
+)
+
+type mBucket struct {
+	mu     sync.Mutex
+	node   []*Node
+	frozen bool
+}
+
+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
+}
+
+// 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 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()
+	}
+}
+
+// Handle is a 'cache handle' of a 'cache node'.
+type Handle struct {
+	n unsafe.Pointer // *Node
+}
+
+// Value returns the value of the 'cache node'.
+func (h *Handle) Value() Value {
+	n := (*Node)(atomic.LoadPointer(&h.n))
+	if n != nil {
+		return n.value
+	}
+	return nil
+}
+
+// Release releases this 'cache handle'.
+// It is safe to call release multiple times.
+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
+}

vendor/github.com/syndtr/goleveldb/leveldb/cache/cache_test.go

@@ -0,0 +1,553 @@
+// 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 (
+	"math/rand"
+	"runtime"
+	"sync"
+	"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 Value
+}
+
+func (r releaserFunc) Release() {
+	if r.fn != nil {
+		r.fn()
+	}
+}
+
+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}
+		}
+		return charge, value
+	})
+}
+
+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
+	}{
+		{1, "vvvvvvvvv"},
+		{100, "v1"},
+		{0, "v2"},
+		{12346, "v3"},
+		{777, "v4"},
+		{999, "v5"},
+		{7654, "v6"},
+		{2, "v7"},
+		{3, "v8"},
+		{9, "v9"},
+	}
+
+	setfin := 0
+	c := NewCache(NewLRU(1000))
+	for i, x := range cases {
+		set(c, 0, x.key, x.value, len(x.value), func() {
+			setfin++
+		}).Release()
+		for j, y := range cases {
+			h := c.Get(0, y.key, nil)
+			if j <= i {
+				// should hit
+				if h == nil {
+					t.Errorf("case '%d' iteration '%d' is miss", i, j)
+				} else {
+					if x := h.Value().(releaserFunc).value.(string); x != y.value {
+						t.Errorf("case '%d' iteration '%d' has invalid value got '%s', want '%s'", i, j, x, y.value)
+					}
+				}
+			} else {
+				// should miss
+				if h != nil {
+					t.Errorf("case '%d' iteration '%d' is hit , value '%s'", i, j, h.Value().(releaserFunc).value.(string))
+				}
+			}
+			if h != nil {
+				h.Release()
+			}
+		}
+	}
+
+	for i, x := range cases {
+		finalizerOk := false
+		c.Delete(0, x.key, func() {
+			finalizerOk = true
+		})
+
+		if !finalizerOk {
+			t.Errorf("case %d delete finalizer not executed", i)
+		}
+
+		for j, y := range cases {
+			h := c.Get(0, y.key, nil)
+			if j > i {
+				// should hit
+				if h == nil {
+					t.Errorf("case '%d' iteration '%d' is miss", i, j)
+				} else {
+					if x := h.Value().(releaserFunc).value.(string); x != y.value {
+						t.Errorf("case '%d' iteration '%d' has invalid value got '%s', want '%s'", i, j, x, y.value)
+					}
+				}
+			} else {
+				// should miss
+				if h != nil {
+					t.Errorf("case '%d' iteration '%d' is hit, value '%s'", i, j, h.Value().(releaserFunc).value.(string))
+				}
+			}
+			if h != nil {
+				h.Release()
+			}
+		}
+	}
+
+	if setfin != len(cases) {
+		t.Errorf("some set finalizer may not be executed, want=%d got=%d", len(cases), setfin)
+	}
+}
+
+func TestLRUCache_Eviction(t *testing.T) {
+	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(c, 0, 9, 9, 10, nil).Release() // 5,2,9
+
+	for _, key := range []uint64{9, 2, 5, 1} {
+		h := c.Get(0, 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()
+	for _, key := range []uint64{1, 2, 5} {
+		h := c.Get(0, 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()
+		}
+	}
+	for _, key := range []uint64{3, 4, 9} {
+		h := c.Get(0, 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()
+		}
+	}
+}
+
+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 {
+				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("Cache.Get on #%d return nil", key)
+		}
+	}
+
+	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)
+	}
+}

vendor/github.com/syndtr/goleveldb/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
+}