Imported existing code

indra/llvfs/llvfs.h

@@ -0,0 +1,174 @@
+/** 
+ * @file llvfs.h
+ * @brief Definition of virtual file system
+ *
+ * $LicenseInfo:firstyear=2002&license=viewergpl$
+ * 
+ * Copyright (c) 2002-2009, Linden Research, Inc.
+ * 
+ * Second Life Viewer Source Code
+ * The source code in this file ("Source Code") is provided by Linden Lab
+ * to you under the terms of the GNU General Public License, version 2.0
+ * ("GPL"), unless you have obtained a separate licensing agreement
+ * ("Other License"), formally executed by you and Linden Lab.  Terms of
+ * the GPL can be found in doc/GPL-license.txt in this distribution, or
+ * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
+ * 
+ * There are special exceptions to the terms and conditions of the GPL as
+ * it is applied to this Source Code. View the full text of the exception
+ * in the file doc/FLOSS-exception.txt in this software distribution, or
+ * online at
+ * http://secondlifegrid.net/programs/open_source/licensing/flossexception
+ * 
+ * By copying, modifying or distributing this software, you acknowledge
+ * that you have read and understood your obligations described above,
+ * and agree to abide by those obligations.
+ * 
+ * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
+ * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
+ * COMPLETENESS OR PERFORMANCE.
+ * $/LicenseInfo$
+ */
+
+#ifndef LL_LLVFS_H
+#define LL_LLVFS_H
+
+#include <deque>
+#include "lluuid.h"
+#include "linked_lists.h"
+#include "llassettype.h"
+#include "llthread.h"
+
+enum EVFSValid 
+{
+	VFSVALID_UNKNOWN = 0, 
+	VFSVALID_OK = 1,
+	VFSVALID_BAD_CORRUPT = 2,
+	VFSVALID_BAD_CANNOT_OPEN_READONLY = 3,
+	VFSVALID_BAD_CANNOT_CREATE = 4
+};
+
+// Lock types for open vfiles, pending async reads, and pending async appends
+// (There are no async normal writes, currently)
+enum EVFSLock
+{
+	VFSLOCK_OPEN = 0,
+	VFSLOCK_READ = 1,
+	VFSLOCK_APPEND = 2,
+
+	VFSLOCK_COUNT = 3
+};
+
+// internal classes
+class LLVFSBlock;
+class LLVFSFileBlock;
+class LLVFSFileSpecifier
+{
+public:
+	LLVFSFileSpecifier();
+	LLVFSFileSpecifier(const LLUUID &file_id, const LLAssetType::EType file_type);
+	bool operator<(const LLVFSFileSpecifier &rhs) const;
+	bool operator==(const LLVFSFileSpecifier &rhs) const;
+
+public:
+	LLUUID mFileID;
+	LLAssetType::EType mFileType;
+};
+
+class LLVFS
+{
+public:
+	// Pass 0 to not presize
+	LLVFS(const std::string& index_filename, const std::string& data_filename, const BOOL read_only, const U32 presize, const BOOL remove_after_crash);
+	~LLVFS();
+
+	BOOL isValid() const			{ return (VFSVALID_OK == mValid); }
+	EVFSValid getValidState() const	{ return mValid; }
+
+	// ---------- The following fucntions lock/unlock mDataMutex ----------
+	BOOL getExists(const LLUUID &file_id, const LLAssetType::EType file_type);
+	S32	 getSize(const LLUUID &file_id, const LLAssetType::EType file_type);
+
+	BOOL checkAvailable(S32 max_size);
+	
+	S32  getMaxSize(const LLUUID &file_id, const LLAssetType::EType file_type);
+	BOOL setMaxSize(const LLUUID &file_id, const LLAssetType::EType file_type, S32 max_size);
+
+	void renameFile(const LLUUID &file_id, const LLAssetType::EType file_type,
+		const LLUUID &new_id, const LLAssetType::EType &new_type);
+	void removeFile(const LLUUID &file_id, const LLAssetType::EType file_type);
+
+	S32 getData(const LLUUID &file_id, const LLAssetType::EType file_type, U8 *buffer, S32 location, S32 length);
+	S32 storeData(const LLUUID &file_id, const LLAssetType::EType file_type, const U8 *buffer, S32 location, S32 length);
+
+	void incLock(const LLUUID &file_id, const LLAssetType::EType file_type, EVFSLock lock);
+	void decLock(const LLUUID &file_id, const LLAssetType::EType file_type, EVFSLock lock);
+	BOOL isLocked(const LLUUID &file_id, const LLAssetType::EType file_type, EVFSLock lock);
+	// ----------------------------------------------------------------
+
+	// Used to trigger evil WinXP behavior of "preloading" entire file into memory.
+	void pokeFiles();
+
+	// Verify that the index file contents match the in-memory file structure
+	// Very slow, do not call routinely. JC
+	void audit();
+	// Check for uninitialized blocks.  Slow, do not call in release. JC
+	void checkMem();
+	// for debugging, prints a map of the vfs
+	void dumpMap();
+	void dumpLockCounts();
+	void dumpStatistics();
+	void listFiles();
+	void dumpFiles();
+
+protected:
+	void removeFileBlock(LLVFSFileBlock *fileblock);
+	
+	void eraseBlockLength(LLVFSBlock *block);
+	void eraseBlock(LLVFSBlock *block);
+	void addFreeBlock(LLVFSBlock *block);
+	//void mergeFreeBlocks();
+	void useFreeSpace(LLVFSBlock *free_block, S32 length);
+	void sync(LLVFSFileBlock *block, BOOL remove = FALSE);
+	void presizeDataFile(const U32 size);
+
+	static LLFILE *openAndLock(const std::string& filename, const char* mode, BOOL read_lock);
+	static void unlockAndClose(FILE *fp);
+	
+	// Can initiate LRU-based file removal to make space.
+	// The immune file block will not be removed.
+	LLVFSBlock *findFreeBlock(S32 size, LLVFSFileBlock *immune = NULL);
+
+	// lock/unlock data mutex (mDataMutex)
+	void lockData() { mDataMutex->lock(); }
+	void unlockData() { mDataMutex->unlock(); }	
+	
+protected:
+	LLMutex* mDataMutex;
+	
+	typedef std::map<LLVFSFileSpecifier, LLVFSFileBlock*> fileblock_map;
+	fileblock_map mFileBlocks;
+
+	typedef std::multimap<S32, LLVFSBlock*>	blocks_length_map_t;
+	blocks_length_map_t 	mFreeBlocksByLength;
+	typedef std::multimap<U32, LLVFSBlock*>	blocks_location_map_t;
+	blocks_location_map_t 	mFreeBlocksByLocation;
+
+	LLFILE *mDataFP;
+	LLFILE *mIndexFP;
+
+	std::deque<S32> mIndexHoles;
+
+	std::string mIndexFilename;
+	std::string mDataFilename;
+	BOOL mReadOnly;
+
+	EVFSValid mValid;
+
+	S32 mLockCounts[VFSLOCK_COUNT];
+	BOOL mRemoveAfterCrash;
+};
+
+extern LLVFS *gVFS;
+
+#endif