Bei Chen Liu / mbed-src

mbed library sources

Fork of mbed-src by mbed official

cpp/FileHandle.h@0:fd0d7bdfcdc2, 2012-11-20 (annotated)

Committer:
mbed_official
Date:
Tue Nov 20 17:24:08 2012 +0000
Revision:
0:fd0d7bdfcdc2
Child:
2:143cac498751
mbed sources

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 0:fd0d7bdfcdc2 1 /* mbed Microcontroller Library
mbed_official 0:fd0d7bdfcdc2 2 * Copyright (c) 2006-2012 ARM Limited
mbed_official 0:fd0d7bdfcdc2 3 *
mbed_official 0:fd0d7bdfcdc2 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
mbed_official 0:fd0d7bdfcdc2 5 * of this software and associated documentation files (the "Software"), to deal
mbed_official 0:fd0d7bdfcdc2 6 * in the Software without restriction, including without limitation the rights
mbed_official 0:fd0d7bdfcdc2 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
mbed_official 0:fd0d7bdfcdc2 8 * copies of the Software, and to permit persons to whom the Software is
mbed_official 0:fd0d7bdfcdc2 9 * furnished to do so, subject to the following conditions:
mbed_official 0:fd0d7bdfcdc2 10 *
mbed_official 0:fd0d7bdfcdc2 11 * The above copyright notice and this permission notice shall be included in
mbed_official 0:fd0d7bdfcdc2 12 * all copies or substantial portions of the Software.
mbed_official 0:fd0d7bdfcdc2 13 *
mbed_official 0:fd0d7bdfcdc2 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
mbed_official 0:fd0d7bdfcdc2 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
mbed_official 0:fd0d7bdfcdc2 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
mbed_official 0:fd0d7bdfcdc2 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
mbed_official 0:fd0d7bdfcdc2 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
mbed_official 0:fd0d7bdfcdc2 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
mbed_official 0:fd0d7bdfcdc2 20 * SOFTWARE.
mbed_official 0:fd0d7bdfcdc2 21 */
mbed_official 0:fd0d7bdfcdc2 22 #ifndef MBED_FILEHANDLE_H
mbed_official 0:fd0d7bdfcdc2 23 #define MBED_FILEHANDLE_H
mbed_official 0:fd0d7bdfcdc2 24
mbed_official 0:fd0d7bdfcdc2 25 typedef int FILEHANDLE;
mbed_official 0:fd0d7bdfcdc2 26
mbed_official 0:fd0d7bdfcdc2 27 #include <stdio.h>
mbed_official 0:fd0d7bdfcdc2 28 #ifdef __ARMCC_VERSION
mbed_official 0:fd0d7bdfcdc2 29 typedef int ssize_t;
mbed_official 0:fd0d7bdfcdc2 30 typedef long off_t;
mbed_official 0:fd0d7bdfcdc2 31 #else
mbed_official 0:fd0d7bdfcdc2 32 #include <sys/types.h>
mbed_official 0:fd0d7bdfcdc2 33 #endif
mbed_official 0:fd0d7bdfcdc2 34
mbed_official 0:fd0d7bdfcdc2 35 namespace mbed {
mbed_official 0:fd0d7bdfcdc2 36
mbed_official 0:fd0d7bdfcdc2 37 /** An OO equivalent of the internal FILEHANDLE variable
mbed_official 0:fd0d7bdfcdc2 38 * and associated _sys_* functions.
mbed_official 0:fd0d7bdfcdc2 39 *
mbed_official 0:fd0d7bdfcdc2 40 * FileHandle is an abstract class, needing at least sys_write and
mbed_official 0:fd0d7bdfcdc2 41 * sys_read to be implmented for a simple interactive device.
mbed_official 0:fd0d7bdfcdc2 42 *
mbed_official 0:fd0d7bdfcdc2 43 * No one ever directly tals to/instanciates a FileHandle - it gets
mbed_official 0:fd0d7bdfcdc2 44 * created by FileSystem, and wrapped up by stdio.
mbed_official 0:fd0d7bdfcdc2 45 */
mbed_official 0:fd0d7bdfcdc2 46 class FileHandle {
mbed_official 0:fd0d7bdfcdc2 47
mbed_official 0:fd0d7bdfcdc2 48 public:
mbed_official 0:fd0d7bdfcdc2 49 /** Write the contents of a buffer to the file
mbed_official 0:fd0d7bdfcdc2 50 *
mbed_official 0:fd0d7bdfcdc2 51 * @param buffer the buffer to write from
mbed_official 0:fd0d7bdfcdc2 52 * @param length the number of characters to write
mbed_official 0:fd0d7bdfcdc2 53 *
mbed_official 0:fd0d7bdfcdc2 54 * @returns
mbed_official 0:fd0d7bdfcdc2 55 * The number of characters written (possibly 0) on success, -1 on error.
mbed_official 0:fd0d7bdfcdc2 56 */
mbed_official 0:fd0d7bdfcdc2 57 virtual ssize_t write(const void* buffer, size_t length) = 0;
mbed_official 0:fd0d7bdfcdc2 58
mbed_official 0:fd0d7bdfcdc2 59 /** Close the file
mbed_official 0:fd0d7bdfcdc2 60 *
mbed_official 0:fd0d7bdfcdc2 61 * @returns
mbed_official 0:fd0d7bdfcdc2 62 * Zero on success, -1 on error.
mbed_official 0:fd0d7bdfcdc2 63 */
mbed_official 0:fd0d7bdfcdc2 64 virtual int close() = 0;
mbed_official 0:fd0d7bdfcdc2 65
mbed_official 0:fd0d7bdfcdc2 66 /** Function read
mbed_official 0:fd0d7bdfcdc2 67 * Reads the contents of the file into a buffer
mbed_official 0:fd0d7bdfcdc2 68 *
mbed_official 0:fd0d7bdfcdc2 69 * @param buffer the buffer to read in to
mbed_official 0:fd0d7bdfcdc2 70 * @param length the number of characters to read
mbed_official 0:fd0d7bdfcdc2 71 *
mbed_official 0:fd0d7bdfcdc2 72 * @returns
mbed_official 0:fd0d7bdfcdc2 73 * The number of characters read (zero at end of file) on success, -1 on error.
mbed_official 0:fd0d7bdfcdc2 74 */
mbed_official 0:fd0d7bdfcdc2 75 virtual ssize_t read(void* buffer, size_t length) = 0;
mbed_official 0:fd0d7bdfcdc2 76
mbed_official 0:fd0d7bdfcdc2 77 /** Check if the handle is for a interactive terminal device.
mbed_official 0:fd0d7bdfcdc2 78 * If so, line buffered behaviour is used by default
mbed_official 0:fd0d7bdfcdc2 79 *
mbed_official 0:fd0d7bdfcdc2 80 * @returns
mbed_official 0:fd0d7bdfcdc2 81 * 1 if it is a terminal,
mbed_official 0:fd0d7bdfcdc2 82 * 0 otherwise
mbed_official 0:fd0d7bdfcdc2 83 */
mbed_official 0:fd0d7bdfcdc2 84 virtual int isatty() = 0;
mbed_official 0:fd0d7bdfcdc2 85
mbed_official 0:fd0d7bdfcdc2 86 /** Move the file position to a given offset from a given location.
mbed_official 0:fd0d7bdfcdc2 87 *
mbed_official 0:fd0d7bdfcdc2 88 * @param offset The offset from whence to move to
mbed_official 0:fd0d7bdfcdc2 89 * @param whence SEEK_SET for the start of the file, SEEK_CUR for the
mbed_official 0:fd0d7bdfcdc2 90 * current file position, or SEEK_END for the end of the file.
mbed_official 0:fd0d7bdfcdc2 91 *
mbed_official 0:fd0d7bdfcdc2 92 * @returns
mbed_official 0:fd0d7bdfcdc2 93 * new file position on success,
mbed_official 0:fd0d7bdfcdc2 94 * -1 on failure or unsupported
mbed_official 0:fd0d7bdfcdc2 95 */
mbed_official 0:fd0d7bdfcdc2 96 virtual off_t lseek(off_t offset, int whence) = 0;
mbed_official 0:fd0d7bdfcdc2 97
mbed_official 0:fd0d7bdfcdc2 98 /** Flush any buffers associated with the FileHandle, ensuring it
mbed_official 0:fd0d7bdfcdc2 99 * is up to date on disk
mbed_official 0:fd0d7bdfcdc2 100 *
mbed_official 0:fd0d7bdfcdc2 101 * @returns
mbed_official 0:fd0d7bdfcdc2 102 * 0 on success or un-needed,
mbed_official 0:fd0d7bdfcdc2 103 * -1 on error
mbed_official 0:fd0d7bdfcdc2 104 */
mbed_official 0:fd0d7bdfcdc2 105 virtual int fsync() = 0;
mbed_official 0:fd0d7bdfcdc2 106
mbed_official 0:fd0d7bdfcdc2 107 virtual off_t flen() {
mbed_official 0:fd0d7bdfcdc2 108 /* remember our current position */
mbed_official 0:fd0d7bdfcdc2 109 off_t pos = lseek(0, SEEK_CUR);
mbed_official 0:fd0d7bdfcdc2 110 if(pos == -1) return -1;
mbed_official 0:fd0d7bdfcdc2 111 /* seek to the end to get the file length */
mbed_official 0:fd0d7bdfcdc2 112 off_t res = lseek(0, SEEK_END);
mbed_official 0:fd0d7bdfcdc2 113 /* return to our old position */
mbed_official 0:fd0d7bdfcdc2 114 lseek(pos, SEEK_SET);
mbed_official 0:fd0d7bdfcdc2 115 return res;
mbed_official 0:fd0d7bdfcdc2 116 }
mbed_official 0:fd0d7bdfcdc2 117
mbed_official 0:fd0d7bdfcdc2 118 virtual ~FileHandle();
mbed_official 0:fd0d7bdfcdc2 119 };
mbed_official 0:fd0d7bdfcdc2 120
mbed_official 0:fd0d7bdfcdc2 121 } // namespace mbed
mbed_official 0:fd0d7bdfcdc2 122
mbed_official 0:fd0d7bdfcdc2 123 #endif