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include/platform/filesystem/io_buffer.h

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+/* -----------------------------------------------------------------------------
+	GSFramework
+	Copyright 2001-2013 Emmanuel Julien. All Rights Reserved.
+----------------------------------------------------------------------------- */
+
+
+#ifndef	__NIOBUFFER__
+#define	__NIOBUFFER__
+
+
+		#include "filesystem/io_handle.h"
+		#include "nstring/nstring.h"
+		#include "memory/nauto_ptr.h"
+		#include "container/narray.h"
+		#include "unit/nunit.h"
+
+
+namespace GS {
+	namespace IO {
+
+//
+struct	IOBuffer
+{
+		Array <char> buffer;
+
+		size_t		start_pos;
+		size_t		usage;
+
+		IOBuffer() : start_pos(0), usage(0) {}
+};
+
+//
+class	BufferHandle : public Handle
+{
+		friend class Buffer;
+
+		AutoPtr <Handle> handle;
+		size_t		size;	// file size on wrapped fs
+		size_t		pos;	// position in source handle
+
+		IOBuffer	read_buffer;
+
+public:
+
+virtual	size_t		GetSize() { return size; }
+
+		BufferHandle(Base *io, Handle *h) : Handle(io), handle(h), size(0), pos(0) {}
+};
+
+/*!
+	@short	Buffered I/O filesystem wrapper.
+	Implements a transparent read/write buffer on top of another filesystem.
+	@author	Emmanuel Julien (ejulien@nworks.fr)
+*/
+class	Buffer : public Base
+{
+		SharedPtr <Base> io;
+
+		size_t		read_buffer_size,
+					write_buffer_size;
+
+public:
+
+virtual	uint		GetCaps() const;
+
+virtual	Handle		*Open(const char *, Mode = ModeRead);
+virtual	void		Close(Handle *);
+
+virtual	String		Hash(const char *);
+virtual	bool		Delete(const char *);
+
+virtual	size_t		Tell(Handle *);
+virtual	size_t		Seek(Handle *, ptrdiff_t offset, SeekRef = SeekCurrent);
+
+virtual	size_t		Read(Handle *, void *, size_t);
+virtual	size_t		Write(Handle *, const void *, size_t);
+
+virtual	bool		MkDir(const char *);
+
+		Buffer(Base *base, size_t read_buffer_size = Units::KB(4), size_t write_buffer_size = Units::KB(4));
+};
+
+	}	// IO
+}	// GS
+
+
+#endif	// __NIOBUFFER__