add ForEachFunc

Author: karlseguin

bucket.go

@@ -17,6 +17,18 @@ func (b *bucket) itemCount() int {
 	return len(b.lookup)
 }
 
+func (b *bucket) forEachFunc(matches func(key string, item *Item) bool) bool {
+	lookup := b.lookup
+	b.RLock()
+	defer b.RUnlock()
+	for key, item := range lookup {
+		if !matches(key, item) {
+			return false
+		}
+	}
+	return true
+}
+
 func (b *bucket) get(key string) *Item {
 	b.RLock()
 	defer b.RUnlock()

cache.go

@@ -76,6 +76,14 @@ func (c *Cache) DeleteFunc(matches func(key string, item *Item) bool) int {
 	return count
 }
 
+func (c *Cache) ForEachFunc(matches func(key string, item *Item) bool) {
+	for _, b := range c.buckets {
+		if !b.forEachFunc(matches) {
+			break
+		}
+	}
+}
+
 // Get an item from the cache. Returns nil if the item wasn't found.
 // This can return an expired item. Use item.Expired() to see if the item
 // is expired and item.TTL() to see how long until the item expires (which
@@ -210,7 +218,7 @@ func (c *Cache) promote(item *Item) {
 	case c.promotables <- item:
 	default:
 	}
-		
+
 }
 
 func (c *Cache) worker() {

cache_test.go

@@ -1,6 +1,7 @@
 package ccache
 
 import (
+	"sort"
 	"strconv"
 	"sync/atomic"
 	"testing"
@@ -273,6 +274,34 @@ func (_ CacheTests) ResizeOnTheFly() {
 	Expect(cache.Get("6").Value()).To.Equal(6)
 }
 
+func (_ CacheTests) ForEachFunc() {
+	cache := New(Configure().MaxSize(3).ItemsToPrune(1))
+	Expect(forEachKeys(cache)).To.Equal([]string{})
+
+	cache.Set("1", 1, time.Minute)
+	Expect(forEachKeys(cache)).To.Equal([]string{"1"})
+
+	cache.Set("2", 2, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeys(cache)).To.Equal([]string{"1", "2"})
+
+	cache.Set("3", 3, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeys(cache)).To.Equal([]string{"1", "2", "3"})
+
+	cache.Set("4", 4, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeys(cache)).To.Equal([]string{"2", "3", "4"})
+
+	cache.Set("stop", 5, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeys(cache)).Not.To.Contain("stop")
+
+	cache.Set("6", 6, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeys(cache)).Not.To.Contain("stop")
+}
+
 type SizedItem struct {
 	id int
 	s  int64
@@ -293,3 +322,16 @@ func gcCache(cache *Cache) {
 	cache.gc()
 	cache.restart()
 }
+
+func forEachKeys(cache *Cache) []string {
+	keys := make([]string, 0, 10)
+	cache.ForEachFunc(func(key string, i *Item) bool {
+		if key == "stop" {
+			return false
+		}
+		keys = append(keys, key)
+		return true
+	})
+	sort.Strings(keys)
+	return keys
+}

layeredbucket.go

@@ -102,6 +102,15 @@ func (b *layeredBucket) deleteAll(primary string, deletables chan *Item) bool {
 	return true
 }
 
+func (b *layeredBucket) forEachFunc(primary string, matches func(key string, item *Item) bool) {
+	b.RLock()
+	bucket, exists := b.buckets[primary]
+	b.RUnlock()
+	if exists {
+		bucket.forEachFunc(matches)
+	}
+}
+
 func (b *layeredBucket) clear() {
 	b.Lock()
 	defer b.Unlock()

layeredcache.go

@@ -73,6 +73,10 @@ func (c *LayeredCache) Get(primary, secondary string) *Item {
 	return item
 }
 
+func (c *LayeredCache) ForEachFunc(primary string, matches func(key string, item *Item) bool) {
+	c.bucket(primary).forEachFunc(primary, matches)
+}
+
 // Get the secondary cache for a given primary key. This operation will
 // never return nil. In the case where the primary key does not exist, a
 // new, underlying, empty bucket will be created and returned.

layeredcache_test.go

@@ -1,6 +1,7 @@
 package ccache
 
 import (
+	"sort"
 	"strconv"
 	"sync/atomic"
 	"testing"
@@ -261,12 +262,6 @@ func (_ LayeredCacheTests) ResizeOnTheFly() {
 	Expect(cache.Get("6", "a").Value()).To.Equal(6)
 }
 
-func newLayered() *LayeredCache {
-	c := Layered(Configure())
-	c.Clear()
-	return c
-}
-
 func (_ LayeredCacheTests) RemovesOldestItemWhenFullBySizer() {
 	cache := Layered(Configure().MaxSize(9).ItemsToPrune(2))
 	for i := 0; i < 7; i++ {
@@ -329,6 +324,41 @@ func (_ LayeredCacheTests) ReplaceChangesSize() {
 	checkLayeredSize(cache, 5)
 }
 
+func (_ LayeredCacheTests) EachFunc() {
+	cache := Layered(Configure().MaxSize(3).ItemsToPrune(1))
+	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{})
+
+	cache.Set("1", "a", 1, time.Minute)
+	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{"a"})
+
+	cache.Set("1", "b", 2, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{"a", "b"})
+
+	cache.Set("1", "c", 3, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{"a", "b", "c"})
+
+	cache.Set("1", "d", 4, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeysLayered(cache, "1")).To.Equal([]string{"b", "c", "d"})
+
+	// iteration is non-deterministic, all we know for sure is "stop" should not be in there
+	cache.Set("1", "stop", 5, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeysLayered(cache, "1")).Not.To.Contain("stop")
+
+	cache.Set("1", "e", 6, time.Minute)
+	time.Sleep(time.Millisecond * 10)
+	Expect(forEachKeysLayered(cache, "1")).Not.To.Contain("stop")
+}
+
+func newLayered() *LayeredCache {
+	c := Layered(Configure())
+	c.Clear()
+	return c
+}
+
 func checkLayeredSize(cache *LayeredCache, sz int64) {
 	cache.Stop()
 	Expect(cache.size).To.Equal(sz)
@@ -340,3 +370,16 @@ func gcLayeredCache(cache *LayeredCache) {
 	cache.gc()
 	cache.restart()
 }
+
+func forEachKeysLayered(cache *LayeredCache, primary string) []string {
+	keys := make([]string, 0, 10)
+	cache.ForEachFunc(primary, func(key string, i *Item) bool {
+		if key == "stop" {
+			return false
+		}
+		keys = append(keys, key)
+		return true
+	})
+	sort.Strings(keys)
+	return keys
+}

readme.md

@@ -97,7 +97,10 @@ cache.Delete("user:4")
 `DeletePrefix` deletes all keys matching the provided prefix. Returns the number of keys removed.
 
 ### DeleteFunc
-`DeleteFunc` deletes all items that the provded matches func evaluates to true. Returns the number of keys removed.
+`DeleteFunc` deletes all items that the provided matches func evaluates to true. Returns the number of keys removed.
+
+### ForEachFunc
+`ForEachFunc` iterates through all keys and values in the map and passes them to the provided function. Iteration stops if the function returns false. Iteration order is random.
 
 ### Clear
 `Clear` clears the cache. If the cache's gc is running, `Clear` waits for it to finish.