C++ InSaveFile::seek方法代码示例

static byte *readSavegameThumbnail(const Common::String &filename, uint &fileSize, bool &isPNG) {
	byte *pFileData;
	Common::SaveFileManager *sfm = g_system->getSavefileManager();
	Common::InSaveFile *file = sfm->openForLoading(lastPathComponent(filename, '/'));
	if (!file)
		error("Save file \"%s\" could not be loaded.", filename.c_str());

	// Seek to the actual PNG image
	loadString(*file);		// Marker (BS25SAVEGAME)
	Common::String storedVersionID = loadString(*file);		// Version
	if (storedVersionID != "SCUMMVM1")
		loadString(*file);

	loadString(*file);		// Description
	uint32 compressedGamedataSize = atoi(loadString(*file).c_str());
	loadString(*file);		// Uncompressed game data size
	file->skip(compressedGamedataSize);	// Skip the game data and move to the thumbnail itself
	uint32 thumbnailStart = file->pos();

	fileSize = file->size() - thumbnailStart;

	// Check if the thumbnail is in our own format, or a PNG file.
	uint32 header = file->readUint32BE();
	isPNG = (header != MKTAG('S','C','R','N'));
	file->seek(-4, SEEK_CUR);

	pFileData = new byte[fileSize];
	file->read(pFileData, fileSize);
	delete file;

	return pFileData;
}

SaveStateList WageMetaEngine::listSaves(const char *target) const {
	const uint32 WAGEflag = MKTAG('W','A','G','E');
	Common::SaveFileManager *saveFileMan = g_system->getSavefileManager();
	Common::StringArray filenames;
	char saveDesc[128] = {0};
	Common::String pattern = target;
	pattern += ".###";

	filenames = saveFileMan->listSavefiles(pattern);

	SaveStateList saveList;
	for (Common::StringArray::const_iterator file = filenames.begin(); file != filenames.end(); ++file) {
		// Obtain the last 3 digits of the filename, since they correspond to the save slot
		int slotNum = atoi(file->c_str() + file->size() - 3);

		if (slotNum >= 0 && slotNum <= 999) {
			Common::InSaveFile *in = saveFileMan->openForLoading(*file);
			if (in) {
				saveDesc[0] = 0;
				in->seek(in->size() - 8);
				uint32 offset = in->readUint32BE();
				uint32 type = in->readUint32BE();
				if (type == WAGEflag) {
					in->seek(offset);

					type = in->readUint32BE();
					if (type == WAGEflag) {
						in->read(saveDesc, 127);
					}
				}
				saveList.push_back(SaveStateDescriptor(slotNum, saveDesc));
				delete in;
			}
		}
	}

	// Sort saves based on slot number.
	Common::sort(saveList.begin(), saveList.end(), SaveStateDescriptorSlotComparator());
	return saveList;
}

Common::SeekableReadStream *EventRecorder::processSaveStream(const Common::String &fileName) {
	Common::InSaveFile *saveFile;
	switch (_recordMode) {
	case kRecorderPlayback:
		debugC(1, kDebugLevelEventRec, "playback:action=\"Process save file\" filename=%s len=%d", fileName.c_str(), _playbackFile->getHeader().saveFiles[fileName].size);
		return new Common::MemoryReadStream(_playbackFile->getHeader().saveFiles[fileName].buffer, _playbackFile->getHeader().saveFiles[fileName].size);
	case kRecorderRecord:
		saveFile = _realSaveManager->openForLoading(fileName);
		if (saveFile != NULL) {
			_playbackFile->addSaveFile(fileName, saveFile);
			saveFile->seek(0);
		}
		return saveFile;
	default:
		return NULL;
		break;
	}
}

SaveStateList DreamWebMetaEngine::listSaves(const char *target) const {
	Common::SaveFileManager *saveFileMan = g_system->getSavefileManager();
	Common::StringArray files = saveFileMan->listSavefiles("DREAMWEB.D??");
	Common::sort(files.begin(), files.end());

	SaveStateList saveList;
	for(uint i = 0; i < files.size(); ++i) {
		const Common::String &file = files[i];
		Common::InSaveFile *stream = saveFileMan->openForLoading(file);
		if (!stream)
			error("cannot open save file %s", file.c_str());
		char name[17] = {};
		stream->seek(0x61);
		stream->read(name, sizeof(name) - 1);
		delete stream;

		int slotNum = atoi(file.c_str() + file.size() - 2);
		SaveStateDescriptor sd(slotNum, name);
		saveList.push_back(sd);
	}

	return saveList;
}

bool PersistenceService::loadGame(uint slotID) {
	Common::SaveFileManager *sfm = g_system->getSavefileManager();
	Common::InSaveFile *file;

	// Überprüfen, ob die Slot-ID zulässig ist.
	if (slotID >= SLOT_COUNT) {
		error("Tried to load from an invalid slot (%d). Only slot ids form 0 to %d are allowed.", slotID, SLOT_COUNT - 1);
		return false;
	}

	SavegameInformation &curSavegameInfo = _impl->_savegameInformations[slotID];

	// Überprüfen, ob der Slot belegt ist.
	if (!curSavegameInfo.isOccupied) {
		error("Tried to load from an empty slot (%d).", slotID);
		return false;
	}

	// Überprüfen, ob der Spielstand im angegebenen Slot mit der aktuellen Engine-Version kompatibel ist.
	// Im Debug-Modus wird dieser Test übersprungen. Für das Testen ist es hinderlich auf die Einhaltung dieser strengen Bedingung zu bestehen,
	// da sich die Versions-ID bei jeder Codeänderung mitändert.
#ifndef DEBUG
	if (!curSavegameInfo.isCompatible) {
		error("Tried to load a savegame (%d) that is not compatible with this engine version.", slotID);
		return false;
	}
#endif

	byte *compressedDataBuffer = new byte[curSavegameInfo.gamedataLength];
	byte *uncompressedDataBuffer = new byte[curSavegameInfo.gamedataUncompressedLength];
	Common::String filename = generateSavegameFilename(slotID);
	file = sfm->openForLoading(filename);

	file->seek(curSavegameInfo.gamedataOffset);
	file->read(reinterpret_cast<char *>(&compressedDataBuffer[0]), curSavegameInfo.gamedataLength);
	if (file->err()) {
		error("Unable to load the gamedata from the savegame file \"%s\".", filename.c_str());
		delete[] compressedDataBuffer;
		delete[] uncompressedDataBuffer;
		return false;
	}

	// Uncompress game data, if needed.
	unsigned long uncompressedBufferSize = curSavegameInfo.gamedataUncompressedLength;

	if (uncompressedBufferSize > curSavegameInfo.gamedataLength) {
		// Older saved game, where the game data was compressed again.
		if (!Common::uncompress(reinterpret_cast<byte *>(&uncompressedDataBuffer[0]), &uncompressedBufferSize,
					   reinterpret_cast<byte *>(&compressedDataBuffer[0]), curSavegameInfo.gamedataLength)) {
			error("Unable to decompress the gamedata from savegame file \"%s\".", filename.c_str());
			delete[] uncompressedDataBuffer;
			delete[] compressedDataBuffer;
			delete file;
			return false;
		}
	} else {
		// Newer saved game with uncompressed game data, copy it as-is.
		memcpy(uncompressedDataBuffer, compressedDataBuffer, uncompressedBufferSize);
	}

	InputPersistenceBlock reader(&uncompressedDataBuffer[0], curSavegameInfo.gamedataUncompressedLength, curSavegameInfo.version);

	// Einzelne Engine-Module depersistieren.
	bool success = true;
	success &= Kernel::getInstance()->getScript()->unpersist(reader);
	// Muss unbedingt nach Script passieren. Da sonst die bereits wiederhergestellten Regions per Garbage-Collection gekillt werden.
	success &= RegionRegistry::instance().unpersist(reader);
	success &= Kernel::getInstance()->getGfx()->unpersist(reader);
	success &= Kernel::getInstance()->getSfx()->unpersist(reader);
	success &= Kernel::getInstance()->getInput()->unpersist(reader);

	delete[] compressedDataBuffer;
	delete[] uncompressedDataBuffer;
	delete file;

	if (!success) {
		error("Unable to unpersist the gamedata from savegame file \"%s\".", filename.c_str());
		return false;
	}

	return true;
}