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Refactoring the Arj decoder code, phase 1

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svn-id: r34922
This commit is contained in:
Max Horn 2008-11-07 09:46:12 +00:00
parent 8baedea4d4
commit 060aa5b002
2 changed files with 167 additions and 154 deletions
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219
common/unarj.cpp
View file

@ -33,6 +33,109 @@
namespace Common { 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 0xEA60
#define HEADER_ID_HI 0xEA #define HEADER_ID_HI 0xEA
#define HEADER_ID_LO 0x60 #define HEADER_ID_LO 0x60
@ -77,6 +180,7 @@ static uint32 GetCRC(byte *data, int len) {
} }
ArjFile::ArjFile() : _uncompressedData(NULL) { ArjFile::ArjFile() : _uncompressedData(NULL) {
_decoder = new ArjDecoder;
InitCRC(); InitCRC();
_isOpen = false; _isOpen = false;
_fallBack = false; _fallBack = false;
@ -87,6 +191,8 @@ ArjFile::~ArjFile() {
for (uint i = 0; i < _headers.size(); i++) for (uint i = 0; i < _headers.size(); i++)
delete _headers[i]; delete _headers[i];
delete _decoder;
} }
void ArjFile::registerArchive(const String &filename) { void ArjFile::registerArchive(const String &filename) {
@ -96,7 +202,7 @@ void ArjFile::registerArchive(const String &filename) {
if (!_currArchive.open(filename)) if (!_currArchive.open(filename))
return; return;
first_hdr_pos = findHeader(); first_hdr_pos = _decoder->findHeader(_currArchive);
if (first_hdr_pos < 0) { if (first_hdr_pos < 0) {
warning("ArjFile::registerArchive(): Could not find a valid header"); 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); _currArchive.seek(first_hdr_pos, SEEK_SET);
if (readHeader() == NULL) if (_decoder->readHeader(_currArchive) == NULL)
return; return;
while ((header = readHeader()) != NULL) { while ((header = _decoder->readHeader(_currArchive)) != NULL) {
_headers.push_back(header); _headers.push_back(header);
_currArchive.seek(header->compSize, SEEK_CUR); _currArchive.seek(header->compSize, SEEK_CUR);
@ -125,37 +231,37 @@ void ArjFile::registerArchive(const String &filename) {
// Source for findHeader and readHeader: arj_arcv.c // Source for findHeader and readHeader: arj_arcv.c
// //
int32 ArjFile::findHeader(void) { int32 ArjDecoder::findHeader(SeekableReadStream &stream) {
long end_pos, tmp_pos; long end_pos, tmp_pos;
int id; int id;
byte header[HEADERSIZE_MAX]; byte header[HEADERSIZE_MAX];
uint32 crc; uint32 crc;
uint16 basic_hdr_size; uint16 basic_hdr_size;
tmp_pos = _currArchive.pos(); tmp_pos = stream.pos();
_currArchive.seek(0L, SEEK_END); stream.seek(0L, SEEK_END);
end_pos = _currArchive.pos() - 2; end_pos = stream.pos() - 2;
if (end_pos >= tmp_pos + HSLIMIT_ARJ) if (end_pos >= tmp_pos + HSLIMIT_ARJ)
end_pos = tmp_pos + HSLIMIT_ARJ; end_pos = tmp_pos + HSLIMIT_ARJ;
while (tmp_pos < end_pos) { while (tmp_pos < end_pos) {
_currArchive.seek(tmp_pos, SEEK_SET); stream.seek(tmp_pos, SEEK_SET);
id = _currArchive.readByte(); id = stream.readByte();
while (tmp_pos < end_pos) { while (tmp_pos < end_pos) {
if (id == HEADER_ID_LO) { if (id == HEADER_ID_LO) {
if ((id = _currArchive.readByte()) == HEADER_ID_HI) if ((id = stream.readByte()) == HEADER_ID_HI)
break; break;
} else } else
id = _currArchive.readByte(); id = stream.readByte();
tmp_pos++; tmp_pos++;
} }
if (tmp_pos >= end_pos) if (tmp_pos >= end_pos)
return -1; return -1;
if ((basic_hdr_size = _currArchive.readUint16LE()) <= HEADERSIZE_MAX) { if ((basic_hdr_size = stream.readUint16LE()) <= HEADERSIZE_MAX) {
_currArchive.read(header, basic_hdr_size); stream.read(header, basic_hdr_size);
crc = GetCRC(header, basic_hdr_size); crc = GetCRC(header, basic_hdr_size);
if (crc == _currArchive.readUint32LE()) { if (crc == stream.readUint32LE()) {
_currArchive.seek(tmp_pos, SEEK_SET); stream.seek(tmp_pos, SEEK_SET);
return tmp_pos; return tmp_pos;
} }
} }
@ -164,20 +270,20 @@ int32 ArjFile::findHeader(void) {
return -1; return -1;
} }
ArjHeader *ArjFile::readHeader() { ArjHeader *ArjDecoder::readHeader(SeekableReadStream &stream) {
ArjHeader header; ArjHeader header;
ArjHeader *head; ArjHeader *head;
byte headData[HEADERSIZE_MAX]; byte headData[HEADERSIZE_MAX];
// Strictly check the header ID // Strictly check the header ID
header.id = _currArchive.readUint16LE(); header.id = stream.readUint16LE();
if (header.id != HEADER_ID) { if (header.id != HEADER_ID) {
warning("ArjFile::readHeader(): Bad header ID (%x)", header.id); warning("ArjFile::readHeader(): Bad header ID (%x)", header.id);
return NULL; return NULL;
} }
header.headerSize = _currArchive.readUint16LE(); header.headerSize = stream.readUint16LE();
if (header.headerSize == 0) if (header.headerSize == 0)
return NULL; // end of archive return NULL; // end of archive
if (header.headerSize > HEADERSIZE_MAX) { if (header.headerSize > HEADERSIZE_MAX) {
@ -186,11 +292,11 @@ ArjHeader *ArjFile::readHeader() {
return NULL; return NULL;
} }
int rSize = _currArchive.read(headData, header.headerSize); int rSize = stream.read(headData, header.headerSize);
MemoryReadStream readS(headData, rSize); MemoryReadStream readS(headData, rSize);
header.headerCrc = _currArchive.readUint32LE(); header.headerCrc = stream.readUint32LE();
if (GetCRC(headData, header.headerSize) != header.headerCrc) { if (GetCRC(headData, header.headerSize) != header.headerCrc) {
warning("ArjFile::readHeader(): Bad header CRC"); warning("ArjFile::readHeader(): Bad header CRC");
return NULL; return NULL;
@ -224,10 +330,10 @@ ArjHeader *ArjFile::readHeader() {
// Process extended headers, if any // Process extended headers, if any
uint16 extHeaderSize; uint16 extHeaderSize;
while ((extHeaderSize = _currArchive.readUint16LE()) != 0) while ((extHeaderSize = stream.readUint16LE()) != 0)
_currArchive.seek((long)(extHeaderSize + 4), SEEK_CUR); stream.seek((long)(extHeaderSize + 4), SEEK_CUR);
header.pos = _currArchive.pos(); header.pos = stream.pos();
head = new ArjHeader(header); head = new ArjHeader(header);
@ -257,42 +363,43 @@ bool ArjFile::open(const Common::String &filename) {
ArjHeader *hdr = _headers[_fileMap[filename]]; ArjHeader *hdr = _headers[_fileMap[filename]];
_compsize = hdr->compSize; _decoder->_compsize = hdr->compSize;
_origsize = hdr->origSize; _decoder->_origsize = hdr->origSize;
// FIXME: This hotfix prevents Drascula from leaking memory. // FIXME: This hotfix prevents Drascula from leaking memory.
// As far as sanity checks go this is not bad, but the engine should be fixed. // 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); _uncompressedData = (byte *)malloc(_decoder->_origsize);
_outstream = new MemoryWriteStream(_uncompressedData, _origsize); _decoder->_outstream = new MemoryWriteStream(_uncompressedData, _decoder->_origsize);
_currArchive.open(_archMap[filename]); _currArchive.open(_archMap[filename]);
_currArchive.seek(hdr->pos, SEEK_SET); _currArchive.seek(hdr->pos, SEEK_SET);
if (hdr->method == 0) { // store printf("Arj archive method %d, file '%s'\n", hdr->method, filename.c_str());
_currArchive.read(_uncompressedData, _origsize);
} else {
_compressedData = (byte *)malloc(_compsize);
_currArchive.read(_compressedData, _compsize);
_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) if (hdr->method == 1 || hdr->method == 2 || hdr->method == 3)
decode(); _decoder->decode();
else if (hdr->method == 4) else if (hdr->method == 4)
decode_f(); _decoder->decode_f();
delete _compressed; delete _decoder->_compressed;
free(_compressedData); free(_compressedData);
} }
_currArchive.close(); _currArchive.close();
delete _outstream; delete _decoder->_outstream;
_outstream = NULL; _decoder->_outstream = NULL;
_uncompressed = new MemoryReadStream(_uncompressedData, _origsize); _uncompressed = new MemoryReadStream(_uncompressedData, _decoder->_origsize);
return true; return true;
} }
@ -340,7 +447,7 @@ bool ArjFile::seek(int32 offset, int whence) {
// Source for init_getbits: arj_file.c (decode_start_stub) // Source for init_getbits: arj_file.c (decode_start_stub)
// //
void ArjFile::init_getbits() { void ArjDecoder::init_getbits() {
_bitbuf = 0; _bitbuf = 0;
_bytebuf = 0; _bytebuf = 0;
_bitcount = 0; _bitcount = 0;
@ -351,7 +458,7 @@ void ArjFile::init_getbits() {
// Source for fillbuf, getbits: decode.c // Source for fillbuf, getbits: decode.c
// //
void ArjFile::fillbuf(int n) { void ArjDecoder::fillbuf(int n) {
while (_bitcount < n) { while (_bitcount < n) {
_bitbuf = (_bitbuf << _bitcount) | (_bytebuf >> (8 - _bitcount)); _bitbuf = (_bitbuf << _bitcount) | (_bytebuf >> (8 - _bitcount));
n -= _bitcount; n -= _bitcount;
@ -369,7 +476,7 @@ void ArjFile::fillbuf(int n) {
} }
// Reads a series of bits into the input buffer */ // Reads a series of bits into the input buffer */
uint16 ArjFile::getbits(int n) { uint16 ArjDecoder::getbits(int n) {
uint16 rc; uint16 rc;
rc = _bitbuf >> (ARJ_CODE_BIT - n); rc = _bitbuf >> (ARJ_CODE_BIT - n);
@ -385,7 +492,7 @@ uint16 ArjFile::getbits(int n) {
// //
// Creates a table for decoding // 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 count[17], weight[17], start[18];
uint16 *p; uint16 *p;
uint i, k, len, ch, jutbits, avail, nextcode, mask; 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++) for (i = 1; i <= 16; i++)
start[i + 1] = start[i] + (count[i] << (16 - i)); start[i + 1] = start[i] + (count[i] << (16 - i));
if (start[17] != (uint16) (1 << 16)) if (start[17] != (uint16) (1 << 16))
error("ArjFile::make_table(): bad file data"); error("ArjDecoder::make_table(): bad file data");
jutbits = 16 - tablebits; jutbits = 16 - tablebits;
for (i = 1; (int)i <= tablebits; i++) { 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]; nextcode = k + weight[len];
if ((int)len <= tablebits) { if ((int)len <= tablebits) {
if (nextcode > (uint)tablesize) 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++) for (i = start[len]; i < nextcode; i++)
table[i] = ch; table[i] = ch;
} else { } else {
@ -453,7 +560,7 @@ void ArjFile::make_table(int nchar, byte *bitlen, int tablebits, uint16 *table,
} }
// Reads length of data pending // 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; int i, n;
int16 c; int16 c;
uint16 mask; uint16 mask;
@ -491,7 +598,7 @@ void ArjFile::read_pt_len(int nn, int nbit, int i_special) {
} }
// Reads a character table // Reads a character table
void ArjFile::read_c_len() { void ArjDecoder::read_c_len() {
int16 i, c, n; int16 i, c, n;
uint16 mask; uint16 mask;
@ -540,7 +647,7 @@ void ArjFile::read_c_len() {
} }
// Decodes a single character // Decodes a single character
uint16 ArjFile::decode_c() { uint16 ArjDecoder::decode_c() {
uint16 j, mask; uint16 j, mask;
if (_blocksize == 0) { if (_blocksize == 0) {
@ -566,7 +673,7 @@ uint16 ArjFile::decode_c() {
} }
// Decodes a control character // Decodes a control character
uint16 ArjFile::decode_p() { uint16 ArjDecoder::decode_p() {
uint16 j, mask; uint16 j, mask;
j = _pt_table[_bitbuf >> 8]; j = _pt_table[_bitbuf >> 8];
@ -589,13 +696,13 @@ uint16 ArjFile::decode_p() {
} }
// Initializes memory for decoding // Initializes memory for decoding
void ArjFile::decode_start() { void ArjDecoder::decode_start() {
_blocksize = 0; _blocksize = 0;
init_getbits(); init_getbits();
} }
// Decodes the entire file // Decodes the entire file
void ArjFile::decode() { void ArjDecoder::decode() {
int16 i; int16 i;
int16 r; int16 r;
int16 c; int16 c;
@ -641,7 +748,7 @@ void ArjFile::decode() {
} }
// Backward pointer decoding // Backward pointer decoding
int16 ArjFile::decode_ptr() { int16 ArjDecoder::decode_ptr() {
int16 c = 0; int16 c = 0;
int16 width; int16 width;
int16 plus; int16 plus;
@ -663,7 +770,7 @@ int16 ArjFile::decode_ptr() {
} }
// Reference length decoding // Reference length decoding
int16 ArjFile::decode_len() { int16 ArjDecoder::decode_len() {
int16 c = 0; int16 c = 0;
int16 width; int16 width;
int16 plus; int16 plus;
@ -685,7 +792,7 @@ int16 ArjFile::decode_len() {
} }
// Decodes the entire file, using method 4 // Decodes the entire file, using method 4
void ArjFile::decode_f() { void ArjDecoder::decode_f() {
int16 i; int16 i;
int16 j; int16 j;
int16 c; int16 c;

102
common/unarj.h
View file

@ -31,57 +31,8 @@
namespace Common { namespace Common {
#define ARJ_UCHAR_MAX 255 struct ArjHeader;
#define ARJ_CHAR_BIT 8 class ArjDecoder;
#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;
};
typedef HashMap<String, int, IgnoreCase_Hash, IgnoreCase_EqualTo> ArjFilesMap; typedef HashMap<String, int, IgnoreCase_Hash, IgnoreCase_EqualTo> ArjFilesMap;
@ -111,58 +62,13 @@ private:
Array<ArjHeader *> _headers; Array<ArjHeader *> _headers;
ArjFilesMap _fileMap; ArjFilesMap _fileMap;
StringMap _archMap; StringMap _archMap;
ReadStream *_stream;
byte *_uncompressedData; byte *_uncompressedData;
byte *_compressedData;
MemoryWriteStream *_outstream;
MemoryReadStream *_compressed;
SeekableReadStream *_uncompressed; SeekableReadStream *_uncompressed;
bool _isOpen; 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);
ArjDecoder *_decoder;
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;
}; };
} // End of namespace Common } // End of namespace Common