Diff: FileHandle.h

Revision:

0:82220227f4fa

Child:

1:6b7f447ca868

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/FileHandle.h	Tue Apr 08 14:12:21 2008 +0000
@@ -0,0 +1,95 @@
+/* mbed Microcontroller Library - FileHandle
+ * Copyright (c) 2007-2008, sford
+ */
+
+#ifndef MBED_FILEHANDLE_H
+#define MBED_FILEHANDLE_H
+
+namespace mbed { 
+
+/* Class: FileHandle
+ *  An OO equivalent of the internal FILEHANDLE variable
+ *  and associated _sys_* functions
+ *
+ * FileHandle is an abstract class, needing at least sys_write and
+ * sys_read to be implmented for a simple interactive device
+ *
+ * No one ever directly tals to/instanciates a FileHandle - it gets 
+ * created by FileSystem, and wrapped up by stdio
+ */
+class FileHandle {
+
+public:
+
+	//virtual ~FileHandle() { }
+	
+	/* Function: sys_write
+	 *  Write the contents of a buffer to the file
+     *
+     * Parameters:
+     *  buffer - the buffer to write from
+     *  length - the number of characters to write
+     *  mode   - the mode of the file, 0 (normal) or 1 (binary); this may be unused?
+     *
+	 * Returns:
+	 *  0 on success, -1 on error, or the number of characters not written on partial success
+     */
+	virtual	int sys_write(const unsigned char* buffer, unsigned int length, int mode) = 0;
+
+	virtual	int sys_close() = 0;
+	
+	/* Function: sys_read
+	 *  Reads the contents of the file into a buffer
+	 *
+     * Parameters:
+     *  buffer - the buffer to read in to
+     *  length - the number of characters to read
+     *  mode   - the mode of the file, 0 (normal) or 1 (binary); this may be unused?
+     *
+     * Returns:
+     *  0 on success, -1 on error, or the number of characters not read on partial success. EOF is 
+     *  signaled by setting the top bit (0x80000000) of the return value. 
+	 */
+	virtual	int sys_read(unsigned char* buffer, unsigned int length, int mode) = 0;
+	
+	/* Function: sys_istty
+	 *  Check if the handle is for a interactive terminal device 
+	 *
+	 * If so, unbuffered behaviour is used by default
+	 *
+	 * Returns:
+	 *  0 - no
+	 *  1 - yes
+	 */
+	virtual	int sys_istty() = 0 ;
+
+	/* Function: sys_seek
+ 	 *  Move the file position to a given offset from the file start
+ 	 *
+ 	 * Returns:
+ 	 *  0 on success, -1 on failure or unsupported
+ 	 */
+	virtual	int sys_seek(int position) = 0;
+	
+	/* Function: sys_ensure
+	 *  Flush any OS buffers associated with the FileHandle, ensuring it
+	 *  is up to date on disk
+	 *
+	 * Returns:
+	 *  0 on success or un-needed, -1 on error
+ 	 */
+	virtual	int sys_ensure() = 0;
+	
+	/* Function: sys_flen
+	 *  Find the current length of the file
+	 *
+	 * Returns:
+	 *  The current length of the file, or -1 on error
+	 */
+	virtual	int sys_flen() = 0;
+		
+};
+
+} // namespace mbed
+
+#endif
\ No newline at end of file