Iftikhar Aziz / mbed-dev

4545

Dependents:   LSS_Rev_1

Fork of mbed-dev by Umar Naeem

drivers/FileHandle.h@166:33361e55dd8c, 2017-08-23 (annotated)

Committer:
iftaziz
Date:
Wed Aug 23 10:32:38 2017 +0000
Revision:
166:33361e55dd8c
Parent:
160:d5399cc887bb 
r1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 149:156823d33999 1 /* mbed Microcontroller Library
<> 149:156823d33999 2 * Copyright (c) 2006-2013 ARM Limited
<> 149:156823d33999 3 *
<> 149:156823d33999 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 149:156823d33999 5 * you may not use this file except in compliance with the License.
<> 149:156823d33999 6 * You may obtain a copy of the License at
<> 149:156823d33999 7 *
<> 149:156823d33999 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 149:156823d33999 9 *
<> 149:156823d33999 10 * Unless required by applicable law or agreed to in writing, software
<> 149:156823d33999 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 149:156823d33999 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 149:156823d33999 13 * See the License for the specific language governing permissions and
<> 149:156823d33999 14 * limitations under the License.
<> 149:156823d33999 15 */
<> 149:156823d33999 16 #ifndef MBED_FILEHANDLE_H
<> 149:156823d33999 17 #define MBED_FILEHANDLE_H
<> 149:156823d33999 18
<> 149:156823d33999 19 typedef int FILEHANDLE;
<> 149:156823d33999 20
<> 149:156823d33999 21 #include <stdio.h>
<> 160:d5399cc887bb 22 #include "platform/platform.h"
<> 149:156823d33999 23
<> 149:156823d33999 24 namespace mbed {
<> 149:156823d33999 25 /** \addtogroup drivers */
<> 149:156823d33999 26 /** @{*/
<> 149:156823d33999 27
<> 149:156823d33999 28 /** An OO equivalent of the internal FILEHANDLE variable
<> 149:156823d33999 29 * and associated _sys_* functions.
<> 149:156823d33999 30 *
<> 149:156823d33999 31 * FileHandle is an abstract class, needing at least sys_write and
<> 149:156823d33999 32 * sys_read to be implmented for a simple interactive device.
<> 149:156823d33999 33 *
<> 149:156823d33999 34 * No one ever directly tals to/instanciates a FileHandle - it gets
<> 149:156823d33999 35 * created by FileSystem, and wrapped up by stdio.
<> 149:156823d33999 36 *
<> 149:156823d33999 37 * @Note Synchronization level: Set by subclass
<> 149:156823d33999 38 */
<> 149:156823d33999 39 class FileHandle {
<> 149:156823d33999 40
<> 149:156823d33999 41 public:
<> 160:d5399cc887bb 42 MBED_DEPRECATED_SINCE("mbed-os-5.4",
<> 160:d5399cc887bb 43 "The mbed 2 filesystem classes have been superseeded by the FileSystem api, "
<> 160:d5399cc887bb 44 "Replaced by File")
<> 160:d5399cc887bb 45 FileHandle() {}
<> 160:d5399cc887bb 46
<> 149:156823d33999 47 /** Write the contents of a buffer to the file
<> 149:156823d33999 48 *
<> 149:156823d33999 49 * @param buffer the buffer to write from
<> 149:156823d33999 50 * @param length the number of characters to write
<> 149:156823d33999 51 *
<> 149:156823d33999 52 * @returns
<> 149:156823d33999 53 * The number of characters written (possibly 0) on success, -1 on error.
<> 149:156823d33999 54 */
<> 149:156823d33999 55 virtual ssize_t write(const void* buffer, size_t length) = 0;
<> 149:156823d33999 56
<> 149:156823d33999 57 /** Close the file
<> 149:156823d33999 58 *
<> 149:156823d33999 59 * @returns
<> 149:156823d33999 60 * Zero on success, -1 on error.
<> 149:156823d33999 61 */
<> 149:156823d33999 62 virtual int close() = 0;
<> 149:156823d33999 63
<> 149:156823d33999 64 /** Function read
<> 149:156823d33999 65 * Reads the contents of the file into a buffer
<> 149:156823d33999 66 *
<> 149:156823d33999 67 * @param buffer the buffer to read in to
<> 149:156823d33999 68 * @param length the number of characters to read
<> 149:156823d33999 69 *
<> 149:156823d33999 70 * @returns
<> 149:156823d33999 71 * The number of characters read (zero at end of file) on success, -1 on error.
<> 149:156823d33999 72 */
<> 149:156823d33999 73 virtual ssize_t read(void* buffer, size_t length) = 0;
<> 149:156823d33999 74
<> 149:156823d33999 75 /** Check if the handle is for a interactive terminal device.
<> 149:156823d33999 76 * If so, line buffered behaviour is used by default
<> 149:156823d33999 77 *
<> 149:156823d33999 78 * @returns
<> 149:156823d33999 79 * 1 if it is a terminal,
<> 149:156823d33999 80 * 0 otherwise
<> 149:156823d33999 81 */
<> 149:156823d33999 82 virtual int isatty() = 0;
<> 149:156823d33999 83
<> 149:156823d33999 84 /** Move the file position to a given offset from a given location.
<> 149:156823d33999 85 *
<> 149:156823d33999 86 * @param offset The offset from whence to move to
<> 149:156823d33999 87 * @param whence SEEK_SET for the start of the file, SEEK_CUR for the
<> 149:156823d33999 88 * current file position, or SEEK_END for the end of the file.
<> 149:156823d33999 89 *
<> 149:156823d33999 90 * @returns
<> 149:156823d33999 91 * new file position on success,
<> 149:156823d33999 92 * -1 on failure or unsupported
<> 149:156823d33999 93 */
<> 149:156823d33999 94 virtual off_t lseek(off_t offset, int whence) = 0;
<> 149:156823d33999 95
<> 149:156823d33999 96 /** Flush any buffers associated with the FileHandle, ensuring it
<> 149:156823d33999 97 * is up to date on disk
<> 149:156823d33999 98 *
<> 149:156823d33999 99 * @returns
<> 149:156823d33999 100 * 0 on success or un-needed,
<> 149:156823d33999 101 * -1 on error
<> 149:156823d33999 102 */
<> 149:156823d33999 103 virtual int fsync() = 0;
<> 149:156823d33999 104
<> 149:156823d33999 105 virtual off_t flen() {
<> 149:156823d33999 106 lock();
<> 149:156823d33999 107 /* remember our current position */
<> 149:156823d33999 108 off_t pos = lseek(0, SEEK_CUR);
<> 149:156823d33999 109 if(pos == -1) {
<> 149:156823d33999 110 unlock();
<> 149:156823d33999 111 return -1;
<> 149:156823d33999 112 }
<> 149:156823d33999 113 /* seek to the end to get the file length */
<> 149:156823d33999 114 off_t res = lseek(0, SEEK_END);
<> 149:156823d33999 115 /* return to our old position */
<> 149:156823d33999 116 lseek(pos, SEEK_SET);
<> 149:156823d33999 117 unlock();
<> 149:156823d33999 118 return res;
<> 149:156823d33999 119 }
<> 149:156823d33999 120
<> 160:d5399cc887bb 121 virtual ~FileHandle() {};
<> 149:156823d33999 122
<> 149:156823d33999 123 protected:
<> 149:156823d33999 124
<> 149:156823d33999 125 /** Acquire exclusive access to this object.
<> 149:156823d33999 126 */
<> 149:156823d33999 127 virtual void lock() {
<> 149:156823d33999 128 // Stub
<> 149:156823d33999 129 }
<> 149:156823d33999 130
<> 149:156823d33999 131 /** Release exclusive access to this object.
<> 149:156823d33999 132 */
<> 149:156823d33999 133 virtual void unlock() {
<> 149:156823d33999 134 // Stub
<> 149:156823d33999 135 }
<> 149:156823d33999 136 };
<> 149:156823d33999 137
<> 149:156823d33999 138 } // namespace mbed
<> 149:156823d33999 139
<> 149:156823d33999 140 #endif
<> 149:156823d33999 141
<> 149:156823d33999 142 /** @}*/