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api/FileHandle.h@10:3bc89ef62ce7, 2013-06-14 (annotated)

Committer:
emilmont
Date:
Fri Jun 14 17:49:17 2013 +0100
Revision:
10:3bc89ef62ce7
Parent:
9:0ce32e54c9a7
Child:
13:0645d8841f51
Unify mbed library sources

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emilmont 10:3bc89ef62ce7 1 /* mbed Microcontroller Library
emilmont 10:3bc89ef62ce7 2 * Copyright (c) 2006-2013 ARM Limited
emilmont 10:3bc89ef62ce7 3 *
emilmont 10:3bc89ef62ce7 4 * Licensed under the Apache License, Version 2.0 (the "License");
emilmont 10:3bc89ef62ce7 5 * you may not use this file except in compliance with the License.
emilmont 10:3bc89ef62ce7 6 * You may obtain a copy of the License at
emilmont 10:3bc89ef62ce7 7 *
emilmont 10:3bc89ef62ce7 8 * http://www.apache.org/licenses/LICENSE-2.0
emilmont 10:3bc89ef62ce7 9 *
emilmont 10:3bc89ef62ce7 10 * Unless required by applicable law or agreed to in writing, software
emilmont 10:3bc89ef62ce7 11 * distributed under the License is distributed on an "AS IS" BASIS,
emilmont 10:3bc89ef62ce7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
emilmont 10:3bc89ef62ce7 13 * See the License for the specific language governing permissions and
emilmont 10:3bc89ef62ce7 14 * limitations under the License.
emilmont 10:3bc89ef62ce7 15 */
emilmont 10:3bc89ef62ce7 16 #ifndef MBED_FILEHANDLE_H
emilmont 10:3bc89ef62ce7 17 #define MBED_FILEHANDLE_H
emilmont 10:3bc89ef62ce7 18
emilmont 10:3bc89ef62ce7 19 typedef int FILEHANDLE;
emilmont 10:3bc89ef62ce7 20
emilmont 10:3bc89ef62ce7 21 #include <stdio.h>
emilmont 10:3bc89ef62ce7 22
emilmont 10:3bc89ef62ce7 23 #if defined(__ARMCC_VERSION) || defined(__ICCARM__)
emilmont 10:3bc89ef62ce7 24 typedef int ssize_t;
emilmont 10:3bc89ef62ce7 25 typedef long off_t;
emilmont 10:3bc89ef62ce7 26
emilmont 10:3bc89ef62ce7 27 #else
emilmont 10:3bc89ef62ce7 28 # include <sys/types.h>
emilmont 10:3bc89ef62ce7 29 #endif
emilmont 10:3bc89ef62ce7 30
emilmont 10:3bc89ef62ce7 31 namespace mbed {
emilmont 10:3bc89ef62ce7 32
emilmont 10:3bc89ef62ce7 33 /** An OO equivalent of the internal FILEHANDLE variable
emilmont 10:3bc89ef62ce7 34 * and associated _sys_* functions.
emilmont 10:3bc89ef62ce7 35 *
emilmont 10:3bc89ef62ce7 36 * FileHandle is an abstract class, needing at least sys_write and
emilmont 10:3bc89ef62ce7 37 * sys_read to be implmented for a simple interactive device.
emilmont 10:3bc89ef62ce7 38 *
emilmont 10:3bc89ef62ce7 39 * No one ever directly tals to/instanciates a FileHandle - it gets
emilmont 10:3bc89ef62ce7 40 * created by FileSystem, and wrapped up by stdio.
emilmont 10:3bc89ef62ce7 41 */
emilmont 10:3bc89ef62ce7 42 class FileHandle {
emilmont 10:3bc89ef62ce7 43
emilmont 10:3bc89ef62ce7 44 public:
emilmont 10:3bc89ef62ce7 45 /** Write the contents of a buffer to the file
emilmont 10:3bc89ef62ce7 46 *
emilmont 10:3bc89ef62ce7 47 * @param buffer the buffer to write from
emilmont 10:3bc89ef62ce7 48 * @param length the number of characters to write
emilmont 10:3bc89ef62ce7 49 *
emilmont 10:3bc89ef62ce7 50 * @returns
emilmont 10:3bc89ef62ce7 51 * The number of characters written (possibly 0) on success, -1 on error.
emilmont 10:3bc89ef62ce7 52 */
emilmont 10:3bc89ef62ce7 53 virtual ssize_t write(const void* buffer, size_t length) = 0;
emilmont 10:3bc89ef62ce7 54
emilmont 10:3bc89ef62ce7 55 /** Close the file
emilmont 10:3bc89ef62ce7 56 *
emilmont 10:3bc89ef62ce7 57 * @returns
emilmont 10:3bc89ef62ce7 58 * Zero on success, -1 on error.
emilmont 10:3bc89ef62ce7 59 */
emilmont 10:3bc89ef62ce7 60 virtual int close() = 0;
emilmont 10:3bc89ef62ce7 61
emilmont 10:3bc89ef62ce7 62 /** Function read
emilmont 10:3bc89ef62ce7 63 * Reads the contents of the file into a buffer
emilmont 10:3bc89ef62ce7 64 *
emilmont 10:3bc89ef62ce7 65 * @param buffer the buffer to read in to
emilmont 10:3bc89ef62ce7 66 * @param length the number of characters to read
emilmont 10:3bc89ef62ce7 67 *
emilmont 10:3bc89ef62ce7 68 * @returns
emilmont 10:3bc89ef62ce7 69 * The number of characters read (zero at end of file) on success, -1 on error.
emilmont 10:3bc89ef62ce7 70 */
emilmont 10:3bc89ef62ce7 71 virtual ssize_t read(void* buffer, size_t length) = 0;
emilmont 10:3bc89ef62ce7 72
emilmont 10:3bc89ef62ce7 73 /** Check if the handle is for a interactive terminal device.
emilmont 10:3bc89ef62ce7 74 * If so, line buffered behaviour is used by default
emilmont 10:3bc89ef62ce7 75 *
emilmont 10:3bc89ef62ce7 76 * @returns
emilmont 10:3bc89ef62ce7 77 * 1 if it is a terminal,
emilmont 10:3bc89ef62ce7 78 * 0 otherwise
emilmont 10:3bc89ef62ce7 79 */
emilmont 10:3bc89ef62ce7 80 virtual int isatty() = 0;
emilmont 10:3bc89ef62ce7 81
emilmont 10:3bc89ef62ce7 82 /** Move the file position to a given offset from a given location.
emilmont 10:3bc89ef62ce7 83 *
emilmont 10:3bc89ef62ce7 84 * @param offset The offset from whence to move to
emilmont 10:3bc89ef62ce7 85 * @param whence SEEK_SET for the start of the file, SEEK_CUR for the
emilmont 10:3bc89ef62ce7 86 * current file position, or SEEK_END for the end of the file.
emilmont 10:3bc89ef62ce7 87 *
emilmont 10:3bc89ef62ce7 88 * @returns
emilmont 10:3bc89ef62ce7 89 * new file position on success,
emilmont 10:3bc89ef62ce7 90 * -1 on failure or unsupported
emilmont 10:3bc89ef62ce7 91 */
emilmont 10:3bc89ef62ce7 92 virtual off_t lseek(off_t offset, int whence) = 0;
emilmont 10:3bc89ef62ce7 93
emilmont 10:3bc89ef62ce7 94 /** Flush any buffers associated with the FileHandle, ensuring it
emilmont 10:3bc89ef62ce7 95 * is up to date on disk
emilmont 10:3bc89ef62ce7 96 *
emilmont 10:3bc89ef62ce7 97 * @returns
emilmont 10:3bc89ef62ce7 98 * 0 on success or un-needed,
emilmont 10:3bc89ef62ce7 99 * -1 on error
emilmont 10:3bc89ef62ce7 100 */
emilmont 10:3bc89ef62ce7 101 virtual int fsync() = 0;
emilmont 10:3bc89ef62ce7 102
emilmont 10:3bc89ef62ce7 103 virtual off_t flen() {
emilmont 10:3bc89ef62ce7 104 /* remember our current position */
emilmont 10:3bc89ef62ce7 105 off_t pos = lseek(0, SEEK_CUR);
emilmont 10:3bc89ef62ce7 106 if(pos == -1) return -1;
emilmont 10:3bc89ef62ce7 107 /* seek to the end to get the file length */
emilmont 10:3bc89ef62ce7 108 off_t res = lseek(0, SEEK_END);
emilmont 10:3bc89ef62ce7 109 /* return to our old position */
emilmont 10:3bc89ef62ce7 110 lseek(pos, SEEK_SET);
emilmont 10:3bc89ef62ce7 111 return res;
emilmont 10:3bc89ef62ce7 112 }
emilmont 10:3bc89ef62ce7 113
emilmont 10:3bc89ef62ce7 114 virtual ~FileHandle();
emilmont 10:3bc89ef62ce7 115 };
emilmont 10:3bc89ef62ce7 116
emilmont 10:3bc89ef62ce7 117 } // namespace mbed
emilmont 10:3bc89ef62ce7 118
emilmont 10:3bc89ef62ce7 119 #endif