Moved Tinsel::Serializer to Common::Serializer, so that I can use it in the SCI engine

svn-id: r39428

2 files changed, 164 insertions, 0 deletions

diff --git a/common/serializer.h b/common/serializer.h
new file mode 100644
index 0000000000..24af9dc6f5
--- /dev/null
+++ b/common/serializer.h
@@ -0,0 +1,160 @@
+/* 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_SERIALIZER_H
+#define COMMON_SERIALIZER_H
+
+#include "common/stream.h"
+#include "common/str.h"
+
+namespace Common {
+
+
+#define SYNC_AS(SUFFIX,TYPE,SIZE) \
+	template <class T> \
+	void syncAs ## SUFFIX(T &val) { \
+		if (_loadStream) \
+			val = static_cast<T>(_loadStream->read ## SUFFIX()); \
+		else { \
+			TYPE tmp = val; \
+			_saveStream->write ## SUFFIX(tmp); \
+		} \
+		_bytesSynced += SIZE; \
+	}
+
+
+// TODO: Write comment for this
+// TODO: Inspired by the SCUMM engine -- move to common/ code and use in more engines?
+class Serializer {
+public:
+	Serializer(Common::SeekableReadStream *in, Common::WriteStream *out)
+		: _loadStream(in), _saveStream(out), _bytesSynced(0) {
+		assert(in || out);
+	}
+
+	bool isSaving() { return (_saveStream != 0); }
+	bool isLoading() { return (_loadStream != 0); }
+
+	uint bytesSynced() const { return _bytesSynced; }
+
+	void syncBytes(byte *buf, uint32 size) {
+		if (_loadStream)
+			_loadStream->read(buf, size);
+		else
+			_saveStream->write(buf, size);
+		_bytesSynced += size;
+	}
+
+	/**
+	 * Sync a C-string, by treating it as a zero-terminated byte sequence.
+	 */
+	void syncString(Common::String &str) {
+		if (_loadStream) {
+			char c;
+			str.clear();
+			while ((c = _loadStream->readByte())) {
+				str += c;
+				_bytesSynced++;
+			}
+			_bytesSynced++;
+		} else {
+			_saveStream->writeString(str);
+			_saveStream->writeByte(0);
+			_bytesSynced += str.size() + 1;
+		}
+	}
+
+	void skip(uint32 size) {
+		_bytesSynced += size;
+		if (_loadStream)
+			_loadStream->skip(size);
+		else {
+			while (size--)
+				_saveStream->writeByte(0);
+		}
+	}
+
+	SYNC_AS(Byte, byte, 1)
+
+	SYNC_AS(Uint16LE, uint16, 2)
+	SYNC_AS(Uint16BE, uint16, 2)
+	SYNC_AS(Sint16LE, int16, 2)
+	SYNC_AS(Sint16BE, int16, 2)
+
+	SYNC_AS(Uint32LE, uint32, 4)
+	SYNC_AS(Uint32BE, uint32, 4)
+	SYNC_AS(Sint32LE, int32, 4)
+	SYNC_AS(Sint32BE, int32, 4)
+
+protected:
+	Common::SeekableReadStream *_loadStream;
+	Common::WriteStream *_saveStream;
+
+	uint _bytesSynced;
+};
+
+#undef SYNC_AS
+
+// TODO: Make a subclass "VersionedSerializer", which makes it easy to support
+//       multiple versions of a savegame format (again inspired by SCUMM).
+/*
+class VersionedSerializer : public Serializer {
+public:
+	// "version" is the version of the savegame we are loading/creating
+	VersionedSerializer(Common::SeekableReadStream *in, Common::OutSaveFile *out, int version)
+		: Serializer(in, out), _version(version) {
+		assert(in || out);
+	}
+
+	void syncBytes(byte *buf, uint16 size, int minVersion = 0, int maxVersion = INF) {
+		if (_version < minVersion || _version > maxVersion)
+			return;	// Do nothing if too old or too new
+		if (_loadStream) {
+			_loadStream->read(buf, size);
+		} else {
+			_saveStream->write(buf, size);
+		}
+	}
+	...
+
+};
+
+*/
+
+// Mixin class / interface
+// TODO Maybe call it ISerializable or SerializableMixin ?
+// TODO: Taken from SCUMM engine -- move to common/ code?
+class Serializable {
+public:
+	virtual ~Serializable() {}
+
+	// Maybe rename this method to "syncWithSerializer" or "syncUsingSerializer" ?
+	virtual void saveLoadWithSerializer(Serializer &ser) = 0;
+};
+
+
+} // end of namespace Common
+
+#endif
diff --git a/common/stream.h b/common/stream.h
index f98ad6aa92..b0fc9f5a8b 100644
--- a/common/stream.h
+++ b/common/stream.h
@@ -154,6 +154,10 @@ public:
 		writeUint32BE((uint32)value);
 	}
 
+	/**
+	 * Write the given string to the stream.
+	 * This writes str.size() characters, but no terminating zero byte.
+	 */
 	void writeString(const String &str);
 };