Mark Turner / mbed

mbed library for slider v2

Dependents:   kl46z_slider_v2

FileHandle.h@0:b7116bd48af6, 2016-09-14 (annotated)

Committer:
mturner5
Date:
Wed Sep 14 07:04:27 2016 +0000
Revision:
0:b7116bd48af6
Tried to use the timer.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mturner5 0:b7116bd48af6 1 /* mbed Microcontroller Library
mturner5 0:b7116bd48af6 2 * Copyright (c) 2006-2013 ARM Limited
mturner5 0:b7116bd48af6 3 *
mturner5 0:b7116bd48af6 4 * Licensed under the Apache License, Version 2.0 (the "License");
mturner5 0:b7116bd48af6 5 * you may not use this file except in compliance with the License.
mturner5 0:b7116bd48af6 6 * You may obtain a copy of the License at
mturner5 0:b7116bd48af6 7 *
mturner5 0:b7116bd48af6 8 * http://www.apache.org/licenses/LICENSE-2.0
mturner5 0:b7116bd48af6 9 *
mturner5 0:b7116bd48af6 10 * Unless required by applicable law or agreed to in writing, software
mturner5 0:b7116bd48af6 11 * distributed under the License is distributed on an "AS IS" BASIS,
mturner5 0:b7116bd48af6 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mturner5 0:b7116bd48af6 13 * See the License for the specific language governing permissions and
mturner5 0:b7116bd48af6 14 * limitations under the License.
mturner5 0:b7116bd48af6 15 */
mturner5 0:b7116bd48af6 16 #ifndef MBED_FILEHANDLE_H
mturner5 0:b7116bd48af6 17 #define MBED_FILEHANDLE_H
mturner5 0:b7116bd48af6 18
mturner5 0:b7116bd48af6 19 typedef int FILEHANDLE;
mturner5 0:b7116bd48af6 20
mturner5 0:b7116bd48af6 21 #include <stdio.h>
mturner5 0:b7116bd48af6 22
mturner5 0:b7116bd48af6 23 #if defined(__ARMCC_VERSION) || defined(__ICCARM__)
mturner5 0:b7116bd48af6 24 typedef int ssize_t;
mturner5 0:b7116bd48af6 25 typedef long off_t;
mturner5 0:b7116bd48af6 26
mturner5 0:b7116bd48af6 27 #else
mturner5 0:b7116bd48af6 28 # include <sys/types.h>
mturner5 0:b7116bd48af6 29 #endif
mturner5 0:b7116bd48af6 30
mturner5 0:b7116bd48af6 31 namespace mbed {
mturner5 0:b7116bd48af6 32
mturner5 0:b7116bd48af6 33 /** An OO equivalent of the internal FILEHANDLE variable
mturner5 0:b7116bd48af6 34 * and associated _sys_* functions.
mturner5 0:b7116bd48af6 35 *
mturner5 0:b7116bd48af6 36 * FileHandle is an abstract class, needing at least sys_write and
mturner5 0:b7116bd48af6 37 * sys_read to be implmented for a simple interactive device.
mturner5 0:b7116bd48af6 38 *
mturner5 0:b7116bd48af6 39 * No one ever directly tals to/instanciates a FileHandle - it gets
mturner5 0:b7116bd48af6 40 * created by FileSystem, and wrapped up by stdio.
mturner5 0:b7116bd48af6 41 *
mturner5 0:b7116bd48af6 42 * @Note Synchronization level: Set by subclass
mturner5 0:b7116bd48af6 43 */
mturner5 0:b7116bd48af6 44 class FileHandle {
mturner5 0:b7116bd48af6 45
mturner5 0:b7116bd48af6 46 public:
mturner5 0:b7116bd48af6 47 /** Write the contents of a buffer to the file
mturner5 0:b7116bd48af6 48 *
mturner5 0:b7116bd48af6 49 * @param buffer the buffer to write from
mturner5 0:b7116bd48af6 50 * @param length the number of characters to write
mturner5 0:b7116bd48af6 51 *
mturner5 0:b7116bd48af6 52 * @returns
mturner5 0:b7116bd48af6 53 * The number of characters written (possibly 0) on success, -1 on error.
mturner5 0:b7116bd48af6 54 */
mturner5 0:b7116bd48af6 55 virtual ssize_t write(const void* buffer, size_t length) = 0;
mturner5 0:b7116bd48af6 56
mturner5 0:b7116bd48af6 57 /** Close the file
mturner5 0:b7116bd48af6 58 *
mturner5 0:b7116bd48af6 59 * @returns
mturner5 0:b7116bd48af6 60 * Zero on success, -1 on error.
mturner5 0:b7116bd48af6 61 */
mturner5 0:b7116bd48af6 62 virtual int close() = 0;
mturner5 0:b7116bd48af6 63
mturner5 0:b7116bd48af6 64 /** Function read
mturner5 0:b7116bd48af6 65 * Reads the contents of the file into a buffer
mturner5 0:b7116bd48af6 66 *
mturner5 0:b7116bd48af6 67 * @param buffer the buffer to read in to
mturner5 0:b7116bd48af6 68 * @param length the number of characters to read
mturner5 0:b7116bd48af6 69 *
mturner5 0:b7116bd48af6 70 * @returns
mturner5 0:b7116bd48af6 71 * The number of characters read (zero at end of file) on success, -1 on error.
mturner5 0:b7116bd48af6 72 */
mturner5 0:b7116bd48af6 73 virtual ssize_t read(void* buffer, size_t length) = 0;
mturner5 0:b7116bd48af6 74
mturner5 0:b7116bd48af6 75 /** Check if the handle is for a interactive terminal device.
mturner5 0:b7116bd48af6 76 * If so, line buffered behaviour is used by default
mturner5 0:b7116bd48af6 77 *
mturner5 0:b7116bd48af6 78 * @returns
mturner5 0:b7116bd48af6 79 * 1 if it is a terminal,
mturner5 0:b7116bd48af6 80 * 0 otherwise
mturner5 0:b7116bd48af6 81 */
mturner5 0:b7116bd48af6 82 virtual int isatty() = 0;
mturner5 0:b7116bd48af6 83
mturner5 0:b7116bd48af6 84 /** Move the file position to a given offset from a given location.
mturner5 0:b7116bd48af6 85 *
mturner5 0:b7116bd48af6 86 * @param offset The offset from whence to move to
mturner5 0:b7116bd48af6 87 * @param whence SEEK_SET for the start of the file, SEEK_CUR for the
mturner5 0:b7116bd48af6 88 * current file position, or SEEK_END for the end of the file.
mturner5 0:b7116bd48af6 89 *
mturner5 0:b7116bd48af6 90 * @returns
mturner5 0:b7116bd48af6 91 * new file position on success,
mturner5 0:b7116bd48af6 92 * -1 on failure or unsupported
mturner5 0:b7116bd48af6 93 */
mturner5 0:b7116bd48af6 94 virtual off_t lseek(off_t offset, int whence) = 0;
mturner5 0:b7116bd48af6 95
mturner5 0:b7116bd48af6 96 /** Flush any buffers associated with the FileHandle, ensuring it
mturner5 0:b7116bd48af6 97 * is up to date on disk
mturner5 0:b7116bd48af6 98 *
mturner5 0:b7116bd48af6 99 * @returns
mturner5 0:b7116bd48af6 100 * 0 on success or un-needed,
mturner5 0:b7116bd48af6 101 * -1 on error
mturner5 0:b7116bd48af6 102 */
mturner5 0:b7116bd48af6 103 virtual int fsync() = 0;
mturner5 0:b7116bd48af6 104
mturner5 0:b7116bd48af6 105 virtual off_t flen() {
mturner5 0:b7116bd48af6 106 lock();
mturner5 0:b7116bd48af6 107 /* remember our current position */
mturner5 0:b7116bd48af6 108 off_t pos = lseek(0, SEEK_CUR);
mturner5 0:b7116bd48af6 109 if(pos == -1) {
mturner5 0:b7116bd48af6 110 unlock();
mturner5 0:b7116bd48af6 111 return -1;
mturner5 0:b7116bd48af6 112 }
mturner5 0:b7116bd48af6 113 /* seek to the end to get the file length */
mturner5 0:b7116bd48af6 114 off_t res = lseek(0, SEEK_END);
mturner5 0:b7116bd48af6 115 /* return to our old position */
mturner5 0:b7116bd48af6 116 lseek(pos, SEEK_SET);
mturner5 0:b7116bd48af6 117 unlock();
mturner5 0:b7116bd48af6 118 return res;
mturner5 0:b7116bd48af6 119 }
mturner5 0:b7116bd48af6 120
mturner5 0:b7116bd48af6 121 virtual ~FileHandle();
mturner5 0:b7116bd48af6 122
mturner5 0:b7116bd48af6 123 protected:
mturner5 0:b7116bd48af6 124
mturner5 0:b7116bd48af6 125 /** Acquire exclusive access to this object.
mturner5 0:b7116bd48af6 126 */
mturner5 0:b7116bd48af6 127 virtual void lock() {
mturner5 0:b7116bd48af6 128 // Stub
mturner5 0:b7116bd48af6 129 }
mturner5 0:b7116bd48af6 130
mturner5 0:b7116bd48af6 131 /** Release exclusive access to this object.
mturner5 0:b7116bd48af6 132 */
mturner5 0:b7116bd48af6 133 virtual void unlock() {
mturner5 0:b7116bd48af6 134 // Stub
mturner5 0:b7116bd48af6 135 }
mturner5 0:b7116bd48af6 136 };
mturner5 0:b7116bd48af6 137
mturner5 0:b7116bd48af6 138 } // namespace mbed
mturner5 0:b7116bd48af6 139
mturner5 0:b7116bd48af6 140 #endif