Initial commit

engines/private/savegame.cpp

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+/* 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "common/debug.h"
+#include "common/stream.h"
+
+#include "engines/private/savegame.h"
+
+namespace Private {
+
+static const uint32 kSavegameHeader = MKTAG('P','E','Y','E');
+
+void writeSavegameMetadata(Common::WriteStream *stream, const SavegameMetadata &meta) {
+	stream->writeUint32BE(kSavegameHeader);
+	stream->writeUint16LE(meta.version);
+	stream->writeSByte(meta.language);
+	stream->writeSByte(meta.platform);
+}
+
+bool readSavegameMetadata(Common::SeekableReadStream *stream, SavegameMetadata &meta) {
+	byte buffer[8];
+	stream->read(buffer, 8);
+	if (stream->eos() || stream->err()) {
+		return false;
+	}
+
+	uint32 header = READ_BE_UINT32(buffer);
+	if (header != kSavegameHeader) {
+		debug(1, "Save does not have metadata header");
+		return false;
+	}
+
+	meta.version = READ_LE_UINT16(buffer + 4);
+	if (meta.version < kMinimumSavegameVersion) {
+		debug(1, "Save version %d lower than minimum %d", meta.version, kMinimumSavegameVersion);
+		return false;
+	}
+	if (meta.version > kCurrentSavegameVersion) {
+		debug(1, "Save version %d newer than current %d", meta.version, kCurrentSavegameVersion);
+		return false;
+	}
+
+	meta.language = (Common::Language)buffer[6];
+	meta.platform = (Common::Platform)buffer[7];
+
+	return true;
+}
+
+} // End of namespace Private