axmol/cocos2dx/support/zip_support/ZipUtils.h

/****************************************************************************
Copyright (c) 2010 cocos2d-x.org

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#ifndef __SUPPORT_ZIPUTILS_H__
#define __SUPPORT_ZIPUTILS_H__

#include <string>
#include "CCPlatformDefine.h"

namespace cocos2d
{
    /* XXX: pragma pack ??? */
    /** @struct CCZHeader
    */
    struct CCZHeader {
        unsigned char   sig[4];             // signature. Should be 'CCZ!' 4 bytes
        unsigned short  compression_type;   // should 0
        unsigned short  version;            // should be 2 (although version type==1 is also supported)
        unsigned int    reserved;           // Reserved for users.
        unsigned int    len;                // size of the uncompressed file
    };

    enum {
        CCZ_COMPRESSION_ZLIB,               // zlib format.
        CCZ_COMPRESSION_BZIP2,              // bzip2 format (not supported yet)
        CCZ_COMPRESSION_GZIP,               // gzip format (not supported yet)
        CCZ_COMPRESSION_NONE,               // plain (not supported yet)
    };

    class CC_DLL ZipUtils
    {
    public:
        /** 
        * Inflates either zlib or gzip deflated memory. The inflated memory is
        * expected to be freed by the caller.
        *
        * It will allocate 256k for the destination buffer. If it is not enough it will multiply the previous buffer size per 2, until there is enough memory.
        * @returns the length of the deflated buffer
        *
        @since v0.8.1
        */
        static int ccInflateMemory(unsigned char *in, unsigned int inLength, unsigned char **out);

        /** 
        * Inflates either zlib or gzip deflated memory. The inflated memory is
        * expected to be freed by the caller.
        *
        * outLenghtHint is assumed to be the needed room to allocate the inflated buffer.
        *
        * @returns the length of the deflated buffer
        *
        @since v1.0.0
        */
        static int ccInflateMemoryWithHint(unsigned char *in, unsigned int inLength, unsigned char **out, unsigned int outLenghtHint);

        /** inflates a GZip file into memory
        *
        * @returns the length of the deflated buffer
        *
        * @since v0.99.5
        */
        static int ccInflateGZipFile(const char *filename, unsigned char **out);

        /** inflates a CCZ file into memory
        *
        * @returns the length of the deflated buffer
        *
        * @since v0.99.5
        */
        static int ccInflateCCZFile(const char *filename, unsigned char **out);

        /** Sets the pvr.ccz encryption key parts separately for added
        * security.
        *
        * Example: If the key used to encrypt the pvr.ccz file is
        * 0xaaaaaaaabbbbbbbbccccccccdddddddd you will call this function 4 
        * different times, preferably from 4 different source files, as follows
        *
        * ZipUtils::ccSetPvrEncryptionKeyPart(0, 0xaaaaaaaa);
        * ZipUtils::ccSetPvrEncryptionKeyPart(1, 0xbbbbbbbb);
        * ZipUtils::ccSetPvrEncryptionKeyPart(2, 0xcccccccc);
        * ZipUtils::ccSetPvrEncryptionKeyPart(3, 0xdddddddd);
        *
        * Splitting the key into 4 parts and calling the function
        * from 4 different source files increases the difficulty to
        * reverse engineer the encryption key. Be aware that encrpytion 
        * is *never* 100% secure and the key code can be cracked by
        * knowledgable persons.
        *
        * IMPORTANT: Be sure to call ccSetPvrEncryptionKey or
        * ccSetPvrEncryptionKeyPart with all of the key parts *before* loading
        * the spritesheet or decryption will fail and the spritesheet
        * will fail to load.
        *
        * @param index part of the key [0..3]
        * @param value value of the key part
        */
        static void ccSetPvrEncryptionKeyPart(int index, unsigned int value);
        
        /** Sets the pvr.ccz encryption key.
        *
        * Example: If the key used to encrypt the pvr.ccz file is
        * 0xaaaaaaaabbbbbbbbccccccccdddddddd you will call this function with
        * the key split into 4 parts as follows
        *
        * ZipUtils::ccSetPvrEncryptionKey(0xaaaaaaaa, 0xbbbbbbbb, 0xcccccccc, 0xdddddddd);
        *
        * Note that using this function makes it easier to reverse engineer and
        * discover the complete key because the key parts are present in one 
        * function call.
        *
        * IMPORTANT: Be sure to call ccSetPvrEncryptionKey or
        * ccSetPvrEncryptionKeyPart with all of the key parts *before* loading 
        * the spritesheet or decryption will fail and the spritesheet
        * will fail to load.
        *
        * @param keyPart1 the key value part 1.
        * @param keyPart2 the key value part 2.
        * @param keyPart3 the key value part 3.
        * @param keyPart4 the key value part 4.
        */
        static void ccSetPvrEncryptionKey(unsigned int keyPart1, unsigned int keyPart2, unsigned int keyPart3, unsigned int keyPart4);

    private:
        static int ccInflateMemoryWithHint(unsigned char *in, unsigned int inLength, unsigned char **out, unsigned int *outLength, 
                                           unsigned int outLenghtHint);
        static inline void ccDecodeEncodedPvr (unsigned int *data, int len);
        static inline unsigned int ccChecksumPvr(const unsigned int *data, int len);

        static unsigned int s_uEncryptedPvrKeyParts[4];
        static unsigned int s_uEncryptionKey[1024];
        static bool s_bEncryptionKeyIsValid;
    };

    // forward declaration
    class ZipFilePrivate;

    /**
    * Zip file - reader helper class.
    *
    * It will cache the file list of a particular zip file with positions inside an archive,
    * so it would be much faster to read some particular files or to check their existance.
    *
    * @since v2.0.5
    */
    class ZipFile
    {
    public:
        /**
        * Constructor, open zip file and store file list.
        *
        * @param zipFile Zip file name
        * @param filter The first part of file names, which should be accessible.
        *               For example, "assets/". Other files will be missed.
        *
        * @since v2.0.5
        */
        ZipFile(const std::string &zipFile, const std::string &filter = std::string());
        virtual ~ZipFile();

        /**
        * Regenerate accessible file list based on a new filter string.
        *
        * @param filter New filter string (first part of files names)
        * @return true whenever zip file is open successfully and it is possible to locate
        *              at least the first file, false otherwise
        *
        * @since v2.0.5
        */
        bool setFilter(const std::string &filter);

        /**
        * Check does a file exists or not in zip file
        *
        * @param fileName File to be checked on existance
        * @return true whenever file exists, false otherwise
        *
        * @since v2.0.5
        */
        bool fileExists(const std::string &fileName) const;

        /**
        * Get resource file data from a zip file.
        * @param fileName File name
        * @param[out] pSize If the file read operation succeeds, it will be the data size, otherwise 0.
        * @return Upon success, a pointer to the data is returned, otherwise NULL.
        * @warning Recall: you are responsible for calling delete[] on any Non-NULL pointer returned.
        *
        * @since v2.0.5
        */
        unsigned char *getFileData(const std::string &fileName, unsigned long *pSize);

    private:
        /** Internal data like zip file pointer / file list array and so on */
        ZipFilePrivate *m_data;
    };
} // end of namespace cocos2d
#endif // __SUPPORT_ZIPUTILS_H__