1 files changed, 274 insertions, 0 deletions
diff --git a/flow/cache.cpp b/flow/cache.cpp
new file mode 100644
index 0000000..80f0349
--- /dev/null
+++ b/flow/cache.cpp
@@ -0,0 +1,274 @@
+    /*
+
+    Copyright (C) 2000 Stefan Westerfeld
+                       stefan@space.twc.de
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+  
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Library General Public License for more details.
+   
+    You should have received a copy of the GNU Library General Public License
+    along with this library; see the file COPYING.LIB.  If not, write to
+    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+    Boston, MA 02110-1301, USA.
+
+    */
+
+#include "cache.h"
+#include "debug.h"
+#include "iomanager.h"
+#include "dispatcher.h"
+#include <iostream>
+#include <assert.h>
+
+using namespace std;
+using namespace Arts;
+
+bool CachedObject::isValid()
+{
+	return true;
+}
+
+void CachedObject::setKey(string key)
+{
+	_object_key = key;
+}
+
+string CachedObject::getKey()
+{
+	return _object_key;
+}
+
+void CachedObject::decRef()
+{
+	_ref_cnt--;
+	time(&_lastAccess);
+}
+
+void CachedObject::incRef()
+{
+	_ref_cnt++;
+}
+
+int CachedObject::refCnt()
+{
+	return _ref_cnt;
+}
+
+time_t CachedObject::lastAccess()
+{
+	return(_lastAccess);
+}
+
+CachedObject::CachedObject(Cache *cache)
+{
+	_ref_cnt = 1;
+	cache->add(this);
+}
+
+CachedObject::~CachedObject()
+{
+	assert(_ref_cnt == 0);
+}
+
+//------------------------- Cache implementation ---------------------------
+long Cache::memused = 0;
+
+CachedObject *Cache::get(string key)
+{
+	list<CachedObject *>::iterator i;
+
+	for(i=objects.begin();i != objects.end(); i++)
+	{
+		if((*i)->getKey() == key && (*i)->isValid())
+		{
+			(*i)->incRef();
+			return(*i);
+		}
+	}
+	return 0;
+}
+
+void Cache::add(CachedObject *object)
+{
+	objects.push_back(object);
+}
+
+long Cache::cleanUp(long cacheLimit)
+{
+	time_t lastAccess;
+
+	list<CachedObject *>::iterator i;
+	long memory = 0;
+
+	// delete all invalid unused entries (invalid entries that are still
+	// in use, e.g. cached wav files which have changed on disk but are
+	// still played can't be deleted!)
+	
+	for(i=objects.begin();i != objects.end(); i++)
+	{
+		CachedObject *co = (*i);
+
+		if(co->refCnt() == 0 && !co->isValid())
+		{
+			objects.remove(co);
+			delete co;
+			i = objects.begin();
+		}
+	}
+
+	for(i=objects.begin();i != objects.end(); i++)
+	{
+		memory += (*i)->memoryUsage();
+	}
+
+	bool freeok = true;
+	while(memory > cacheLimit && freeok)
+	{
+		CachedObject *freeme;
+
+		freeok = false;
+
+		// only start freeing objects which have not been accessed
+		// in the last 5 seconds
+
+		time(&lastAccess);
+		lastAccess -= 5;
+
+
+		for(i=objects.begin();!freeok && (i != objects.end()); i++)
+		{
+			CachedObject *co = (*i);
+
+			assert(co->refCnt() >= 0);
+			if(co->refCnt() == 0 && (co->lastAccess() < lastAccess))
+			{
+				lastAccess = co->lastAccess();
+				freeme = co;
+				freeok = true;
+			}
+			else
+			{
+				//artsdebug("%d => %ld\n",co->refCnt(),co->lastAccess());
+			}
+		}
+
+		if(freeok)
+		{
+			memory -= freeme->memoryUsage();
+			objects.remove(freeme);
+			delete(freeme);
+		}
+		else
+		{
+			//artsdebug("cache problem: memory overused, but nothing there to free\n");
+		}
+	}
+
+	memused = memory/1024;
+	return(memory);
+}
+
+Cache *Cache::_instance = 0;
+
+Cache::Cache()
+{
+	assert(!_instance);
+	_instance = this;
+}
+
+Cache::~Cache()
+{
+	list<CachedObject *>::iterator i;
+	for(i=objects.begin(); i != objects.end(); i++)
+		delete (*i);
+	objects.clear();
+
+	assert(_instance);
+	_instance = 0;
+}
+
+
+Cache *Cache::the()
+{
+	if(!_instance) _instance = new Cache();
+	return _instance;
+}
+
+void Cache::shutdown()
+{
+	if(_instance)
+	{
+		list<CachedObject *>::iterator i;
+		long rcnt = 0;
+		for(i=_instance->objects.begin(); i != _instance->objects.end(); i++)
+			rcnt += (*i)->refCnt();
+
+		if(rcnt == 0)
+		{
+			delete _instance;
+			_instance = 0;
+		}
+		else
+		{
+			arts_warning("cache shutdown while still active objects in cache");
+		}
+	}
+}
+
+namespace Arts {			// internal helpers
+
+// periodic cache clean
+class CacheClean : public TimeNotify {
+public:
+	CacheClean();
+	void notifyTime();
+	virtual ~CacheClean();
+};
+
+// cache startup & shutdown
+class CacheStartup :public StartupClass
+{
+public:
+	void startup();
+	void shutdown();
+private:
+	CacheClean *cacheClean;
+};
+
+}
+
+CacheClean::CacheClean()
+{
+	Dispatcher::the()->ioManager()->addTimer(5000, this);
+}
+
+void CacheClean::notifyTime()
+{
+	// TODO: make this configurable
+	Cache::the()->cleanUp(8192*1024);
+}
+
+CacheClean::~CacheClean()
+{
+	Dispatcher::the()->ioManager()->removeTimer(this);
+}
+
+void CacheStartup::startup()
+{
+	cacheClean = new CacheClean;	
+}
+
+void CacheStartup::shutdown()
+{
+	delete cacheClean;
+	Cache::shutdown();
+}
+
+static CacheStartup cacheStartup;