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include/modules/archive/archive.h

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+/* -----------------------------------------------------------------------------
+	GSFramework
+	Copyright 2001-2013 Emmanuel Julien. All Rights Reserved.
+----------------------------------------------------------------------------- */
+
+
+#ifndef	__NARCHIVE__
+#define	__NARCHIVE__
+
+
+		#include "nstring/nstring.h"
+		#include "container/nlist.h"
+		#include "memory/nauto_ptr.h"
+		#include "filesystem/io_handle.h"
+
+
+namespace GS {
+	namespace Threading { class Mutex; }
+
+/// Archive index entry.
+struct	ArchiveEntry
+{
+		// Do not change this enumeration order!
+enum	Method
+{
+	MethodRaw			=	0,
+	MethodZLibCompress
+};
+
+		String			path;				///< Entry path.
+
+		char			method;				///< Compression method.
+		size_t			offset;				///< Data offset in archive.
+		size_t			length;				///< Original length.
+		size_t			compressed_length;	///< Compressed length.
+};
+
+/*!
+	@short	Archive index.
+	@author Emmanuel Julien (ejulien@gsworks.fr)
+*/
+class	ArchiveIndex
+{
+		friend class Archive;
+
+protected:
+
+		AutoList <ArchiveEntry *> index;
+
+public:
+		/// Find an entry in the index file.
+		ArchiveEntry	*FindEntry(const char *alias) const;
+
+		/// Load archive index.
+		bool			Load(const char *uri);
+		/// Save archive index.
+		bool			Save(const char *uri);
+};
+
+/*!
+	@short	Archive storage.
+
+	A pretty straightforward solid archive file format.
+	Supports per-file compression algorithm selection.
+
+	@author Emmanuel Julien
+*/
+class	Archive
+{
+public:
+
+enum	Revision
+{
+	Legacy				=	0,
+	EnhancedLegacy
+};
+
+protected:
+
+		AutoPtr <Threading::Mutex> access_mutex;
+
+		bool			verbose;
+		bool			append_mode;		///< Archive open in append mode.
+
+		ArchiveIndex	index;				///< Archive index table.
+
+		AutoPtr <IO::Handle> handle;
+
+		Revision		revision;
+		size_t			offset_padding,		///< File offset padding.
+						size_padding;		///< File size padding.
+
+public:
+
+		/*!
+			@short	Set file offset padding.
+
+			Padding archive content is necessary on some platforms that do not
+			support seeking or reading an arbitrary amount of bytes inside a
+			file. This is often the case with the DVD unit of console systems.
+		*/
+		void			SetOffsetPadding(size_t padding = 0)
+		{	offset_padding = padding;	}
+		/*!
+			@short	Set file size padding.
+			@see	SetOffsetPadding().
+		*/
+		void			SetSizePadding(size_t padding = 0)
+		{	size_padding = padding;	}
+
+		/// Return internal index object.
+		const List <ArchiveEntry *> &GetIndex() const
+		{	return index.index;	}
+
+		/// Set the verbose mode.
+		void			SetVerbose(bool v = true)
+		{	verbose = v;	}
+
+		/// Load current archive index file.
+		bool			LoadIndex(const char *path);
+		/// Save current archive index file.
+		bool			SaveIndex(const char *path);
+
+		/*!
+			@short	Open archive.
+
+			@note	If no index is provided one will automatically be created
+					upon archive opening. Although this a fast process it
+					requires that the archive be opened on a stream-able
+					file system and that the whole archive be seeked through.
+		*/
+		bool			OpenRead(const char *uri, const char *index_uri = 0);
+		/// Create a new archive.
+		bool			CreateNew(const char *);
+		/// Close archive.
+		void			Close();
+
+		/// Check if a file exists in archive.
+		ArchiveEntry	*Exists(const char *path) const
+		{	return index.FindEntry(path);	}
+
+		/*!
+			@short	Load a file from the archive.
+
+			@note	The output buffer is expected to old enough room to store
+					the decompressed data.
+			@see	Exists().
+		*/
+		bool			FileRead(const char *, void *);
+
+		/// Write a memory block to the archive.
+		ArchiveEntry	*MemoryBlockWrite(const char *, const void *, size_t, int compression_level = 6);
+		/// Write a file to the archive.
+		ArchiveEntry	*FileWrite(const char *path, const char *alias = 0, int compression_level = 6);
+
+		Archive();
+		~Archive();
+};
+
+}	// GS
+
+
+#endif	// __NARCHIVE__