Revert "feat: add cache front/back method to get the first/last element"

This reverts commit e8cdb07.

Author: shaj13

arc/arc.go

@@ -32,20 +32,6 @@ type arc struct {
 	b2 *internal.Cache
 }
 
-func (a *arc) Front() interface{} {
-	if k := a.t1.Front(); k != nil {
-		return k
-	}
-	return a.t2.Front()
-}
-
-func (a *arc) Back() interface{} {
-	if k := a.t1.Back(); k != nil {
-		return k
-	}
-	return a.t2.Back()
-}
-
 func (a *arc) Load(key interface{}) (value interface{}, ok bool) {
 	if val, ok := a.t1.Peek(key); ok {
 		exp, _ := a.t1.Expiry(key)

arc/arc_test.go

@@ -53,11 +53,8 @@ func TestARCc(t *testing.T) {
 
 	a.Store(1, 1)
 	a.Load(1)
-
 	assert.Equal(t, 0, a.t1.Len())
 	assert.Equal(t, 1, a.t2.Len())
-	assert.Equal(t, 1, a.Front())
-	assert.Equal(t, 1, a.Back())
 
 	a.Delete(1)
 }

cache.go

@@ -24,20 +24,6 @@ type Event = internal.Event
 
 // Cache stores data so that future requests for that data can be served faster.
 type Cache interface {
-	// Front returns the first key of cache or nil if the cache is empty.
-	//
-	// # Experimental
-	//
-	// Notice: This func is EXPERIMENTAL and may be changed or removed in a
-	// later release.
-	Front() interface{}
-	// Back returns the last key of cache or nil if the cache is empty.
-	//
-	// # Experimental
-	//
-	// Notice: This func is EXPERIMENTAL and may be changed or removed in a
-	// later release.
-	Back() interface{}
 	// Load returns key value.
 	Load(key interface{}) (interface{}, bool)
 	// Peek returns key value without updating the underlying "recent-ness".
@@ -105,7 +91,7 @@ type Cache interface {
 // GC is a long running function, it returns when ctx done, therefore the
 // caller must start it in its own goroutine.
 //
-// # Experimental
+// Experimental
 //
 // Notice: This func is EXPERIMENTAL and may be changed or removed in a
 // later release.
@@ -156,20 +142,6 @@ type cache struct {
 	unsafe Cache
 }
 
-func (c *cache) Front() interface{} {
-	c.mu.Lock()
-	k := c.unsafe.Front()
-	c.mu.Unlock()
-	return k
-}
-
-func (c *cache) Back() interface{} {
-	c.mu.Lock()
-	k := c.unsafe.Back()
-	c.mu.Unlock()
-	return k
-}
-
 func (c *cache) Load(key interface{}) (interface{}, bool) {
 	c.mu.Lock()
 	v, ok := c.unsafe.Load(key)

fifo/fifo.go

@@ -42,20 +42,6 @@ func (c *collection) Discard() (e *internal.Entry) {
 	return
 }
 
-func (c *collection) Front() (e *internal.Entry) {
-	if le := c.ll.Front(); le != nil {
-		e = le.Value.(*internal.Entry)
-	}
-	return
-}
-
-func (c *collection) Back() (e *internal.Entry) {
-	if le := c.ll.Back(); le != nil {
-		e = le.Value.(*internal.Entry)
-	}
-	return
-}
-
 func (c *collection) Len() int {
 	return c.ll.Len()
 }

fifo/fifo_test.go

@@ -28,14 +28,11 @@ func TestCollection(t *testing.T) {
 		}
 	}
 
-	front := c.Front()
-	back := c.Back()
 	oldest := c.Discard()
 	c.Remove(entries[2])
+	back := c.ll.Back().Value.(*internal.Entry)
 
-	assert.Equal(t, 1, front.Key)
-	assert.Equal(t, 3, back.Key)
 	assert.Equal(t, 1, oldest.Key)
 	assert.Equal(t, 1, c.Len())
-	assert.Equal(t, 2, c.Back().Key)
+	assert.Equal(t, 2, back.Key)
 }

idle/idle.go

@@ -18,8 +18,6 @@ func New(cap int) libcache.Cache {
 
 type idle struct{}
 
-func (idle) Front() (v interface{})                               { return }
-func (idle) Back() (v interface{})                                { return }
 func (idle) Load(interface{}) (v interface{}, ok bool)            { return }
 func (idle) Peek(interface{}) (v interface{}, ok bool)            { return }
 func (idle) Keys() (keys []interface{})                           { return }

internal/cache.go

@@ -53,8 +53,6 @@ type Collection interface {
 	Add(*Entry)
 	Remove(*Entry)
 	Discard() *Entry
-	Front() *Entry
-	Back() *Entry
 	Len() int
 	Init()
 }
@@ -99,30 +97,6 @@ type Cache struct {
 	capacity int
 }
 
-// Front returns the first key of cache or nil if the cache is empty.
-func (c *Cache) Front() interface{} {
-	// Run GC inline before get the front entry.
-	c.GC()
-
-	if e := c.coll.Front(); e != nil {
-		return e.Key
-	}
-
-	return nil
-}
-
-// Back returns the last key of cache or nil if the cache is empty.
-func (c *Cache) Back() interface{} {
-	// Run GC inline before get the back entry.
-	c.GC()
-
-	if e := c.coll.Back(); e != nil {
-		return e.Key
-	}
-
-	return nil
-}
-
 // Load returns key value.
 func (c *Cache) Load(key interface{}) (interface{}, bool) {
 	return c.get(key, false)

lfu/lfu.go

@@ -57,20 +57,6 @@ func (f *collection) Discard() (e *internal.Entry) {
 	return heap.Pop(f).(*element).value
 }
 
-func (f *collection) Front() (e *internal.Entry) {
-	if f.Len() > 0 {
-		e = (*f)[f.Len()-1].value
-	}
-	return
-}
-
-func (f *collection) Back() (e *internal.Entry) {
-	if f.Len() > 0 {
-		e = (*f)[0].value
-	}
-	return
-}
-
 func (f *collection) Move(e *internal.Entry) {
 	ele := e.Element.(*element)
 	ele.count++

lfu/lfu_test.go

@@ -27,13 +27,9 @@ func TestCollection(t *testing.T) {
 		}
 	}
 
-	front := f.Front()
-	back := f.Back()
 	oldest := f.Discard()
 	f.Remove(entries[2])
 
-	assert.Equal(t, front.Key, 2)
-	assert.Equal(t, back.Key, 1)
 	assert.Equal(t, oldest.Key, 1)
 	assert.Equal(t, f.Len(), 1)
 	assert.Equal(t, (*f)[0].value.Key, 2)

lifo/lifo.go

@@ -42,20 +42,6 @@ func (c *collection) Discard() (e *internal.Entry) {
 	return
 }
 
-func (c *collection) Front() (e *internal.Entry) {
-	if le := c.ll.Front(); le != nil {
-		e = le.Value.(*internal.Entry)
-	}
-	return
-}
-
-func (c *collection) Back() (e *internal.Entry) {
-	if le := c.ll.Back(); le != nil {
-		e = le.Value.(*internal.Entry)
-	}
-	return
-}
-
 func (c *collection) Len() int {
 	return c.ll.Len()
 }