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CrySystem/ZipDirCacheFactory.h

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+//////////////////////////////////////////////////////////////////////////
+// This is the class that can read the directory from Zip file,
+// and store it into the directory cache
+#ifndef _ZIP_DIR_READER_HDR_
+#define _ZIP_DIR_READER_HDR_
+
+namespace ZipDir
+{
+
+class CacheRW;
+TYPEDEF_AUTOPTR(CacheRW);
+typedef CacheRW_AutoPtr CacheRWPtr;
+
+
+// an instance of this class is temporarily created on stack to initialize the CZipFile instance
+class CacheFactory
+{
+public:
+	enum 
+	{
+		// open RW cache in read-only mode
+		FLAGS_READ_ONLY = 1,
+		// do not compact RW-cached zip upon destruction
+		FLAGS_DONT_COMPACT = 1 << 1,
+		// if this is set, then the zip paths won't be memorized in the cache objects
+		FLAGS_DONT_MEMORIZE_ZIP_PATH = 1 << 2,
+		// if this is set, the archive will be created anew (the existing file will be overwritten)
+		FLAGS_CREATE_NEW = 1 << 3
+	};
+
+	// initializes the internal structures
+	// nFlags can have FLAGS_READ_ONLY flag, in this case the object will be opened only for reading
+	CacheFactory (CMTSafeHeap* pHeap, InitMethodEnum nInitMethod, unsigned nFlags = 0);
+	~CacheFactory();
+
+	// the new function creates a new cache
+	CachePtr New(const char* szFileName);// throw (ErrorEnum);
+
+	CacheRWPtr NewRW(const char* szFileName);
+
+protected:
+	// reads the zip file into the file entry tree.
+	void Read (CacheRW& rwCache);
+
+	// creates from the m_f file
+	// reserves the given number of bytes for future expansion of the object
+	// upon return, pReserve contains the actual number of bytes that were allocated (more might have been allocated)
+	CachePtr MakeCache (const char* szFile);
+
+	// this sets the window size of the blocks of data read from the end of the file to find the Central Directory Record
+	// since normally there are no 
+	enum {g_nCDRSearchWindowSize = 0x100};
+
+	void Clear();
+
+	// reads everything and prepares the maps
+	void Prepare();
+
+	// searches for CDREnd record in the given file
+	void FindCDREnd();// throw(ErrorEnum);
+
+	// uses the found CDREnd to scan the CDR and probably the Zip file itself
+	// builds up the m_mapFileEntries
+	void BuildFileEntryMap();// throw (ErrorEnum);
+
+	// give the CDR File Header entry, reads the local file header to validate and determine where
+	// the actual file lies
+	void AddFileEntry (const string& strFilePath, const ZipFile::CDRFileHeader* pFileHeader);// throw (ErrorEnum);
+
+	// extracts the file path from the file header with subsequent information
+	// may, or may not, put all letters to lower-case (depending on whether the system is to be case-sensitive or not)
+	// it's the responsibility of the caller to ensure that the file name is in readable valid memory
+	string GetFilePath (const ZipFile::CDRFileHeader* pFileHeader)
+	{
+		return GetFilePath((const char*)(pFileHeader + 1), pFileHeader->nFileNameLength);
+	}
+	// extracts the file path from the file header with subsequent information
+	// may, or may not, put all letters to lower-case (depending on whether the system is to be case-sensitive or not)
+	// it's the responsibility of the caller to ensure that the file name is in readable valid memory
+	string GetFilePath (const ZipFile::LocalFileHeader* pFileHeader)
+	{
+		return GetFilePath((const char*)(pFileHeader + 1), pFileHeader->nFileNameLength);
+	}
+	// extracts the file path from the file header with subsequent information
+	// may, or may not, put all letters to lower-case (depending on whether the system is to be case-sensitive or not)
+	// it's the responsibility of the caller to ensure that the file name is in readable valid memory
+	string GetFilePath (const char* pFileName, ZipFile::ushort nFileNameLength);
+
+	// validates (if the init method has the corresponding value) the given file/header
+	void Validate(const FileEntry& fileEntry);
+
+	// initializes the actual data offset in the file in the fileEntry structure
+	// searches to the local file header, reads it and calculates the actual offset in the file
+	void InitDataOffset (FileEntry& fileEntry, const ZipFile::CDRFileHeader* pFileHeader);
+
+	// seeks in the file relative to the starting position
+	void Seek (ZipFile::ulong nPos, int nOrigin = SEEK_SET); // throw
+	long Tell (); // throw
+	void Read (void* pDest, unsigned nSize); // throw
+protected:
+	
+	FILE* m_f;
+	InitMethodEnum m_nInitMethod;
+	unsigned m_nFlags;
+	ZipFile::CDREnd m_CDREnd;
+
+	// compatible with zlib memory-management functions used both
+	// to allocate/free this instance and for decompression operations
+	CMTSafeHeap* m_pHeap;
+
+	unsigned m_nCDREndPos; // position of the CDR End in the file
+
+	// Map: Relative file path => file entry info
+	typedef std::map<string, ZipDir::FileEntry> FileEntryMap;
+	FileEntryMap m_mapFileEntries;
+
+	FileEntryTree m_treeFileEntries;
+
+	bool m_bBuildFileEntryMap;
+	bool m_bBuildFileEntryTree;
+};
+}
+
+#endif