diff options
| -rw-r--r-- | backends/saves/compressed/compressed-saves.cpp | 288 | ||||
| -rw-r--r-- | common/gzip-stream.cpp | 327 | ||||
| -rw-r--r-- | common/gzip-stream.h | 58 | ||||
| -rw-r--r-- | common/module.mk | 1 |
4 files changed, 389 insertions, 285 deletions
diff --git a/backends/saves/compressed/compressed-saves.cpp b/backends/saves/compressed/compressed-saves.cpp index 5596bf96a8..d4601f77c9 100644 --- a/backends/saves/compressed/compressed-saves.cpp +++ b/backends/saves/compressed/compressed-saves.cpp @@ -23,296 +23,14 @@ * */ -#include "common/savefile.h" -#include "common/util.h" +#include "common/gzip-stream.h" #include "backends/saves/compressed/compressed-saves.h" -#if defined(USE_ZLIB) -#include <zlib.h> - -#if ZLIB_VERNUM < 0x1204 -#error Version 1.2.0.4 or newer of zlib is required for this code -#endif - -/** - * A simple wrapper class which can be used to wrap around an arbitrary - * other InSaveFile and will then provide on-the-fly decompression support. - * Assumes the compressed data to be in gzip format. - */ -class CompressedInSaveFile : public Common::InSaveFile { -protected: - enum { - BUFSIZE = 16384 // 1 << MAX_WBITS - }; - - byte _buf[BUFSIZE]; - - Common::InSaveFile *_wrapped; - z_stream _stream; - int _zlibErr; - uint32 _pos; - uint32 _origSize; - bool _eos; - -public: - - CompressedInSaveFile(Common::InSaveFile *w) : _wrapped(w) { - assert(w != 0); - - _stream.zalloc = Z_NULL; - _stream.zfree = Z_NULL; - _stream.opaque = Z_NULL; - - // Verify file header is correct - w->seek(0, SEEK_SET); - uint16 header = w->readUint16BE(); - assert(header == 0x1F8B || - ((header & 0x0F00) == 0x0800 && header % 31 == 0)); - - if (header == 0x1F8B) { - // Retrieve the original file size - w->seek(-4, SEEK_END); - _origSize = w->readUint32LE(); - } else { - // Original size not available in zlib format - _origSize = 0; - } - _pos = 0; - w->seek(0, SEEK_SET); - _eos = false; - - // Adding 32 to windowBits indicates to zlib that it is supposed to - // automatically detect whether gzip or zlib headers are used for - // the compressed file. This feature was added in zlib 1.2.0.4, - // released 10 August 2003. - // Note: This is *crucial* for savegame compatibility, do *not* remove! - _zlibErr = inflateInit2(&_stream, MAX_WBITS + 32); - if (_zlibErr != Z_OK) - return; - - // Setup input buffer - _stream.next_in = _buf; - _stream.avail_in = 0; - } - - ~CompressedInSaveFile() { - inflateEnd(&_stream); - delete _wrapped; - } - - bool err() const { return (_zlibErr != Z_OK) && (_zlibErr != Z_STREAM_END); } - void clearErr() { - // only reset _eos; I/O errors are not recoverable - _eos = false; - } - - uint32 read(void *dataPtr, uint32 dataSize) { - _stream.next_out = (byte *)dataPtr; - _stream.avail_out = dataSize; - - // Keep going while we get no error - while (_zlibErr == Z_OK && _stream.avail_out) { - if (_stream.avail_in == 0 && !_wrapped->eos()) { - // If we are out of input data: Read more data, if available. - _stream.next_in = _buf; - _stream.avail_in = _wrapped->read(_buf, BUFSIZE); - } - _zlibErr = inflate(&_stream, Z_NO_FLUSH); - } - - // Update the position counter - _pos += dataSize - _stream.avail_out; - - if (_zlibErr == Z_STREAM_END && _stream.avail_out > 0) - _eos = true; - - return dataSize - _stream.avail_out; - } - - bool eos() const { - return _eos; - } - int32 pos() const { - return _pos; - } - int32 size() const { - return _origSize; - } - bool seek(int32 offset, int whence = SEEK_SET) { - int32 newPos = 0; - assert(whence != SEEK_END); // SEEK_END not supported - switch(whence) { - case SEEK_SET: - newPos = offset; - break; - case SEEK_CUR: - newPos = _pos + offset; - } - - assert(newPos >= 0); - - if ((uint32)newPos < _pos) { - // To search backward, we have to restart the whole decompression - // from the start of the file. A rather wasteful operation, best - // to avoid it. :/ -#if DEBUG - warning("Backward seeking in CompressedInSaveFile detected"); -#endif - _pos = 0; - _wrapped->seek(0, SEEK_SET); - _zlibErr = inflateReset(&_stream); - if (_zlibErr != Z_OK) - return false; // FIXME: STREAM REWRITE - _stream.next_in = _buf; - _stream.avail_in = 0; - } - - offset = newPos - _pos; - - // Skip the given amount of data (very inefficient if one tries to skip - // huge amounts of data, but usually client code will only skip a few - // bytes, so this should be fine. - byte tmpBuf[1024]; - while (!err() && offset > 0) { - offset -= read(tmpBuf, MIN((int32)sizeof(tmpBuf), offset)); - } - - _eos = false; - return true; // FIXME: STREAM REWRITE - } -}; - -/** - * A simple wrapper class which can be used to wrap around an arbitrary - * other OutSaveFile and will then provide on-the-fly compression support. - * The compressed data is written in the gzip format. - */ -class CompressedOutSaveFile : public Common::OutSaveFile { -protected: - enum { - BUFSIZE = 16384 // 1 << MAX_WBITS - }; - - byte _buf[BUFSIZE]; - Common::OutSaveFile *_wrapped; - z_stream _stream; - int _zlibErr; - - void processData(int flushType) { - // This function is called by both write() and finalize(). - while (_zlibErr == Z_OK && (_stream.avail_in || flushType == Z_FINISH)) { - if (_stream.avail_out == 0) { - if (_wrapped->write(_buf, BUFSIZE) != BUFSIZE) { - _zlibErr = Z_ERRNO; - break; - } - _stream.next_out = _buf; - _stream.avail_out = BUFSIZE; - } - _zlibErr = deflate(&_stream, flushType); - } - } - -public: - CompressedOutSaveFile(Common::OutSaveFile *w) : _wrapped(w) { - assert(w != 0); - _stream.zalloc = Z_NULL; - _stream.zfree = Z_NULL; - _stream.opaque = Z_NULL; - - // Adding 16 to windowBits indicates to zlib that it is supposed to - // write gzip headers. This feature was added in zlib 1.2.0.4, - // released 10 August 2003. - // Note: This is *crucial* for savegame compatibility, do *not* remove! - _zlibErr = deflateInit2(&_stream, - Z_DEFAULT_COMPRESSION, - Z_DEFLATED, - MAX_WBITS + 16, - 8, - Z_DEFAULT_STRATEGY); - assert(_zlibErr == Z_OK); - - _stream.next_out = _buf; - _stream.avail_out = BUFSIZE; - _stream.avail_in = 0; - _stream.next_in = 0; - } - - ~CompressedOutSaveFile() { - finalize(); - deflateEnd(&_stream); - delete _wrapped; - } - - bool err() const { - // CHECKME: does Z_STREAM_END make sense here? - return (_zlibErr != Z_OK && _zlibErr != Z_STREAM_END) || _wrapped->err(); - } - - void clearErr() { - // Note: we don't reset the _zlibErr here, as it is not - // clear in general how - _wrapped->clearErr(); - } - - void finalize() { - if (_zlibErr != Z_OK) - return; - - // Process whatever remaining data there is. - processData(Z_FINISH); - - // Since processData only writes out blocks of size BUFSIZE, - // we may have to flush some stragglers. - uint remainder = BUFSIZE - _stream.avail_out; - if (remainder > 0) { - if (_wrapped->write(_buf, remainder) != remainder) { - _zlibErr = Z_ERRNO; - } - } - - // Finalize the wrapped savefile, too - _wrapped->finalize(); - } - - uint32 write(const void *dataPtr, uint32 dataSize) { - if (err()) - return 0; - - // Hook in the new data ... - // Note: We need to make a const_cast here, as zlib is not aware - // of the const keyword. - _stream.next_in = const_cast<byte *>((const byte *)dataPtr); - _stream.avail_in = dataSize; - - // ... and flush it to disk - processData(Z_NO_FLUSH); - - return dataSize - _stream.avail_in; - } -}; - -#endif // USE_ZLIB Common::InSaveFile *wrapInSaveFile(Common::InSaveFile *toBeWrapped) { -#if defined(USE_ZLIB) - if (toBeWrapped) { - uint16 header = toBeWrapped->readUint16BE(); - bool isCompressed = (header == 0x1F8B || - ((header & 0x0F00) == 0x0800 && - header % 31 == 0)); - toBeWrapped->seek(-2, SEEK_CUR); - if (isCompressed) - return new CompressedInSaveFile(toBeWrapped); - } -#endif - return toBeWrapped; + return Common::wrapCompressedReadStream(toBeWrapped); } Common::OutSaveFile *wrapOutSaveFile(Common::OutSaveFile *toBeWrapped) { -#if defined(USE_ZLIB) - if (toBeWrapped) - return new CompressedOutSaveFile(toBeWrapped); -#endif - return toBeWrapped; + return Common::wrapCompressedWriteStream(toBeWrapped); } diff --git a/common/gzip-stream.cpp b/common/gzip-stream.cpp new file mode 100644 index 0000000000..2756fe1b5c --- /dev/null +++ b/common/gzip-stream.cpp @@ -0,0 +1,327 @@ +/* ScummVM - Graphic Adventure Engine + * + * ScummVM is the legal property of its developers, whose names + * are too numerous to list here. Please refer to the COPYRIGHT + * file distributed with this source distribution. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * $URL$ + * $Id$ + * + */ + +#include "common/gzip-stream.h" +#include "common/util.h" + +#if defined(USE_ZLIB) + #include <zlib.h> + + #if ZLIB_VERNUM < 0x1204 + #error Version 1.2.0.4 or newer of zlib is required for this code + #endif +#endif + + +namespace Common { + + +#if defined(USE_ZLIB) + +/** + * A simple wrapper class which can be used to wrap around an arbitrary + * other SeekableReadStream and will then provide on-the-fly decompression support. + * Assumes the compressed data to be in gzip format. + */ +class GZipReadStream : public Common::SeekableReadStream { +protected: + enum { + BUFSIZE = 16384 // 1 << MAX_WBITS + }; + + byte _buf[BUFSIZE]; + + Common::SeekableReadStream *_wrapped; + z_stream _stream; + int _zlibErr; + uint32 _pos; + uint32 _origSize; + bool _eos; + +public: + + GZipReadStream(Common::SeekableReadStream *w) : _wrapped(w) { + assert(w != 0); + + _stream.zalloc = Z_NULL; + _stream.zfree = Z_NULL; + _stream.opaque = Z_NULL; + + // Verify file header is correct + w->seek(0, SEEK_SET); + uint16 header = w->readUint16BE(); + assert(header == 0x1F8B || + ((header & 0x0F00) == 0x0800 && header % 31 == 0)); + + if (header == 0x1F8B) { + // Retrieve the original file size + w->seek(-4, SEEK_END); + _origSize = w->readUint32LE(); + } else { + // Original size not available in zlib format + _origSize = 0; + } + _pos = 0; + w->seek(0, SEEK_SET); + _eos = false; + + // Adding 32 to windowBits indicates to zlib that it is supposed to + // automatically detect whether gzip or zlib headers are used for + // the compressed file. This feature was added in zlib 1.2.0.4, + // released 10 August 2003. + // Note: This is *crucial* for savegame compatibility, do *not* remove! + _zlibErr = inflateInit2(&_stream, MAX_WBITS + 32); + if (_zlibErr != Z_OK) + return; + + // Setup input buffer + _stream.next_in = _buf; + _stream.avail_in = 0; + } + + ~GZipReadStream() { + inflateEnd(&_stream); + delete _wrapped; + } + + bool err() const { return (_zlibErr != Z_OK) && (_zlibErr != Z_STREAM_END); } + void clearErr() { + // only reset _eos; I/O errors are not recoverable + _eos = false; + } + + uint32 read(void *dataPtr, uint32 dataSize) { + _stream.next_out = (byte *)dataPtr; + _stream.avail_out = dataSize; + + // Keep going while we get no error + while (_zlibErr == Z_OK && _stream.avail_out) { + if (_stream.avail_in == 0 && !_wrapped->eos()) { + // If we are out of input data: Read more data, if available. + _stream.next_in = _buf; + _stream.avail_in = _wrapped->read(_buf, BUFSIZE); + } + _zlibErr = inflate(&_stream, Z_NO_FLUSH); + } + + // Update the position counter + _pos += dataSize - _stream.avail_out; + + if (_zlibErr == Z_STREAM_END && _stream.avail_out > 0) + _eos = true; + + return dataSize - _stream.avail_out; + } + + bool eos() const { + return _eos; + } + int32 pos() const { + return _pos; + } + int32 size() const { + return _origSize; + } + bool seek(int32 offset, int whence = SEEK_SET) { + int32 newPos = 0; + assert(whence != SEEK_END); // SEEK_END not supported + switch(whence) { + case SEEK_SET: + newPos = offset; + break; + case SEEK_CUR: + newPos = _pos + offset; + } + + assert(newPos >= 0); + + if ((uint32)newPos < _pos) { + // To search backward, we have to restart the whole decompression + // from the start of the file. A rather wasteful operation, best + // to avoid it. :/ +#if DEBUG + warning("Backward seeking in GZipReadStream detected"); +#endif + _pos = 0; + _wrapped->seek(0, SEEK_SET); + _zlibErr = inflateReset(&_stream); + if (_zlibErr != Z_OK) + return false; // FIXME: STREAM REWRITE + _stream.next_in = _buf; + _stream.avail_in = 0; + } + + offset = newPos - _pos; + + // Skip the given amount of data (very inefficient if one tries to skip + // huge amounts of data, but usually client code will only skip a few + // bytes, so this should be fine. + byte tmpBuf[1024]; + while (!err() && offset > 0) { + offset -= read(tmpBuf, MIN((int32)sizeof(tmpBuf), offset)); + } + + _eos = false; + return true; // FIXME: STREAM REWRITE + } +}; + +/** + * A simple wrapper class which can be used to wrap around an arbitrary + * other WriteStream and will then provide on-the-fly compression support. + * The compressed data is written in the gzip format. + */ +class GZipWriteStream : public Common::WriteStream { +protected: + enum { + BUFSIZE = 16384 // 1 << MAX_WBITS + }; + + byte _buf[BUFSIZE]; + Common::WriteStream *_wrapped; + z_stream _stream; + int _zlibErr; + + void processData(int flushType) { + // This function is called by both write() and finalize(). + while (_zlibErr == Z_OK && (_stream.avail_in || flushType == Z_FINISH)) { + if (_stream.avail_out == 0) { + if (_wrapped->write(_buf, BUFSIZE) != BUFSIZE) { + _zlibErr = Z_ERRNO; + break; + } + _stream.next_out = _buf; + _stream.avail_out = BUFSIZE; + } + _zlibErr = deflate(&_stream, flushType); + } + } + +public: + GZipWriteStream(Common::WriteStream *w) : _wrapped(w) { + assert(w != 0); + _stream.zalloc = Z_NULL; + _stream.zfree = Z_NULL; + _stream.opaque = Z_NULL; + + // Adding 16 to windowBits indicates to zlib that it is supposed to + // write gzip headers. This feature was added in zlib 1.2.0.4, + // released 10 August 2003. + // Note: This is *crucial* for savegame compatibility, do *not* remove! + _zlibErr = deflateInit2(&_stream, + Z_DEFAULT_COMPRESSION, + Z_DEFLATED, + MAX_WBITS + 16, + 8, + Z_DEFAULT_STRATEGY); + assert(_zlibErr == Z_OK); + + _stream.next_out = _buf; + _stream.avail_out = BUFSIZE; + _stream.avail_in = 0; + _stream.next_in = 0; + } + + ~GZipWriteStream() { + finalize(); + deflateEnd(&_stream); + delete _wrapped; + } + + bool err() const { + // CHECKME: does Z_STREAM_END make sense here? + return (_zlibErr != Z_OK && _zlibErr != Z_STREAM_END) || _wrapped->err(); + } + + void clearErr() { + // Note: we don't reset the _zlibErr here, as it is not + // clear in general how + _wrapped->clearErr(); + } + + void finalize() { + if (_zlibErr != Z_OK) + return; + + // Process whatever remaining data there is. + processData(Z_FINISH); + + // Since processData only writes out blocks of size BUFSIZE, + // we may have to flush some stragglers. + uint remainder = BUFSIZE - _stream.avail_out; + if (remainder > 0) { + if (_wrapped->write(_buf, remainder) != remainder) { + _zlibErr = Z_ERRNO; + } + } + + // Finalize the wrapped savefile, too + _wrapped->finalize(); + } + + uint32 write(const void *dataPtr, uint32 dataSize) { + if (err()) + return 0; + + // Hook in the new data ... + // Note: We need to make a const_cast here, as zlib is not aware + // of the const keyword. + _stream.next_in = const_cast<byte *>((const byte *)dataPtr); + _stream.avail_in = dataSize; + + // ... and flush it to disk + processData(Z_NO_FLUSH); + + return dataSize - _stream.avail_in; + } +}; + +#endif // USE_ZLIB + +Common::SeekableReadStream *wrapCompressedReadStream(Common::SeekableReadStream *toBeWrapped) { +#if defined(USE_ZLIB) + if (toBeWrapped) { + uint16 header = toBeWrapped->readUint16BE(); + bool isCompressed = (header == 0x1F8B || + ((header & 0x0F00) == 0x0800 && + header % 31 == 0)); + toBeWrapped->seek(-2, SEEK_CUR); + if (isCompressed) + return new GZipReadStream(toBeWrapped); + } +#endif + return toBeWrapped; +} + +Common::WriteStream *wrapCompressedWriteStream(Common::WriteStream *toBeWrapped) { +#if defined(USE_ZLIB) + if (toBeWrapped) + return new GZipWriteStream(toBeWrapped); +#endif + return toBeWrapped; +} + + +} // End of namespace Common diff --git a/common/gzip-stream.h b/common/gzip-stream.h new file mode 100644 index 0000000000..557f507044 --- /dev/null +++ b/common/gzip-stream.h @@ -0,0 +1,58 @@ +/* ScummVM - Graphic Adventure Engine + * + * ScummVM is the legal property of its developers, whose names + * are too numerous to list here. Please refer to the COPYRIGHT + * file distributed with this source distribution. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * $URL$ + * $Id$ + * + */ + +#ifndef COMMON_GZIP_STREAM_H +#define COMMON_GZIP_STREAM_H + +#include "common/stream.h" + +namespace Common { + +/** + * Take an arbitrary SeekableReadStream and wrap it in a custom stream which + * provides transparent on-the-fly decompression. Assumes the data it + * retrieves from the wrapped stream to be either uncompressed or in gzip + * format. In the former case, the original stream is returned unmodified + * (and in particular, not wrapped). + * + * It is safe to call this with a NULL parameter (in this case, NULL is + * returned). + */ +Common::SeekableReadStream *wrapCompressedReadStream(Common::SeekableReadStream *toBeWrapped); + +/** + * Take an arbitrary WriteStream and wrap it in a custom stream which provides + * transparent on-the-fly compression. The compressed data is written in the + * gzip format, unless ZLIB support has been disabled, in which case the given + * stream is returned unmodified (and in particular, not wrapped). + * + * It is safe to call this with a NULL parameter (in this case, NULL is + * returned). + */ +Common::WriteStream *wrapCompressedWriteStream(Common::WriteStream *toBeWrapped); + +} // End of namespace Common + +#endif diff --git a/common/module.mk b/common/module.mk index 599ffcf8a6..45a915a613 100644 --- a/common/module.mk +++ b/common/module.mk @@ -7,6 +7,7 @@ MODULE_OBJS := \ config-manager.o \ file.o \ fs.o \ + gzip-stream.o \ hashmap.o \ memorypool.o \ md5.o \ |