o3de/Code/Tools/CryCommonTools/ZipDir/ZipDirCacheFactory.h

/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/
// Original file Copyright Crytek GMBH or its affiliates, used under license.

// This is the class that can read the directory from Zip file,
// and store it into the directory cache

#ifndef CRYINCLUDE_CRYCOMMONTOOLS_ZIPDIR_ZIPDIRCACHEFACTORY_H
#define CRYINCLUDE_CRYCOMMONTOOLS_ZIPDIR_ZIPDIRCACHEFACTORY_H
#pragma once


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 (InitMethodEnum nInitMethod, unsigned nFlags = 0);
        ~CacheFactory();

        // the new function creates a new cache
        CachePtr New(const char* szFileName, const uint32 decryptionKey[4]);// throw (ErrorEnum);

        CacheRWPtr NewRW(const char* szFileName, size_t fileAlignment, bool encrypted, const uint32 encryptionKey[4]);

    protected:
        // reads the zip file into the file entry tree.
        bool ReadCacheRW (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
        bool Prepare();

        // searches for CDREnd record in the given file
        bool FindCDREnd();// throw(ErrorEnum);

        // uses the found CDREnd to scan the CDR and probably the Zip file itself
        // builds up the m_mapFileEntries
        bool BuildFileEntryMap();// throw (ErrorEnum);

        // give the CDR File Header entry, reads the local file header to validate and determine where
        // the actual file lies
        // This function can actually modify strFilePath and strUnifiedPath variables, make sure you use copies of real paths.
        void AddFileEntry (char* strFilePath, char* strUnifiedPath, const ZipFile::CDRFileHeader* pFileHeader, const SExtraZipFileData& extra);// 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
        char* 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
        char* 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
        char* 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
        unsigned long Tell (); // throw
        void Read (void* pDest, unsigned nSize); // throw
        void ReadHeaderData  (void* pDest, unsigned nSize);// throw
    protected:

        FILE* m_f;
        InitMethodEnum m_nInitMethod;
        unsigned m_nFlags;
        ZipFile::CDREnd m_CDREnd;

        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;

        DynArray<char> m_CDR_buffer;
        DynArray<char> m_unifiedNameBuffer;

        EncryptionKey m_encryptionKey;
        bool m_bEncryptedHeaders;
        bool m_bBuildFileEntryMap;
        bool m_bBuildFileEntryTree;
    };
}

#endif // CRYINCLUDE_CRYCOMMONTOOLS_ZIPDIR_ZIPDIRCACHEFACTORY_H