Added draft of IO memeory buffer

lib/filesystem/CMemoryBuffer.h

@@ -0,0 +1,87 @@
+#pragma once
+
+/*
+ * CMemoryBuffer.h, part of VCMI engine
+ *
+ * Authors: listed in file AUTHORS in main folder
+ *
+ * License: GNU General Public License v2.0 or later
+ * Full text of license available in license.txt file, in main folder
+ *
+ */
+ 
+
+#include "CInputStream.h"
+#include "COutputStream.h"
+
+/**
+ * A class which provides IO memory buffer.
+ */
+ 
+class DLL_LINKAGE CMemoryBuffer : public CInputStream, public COutputStream
+{
+public:
+	typedef std::vector<ui8> TBuffer;
+
+	/**
+	 * C-tor.
+	 *
+	 */
+	CMemoryBuffer();
+	
+	/**
+	 * Write n bytes from the stream into the data buffer.
+	 *
+	 * @param data A pointer to the destination data array.
+	 * @param size The number of bytes to write.
+	 * @return the number of bytes written actually.
+	 */
+	si64 write(ui8 * data, si64 size) override;	
+
+	/**
+	 * Reads n bytes from the stream into the data buffer.
+	 *
+	 * @param data A pointer to the destination data array.
+	 * @param size The number of bytes to read.
+	 * @return the number of bytes read actually.
+	 */
+	si64 read(ui8 * data, si64 size) override;
+
+	/**
+	 * Seeks the internal read pointer to the specified position.
+	 *
+	 * @param position The read position from the beginning.
+	 * @return the position actually moved to, -1 on error.
+	 */
+	si64 seek(si64 position) override;
+
+	/**
+	 * Gets the current read position in the stream.
+	 *
+	 * @return the read position.
+	 */
+	si64 tell() override;
+
+	/**
+	 * Skips delta numbers of bytes.
+	 *
+	 * @param delta The count of bytes to skip.
+	 * @return the count of bytes skipped actually.
+	 */
+	si64 skip(si64 delta) override;
+
+	/**
+	 * Gets the length in bytes of the stream.
+	 *
+	 * @return the length in bytes of the stream.
+	 */
+	si64 getSize() override;
+
+private:
+	/** Actual data. */
+	TBuffer buffer;
+	
+	/** Current reading position of the stream. */
+	si64 position;
+};
+