Improve(fakeip): use lru cache to avoid outdate

common/cache/cache_test.go

@@ -4,6 +4,8 @@ import (
 	"runtime"
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestCache_Basic(t *testing.T) {
@@ -14,32 +16,30 @@ func TestCache_Basic(t *testing.T) {
 	c.Put("string", "a", ttl)
 
 	i := c.Get("int")
-	if i.(int) != 1 {
-		t.Error("should recv 1")
-	}
+	assert.Equal(t, i.(int), 1, "should recv 1")
 
 	s := c.Get("string")
-	if s.(string) != "a" {
-		t.Error("should recv 'a'")
-	}
+	assert.Equal(t, s.(string), "a", "should recv 'a'")
 }
 
 func TestCache_TTL(t *testing.T) {
 	interval := 200 * time.Millisecond
 	ttl := 20 * time.Millisecond
+	now := time.Now()
 	c := New(interval)
 	c.Put("int", 1, ttl)
+	c.Put("int2", 2, ttl)
 
 	i := c.Get("int")
-	if i.(int) != 1 {
-		t.Error("should recv 1")
-	}
+	_, expired := c.GetWithExpire("int2")
+	assert.Equal(t, i.(int), 1, "should recv 1")
+	assert.True(t, now.Before(expired))
 
 	time.Sleep(ttl * 2)
 	i = c.Get("int")
-	if i != nil {
-		t.Error("should recv nil")
-	}
+	j, _ := c.GetWithExpire("int2")
+	assert.Nil(t, i, "should recv nil")
+	assert.Nil(t, j, "should recv nil")
 }
 
 func TestCache_AutoCleanup(t *testing.T) {
@@ -50,9 +50,9 @@ func TestCache_AutoCleanup(t *testing.T) {
 
 	time.Sleep(ttl * 2)
 	i := c.Get("int")
-	if i != nil {
-		t.Error("should recv nil")
-	}
+	j, _ := c.GetWithExpire("int")
+	assert.Nil(t, i, "should recv nil")
+	assert.Nil(t, j, "should recv nil")
 }
 
 func TestCache_AutoGC(t *testing.T) {

common/cache/lrucache.go

@@ -0,0 +1,148 @@
+package cache
+
+// Modified by https://github.com/die-net/lrucache
+
+import (
+	"container/list"
+	"sync"
+	"time"
+)
+
+// Option is part of Functional Options Pattern
+type Option func(*LruCache)
+
+// WithUpdateAgeOnGet update expires when Get element
+func WithUpdateAgeOnGet() Option {
+	return func(l *LruCache) {
+		l.updateAgeOnGet = true
+	}
+}
+
+// WithAge defined element max age (second)
+func WithAge(maxAge int64) Option {
+	return func(l *LruCache) {
+		l.maxAge = maxAge
+	}
+}
+
+// WithSize defined max length of LruCache
+func WithSize(maxSize int) Option {
+	return func(l *LruCache) {
+		l.maxSize = maxSize
+	}
+}
+
+// LruCache is a thread-safe, in-memory lru-cache that evicts the
+// least recently used entries from memory when (if set) the entries are
+// older than maxAge (in seconds).  Use the New constructor to create one.
+type LruCache struct {
+	maxAge         int64
+	maxSize        int
+	mu             sync.Mutex
+	cache          map[interface{}]*list.Element
+	lru            *list.List // Front is least-recent
+	updateAgeOnGet bool
+}
+
+// NewLRUCache creates an LruCache
+func NewLRUCache(options ...Option) *LruCache {
+	lc := &LruCache{
+		lru:   list.New(),
+		cache: make(map[interface{}]*list.Element),
+	}
+
+	for _, option := range options {
+		option(lc)
+	}
+
+	return lc
+}
+
+// Get returns the interface{} representation of a cached response and a bool
+// set to true if the key was found.
+func (c *LruCache) Get(key interface{}) (interface{}, bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	le, ok := c.cache[key]
+	if !ok {
+		return nil, false
+	}
+
+	if c.maxAge > 0 && le.Value.(*entry).expires <= time.Now().Unix() {
+		c.deleteElement(le)
+		c.maybeDeleteOldest()
+
+		return nil, false
+	}
+
+	c.lru.MoveToBack(le)
+	entry := le.Value.(*entry)
+	if c.maxAge > 0 && c.updateAgeOnGet {
+		entry.expires = time.Now().Unix() + c.maxAge
+	}
+	value := entry.value
+
+	return value, true
+}
+
+// Set stores the interface{} representation of a response for a given key.
+func (c *LruCache) Set(key interface{}, value interface{}) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	expires := int64(0)
+	if c.maxAge > 0 {
+		expires = time.Now().Unix() + c.maxAge
+	}
+
+	if le, ok := c.cache[key]; ok {
+		c.lru.MoveToBack(le)
+		e := le.Value.(*entry)
+		e.value = value
+		e.expires = expires
+	} else {
+		e := &entry{key: key, value: value, expires: expires}
+		c.cache[key] = c.lru.PushBack(e)
+
+		if c.maxSize > 0 {
+			if len := c.lru.Len(); len > c.maxSize {
+				c.deleteElement(c.lru.Front())
+			}
+		}
+	}
+
+	c.maybeDeleteOldest()
+}
+
+// Delete removes the value associated with a key.
+func (c *LruCache) Delete(key string) {
+	c.mu.Lock()
+
+	if le, ok := c.cache[key]; ok {
+		c.deleteElement(le)
+	}
+
+	c.mu.Unlock()
+}
+
+func (c *LruCache) maybeDeleteOldest() {
+	if c.maxAge > 0 {
+		now := time.Now().Unix()
+		for le := c.lru.Front(); le != nil && le.Value.(*entry).expires <= now; le = c.lru.Front() {
+			c.deleteElement(le)
+		}
+	}
+}
+
+func (c *LruCache) deleteElement(le *list.Element) {
+	c.lru.Remove(le)
+	e := le.Value.(*entry)
+	delete(c.cache, e.key)
+}
+
+type entry struct {
+	key     interface{}
+	value   interface{}
+	expires int64
+}

common/cache/lrucache_test.go

@@ -0,0 +1,117 @@
+package cache
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var entries = []struct {
+	key   string
+	value string
+}{
+	{"1", "one"},
+	{"2", "two"},
+	{"3", "three"},
+	{"4", "four"},
+	{"5", "five"},
+}
+
+func TestLRUCache(t *testing.T) {
+	c := NewLRUCache()
+
+	for _, e := range entries {
+		c.Set(e.key, e.value)
+	}
+
+	c.Delete("missing")
+	_, ok := c.Get("missing")
+	assert.False(t, ok)
+
+	for _, e := range entries {
+		value, ok := c.Get(e.key)
+		if assert.True(t, ok) {
+			assert.Equal(t, e.value, value.(string))
+		}
+	}
+
+	for _, e := range entries {
+		c.Delete(e.key)
+
+		_, ok := c.Get(e.key)
+		assert.False(t, ok)
+	}
+}
+
+func TestLRUMaxAge(t *testing.T) {
+	c := NewLRUCache(WithAge(86400))
+
+	now := time.Now().Unix()
+	expected := now + 86400
+
+	// Add one expired entry
+	c.Set("foo", "bar")
+	c.lru.Back().Value.(*entry).expires = now
+
+	// Reset
+	c.Set("foo", "bar")
+	e := c.lru.Back().Value.(*entry)
+	assert.True(t, e.expires >= now)
+	c.lru.Back().Value.(*entry).expires = now
+
+	// Set a few and verify expiration times
+	for _, s := range entries {
+		c.Set(s.key, s.value)
+		e := c.lru.Back().Value.(*entry)
+		assert.True(t, e.expires >= expected && e.expires <= expected+10)
+	}
+
+	// Make sure we can get them all
+	for _, s := range entries {
+		_, ok := c.Get(s.key)
+		assert.True(t, ok)
+	}
+
+	// Expire all entries
+	for _, s := range entries {
+		le, ok := c.cache[s.key]
+		if assert.True(t, ok) {
+			le.Value.(*entry).expires = now
+		}
+	}
+
+	// Get one expired entry, which should clear all expired entries
+	_, ok := c.Get("3")
+	assert.False(t, ok)
+	assert.Equal(t, c.lru.Len(), 0)
+}
+
+func TestLRUpdateOnGet(t *testing.T) {
+	c := NewLRUCache(WithAge(86400), WithUpdateAgeOnGet())
+
+	now := time.Now().Unix()
+	expires := now + 86400/2
+
+	// Add one expired entry
+	c.Set("foo", "bar")
+	c.lru.Back().Value.(*entry).expires = expires
+
+	_, ok := c.Get("foo")
+	assert.True(t, ok)
+	assert.True(t, c.lru.Back().Value.(*entry).expires > expires)
+}
+
+func TestMaxSize(t *testing.T) {
+	c := NewLRUCache(WithSize(2))
+	// Add one expired entry
+	c.Set("foo", "bar")
+	_, ok := c.Get("foo")
+	assert.True(t, ok)
+
+	c.Set("bar", "foo")
+	c.Set("baz", "foo")
+
+	_, ok = c.Get("foo")
+	assert.False(t, ok)
+}