X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;ds=sidebyside;f=source%2Fcore%2Frefptr.h;h=8ab1b7cbfbdb6e752afd4b7634e807a8a836e10a;hb=74e62aabadda67d02b3eab09baa37c9d7640b794;hp=dd07256d79d45ca1fa1ff558eacab32ca925ed79;hpb=cfc8e0b7b15ea505bd6a6a9599cbc5ce1e316963;p=libs%2Fcore.git

diff --git a/source/core/refptr.h b/source/core/refptr.h
index dd07256..8ab1b7c 100644
--- a/source/core/refptr.h
+++ b/source/core/refptr.h
@@ -1,15 +1,21 @@
-/* $Id$
-
-This file is part of libmspcore
-Copyright © 2006-2007 Mikko Rasa, Mikkosoft Productions
-Distributed under the LGPL
-*/
-
 #ifndef MSP_CORE_REFPTR_H_
 #define MSP_CORE_REFPTR_H_
 
 namespace Msp {
 
+struct RefCounts
+{
+	enum
+	{
+		KEEP = 1U<<(sizeof(unsigned)*8-1)
+	};
+
+	unsigned count;
+
+	RefCounts(): count(0) { }
+};
+
+
 /**
 A reference counting smart pointer.  When the last RefPtr for the data gets
 destroyed, the data is deleted as well.
@@ -17,65 +23,109 @@ destroyed, the data is deleted as well.
 template<typename T>
 class RefPtr
 {
+	template<typename U> friend class RefPtr;
+
+private:
+	T *data;
+	RefCounts *counts;
+
+public:
+	RefPtr(): data(0), counts(0) { }
+	RefPtr(T *d): data(d), counts(data ? new RefCounts : 0) { incref(); }
+private:
+	RefPtr(T *d, RefCounts *c): data(d), counts(d ? c : 0) { incref(); }
+
 public:
-	RefPtr(): data(0), count(0) { }
-	RefPtr(T *d): data(d), count(0) { if(data) count=new unsigned(1); }
-	RefPtr(const RefPtr &p): data(p.data), count(p.count) { incref(); }
-	RefPtr &operator=(const RefPtr &p)
+	/* Must have this or the compiler will generate a default copy-c'tor despite
+	the template version */
+	RefPtr(const RefPtr &p): data(p.data), counts(p.counts) { incref(); }
+
+	template<typename U>
+	RefPtr(const RefPtr<U> &p): data(p.data), counts(p.counts) { incref(); }
+
+	~RefPtr() { decref(); }
+
+	RefPtr &operator=(T *d)
 	{
 		decref();
-		data=p.data;
-		count=p.count;
+		data = d;
+		counts = (d ? new RefCounts : 0);
 		incref();
 		return *this;
 	}
-	
-	~RefPtr() { decref(); }
 
-	/**
-	Makes the RefPtr release its reference of the data.  Note that if there are
-	other RefPtrs left with the same data, it might still get deleted
-	automatically.
-	*/
+	// Likewise for the assignment operator
+	RefPtr &operator=(const RefPtr &p) { return assign(p); }
+
+	template<typename U>
+	RefPtr &operator=(const RefPtr<U> &p) { return assign(p); }
+
+private:
+	template<typename U>
+	RefPtr &assign(const RefPtr<U> &p)
+	{
+		decref();
+		data = p.data;
+		counts = p.counts;
+		incref();
+		return *this;
+	}
+
+public:
+	/** Makes the RefPtr release its reference of the data without deleting it.
+	Note that if there are other RefPtrs left with the same data, it might
+	still get deleted automatically. */
 	T *release()
 	{
-		T *d=data;
-		data=0;
+		T *d = data;
+		data = 0;
 		decref();
-		count=0;
+		counts = 0;
 		return d;
 	}
 
-	T *get() const        { return data; }
-	T &operator*() const  { return *data; }
+	/** Marks the data to not be deleted.  This affects all RefPtrs with the
+	same data. */
+	void keep()
+	{
+		if(counts)
+			counts->count |= RefCounts::KEEP;
+	}
+
+	T *get() const { return data; }
+	T &operator*() const { return *data; }
 	T *operator->() const { return data; }
 	operator bool() const { return data!=0; }
 
-	template<typename U>
-	static RefPtr<T> cast_dynamic(const RefPtr<U> &p)  { return RefPtr<T>(dynamic_cast<T *>(p.data), p.count); }
-	template<typename U> friend class RefPtr;
-private:
-	T        *data;
-	unsigned *count;
+	unsigned refcount() const { return (data ? counts->count : 0); }
 
-	RefPtr(T *d, unsigned *c): data(d), count(c) { incref(); }
+	template<typename U>
+	static RefPtr<T> cast_dynamic(const RefPtr<U> &p)
+	{ return RefPtr<T>(dynamic_cast<T *>(p.data), p.counts); }
 
-	void  incref()
+private:
+	void incref()
 	{
-		if(!count) return;
-		++*count;
+		if(!counts) return;
+		++counts->count;
 	}
 
-	void  decref()
+	void decref()
 	{
-		if(!count) return;
-		--*count;
-		if(!*count)
+		if(!counts) return;
+		--counts->count;
+		if(!counts->count)
 		{
 			delete data;
-			delete count;
-			data=0;
-			count=0;
+			delete counts;
+			data = 0;
+			counts = 0;
+		}
+		else if(counts->count==RefCounts::KEEP)
+		{
+			delete counts;
+			data = 0;
+			counts = 0;
 		}
 	}
 };