Steven Wray / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by mbed official

api/FileHandle.h@148:e70627d019e9, 2016-09-28 (annotated)

Committer:
StevieWray
Date:
Wed Sep 28 08:45:18 2016 +0000
Revision:
148:e70627d019e9
Parent:
144:ef7eb2e8f9f7 
Fixed DAC output on STM32F3 boards to allow 3 outputs

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2013 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #ifndef MBED_FILEHANDLE_H
<> 144:ef7eb2e8f9f7 17 #define MBED_FILEHANDLE_H
<> 144:ef7eb2e8f9f7 18
<> 144:ef7eb2e8f9f7 19 typedef int FILEHANDLE;
<> 144:ef7eb2e8f9f7 20
<> 144:ef7eb2e8f9f7 21 #include <stdio.h>
<> 144:ef7eb2e8f9f7 22
<> 144:ef7eb2e8f9f7 23 #if defined(__ARMCC_VERSION) || defined(__ICCARM__)
<> 144:ef7eb2e8f9f7 24 typedef int ssize_t;
<> 144:ef7eb2e8f9f7 25 typedef long off_t;
<> 144:ef7eb2e8f9f7 26
<> 144:ef7eb2e8f9f7 27 #else
<> 144:ef7eb2e8f9f7 28 # include <sys/types.h>
<> 144:ef7eb2e8f9f7 29 #endif
<> 144:ef7eb2e8f9f7 30
<> 144:ef7eb2e8f9f7 31 namespace mbed {
<> 144:ef7eb2e8f9f7 32
<> 144:ef7eb2e8f9f7 33 /** An OO equivalent of the internal FILEHANDLE variable
<> 144:ef7eb2e8f9f7 34 * and associated _sys_* functions.
<> 144:ef7eb2e8f9f7 35 *
<> 144:ef7eb2e8f9f7 36 * FileHandle is an abstract class, needing at least sys_write and
<> 144:ef7eb2e8f9f7 37 * sys_read to be implmented for a simple interactive device.
<> 144:ef7eb2e8f9f7 38 *
<> 144:ef7eb2e8f9f7 39 * No one ever directly tals to/instanciates a FileHandle - it gets
<> 144:ef7eb2e8f9f7 40 * created by FileSystem, and wrapped up by stdio.
<> 144:ef7eb2e8f9f7 41 *
<> 144:ef7eb2e8f9f7 42 * @Note Synchronization level: Set by subclass
<> 144:ef7eb2e8f9f7 43 */
<> 144:ef7eb2e8f9f7 44 class FileHandle {
<> 144:ef7eb2e8f9f7 45
<> 144:ef7eb2e8f9f7 46 public:
<> 144:ef7eb2e8f9f7 47 /** Write the contents of a buffer to the file
<> 144:ef7eb2e8f9f7 48 *
<> 144:ef7eb2e8f9f7 49 * @param buffer the buffer to write from
<> 144:ef7eb2e8f9f7 50 * @param length the number of characters to write
<> 144:ef7eb2e8f9f7 51 *
<> 144:ef7eb2e8f9f7 52 * @returns
<> 144:ef7eb2e8f9f7 53 * The number of characters written (possibly 0) on success, -1 on error.
<> 144:ef7eb2e8f9f7 54 */
<> 144:ef7eb2e8f9f7 55 virtual ssize_t write(const void* buffer, size_t length) = 0;
<> 144:ef7eb2e8f9f7 56
<> 144:ef7eb2e8f9f7 57 /** Close the file
<> 144:ef7eb2e8f9f7 58 *
<> 144:ef7eb2e8f9f7 59 * @returns
<> 144:ef7eb2e8f9f7 60 * Zero on success, -1 on error.
<> 144:ef7eb2e8f9f7 61 */
<> 144:ef7eb2e8f9f7 62 virtual int close() = 0;
<> 144:ef7eb2e8f9f7 63
<> 144:ef7eb2e8f9f7 64 /** Function read
<> 144:ef7eb2e8f9f7 65 * Reads the contents of the file into a buffer
<> 144:ef7eb2e8f9f7 66 *
<> 144:ef7eb2e8f9f7 67 * @param buffer the buffer to read in to
<> 144:ef7eb2e8f9f7 68 * @param length the number of characters to read
<> 144:ef7eb2e8f9f7 69 *
<> 144:ef7eb2e8f9f7 70 * @returns
<> 144:ef7eb2e8f9f7 71 * The number of characters read (zero at end of file) on success, -1 on error.
<> 144:ef7eb2e8f9f7 72 */
<> 144:ef7eb2e8f9f7 73 virtual ssize_t read(void* buffer, size_t length) = 0;
<> 144:ef7eb2e8f9f7 74
<> 144:ef7eb2e8f9f7 75 /** Check if the handle is for a interactive terminal device.
<> 144:ef7eb2e8f9f7 76 * If so, line buffered behaviour is used by default
<> 144:ef7eb2e8f9f7 77 *
<> 144:ef7eb2e8f9f7 78 * @returns
<> 144:ef7eb2e8f9f7 79 * 1 if it is a terminal,
<> 144:ef7eb2e8f9f7 80 * 0 otherwise
<> 144:ef7eb2e8f9f7 81 */
<> 144:ef7eb2e8f9f7 82 virtual int isatty() = 0;
<> 144:ef7eb2e8f9f7 83
<> 144:ef7eb2e8f9f7 84 /** Move the file position to a given offset from a given location.
<> 144:ef7eb2e8f9f7 85 *
<> 144:ef7eb2e8f9f7 86 * @param offset The offset from whence to move to
<> 144:ef7eb2e8f9f7 87 * @param whence SEEK_SET for the start of the file, SEEK_CUR for the
<> 144:ef7eb2e8f9f7 88 * current file position, or SEEK_END for the end of the file.
<> 144:ef7eb2e8f9f7 89 *
<> 144:ef7eb2e8f9f7 90 * @returns
<> 144:ef7eb2e8f9f7 91 * new file position on success,
<> 144:ef7eb2e8f9f7 92 * -1 on failure or unsupported
<> 144:ef7eb2e8f9f7 93 */
<> 144:ef7eb2e8f9f7 94 virtual off_t lseek(off_t offset, int whence) = 0;
<> 144:ef7eb2e8f9f7 95
<> 144:ef7eb2e8f9f7 96 /** Flush any buffers associated with the FileHandle, ensuring it
<> 144:ef7eb2e8f9f7 97 * is up to date on disk
<> 144:ef7eb2e8f9f7 98 *
<> 144:ef7eb2e8f9f7 99 * @returns
<> 144:ef7eb2e8f9f7 100 * 0 on success or un-needed,
<> 144:ef7eb2e8f9f7 101 * -1 on error
<> 144:ef7eb2e8f9f7 102 */
<> 144:ef7eb2e8f9f7 103 virtual int fsync() = 0;
<> 144:ef7eb2e8f9f7 104
<> 144:ef7eb2e8f9f7 105 virtual off_t flen() {
<> 144:ef7eb2e8f9f7 106 lock();
<> 144:ef7eb2e8f9f7 107 /* remember our current position */
<> 144:ef7eb2e8f9f7 108 off_t pos = lseek(0, SEEK_CUR);
<> 144:ef7eb2e8f9f7 109 if(pos == -1) {
<> 144:ef7eb2e8f9f7 110 unlock();
<> 144:ef7eb2e8f9f7 111 return -1;
<> 144:ef7eb2e8f9f7 112 }
<> 144:ef7eb2e8f9f7 113 /* seek to the end to get the file length */
<> 144:ef7eb2e8f9f7 114 off_t res = lseek(0, SEEK_END);
<> 144:ef7eb2e8f9f7 115 /* return to our old position */
<> 144:ef7eb2e8f9f7 116 lseek(pos, SEEK_SET);
<> 144:ef7eb2e8f9f7 117 unlock();
<> 144:ef7eb2e8f9f7 118 return res;
<> 144:ef7eb2e8f9f7 119 }
<> 144:ef7eb2e8f9f7 120
<> 144:ef7eb2e8f9f7 121 virtual ~FileHandle();
<> 144:ef7eb2e8f9f7 122
<> 144:ef7eb2e8f9f7 123 protected:
<> 144:ef7eb2e8f9f7 124
<> 144:ef7eb2e8f9f7 125 /** Acquire exclusive access to this object.
<> 144:ef7eb2e8f9f7 126 */
<> 144:ef7eb2e8f9f7 127 virtual void lock() {
<> 144:ef7eb2e8f9f7 128 // Stub
<> 144:ef7eb2e8f9f7 129 }
<> 144:ef7eb2e8f9f7 130
<> 144:ef7eb2e8f9f7 131 /** Release exclusive access to this object.
<> 144:ef7eb2e8f9f7 132 */
<> 144:ef7eb2e8f9f7 133 virtual void unlock() {
<> 144:ef7eb2e8f9f7 134 // Stub
<> 144:ef7eb2e8f9f7 135 }
<> 144:ef7eb2e8f9f7 136 };
<> 144:ef7eb2e8f9f7 137
<> 144:ef7eb2e8f9f7 138 } // namespace mbed
<> 144:ef7eb2e8f9f7 139
<> 144:ef7eb2e8f9f7 140 #endif