From 4808617ef54d40efcf1a3ed30525898defb74e10 Mon Sep 17 00:00:00 2001
From: Mike Buland <eichlan@xagasoft.com>
Date: Thu, 9 Oct 2008 20:20:34 +0000
Subject: More cache development.  I'm going to have to switch from template
 functions to functors.  I like template functions a little more, but functors
 can be at least as fast.  It won't be much of a change.

---
 src/cachable.cpp    | 15 +++++++++++++++
 src/cachable.h      | 19 +++++++++++++++++++
 src/cache.h         | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 src/cptr.h          | 14 +++++++++++---
 src/membuf.cpp      |  2 +-
 src/tests/cache.cpp | 31 +++++++++++++++++++++++++++++++
 6 files changed, 126 insertions(+), 4 deletions(-)
 create mode 100644 src/cachable.cpp
 create mode 100644 src/cachable.h
 create mode 100644 src/tests/cache.cpp

diff --git a/src/cachable.cpp b/src/cachable.cpp
new file mode 100644
index 0000000..7fa2d23
--- /dev/null
+++ b/src/cachable.cpp
@@ -0,0 +1,15 @@
+#include "bu/cachable.h"
+
+Bu::Cachable::Cachable()
+{
+}
+
+Bu::Cachable::~Cachable()
+{
+}
+
+template<> long Bu::getCacheId<Bu::Cachable>( const Bu::Cachable *o )
+{
+	return o->getCacheId();
+}
+
diff --git a/src/cachable.h b/src/cachable.h
new file mode 100644
index 0000000..529da6f
--- /dev/null
+++ b/src/cachable.h
@@ -0,0 +1,19 @@
+#ifndef BU_CACHABLE_H
+#define BU_CACHABLE_H
+
+namespace Bu
+{
+	class Cachable
+	{
+	public:
+		Cachable();
+		virtual ~Cachable();
+
+		virtual long getCacheId() const =0;
+	};
+
+	template<class obtype> long getCacheId( const obtype *o );
+	template<> long getCacheId<Cachable>( const Cachable *o );
+};
+
+#endif
diff --git a/src/cache.h b/src/cache.h
index 24ef652..344d1c6 100644
--- a/src/cache.h
+++ b/src/cache.h
@@ -1,20 +1,69 @@
 #ifndef BU_CACHE_H
 #define BU_CACHE_H
 
+#include "bu/cptr.h"
+#include "bu/hash.h"
+
+#define BU_TRACE
+#include "bu/trace.h"
+
 namespace Bu
 {
+	template<class obtype> class Cache;
+	template<class obtype> long getCacheId( const obtype *o );
+
 	template<class obtype>
 	class Cache
 	{
+	friend class Bu::CPtr<obtype>;
+	typedef Bu::CPtr<obtype> Ptr;
+	public:
+		typedef long cid;	/**< Cache ID type. Unique cache entry ID. */
+
 	public:
 		Cache()
 		{
+			TRACE();
 		}
 
 		virtual ~Cache()
 		{
+			TRACE();
+		}
+
+		Ptr insert( obtype *pData )
+		{
+			TRACE();
+			CacheEntry e = {pData, 0};
+			hEnt.insert( getCacheId( pData ), e );
+			return Ptr( *this, pData );
 		}
 
+	private:
+		void incRef( obtype *pData )
+		{
+			TRACE();
+			hEnt.get( getCacheId( pData ) ).iRefs++;
+		}
+
+		void decRef( obtype *pData )
+		{
+			TRACE();
+			CacheEntry &e = hEnt.get( getCacheId( pData ) );
+			e.iRefs--;
+		}
+
+	private:
+		typedef struct CacheEntry
+		{
+			obtype *pData;
+			int iRefs;
+		} CacheEntry;
+
+		//typedef Bu::Hash<ptrdiff_t, int> RefHash;
+		typedef Bu::Hash<cid, CacheEntry> CidHash;
+		//RefHash hRefs;
+		CidHash hEnt;
 	};
 };
 
diff --git a/src/cptr.h b/src/cptr.h
index 1f8c43d..138ace8 100644
--- a/src/cptr.h
+++ b/src/cptr.h
@@ -1,23 +1,31 @@
 #ifndef BU_C_PTR_H
 #define BU_C_PTR_H
 
-#include "bu/cache.h"
-
 namespace Bu
 {
+	template<class obtype> class Cache;
+
 	template<class obtype>
 	class CPtr
 	{
 	friend class Bu::Cache<obtype>;
 	private:
-		CPtr( Cache<obtype> &rCache, obtype &rData )
+		CPtr( Cache<obtype> &rCache, obtype *pData ) :
+			rCache( rCache ),
+			pData( pData )
 		{
+			rCache.incRef( pData );
 		}
 
 	public:
 		virtual ~CPtr()
 		{
+			rCache.decRef( pData );
 		}
+
+	private:
+		Bu::Cache<obtype> &rCache;
+		obtype *pData;
 	};
 };
 
diff --git a/src/membuf.cpp b/src/membuf.cpp
index e7c7ac8..f22a8de 100644
--- a/src/membuf.cpp
+++ b/src/membuf.cpp
@@ -52,7 +52,7 @@ size_t Bu::MemBuf::write( const void *pBuf, size_t nBytes )
 	{
 		// Trickier, we must do this in two parts, overwrite, then append
 		// Frist, overwrite.
-		int iOver = sBuf.getSize() - nPos;
+		size_t iOver = sBuf.getSize() - nPos;
 		if( iOver > nBytes )
 			iOver = nBytes;
 		memcpy( sBuf.getStr()+nPos, pBuf, iOver );
diff --git a/src/tests/cache.cpp b/src/tests/cache.cpp
new file mode 100644
index 0000000..e51c31b
--- /dev/null
+++ b/src/tests/cache.cpp
@@ -0,0 +1,31 @@
+#include <stdio.h>
+
+#include "bu/cache.h"
+#include "bu/cachable.h"
+
+class Bob : public Bu::Cachable
+{
+public:
+	Bob()
+	{
+	}
+
+	virtual ~Bob()
+	{
+	}
+
+	long getCacheId() const
+	{
+		return 0;
+	}
+
+	int iInt;
+};
+
+int main()
+{
+	Bu::Cache<Bob> bobCache;
+
+//	Bu::CPtr<Bob> pB = bobCache.insert( new Bob() );
+}
+
-- 
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