Erik van de Coevering / quadV3

This is my quadcopter prototype software, still in development!

quadv3/mbed/FileHandle.h@1:ac68f0368a77, 2013-07-23 (annotated)

Committer:
Anaesthetix
Date:
Tue Jul 23 14:01:42 2013 +0000
Revision:
1:ac68f0368a77
Parent:
0:978110f7f027 
Other accelerometer added

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Anaesthetix 0:978110f7f027 1 /* mbed Microcontroller Library - FileHandler
Anaesthetix 0:978110f7f027 2 * Copyright (c) 2007-2009 ARM Limited. All rights reserved.
Anaesthetix 0:978110f7f027 3 */
Anaesthetix 0:978110f7f027 4
Anaesthetix 0:978110f7f027 5 #ifndef MBED_FILEHANDLE_H
Anaesthetix 0:978110f7f027 6 #define MBED_FILEHANDLE_H
Anaesthetix 0:978110f7f027 7
Anaesthetix 0:978110f7f027 8 typedef int FILEHANDLE;
Anaesthetix 0:978110f7f027 9
Anaesthetix 0:978110f7f027 10 #include <stdio.h>
Anaesthetix 0:978110f7f027 11 #ifdef __ARMCC_VERSION
Anaesthetix 0:978110f7f027 12 typedef int ssize_t;
Anaesthetix 0:978110f7f027 13 typedef long off_t;
Anaesthetix 0:978110f7f027 14 #else
Anaesthetix 0:978110f7f027 15 #include <sys/types.h>
Anaesthetix 0:978110f7f027 16 #endif
Anaesthetix 0:978110f7f027 17
Anaesthetix 0:978110f7f027 18 namespace mbed {
Anaesthetix 0:978110f7f027 19
Anaesthetix 0:978110f7f027 20 /* Class FileHandle
Anaesthetix 0:978110f7f027 21 * An OO equivalent of the internal FILEHANDLE variable
Anaesthetix 0:978110f7f027 22 * and associated _sys_* functions
Anaesthetix 0:978110f7f027 23 *
Anaesthetix 0:978110f7f027 24 * FileHandle is an abstract class, needing at least sys_write and
Anaesthetix 0:978110f7f027 25 * sys_read to be implmented for a simple interactive device
Anaesthetix 0:978110f7f027 26 *
Anaesthetix 0:978110f7f027 27 * No one ever directly tals to/instanciates a FileHandle - it gets
Anaesthetix 0:978110f7f027 28 * created by FileSystem, and wrapped up by stdio
Anaesthetix 0:978110f7f027 29 */
Anaesthetix 0:978110f7f027 30 class FileHandle {
Anaesthetix 0:978110f7f027 31
Anaesthetix 0:978110f7f027 32 public:
Anaesthetix 0:978110f7f027 33
Anaesthetix 0:978110f7f027 34 /* Function write
Anaesthetix 0:978110f7f027 35 * Write the contents of a buffer to the file
Anaesthetix 0:978110f7f027 36 *
Anaesthetix 0:978110f7f027 37 * Parameters
Anaesthetix 0:978110f7f027 38 * buffer - the buffer to write from
Anaesthetix 0:978110f7f027 39 * length - the number of characters to write
Anaesthetix 0:978110f7f027 40 *
Anaesthetix 0:978110f7f027 41 * Returns
Anaesthetix 0:978110f7f027 42 * The number of characters written (possibly 0) on success, -1 on error.
Anaesthetix 0:978110f7f027 43 */
Anaesthetix 0:978110f7f027 44 virtual ssize_t write(const void* buffer, size_t length) = 0;
Anaesthetix 0:978110f7f027 45
Anaesthetix 0:978110f7f027 46 /* Function close
Anaesthetix 0:978110f7f027 47 * Close the file
Anaesthetix 0:978110f7f027 48 *
Anaesthetix 0:978110f7f027 49 * Returns
Anaesthetix 0:978110f7f027 50 * Zero on success, -1 on error.
Anaesthetix 0:978110f7f027 51 */
Anaesthetix 0:978110f7f027 52 virtual int close() = 0;
Anaesthetix 0:978110f7f027 53
Anaesthetix 0:978110f7f027 54 /* Function read
Anaesthetix 0:978110f7f027 55 * Reads the contents of the file into a buffer
Anaesthetix 0:978110f7f027 56 *
Anaesthetix 0:978110f7f027 57 * Parameters
Anaesthetix 0:978110f7f027 58 * buffer - the buffer to read in to
Anaesthetix 0:978110f7f027 59 * length - the number of characters to read
Anaesthetix 0:978110f7f027 60 *
Anaesthetix 0:978110f7f027 61 * Returns
Anaesthetix 0:978110f7f027 62 * The number of characters read (zero at end of file) on success, -1 on error.
Anaesthetix 0:978110f7f027 63 */
Anaesthetix 0:978110f7f027 64 virtual ssize_t read(void* buffer, size_t length) = 0;
Anaesthetix 0:978110f7f027 65
Anaesthetix 0:978110f7f027 66 /* Function isatty
Anaesthetix 0:978110f7f027 67 * Check if the handle is for a interactive terminal device
Anaesthetix 0:978110f7f027 68 *
Anaesthetix 0:978110f7f027 69 * If so, line buffered behaviour is used by default
Anaesthetix 0:978110f7f027 70 *
Anaesthetix 0:978110f7f027 71 * Returns
Anaesthetix 0:978110f7f027 72 * 1 if it is a terminal, 0 otherwise
Anaesthetix 0:978110f7f027 73 */
Anaesthetix 0:978110f7f027 74 virtual int isatty() = 0 ;
Anaesthetix 0:978110f7f027 75
Anaesthetix 0:978110f7f027 76 /* Function lseek
Anaesthetix 0:978110f7f027 77 * Move the file position to a given offset from a given location.
Anaesthetix 0:978110f7f027 78 *
Anaesthetix 0:978110f7f027 79 * Parameters
Anaesthetix 0:978110f7f027 80 * offset - The offset from whence to move to
Anaesthetix 0:978110f7f027 81 * whence - SEEK_SET for the start of the file, SEEK_CUR for the
Anaesthetix 0:978110f7f027 82 * current file position, or SEEK_END for the end of the file.
Anaesthetix 0:978110f7f027 83 *
Anaesthetix 0:978110f7f027 84 * Returns
Anaesthetix 0:978110f7f027 85 * New file position on success, -1 on failure or unsupported
Anaesthetix 0:978110f7f027 86 */
Anaesthetix 0:978110f7f027 87 virtual off_t lseek(off_t offset, int whence) = 0;
Anaesthetix 0:978110f7f027 88
Anaesthetix 0:978110f7f027 89 /* Function fsync
Anaesthetix 0:978110f7f027 90 * Flush any buffers associated with the FileHandle, ensuring it
Anaesthetix 0:978110f7f027 91 * is up to date on disk
Anaesthetix 0:978110f7f027 92 *
Anaesthetix 0:978110f7f027 93 * Returns
Anaesthetix 0:978110f7f027 94 * 0 on success or un-needed, -1 on error
Anaesthetix 0:978110f7f027 95 */
Anaesthetix 0:978110f7f027 96 virtual int fsync() = 0;
Anaesthetix 0:978110f7f027 97
Anaesthetix 0:978110f7f027 98 virtual off_t flen() {
Anaesthetix 0:978110f7f027 99 /* remember our current position */
Anaesthetix 0:978110f7f027 100 off_t pos = lseek(0, SEEK_CUR);
Anaesthetix 0:978110f7f027 101 if(pos == -1) return -1;
Anaesthetix 0:978110f7f027 102 /* seek to the end to get the file length */
Anaesthetix 0:978110f7f027 103 off_t res = lseek(0, SEEK_END);
Anaesthetix 0:978110f7f027 104 /* return to our old position */
Anaesthetix 0:978110f7f027 105 lseek(pos, SEEK_SET);
Anaesthetix 0:978110f7f027 106 return res;
Anaesthetix 0:978110f7f027 107 }
Anaesthetix 0:978110f7f027 108
Anaesthetix 0:978110f7f027 109 };
Anaesthetix 0:978110f7f027 110
Anaesthetix 0:978110f7f027 111 } // namespace mbed
Anaesthetix 0:978110f7f027 112
Anaesthetix 0:978110f7f027 113 #endif
Anaesthetix 0:978110f7f027 114