Add love.data module.

- Moved love.math.compress / decompress / decode / encode / hash to love.data.
- Changed love.data.compress/decompress to take the format argument first instead of second.
- Added love.data.newDataView. Returns a read-only subsection of an existing Data object.
- Added love.data.newByteData. Mostly useful in combination with LuaJIT's FFI as it has no extra methods currently.
- Added implementations of Lua 5.3's data packing APIs: love.data.packString / packData / unpack / getPackedSize.

Resolves issue #1336.
Resolves issue #1331.

--HG--
branch : minor

src/modules/data/HashFunction.h

@@ -0,0 +1,96 @@
+/**
+ * Copyright (c) 2006-2017 LOVE Development Team
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty.  In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ *    claim that you wrote the original software. If you use this software
+ *    in a product, an acknowledgment in the product documentation would be
+ *    appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ *    misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
+ **/
+
+#pragma once
+
+// LOVE
+#include "common/Data.h"
+#include "common/StringMap.h"
+#include "common/int.h"
+
+namespace love
+{
+namespace data
+{
+
+class HashFunction
+{
+public:
+
+	enum Function
+	{
+		FUNCTION_MD5,
+		FUNCTION_SHA1,
+		FUNCTION_SHA224,
+		FUNCTION_SHA256,
+		FUNCTION_SHA384,
+		FUNCTION_SHA512,
+		FUNCTION_MAX_ENUM
+	};
+
+	struct Value
+	{
+		char data[64]; // Maximum possible size (SHA512).
+		size_t size;
+	};
+
+	/**
+	 * Get a HashFunction instance for the given function.
+	 *
+	 * @param[in] function The selected hash function.
+	 * @return An instance of HashFunction for the given function, or NULL if
+	 *         not available.
+	 **/
+	static HashFunction *getHashFunction(Function function);
+
+	virtual ~HashFunction() {}
+
+	/**
+	 * Hash the input, producing an set of bytes as output.
+	 *
+	 * @param[in] function The selected hash function.
+	 * @param[in] input The input data to hash.
+	 * @param[in] length The length of the input data.
+	 * @param[out] output The result of the hash function.
+	 **/
+	virtual void hash(Function function, const char *input, uint64 length, Value &output) const = 0;
+
+	/**
+	 * @param[in] function The requested hash function.
+	 * @return Whether this HashFunction instance implements the given function.
+	 **/
+	virtual bool isSupported(Function function) const = 0;
+
+	static bool getConstant(const char *in, Function &out);
+	static bool getConstant(const Function &in, const char *&out);
+
+protected:
+
+	HashFunction() {}
+
+private:
+
+	static StringMap<Function, FUNCTION_MAX_ENUM>::Entry functionEntries[];
+	static StringMap<Function, FUNCTION_MAX_ENUM> functionNames;
+
+}; // HashFunction
+
+} // data
+} // love