Merge pull request #698 from jfontan/improvement/use-decoder-cache

plumbing: cache, enforce the use of cache in packfile decoder

3 files changed, 67 insertions, 41 deletions

diff --git a/plumbing/cache/common.go b/plumbing/cache/common.go
index 9efc26c..e77baf0 100644
--- a/plumbing/cache/common.go
+++ b/plumbing/cache/common.go
@@ -11,6 +11,8 @@ const (
 
 type FileSize int64
 
+const DefaultMaxSize FileSize = 96 * MiByte
+
 // Object is an interface to a object cache.
 type Object interface {
 	// Put puts the given object into the cache. Whether this object will
diff --git a/plumbing/cache/object_lru.go b/plumbing/cache/object_lru.go
index e8414ab..d99a5c9 100644
--- a/plumbing/cache/object_lru.go
+++ b/plumbing/cache/object_lru.go
@@ -24,6 +24,11 @@ func NewObjectLRU(maxSize FileSize) *ObjectLRU {
 	return &ObjectLRU{MaxSize: maxSize}
 }
 
+// NewObjectLRUDefault creates a new ObjectLRU with the default cache size.
+func NewObjectLRUDefault() *ObjectLRU {
+	return &ObjectLRU{MaxSize: DefaultMaxSize}
+}
+
 // Put puts an object into the cache. If the object is already in the cache, it
 // will be marked as used. Otherwise, it will be inserted. A single object might
 // be evicted to make room for the new object.
diff --git a/plumbing/cache/object_test.go b/plumbing/cache/object_test.go
index b38272f..ec01d60 100644
--- a/plumbing/cache/object_test.go
+++ b/plumbing/cache/object_test.go
@@ -14,7 +14,7 @@ import (
 func Test(t *testing.T) { TestingT(t) }
 
 type ObjectSuite struct {
-	c       Object
+	c       map[string]Object
 	aObject plumbing.EncodedObject
 	bObject plumbing.EncodedObject
 	cObject plumbing.EncodedObject
@@ -29,70 +29,89 @@ func (s *ObjectSuite) SetUpTest(c *C) {
 	s.cObject = newObject("cccccccccccccccccccccccccccccccccccccccc", 1*Byte)
 	s.dObject = newObject("dddddddddddddddddddddddddddddddddddddddd", 1*Byte)
 
-	s.c = NewObjectLRU(2 * Byte)
+	s.c = make(map[string]Object)
+	s.c["two_bytes"] = NewObjectLRU(2 * Byte)
+	s.c["default_lru"] = NewObjectLRUDefault()
 }
 
 func (s *ObjectSuite) TestPutSameObject(c *C) {
-	s.c.Put(s.aObject)
-	s.c.Put(s.aObject)
-	_, ok := s.c.Get(s.aObject.Hash())
-	c.Assert(ok, Equals, true)
+	for _, o := range s.c {
+		o.Put(s.aObject)
+		o.Put(s.aObject)
+		_, ok := o.Get(s.aObject.Hash())
+		c.Assert(ok, Equals, true)
+	}
 }
 
 func (s *ObjectSuite) TestPutBigObject(c *C) {
-	s.c.Put(s.bObject)
-	_, ok := s.c.Get(s.aObject.Hash())
-	c.Assert(ok, Equals, false)
+	for _, o := range s.c {
+		o.Put(s.bObject)
+		_, ok := o.Get(s.aObject.Hash())
+		c.Assert(ok, Equals, false)
+	}
 }
 
 func (s *ObjectSuite) TestPutCacheOverflow(c *C) {
-	s.c.Put(s.aObject)
-	s.c.Put(s.cObject)
-	s.c.Put(s.dObject)
+	// this test only works with an specific size
+	o := s.c["two_bytes"]
+
+	o.Put(s.aObject)
+	o.Put(s.cObject)
+	o.Put(s.dObject)
 
-	obj, ok := s.c.Get(s.aObject.Hash())
+	obj, ok := o.Get(s.aObject.Hash())
 	c.Assert(ok, Equals, false)
 	c.Assert(obj, IsNil)
-	obj, ok = s.c.Get(s.cObject.Hash())
+	obj, ok = o.Get(s.cObject.Hash())
 	c.Assert(ok, Equals, true)
 	c.Assert(obj, NotNil)
-	obj, ok = s.c.Get(s.dObject.Hash())
+	obj, ok = o.Get(s.dObject.Hash())
 	c.Assert(ok, Equals, true)
 	c.Assert(obj, NotNil)
 }
 
 func (s *ObjectSuite) TestClear(c *C) {
-	s.c.Put(s.aObject)
-	s.c.Clear()
-	obj, ok := s.c.Get(s.aObject.Hash())
-	c.Assert(ok, Equals, false)
-	c.Assert(obj, IsNil)
+	for _, o := range s.c {
+		o.Put(s.aObject)
+		o.Clear()
+		obj, ok := o.Get(s.aObject.Hash())
+		c.Assert(ok, Equals, false)
+		c.Assert(obj, IsNil)
+	}
 }
 
 func (s *ObjectSuite) TestConcurrentAccess(c *C) {
-	var wg sync.WaitGroup
-
-	for i := 0; i < 1000; i++ {
-		wg.Add(3)
-		go func(i int) {
-			s.c.Put(newObject(fmt.Sprint(i), FileSize(i)))
-			wg.Done()
-		}(i)
-
-		go func(i int) {
-			if i%30 == 0 {
-				s.c.Clear()
-			}
-			wg.Done()
-		}(i)
-
-		go func(i int) {
-			s.c.Get(plumbing.NewHash(fmt.Sprint(i)))
-			wg.Done()
-		}(i)
+	for _, o := range s.c {
+		var wg sync.WaitGroup
+
+		for i := 0; i < 1000; i++ {
+			wg.Add(3)
+			go func(i int) {
+				o.Put(newObject(fmt.Sprint(i), FileSize(i)))
+				wg.Done()
+			}(i)
+
+			go func(i int) {
+				if i%30 == 0 {
+					o.Clear()
+				}
+				wg.Done()
+			}(i)
+
+			go func(i int) {
+				o.Get(plumbing.NewHash(fmt.Sprint(i)))
+				wg.Done()
+			}(i)
+		}
+
+		wg.Wait()
 	}
+}
+
+func (s *ObjectSuite) TestDefaultLRU(c *C) {
+	defaultLRU := s.c["default_lru"].(*ObjectLRU)
 
-	wg.Wait()
+	c.Assert(defaultLRU.MaxSize, Equals, DefaultMaxSize)
 }
 
 type dummyObject struct {