Cache textures by checksum

src/filecache.h

@@ -0,0 +1,79 @@
+/*
+Minetest-c55
+Copyright (C) 2010 celeron55, Perttu Ahola <celeron55@gmail.com>
+Copyright (C) 2012 Jonathan Neuschäfer <j.neuschaefer@gmx.net>
+
+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.
+*/
+
+#ifndef FILECACHE_HEADER
+#define FILECACHE_HEADER
+
+#include <string>
+#include <iostream>
+
+class FileCache
+{
+public:
+	/*
+		'dir' is the file cache directory to use.
+	*/
+	FileCache(std::string dir):
+		m_dir(dir)
+	{
+	}
+
+	/*
+		Searches the cache for a file with a given name.
+		If the file is found, lookup copies it into 'os' and
+		returns true. Otherwise false is returned.
+	*/
+	bool loadByName(const std::string &name, std::ostream &os);
+
+	/*
+		Stores a file in the cache based on its name.
+		Returns true on success, false otherwise.
+	*/
+	bool updateByName(const std::string &name, const std::string &data);
+
+	/*
+		Loads a file based on a check sum, which may be any kind of
+		rather unique byte sequence. Returns true, if the file could
+		be written into os, false otherwise.
+		A file name is required to give the disk file a name that
+		has the right file name extension (e.g. ".png").
+	*/
+	bool loadByChecksum(const std::string &name, std::ostream &os,
+			const std::string &checksum);
+
+	/*
+		Stores a file in the cache based on its checksum.
+		Returns true on success, false otherwise.
+	*/
+	bool updateByChecksum(const std::string &name, const std::string &data,
+			const std::string &checksum);
+
+private:
+	std::string m_dir;
+
+	bool loadByPath(const std::string &name, std::ostream &os,
+			const std::string &path);
+	bool updateByPath(const std::string &name, const std::string &data,
+			const std::string &path);
+	std::string getPathFromChecksum(const std::string &name,
+			const std::string &checksum);
+};
+
+#endif