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Diffstat (limited to 'engines/cge/fileio.cpp')
| -rw-r--r-- | engines/cge/fileio.cpp | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/engines/cge/fileio.cpp b/engines/cge/fileio.cpp new file mode 100644 index 0000000000..6db0818287 --- /dev/null +++ b/engines/cge/fileio.cpp @@ -0,0 +1,240 @@ +/* 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. + * + */ + +/* + * This code is based on original Soltys source code + * Copyright (c) 1994-1995 Janus B. Wisniewski and L.K. Avalon + */ + +#include "common/system.h" +#include "common/str.h" +#include "common/debug.h" +#include "common/debug-channels.h" +#include "common/memstream.h" +#include "cge/cge.h" +#include "cge/fileio.h" + +namespace CGE { + +/*----------------------------------------------------------------------- + * BtPage + *-----------------------------------------------------------------------*/ +void BtPage::readBTree(Common::ReadStream &s) { + _header._count = s.readUint16LE(); + _header._down = s.readUint16LE(); + + if (_header._down == kBtValNone) { + // Leaf list + for (int i = 0; i < kBtLeafCount; ++i) { + s.read(_leaf[i]._key, kBtKeySize); + _leaf[i]._pos = s.readUint32LE(); + _leaf[i]._size = s.readUint16LE(); + } + } else { + // Root index + for (int i = 0; i < kBtInnerCount; ++i) { + s.read(_inner[i]._key, kBtKeySize); + _inner[i]._down = s.readUint16LE(); + } + } +} + +/*----------------------------------------------------------------------- + * ResourceManager + *-----------------------------------------------------------------------*/ +ResourceManager::ResourceManager() { + debugC(1, kCGEDebugFile, "ResourceManager::ResourceManager()"); + + _datFile = new Common::File(); + _datFile->open(kDatName); + + _catFile = new Common::File(); + _catFile->open(kCatName); + + if ((!_datFile) || (!_catFile)) + error("Unable to open data files"); + + for (int i = 0; i < kBtLevel; i++) { + _buff[i]._page = new BtPage; + _buff[i]._pageNo = kBtValNone; + _buff[i]._index = -1; + assert(_buff[i]._page != NULL); + } +} + +ResourceManager::~ResourceManager() { + debugC(1, kCGEDebugFile, "ResourceManager::~ResourceManager()"); + _datFile->close(); + delete _datFile; + + _catFile->close(); + delete _catFile; + + for (int i = 0; i < kBtLevel; i++) + delete _buff[i]._page; +} + +uint16 ResourceManager::XCrypt(void *buf, uint16 length) { + byte *b = static_cast<byte *>(buf); + + for (uint16 i = 0; i < length; i++) + *b++ ^= kCryptSeed; + + return kCryptSeed; +} + +bool ResourceManager::seek(int32 offs, int whence) { + return _datFile->seek(offs, whence); +} + +uint16 ResourceManager::read(void *buf, uint16 length) { + if (!_datFile->isOpen()) + return 0; + + uint16 bytesRead = _datFile->read(buf, length); + if (!bytesRead) + error("Read %s - %d bytes", _datFile->getName(), length); + XCrypt(buf, length); + return bytesRead; +} + +BtPage *ResourceManager::getPage(int level, uint16 pageId) { + debugC(1, kCGEDebugFile, "IoHand::getPage(%d, %d)", level, pageId); + + if (_buff[level]._pageNo != pageId) { + int32 pos = pageId * kBtSize; + _buff[level]._pageNo = pageId; + assert(_catFile->size() > pos); + // In the original, there was a check verifying if the + // purpose was to write a new file. This should only be + // to create a new file, thus it was removed. + _catFile->seek(pageId * kBtSize, SEEK_SET); + + // Read in the page + byte buffer[kBtSize]; + int bytesRead = catRead(buffer, kBtSize); + + // Unpack it into the page structure + Common::MemoryReadStream stream(buffer, bytesRead, DisposeAfterUse::NO); + _buff[level]._page->readBTree(stream); + _buff[level]._index = -1; + } + return _buff[level]._page; +} + +BtKeypack *ResourceManager::find(const char *key) { + debugC(1, kCGEDebugFile, "IoHand::find(%s)", key); + + int lev = 0; + uint16 nxt = kBtValRoot; + while (!_catFile->eos()) { + BtPage *pg = getPage(lev, nxt); + // search + if (pg->_header._down != kBtValNone) { + int i; + for (i = 0; i < pg->_header._count; i++) { + // Does this work, or does it have to compare the entire buffer? + if (scumm_strnicmp((const char *)key, (const char*)pg->_inner[i]._key, kBtKeySize) < 0) + break; + } + nxt = (i) ? pg->_inner[i - 1]._down : pg->_header._down; + _buff[lev]._index = i - 1; + lev++; + } else { + int i; + for (i = 0; i < pg->_header._count - 1; i++) { + if (scumm_stricmp((const char *)key, (const char *)pg->_leaf[i]._key) <= 0) + break; + } + _buff[lev]._index = i; + return &pg->_leaf[i]; + } + } + return NULL; +} + +bool ResourceManager::exist(const char *name) { + debugC(1, kCGEDebugFile, "ResourceManager::exist(%s)", name); + + return scumm_stricmp(find(name)->_key, name) == 0; +} + +uint16 ResourceManager::catRead(void *buf, uint16 length) { + if (!_catFile->isOpen()) + return 0; + + uint16 bytesRead = _catFile->read(buf, length); + if (!bytesRead) + error("Read %s - %d bytes", _catFile->getName(), length); + XCrypt(buf, length); + return bytesRead; +} + +/*----------------------------------------------------------------------- + * EncryptedStream + *-----------------------------------------------------------------------*/ +EncryptedStream::EncryptedStream(CGEEngine *vm, const char *name) : _vm(vm) { + debugC(3, kCGEDebugFile, "EncryptedStream::EncryptedStream(%s)", name); + + _error = false; + BtKeypack *kp = _vm->_resman->find(name); + if (scumm_stricmp(kp->_key, name) != 0) + _error = true; + + _vm->_resman->seek(kp->_pos); + byte *dataBuffer = (byte *)malloc(kp->_size); + _vm->_resman->read(dataBuffer, kp->_size); + _readStream = new Common::MemoryReadStream(dataBuffer, kp->_size, DisposeAfterUse::YES); +} + +uint32 EncryptedStream::read(void *dataPtr, uint32 dataSize) { + return _readStream->read(dataPtr, dataSize); +} + +bool EncryptedStream::err() { + return (_error & _readStream->err()); +} + +bool EncryptedStream::eos() { + return _readStream->eos(); +} + +bool EncryptedStream::seek(int32 offset) { + return _readStream->seek(offset); +} + +Common::String EncryptedStream::readLine() { + return _readStream->readLine(); +} + +int32 EncryptedStream::size() { + return _readStream->size(); +} + +int32 EncryptedStream::pos() { + return _readStream->pos(); +} + +EncryptedStream::~EncryptedStream() { +} + +} // End of namespace CGE |