add RageFileDriverMemory; this is just a very simple memory "filesystem"

for caching stuff.  (Not yet used, just committing for testing ...)

stepmania/src/RageFileDriverMemory.cpp

@@ -0,0 +1,204 @@
+#include "global.h"
+#include "RageFileDriverMemory.h"
+#include "RageUtil.h"
+#include "RageUtil_FileDB.h"
+
+struct RageFileObjMemFile
+{
+	RageFileObjMemFile():
+		m_iRefs(0),
+		m_bDeleted(false),
+		m_Mutex("RageFileObjMemFile") { }
+	CString m_sBuf;
+	int m_iRefs;
+	bool m_bDeleted;
+	RageMutex m_Mutex;
+};
+
+class RageFileObjMem: public RageFileObj
+{
+private:
+	RageFileObjMemFile *m_pFile;
+	int m_iFilePos;
+
+public:
+	RageFileObjMem( RageFileObjMemFile *pFile, RageFile &p ):
+		RageFileObj(p)
+	{
+		m_pFile = pFile;
+		m_iFilePos = 0;
+		++m_pFile->m_iRefs;
+	}
+
+	~RageFileObjMem()
+	{
+		m_pFile->m_Mutex.Lock();
+		const int iRefs = --m_pFile->m_iRefs;
+		const bool bShouldDelete = (iRefs == 0 && m_pFile->m_bDeleted);
+		m_pFile->m_Mutex.Unlock();
+		ASSERT( iRefs >= 0 );
+
+		/* If the file was removed while we still had it open, and is now unreferenced,
+		 * delete it. */
+		if( bShouldDelete )
+			delete m_pFile;
+	}
+
+	int Read( void *buffer, size_t bytes )
+	{
+		m_pFile->m_Mutex.Lock();
+
+		m_iFilePos = min( m_iFilePos, GetFileSize() );
+		bytes = min( bytes, (size_t) GetFileSize() - m_iFilePos );
+		memcpy( buffer, &m_pFile->m_sBuf[m_iFilePos], bytes );
+		m_iFilePos += bytes;
+		m_pFile->m_Mutex.Unlock();
+
+		return bytes;
+	}
+
+	int Write( const void *buffer, size_t bytes )
+	{
+		m_pFile->m_Mutex.Lock();
+		m_pFile->m_sBuf.append( (const char *) buffer, bytes );
+		m_pFile->m_Mutex.Unlock();
+
+		m_iFilePos += bytes;
+		return bytes;
+	}
+
+	void Rewind()
+	{
+		m_iFilePos = 0;
+	}
+
+	int Seek( int offset )
+	{
+		m_iFilePos = clamp( offset, 0, GetFileSize() );
+		return m_iFilePos;
+	}
+
+	int GetFileSize()
+	{
+		LockMut(m_pFile->m_Mutex);
+		return m_pFile->m_sBuf.size();
+	}
+
+	RageFileObj *Copy( RageFile &p ) const
+	{
+		m_pFile->m_Mutex.Unlock();
+		++m_pFile->m_iRefs;
+		m_pFile->m_Mutex.Lock();
+
+		RageFileObjMem *pRet = new RageFileObjMem( m_pFile, p );
+		pRet->m_iFilePos = m_iFilePos;
+
+		return pRet;
+	}
+};
+
+
+RageFileDriverMem::RageFileDriverMem():
+	m_Mutex("RageFileDriverMem"),
+	RageFileDriver( new NullFilenameDB )
+{
+}
+
+RageFileDriverMem::~RageFileDriverMem()
+{
+	for( unsigned i = 0; i < m_Files.size(); ++i )
+	{
+		RageFileObjMemFile *pFile = m_Files[i];
+		ASSERT( !pFile->m_iRefs );
+
+		delete pFile;
+	}
+}
+
+RageFileObj *RageFileDriverMem::Open( const CString &sPath, int mode, RageFile &p, int &err )
+{
+	LockMut(m_Mutex);
+
+	if( mode == RageFile::WRITE )
+	{
+		/* If the file exists, delete it. */
+		Remove( sPath );
+
+		RageFileObjMemFile *pFile = new RageFileObjMemFile;
+
+		m_Files.push_back( pFile );
+		FDB->AddFile( sPath, 0, 0, pFile );
+
+		return new RageFileObjMem( pFile, p );
+	}
+
+	RageFileObjMemFile *pFile = (RageFileObjMemFile *) FDB->GetFilePriv( sPath );
+	if( pFile == NULL )
+	{
+		err = ENOENT;
+		return NULL;
+	}
+
+	return new RageFileObjMem( pFile, p );
+}
+
+bool RageFileDriverMem::Remove( const CString &sPath )
+{
+	LockMut(m_Mutex);
+
+	RageFileObjMemFile *pFile = (RageFileObjMemFile *) FDB->GetFilePriv( sPath );
+	if( pFile == NULL )
+		return false;
+
+	/* Unregister the file. */
+	FDB->DelFile( sPath );
+	vector<RageFileObjMemFile *>::iterator it = find( m_Files.begin(), m_Files.end(), pFile );
+	ASSERT( it != m_Files.end() );
+	m_Files.erase( it );
+
+	pFile->m_Mutex.Lock();
+	if( pFile->m_iRefs )
+	{
+		/* The file is in use.  The last RageFileObjMem dtor will delete it. */
+		pFile->m_bDeleted = true;
+		pFile->m_Mutex.Unlock();
+	}
+	else
+	{
+		pFile->m_Mutex.Unlock();
+		delete pFile;
+	}
+
+	return true;
+}
+
+static struct FileDriverEntry_MEM: public FileDriverEntry
+{
+	FileDriverEntry_MEM(): FileDriverEntry( "MEM" ) { }
+	RageFileDriver *Create( CString Root ) const { return new RageFileDriverMem(); }
+} const g_RegisterDriver;
+
+/*
+ * (c) 2004 Glenn Maynard
+ * All rights reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, and/or sell copies of the Software, and to permit persons to
+ * whom the Software is furnished to do so, provided that the above
+ * copyright notice(s) and this permission notice appear in all copies of
+ * the Software and that both the above copyright notice(s) and this
+ * permission notice appear in supporting documentation.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
+ * THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
+ * INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
+ * OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+ * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */