commandline.h / commandline.cpp class CommandLine; This class is used to process the command line arguments passed to par2cmdline. Basic verification is done to ensure that invalid combinations of options are not used and that files exist. crc.h / crc.cpp u32 CRCUpdateChar(u32 crc, u8 ch); u32 CRCUpdateBlock(u32 crc, size_t length, const void *buffer); u32 CRCUpdateBlock(u32 crc, size_t length); void GenerateWindowTable(u64 window, u32 (&windowtable)[256]); u32 ComputeWindowMask(u64 window); u32 CRCSlideChar(u32 crc, u8 chNew, u8 chOld, const u32 (&windowtable)[256]); These functions are used to calculate and verify the CCITT CRC32 values for blocks of data in data files. The latter three functions allow the rapid computation of the crc for data in a sliding window. creatorpacket.h / creatorpacket.cpp class CreatorPacket; This class is used to read and write "Creator Packets" to a recovery file. criticalpacket.h / criticalpacket.cpp class CriticalPacket; class CriticalPacketEntry; CriticalPacket is the base class for DesriptionPacket, VerificationPacket, MainPacket, and CreatorPacket. CriticalPacket encapsulates memory allocation for the packet, computation of the packet hash and writing the packet to disk. CriticalPacketEntry is used to record that a copy of a specific critical packet will be written to a particular file at a specific offset. datablock.h / datablock.cpp class DataBlock; Objects of this type are used to track blocks of data that belong to different files. When data is read from or written to a datablock, it calculates the correct file offset and length to use. descriptionpacket.h / descriptionpacket.cpp class DescriptionPacket; This class is used to read and write "File Description Packets" to a recovery file. The class can compute the file id for the file when creating recovery files and will verify that the packet is ok when it is loaded from a recovery file. diskfile.h / diskfile.cpp class DiskFile; class DiskFileMap; The DiskFile class encapsulates all file access. Each object of this type represents on file that par2cmdline is using, and references to it are used in any other object that needs to refer to a file. The DiskFileMap class is used to track which files have been processed. filechecksummer.h / filechecksummer.cpp class FileCheckSummer; The FileCheckSummer is used to compute the CRC and HASH of a sliding window onto a data file. The CRC is updated continuously as the window is slid allong the file, and the HASH is only calculated when it is needed. galois.h / galois.cpp class Galois; class GaloisTable; class GaloisLongMultiplyTable; The Galois object is used for galois arithmetic. GaloisTable encapsulates the log and antilog tables used for fast multiplation and division, and GaloisLongMultiplyTable is used by the ReedSolomon object to allow rapid multiplication of a block of data by the same value. mainpacket.h / mainpacket.cpp class MainPacket; The MainPacket is used to read and write a "Main Packet" to and from a recovery file. md5.h / md5.cpp class MD5Hash; class MD5Context; MD5Context objects are used to calculate the hash of a block of data. The resulting hash value is then stored in an MD5Hash object. par2cmdline.h / par2cmdline.cpp int main(int argc, char *argv[]); par2cmdline.cpp defines the main() function which is responsible for creating a CommandLine object to parse the command line parameters, and then to create either a Par2Creator or a Par2Repairer to either create recovery files or use them to verify and repair data files. par2cmdline.h contains #include lines for all required header files, as well as a number of type definitions. par2creator.h / par2creator.cpp class Par2Creator; This class encapsulates all of the procedures required to create recovery files from a set of data files. par2creatorsourcefile.h / par2creatorsourcefile.cpp class Par2CreatorSourceFile; Each object of this type represent one of the data files for which recovery files are to be created. It handles creation of a DescriptionPacket and a VerificationPacket, computation of the full file hash and 16k hash values and the calculation and recording of the crc and hash values for each data block withint the file. par2fileformat.h / par2fileformat.cpp struct PACKET_HEADER; struct FILEVERIFICATIONPACKET; struct FILEDESCRIPTIONPACKET; struct MAINPACKET; struct CREATORPACKET; struct RECOVERYBLOCKPACKET; These structures define the exact format used to store the various packets in a recovery file. par2repairer.h / par2repairer.cpp class Par2Repairer; This class encapsulates all of the procedures required to use a set of recovery files to verify and repair the data files for which they were created. par2repairersourcefile.h / par2repairersourcefile.cpp class Par2RepairerSourceFile; Each object of this class represents one of the data files that is being verified and repaired. It has a copy of the description packet and verification packet from the recovery files, and keeps track of exactly which disk files contain data blocks that belong to it. recoverypacket.h / recoverypacket.cpp class RecoveryPacket; This class is used to read and write the header of a Recovery Packet. If contains a DataBlock object which is used to read and write data to or from the rest of the recovery packet. verificationhashtable.h / verificationhashtable.cpp class VerificationHashTable; class VerificationHashEntry; The VerificationHashTable is to store details obtained from all of the verification packets. It is used to check whether or not the crc and hash values calculated by the FileCheckSummer match any of the data blocks from the data files. verificationpacket.h / verificationpacket.cpp class VerificationPacket; This class is used to read a write Verification Packets to and from recovery files. letype.h class leu32; class leu64; These two types are used by fileformat.h and are used to handle the type conversion between little endian and big endian numerical formats.
