From 060aa5b002a7c1808e6e54ab5585a40a18c5a0b4 Mon Sep 17 00:00:00 2001 From: Max Horn Date: Fri, 7 Nov 2008 09:46:12 +0000 Subject: [PATCH] Refactoring the Arj decoder code, phase 1 svn-id: r34922 --- common/unarj.cpp | 219 +++++++++++++++++++++++++++++++++++------------ common/unarj.h | 102 +--------------------- 2 files changed, 167 insertions(+), 154 deletions(-) diff --git a/common/unarj.cpp b/common/unarj.cpp index c09b515640d..7966fba135f 100644 --- a/common/unarj.cpp +++ b/common/unarj.cpp @@ -33,6 +33,109 @@ namespace Common { + +#define ARJ_UCHAR_MAX 255 +#define ARJ_CHAR_BIT 8 + +#define ARJ_COMMENT_MAX 2048 +#define ARJ_FILENAME_MAX 512 + +#define ARJ_CODE_BIT 16 +#define ARJ_THRESHOLD 3 +#define ARJ_DICSIZ 26624 +#define ARJ_FDICSIZ ARJ_DICSIZ +#define ARJ_MAXDICBIT 16 +#define ARJ_MAXMATCH 256 +#define ARJ_NC (ARJ_UCHAR_MAX + ARJ_MAXMATCH + 2 - ARJ_THRESHOLD) +#define ARJ_NP (ARJ_MAXDICBIT + 1) +#define ARJ_NT (ARJ_CODE_BIT + 3) + +#if ARJ_NT > ARJ_NP +#define ARJ_NPT ARJ_NT +#else +#define ARJ_NPT ARJ_NP +#endif + +#define ARJ_CTABLESIZE 4096 +#define ARJ_PTABLESIZE 256 + + +struct ArjHeader { + int32 pos; + uint16 id; + uint16 headerSize; + // + byte firstHdrSize; + byte nbr; + byte xNbr; + byte hostOs; + byte flags; + byte method; + byte fileType; + byte pad; + uint32 timeStamp; + int32 compSize; + int32 origSize; + uint32 fileCRC; + uint16 entryPos; + uint16 fileMode; + uint16 hostData; + char filename[ARJ_FILENAME_MAX]; + char comment[ARJ_COMMENT_MAX]; + + uint32 headerCrc; +}; + +class ArjDecoder { +public: + int32 findHeader(SeekableReadStream &stream); + ArjHeader *readHeader(SeekableReadStream &stream); + + void decode(); + void decode_f(); + + MemoryReadStream *_compressed; + MemoryWriteStream *_outstream; + +//protected: + uint16 _bitbuf; + uint16 _bytebuf; + int32 _compsize; + int32 _origsize; + byte _subbitbuf; + int _bitcount; + + void init_getbits(); + void fillbuf(int n); + uint16 getbits(int n); + + + void make_table(int nchar, byte *bitlen, int tablebits, uint16 *table, int tablesize); + void read_pt_len(int nn, int nbit, int i_special); + void read_c_len(void); + uint16 decode_c(void); + uint16 decode_p(void); + void decode_start(void); + int16 decode_ptr(void); + int16 decode_len(void); + +private: + byte _ntext[ARJ_FDICSIZ]; + + int16 _getlen; + int16 _getbuf; + + uint16 _left[2 * ARJ_NC - 1]; + uint16 _right[2 * ARJ_NC - 1]; + byte _c_len[ARJ_NC]; + byte _pt_len[ARJ_NPT]; + + uint16 _c_table[ARJ_CTABLESIZE]; + uint16 _pt_table[ARJ_PTABLESIZE]; + uint16 _blocksize; +}; + + #define HEADER_ID 0xEA60 #define HEADER_ID_HI 0xEA #define HEADER_ID_LO 0x60 @@ -77,6 +180,7 @@ static uint32 GetCRC(byte *data, int len) { } ArjFile::ArjFile() : _uncompressedData(NULL) { + _decoder = new ArjDecoder; InitCRC(); _isOpen = false; _fallBack = false; @@ -87,6 +191,8 @@ ArjFile::~ArjFile() { for (uint i = 0; i < _headers.size(); i++) delete _headers[i]; + + delete _decoder; } void ArjFile::registerArchive(const String &filename) { @@ -96,7 +202,7 @@ void ArjFile::registerArchive(const String &filename) { if (!_currArchive.open(filename)) return; - first_hdr_pos = findHeader(); + first_hdr_pos = _decoder->findHeader(_currArchive); if (first_hdr_pos < 0) { warning("ArjFile::registerArchive(): Could not find a valid header"); @@ -104,10 +210,10 @@ void ArjFile::registerArchive(const String &filename) { } _currArchive.seek(first_hdr_pos, SEEK_SET); - if (readHeader() == NULL) + if (_decoder->readHeader(_currArchive) == NULL) return; - while ((header = readHeader()) != NULL) { + while ((header = _decoder->readHeader(_currArchive)) != NULL) { _headers.push_back(header); _currArchive.seek(header->compSize, SEEK_CUR); @@ -125,37 +231,37 @@ void ArjFile::registerArchive(const String &filename) { // Source for findHeader and readHeader: arj_arcv.c // -int32 ArjFile::findHeader(void) { +int32 ArjDecoder::findHeader(SeekableReadStream &stream) { long end_pos, tmp_pos; int id; byte header[HEADERSIZE_MAX]; uint32 crc; uint16 basic_hdr_size; - tmp_pos = _currArchive.pos(); - _currArchive.seek(0L, SEEK_END); - end_pos = _currArchive.pos() - 2; + tmp_pos = stream.pos(); + stream.seek(0L, SEEK_END); + end_pos = stream.pos() - 2; if (end_pos >= tmp_pos + HSLIMIT_ARJ) end_pos = tmp_pos + HSLIMIT_ARJ; while (tmp_pos < end_pos) { - _currArchive.seek(tmp_pos, SEEK_SET); - id = _currArchive.readByte(); + stream.seek(tmp_pos, SEEK_SET); + id = stream.readByte(); while (tmp_pos < end_pos) { if (id == HEADER_ID_LO) { - if ((id = _currArchive.readByte()) == HEADER_ID_HI) + if ((id = stream.readByte()) == HEADER_ID_HI) break; } else - id = _currArchive.readByte(); + id = stream.readByte(); tmp_pos++; } if (tmp_pos >= end_pos) return -1; - if ((basic_hdr_size = _currArchive.readUint16LE()) <= HEADERSIZE_MAX) { - _currArchive.read(header, basic_hdr_size); + if ((basic_hdr_size = stream.readUint16LE()) <= HEADERSIZE_MAX) { + stream.read(header, basic_hdr_size); crc = GetCRC(header, basic_hdr_size); - if (crc == _currArchive.readUint32LE()) { - _currArchive.seek(tmp_pos, SEEK_SET); + if (crc == stream.readUint32LE()) { + stream.seek(tmp_pos, SEEK_SET); return tmp_pos; } } @@ -164,20 +270,20 @@ int32 ArjFile::findHeader(void) { return -1; } -ArjHeader *ArjFile::readHeader() { +ArjHeader *ArjDecoder::readHeader(SeekableReadStream &stream) { ArjHeader header; ArjHeader *head; byte headData[HEADERSIZE_MAX]; // Strictly check the header ID - header.id = _currArchive.readUint16LE(); + header.id = stream.readUint16LE(); if (header.id != HEADER_ID) { warning("ArjFile::readHeader(): Bad header ID (%x)", header.id); return NULL; } - header.headerSize = _currArchive.readUint16LE(); + header.headerSize = stream.readUint16LE(); if (header.headerSize == 0) return NULL; // end of archive if (header.headerSize > HEADERSIZE_MAX) { @@ -186,11 +292,11 @@ ArjHeader *ArjFile::readHeader() { return NULL; } - int rSize = _currArchive.read(headData, header.headerSize); + int rSize = stream.read(headData, header.headerSize); MemoryReadStream readS(headData, rSize); - header.headerCrc = _currArchive.readUint32LE(); + header.headerCrc = stream.readUint32LE(); if (GetCRC(headData, header.headerSize) != header.headerCrc) { warning("ArjFile::readHeader(): Bad header CRC"); return NULL; @@ -224,10 +330,10 @@ ArjHeader *ArjFile::readHeader() { // Process extended headers, if any uint16 extHeaderSize; - while ((extHeaderSize = _currArchive.readUint16LE()) != 0) - _currArchive.seek((long)(extHeaderSize + 4), SEEK_CUR); + while ((extHeaderSize = stream.readUint16LE()) != 0) + stream.seek((long)(extHeaderSize + 4), SEEK_CUR); - header.pos = _currArchive.pos(); + header.pos = stream.pos(); head = new ArjHeader(header); @@ -257,42 +363,43 @@ bool ArjFile::open(const Common::String &filename) { ArjHeader *hdr = _headers[_fileMap[filename]]; - _compsize = hdr->compSize; - _origsize = hdr->origSize; + _decoder->_compsize = hdr->compSize; + _decoder->_origsize = hdr->origSize; // FIXME: This hotfix prevents Drascula from leaking memory. // As far as sanity checks go this is not bad, but the engine should be fixed. - if (_uncompressedData) - free(_uncompressedData); + free(_uncompressedData); - _uncompressedData = (byte *)malloc(_origsize); - _outstream = new MemoryWriteStream(_uncompressedData, _origsize); + _uncompressedData = (byte *)malloc(_decoder->_origsize); + _decoder->_outstream = new MemoryWriteStream(_uncompressedData, _decoder->_origsize); _currArchive.open(_archMap[filename]); _currArchive.seek(hdr->pos, SEEK_SET); - if (hdr->method == 0) { // store - _currArchive.read(_uncompressedData, _origsize); - } else { - _compressedData = (byte *)malloc(_compsize); - _currArchive.read(_compressedData, _compsize); +printf("Arj archive method %d, file '%s'\n", hdr->method, filename.c_str()); - _compressed = new MemoryReadStream(_compressedData, _compsize); + if (hdr->method == 0) { // store + _currArchive.read(_uncompressedData, _decoder-> _origsize); + } else { + byte *_compressedData = (byte *)malloc(_decoder->_compsize); + _currArchive.read(_compressedData, _decoder->_compsize); + + _decoder->_compressed = new MemoryReadStream(_compressedData, _decoder->_compsize); if (hdr->method == 1 || hdr->method == 2 || hdr->method == 3) - decode(); + _decoder->decode(); else if (hdr->method == 4) - decode_f(); + _decoder->decode_f(); - delete _compressed; + delete _decoder->_compressed; free(_compressedData); } _currArchive.close(); - delete _outstream; - _outstream = NULL; + delete _decoder->_outstream; + _decoder->_outstream = NULL; - _uncompressed = new MemoryReadStream(_uncompressedData, _origsize); + _uncompressed = new MemoryReadStream(_uncompressedData, _decoder->_origsize); return true; } @@ -340,7 +447,7 @@ bool ArjFile::seek(int32 offset, int whence) { // Source for init_getbits: arj_file.c (decode_start_stub) // -void ArjFile::init_getbits() { +void ArjDecoder::init_getbits() { _bitbuf = 0; _bytebuf = 0; _bitcount = 0; @@ -351,7 +458,7 @@ void ArjFile::init_getbits() { // Source for fillbuf, getbits: decode.c // -void ArjFile::fillbuf(int n) { +void ArjDecoder::fillbuf(int n) { while (_bitcount < n) { _bitbuf = (_bitbuf << _bitcount) | (_bytebuf >> (8 - _bitcount)); n -= _bitcount; @@ -369,7 +476,7 @@ void ArjFile::fillbuf(int n) { } // Reads a series of bits into the input buffer */ -uint16 ArjFile::getbits(int n) { +uint16 ArjDecoder::getbits(int n) { uint16 rc; rc = _bitbuf >> (ARJ_CODE_BIT - n); @@ -385,7 +492,7 @@ uint16 ArjFile::getbits(int n) { // // Creates a table for decoding -void ArjFile::make_table(int nchar, byte *bitlen, int tablebits, uint16 *table, int tablesize) { +void ArjDecoder::make_table(int nchar, byte *bitlen, int tablebits, uint16 *table, int tablesize) { uint16 count[17], weight[17], start[18]; uint16 *p; uint i, k, len, ch, jutbits, avail, nextcode, mask; @@ -399,7 +506,7 @@ void ArjFile::make_table(int nchar, byte *bitlen, int tablebits, uint16 *table, for (i = 1; i <= 16; i++) start[i + 1] = start[i] + (count[i] << (16 - i)); if (start[17] != (uint16) (1 << 16)) - error("ArjFile::make_table(): bad file data"); + error("ArjDecoder::make_table(): bad file data"); jutbits = 16 - tablebits; for (i = 1; (int)i <= tablebits; i++) { @@ -427,7 +534,7 @@ void ArjFile::make_table(int nchar, byte *bitlen, int tablebits, uint16 *table, nextcode = k + weight[len]; if ((int)len <= tablebits) { if (nextcode > (uint)tablesize) - error("ArjFile::make_table(): bad file data"); + error("ArjDecoder::make_table(): bad file data"); for (i = start[len]; i < nextcode; i++) table[i] = ch; } else { @@ -453,7 +560,7 @@ void ArjFile::make_table(int nchar, byte *bitlen, int tablebits, uint16 *table, } // Reads length of data pending -void ArjFile::read_pt_len(int nn, int nbit, int i_special) { +void ArjDecoder::read_pt_len(int nn, int nbit, int i_special) { int i, n; int16 c; uint16 mask; @@ -491,7 +598,7 @@ void ArjFile::read_pt_len(int nn, int nbit, int i_special) { } // Reads a character table -void ArjFile::read_c_len() { +void ArjDecoder::read_c_len() { int16 i, c, n; uint16 mask; @@ -540,7 +647,7 @@ void ArjFile::read_c_len() { } // Decodes a single character -uint16 ArjFile::decode_c() { +uint16 ArjDecoder::decode_c() { uint16 j, mask; if (_blocksize == 0) { @@ -566,7 +673,7 @@ uint16 ArjFile::decode_c() { } // Decodes a control character -uint16 ArjFile::decode_p() { +uint16 ArjDecoder::decode_p() { uint16 j, mask; j = _pt_table[_bitbuf >> 8]; @@ -589,13 +696,13 @@ uint16 ArjFile::decode_p() { } // Initializes memory for decoding -void ArjFile::decode_start() { +void ArjDecoder::decode_start() { _blocksize = 0; init_getbits(); } // Decodes the entire file -void ArjFile::decode() { +void ArjDecoder::decode() { int16 i; int16 r; int16 c; @@ -641,7 +748,7 @@ void ArjFile::decode() { } // Backward pointer decoding -int16 ArjFile::decode_ptr() { +int16 ArjDecoder::decode_ptr() { int16 c = 0; int16 width; int16 plus; @@ -663,7 +770,7 @@ int16 ArjFile::decode_ptr() { } // Reference length decoding -int16 ArjFile::decode_len() { +int16 ArjDecoder::decode_len() { int16 c = 0; int16 width; int16 plus; @@ -685,7 +792,7 @@ int16 ArjFile::decode_len() { } // Decodes the entire file, using method 4 -void ArjFile::decode_f() { +void ArjDecoder::decode_f() { int16 i; int16 j; int16 c; diff --git a/common/unarj.h b/common/unarj.h index d16d748ad36..4e9750609e5 100644 --- a/common/unarj.h +++ b/common/unarj.h @@ -31,57 +31,8 @@ namespace Common { -#define ARJ_UCHAR_MAX 255 -#define ARJ_CHAR_BIT 8 - -#define ARJ_COMMENT_MAX 2048 -#define ARJ_FILENAME_MAX 512 - -#define ARJ_CODE_BIT 16 -#define ARJ_THRESHOLD 3 -#define ARJ_DICSIZ 26624 -#define ARJ_FDICSIZ ARJ_DICSIZ -#define ARJ_MAXDICBIT 16 -#define ARJ_MAXMATCH 256 -#define ARJ_NC (ARJ_UCHAR_MAX + ARJ_MAXMATCH + 2 - ARJ_THRESHOLD) -#define ARJ_NP (ARJ_MAXDICBIT + 1) -#define ARJ_NT (ARJ_CODE_BIT + 3) - -#if ARJ_NT > ARJ_NP -#define ARJ_NPT ARJ_NT -#else -#define ARJ_NPT ARJ_NP -#endif - -#define ARJ_CTABLESIZE 4096 -#define ARJ_PTABLESIZE 256 - - -struct ArjHeader { - int32 pos; - uint16 id; - uint16 headerSize; - // - byte firstHdrSize; - byte nbr; - byte xNbr; - byte hostOs; - byte flags; - byte method; - byte fileType; - byte pad; - uint32 timeStamp; - int32 compSize; - int32 origSize; - uint32 fileCRC; - uint16 entryPos; - uint16 fileMode; - uint16 hostData; - char filename[ARJ_FILENAME_MAX]; - char comment[ARJ_COMMENT_MAX]; - - uint32 headerCrc; -}; +struct ArjHeader; +class ArjDecoder; typedef HashMap ArjFilesMap; @@ -111,58 +62,13 @@ private: Array _headers; ArjFilesMap _fileMap; StringMap _archMap; - ReadStream *_stream; + byte *_uncompressedData; - byte *_compressedData; - MemoryWriteStream *_outstream; - MemoryReadStream *_compressed; SeekableReadStream *_uncompressed; bool _isOpen; - - int32 findHeader(void); - ArjHeader *readHeader(); - - void decode(); - void decode_f(); - - uint16 _bitbuf; - uint16 _bytebuf; - int32 _compsize; - int32 _origsize; - byte _subbitbuf; - int _bitcount; - - void init_getbits(); - void fillbuf(int n); - uint16 getbits(int n); - - void make_table(int nchar, byte *bitlen, int tablebits, uint16 *table, int tablesize); - void read_pt_len(int nn, int nbit, int i_special); - void read_c_len(void); - uint16 decode_c(void); - uint16 decode_p(void); - void decode_start(void); - int16 decode_ptr(void); - int16 decode_len(void); - -private: - byte _ntext[ARJ_FDICSIZ]; - - int16 _getlen; - int16 _getbuf; - - uint16 _left[2 * ARJ_NC - 1]; - uint16 _right[2 * ARJ_NC - 1]; - byte _c_len[ARJ_NC]; - byte _pt_len[ARJ_NPT]; - - uint16 _c_table[ARJ_CTABLESIZE]; - uint16 _pt_table[ARJ_PTABLESIZE]; - uint16 _blocksize; - - + ArjDecoder *_decoder; }; } // End of namespace Common