Initial commit of the new BaseFile implementation. It provides a common ground for file objects across platforms and divides responsibilities between the Common::File class and a base file implementation.

Also rearranged the factories into a new directory for clarity.

Note 1: The posix-file.h and cpp files are for testing only. Only the ds, ps2 and symbian architecture will use special BaseFile based objects.

Note 2: The current code does not yet make use of this new structure, since the Common::File remains intact.

svn-id: r28395

1 files changed, 180 insertions, 0 deletions

diff --git a/backends/file/base-file.h b/backends/file/base-file.h
new file mode 100644
index 0000000000..f383a1a453
--- /dev/null
+++ b/backends/file/base-file.h
@@ -0,0 +1,180 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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.
+ *
+ * $URL: $
+ * $Id: $
+ */
+
+#ifndef BACKENDS_BASE_FILE_H
+#define BACKENDS_BASE_FILE_H
+
+#include "common/stdafx.h"
+#include "common/scummsys.h"
+#include "common/str.h"
+#include "common/stream.h"
+
+using namespace Common;
+
+/**
+ * Implements several file related functions used by the Common::File wrapper.
+ */
+class BaseFile : public Common::SeekableReadStream {
+protected:
+	/** File handle to the actual file; 0 if no file is open. */
+	void *_handle;
+
+	/** Status flag which tells about recent I/O failures. */
+	bool _ioFailed;
+
+	/** The name of this file, for debugging. */
+	String _name;
+	
+	/**
+	 * The following functions are meant to be redefined by subclasses if needed. E.g. ps2-file.h or ds-file.h
+	 * They behave as the C++ standard I/O methods so refer to the standard documentation for usage.
+	 * 
+	 * This design was inspired on the Template pattern.
+	 */
+	void _clearerr(FILE *stream);
+	int _fclose(FILE *stream);
+	int _feof(FILE *stream) const;
+	FILE *_fopen(const char * filename, const char * mode);
+	int _fread(void *buffer, size_t obj_size, size_t num, FILE *stream);
+	int _fseek(FILE * stream, long int offset, int origin) const;
+	long _ftell(FILE *stream) const;
+	int _fwrite(const void * ptr, size_t obj_size, size_t count, FILE * stream);
+
+private:
+	// Disallow copying BaseFile objects. There is not strict reason for this,
+	// except that so far we never had real need for such a feature, and
+	// code that accidentally copied File objects tended to break in strange
+	// ways.
+	BaseFile(const BaseFile &f);
+	BaseFile &operator =(const BaseFile &f);
+	
+public:
+	enum AccessMode {
+		kFileReadMode = 1,
+		kFileWriteMode = 2
+	};
+	
+	BaseFile();
+	virtual ~BaseFile();
+	
+	/**
+	 * Clears the flag for the last ocurred IO failure.
+	 */
+	void clearIOFailed();
+	
+	/**
+	 * Closes the file handle.
+	 */
+	virtual void close();
+	
+	/**
+	 * Checks for end of file.
+	 *
+	 * @return: true if the end of file is reached, false otherwise.
+	 */
+	bool eof() const;
+	
+	/**
+	 * Checks for the end of the stream. In this case it's equivalent to eof().
+	 * 
+	 * @return: true if the end of the stream is reached, false otherwise.
+	 */
+	bool eos() const { return eof(); }
+	
+	/**
+	 * Checks whether the last IO operation failed.
+	 * 
+	 * @return: true if the last IO operation failed, false otherwise.
+	 */
+	bool ioFailed() const;
+	
+	/**
+	 * Obtain the filename of the opened file.
+	 *
+	 * @return: the filename of the opened file.
+	 */
+	const char *name() const { return _name.c_str(); }
+	
+	/**
+	 * Checks if the object opened a file successfully.
+	 *
+	 * @return: true if any file is opened, false otherwise.
+	 */
+	bool isOpen() const;
+	
+	/**
+	 * Opens a given file.
+	 * 
+	 * @param filename Path of the file to be opened.
+	 * @param mode Mode to open to file. Read or write.
+	 */
+	virtual bool open(const String &filename, AccessMode mode = kFileReadMode);
+	
+	/**
+	 * Obtain the position of the seek pointer.
+	 * 
+	 * @return The position of the seek pointer within the file.
+	 */
+	uint32 pos() const;
+	
+	/**
+	 * Read a chunk of data from the file.
+	 * 
+	 * @param dataPtr Buffer to the place the read contents.
+	 * @param dataSize Amount of bytes to read from the file.
+	 * @return Amount of read bytes.
+	 */
+	uint32 read(void *dataPtr, uint32 dataSize);
+	
+	/**
+	 * Remove a given file from the filesystem.
+	 * 
+	 * @param filename Path to the file to be removed.
+	 * @return true if the file was removed succesfully, false otherwise.
+	 */
+	virtual bool remove(const String &filename);
+	
+	/**
+	 * Move the seek pointer within the file.
+	 * 
+	 * @param offs Amount of bytes to move the pointer within the file.
+	 * @param whence Starting point of the seek cursor.
+	 */
+	void seek(int32 offs, int whence = SEEK_SET);
+	
+	/**
+	 * Obtain the size of the file.
+	 * 
+	 * @return The size of the file in bytes.
+	 */
+	uint32 size() const;
+	
+	//TODO: Remove the write functions? Also remove the enum then
+	/**
+	 * Write a chunk of data to the file.
+	 */
+	//uint32 write(const void *dataPtr, uint32 dataSize);	
+};
+
+#endif	//BACKENDS_BASE_FILE_H