Aditya Mehrotra / mbed-dev

Biomimetics MBED Library w/ Added Support for CAN3

Dependents:   CAN_TEST SPIne_Plus_DYNO_SENSORS SPIne_Plus_v2 SPIne_Plus_Dyno_v2

platform/FileHandle.h@3:993b4d6ff61e, 2021-03-09 (annotated)

Committer:
adimmit
Date:
Tue Mar 09 20:33:24 2021 +0000
Revision:
3:993b4d6ff61e
Parent:
0:083111ae2a11 
added CAN3

Who changed what in which revision?

UserRevisionLine numberNew contents of line
saloutos 0:083111ae2a11 1 /* mbed Microcontroller Library
saloutos 0:083111ae2a11 2 * Copyright (c) 2017 ARM Limited
saloutos 0:083111ae2a11 3 *
saloutos 0:083111ae2a11 4 * Licensed under the Apache License, Version 2.0 (the "License");
saloutos 0:083111ae2a11 5 * you may not use this file except in compliance with the License.
saloutos 0:083111ae2a11 6 * You may obtain a copy of the License at
saloutos 0:083111ae2a11 7 *
saloutos 0:083111ae2a11 8 * http://www.apache.org/licenses/LICENSE-2.0
saloutos 0:083111ae2a11 9 *
saloutos 0:083111ae2a11 10 * Unless required by applicable law or agreed to in writing, software
saloutos 0:083111ae2a11 11 * distributed under the License is distributed on an "AS IS" BASIS,
saloutos 0:083111ae2a11 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
saloutos 0:083111ae2a11 13 * See the License for the specific language governing permissions and
saloutos 0:083111ae2a11 14 * limitations under the License.
saloutos 0:083111ae2a11 15 */
saloutos 0:083111ae2a11 16 #ifndef MBED_FILEHANDLE_H
saloutos 0:083111ae2a11 17 #define MBED_FILEHANDLE_H
saloutos 0:083111ae2a11 18
saloutos 0:083111ae2a11 19 typedef int FILEHANDLE;
saloutos 0:083111ae2a11 20
saloutos 0:083111ae2a11 21 #include <cstdio>
saloutos 0:083111ae2a11 22 #include "Callback.h"
saloutos 0:083111ae2a11 23 #include "platform/mbed_poll.h"
saloutos 0:083111ae2a11 24 #include "platform/platform.h"
saloutos 0:083111ae2a11 25 #include "platform/NonCopyable.h"
saloutos 0:083111ae2a11 26
saloutos 0:083111ae2a11 27 namespace mbed {
saloutos 0:083111ae2a11 28 /** \addtogroup platform */
saloutos 0:083111ae2a11 29
saloutos 0:083111ae2a11 30
saloutos 0:083111ae2a11 31 /** Class FileHandle
saloutos 0:083111ae2a11 32 *
saloutos 0:083111ae2a11 33 * An abstract interface that represents operations on a file-like
saloutos 0:083111ae2a11 34 * object. The core functions are read, write, and seek, but only
saloutos 0:083111ae2a11 35 * a subset of these operations can be provided.
saloutos 0:083111ae2a11 36 *
saloutos 0:083111ae2a11 37 * @note to create a file, @see File
saloutos 0:083111ae2a11 38 * @note Synchronization level: Set by subclass
saloutos 0:083111ae2a11 39 * @ingroup platform
saloutos 0:083111ae2a11 40 */
saloutos 0:083111ae2a11 41 class FileHandle : private NonCopyable<FileHandle> {
saloutos 0:083111ae2a11 42 public:
saloutos 0:083111ae2a11 43 virtual ~FileHandle() {}
saloutos 0:083111ae2a11 44
saloutos 0:083111ae2a11 45 /** Read the contents of a file into a buffer
saloutos 0:083111ae2a11 46 *
saloutos 0:083111ae2a11 47 * Devices acting as FileHandles should follow POSIX semantics:
saloutos 0:083111ae2a11 48 *
saloutos 0:083111ae2a11 49 * * if no data is available, and non-blocking set return -EAGAIN
saloutos 0:083111ae2a11 50 * * if no data is available, and blocking set, wait until data is available
saloutos 0:083111ae2a11 51 * * If any data is available, call returns immediately
saloutos 0:083111ae2a11 52 *
saloutos 0:083111ae2a11 53 * @param buffer The buffer to read in to
saloutos 0:083111ae2a11 54 * @param size The number of bytes to read
saloutos 0:083111ae2a11 55 * @return The number of bytes read, 0 at end of file, negative error on failure
saloutos 0:083111ae2a11 56 */
saloutos 0:083111ae2a11 57 virtual ssize_t read(void *buffer, size_t size) = 0;
saloutos 0:083111ae2a11 58
saloutos 0:083111ae2a11 59 /** Write the contents of a buffer to a file
saloutos 0:083111ae2a11 60 *
saloutos 0:083111ae2a11 61 * @param buffer The buffer to write from
saloutos 0:083111ae2a11 62 * @param size The number of bytes to write
saloutos 0:083111ae2a11 63 * @return The number of bytes written, negative error on failure
saloutos 0:083111ae2a11 64 */
saloutos 0:083111ae2a11 65 virtual ssize_t write(const void *buffer, size_t size) = 0;
saloutos 0:083111ae2a11 66
saloutos 0:083111ae2a11 67 /** Move the file position to a given offset from from a given location
saloutos 0:083111ae2a11 68 *
saloutos 0:083111ae2a11 69 * @param offset The offset from whence to move to
saloutos 0:083111ae2a11 70 * @param whence The start of where to seek
saloutos 0:083111ae2a11 71 * SEEK_SET to start from beginning of file,
saloutos 0:083111ae2a11 72 * SEEK_CUR to start from current position in file,
saloutos 0:083111ae2a11 73 * SEEK_END to start from end of file
saloutos 0:083111ae2a11 74 * @return The new offset of the file, negative error code on failure
saloutos 0:083111ae2a11 75 */
saloutos 0:083111ae2a11 76 virtual off_t seek(off_t offset, int whence = SEEK_SET) = 0;
saloutos 0:083111ae2a11 77
saloutos 0:083111ae2a11 78 /** Close a file
saloutos 0:083111ae2a11 79 *
saloutos 0:083111ae2a11 80 * @return 0 on success, negative error code on failure
saloutos 0:083111ae2a11 81 */
saloutos 0:083111ae2a11 82 virtual int close() = 0;
saloutos 0:083111ae2a11 83
saloutos 0:083111ae2a11 84 /** Flush any buffers associated with the file
saloutos 0:083111ae2a11 85 *
saloutos 0:083111ae2a11 86 * @return 0 on success, negative error code on failure
saloutos 0:083111ae2a11 87 */
saloutos 0:083111ae2a11 88 virtual int sync()
saloutos 0:083111ae2a11 89 {
saloutos 0:083111ae2a11 90 return 0;
saloutos 0:083111ae2a11 91 }
saloutos 0:083111ae2a11 92
saloutos 0:083111ae2a11 93 /** Check if the file in an interactive terminal device
saloutos 0:083111ae2a11 94 *
saloutos 0:083111ae2a11 95 * @return True if the file is a terminal
saloutos 0:083111ae2a11 96 * @return False if the file is not a terminal
saloutos 0:083111ae2a11 97 * @return Negative error code on failure
saloutos 0:083111ae2a11 98 */
saloutos 0:083111ae2a11 99 virtual int isatty()
saloutos 0:083111ae2a11 100 {
saloutos 0:083111ae2a11 101 return false;
saloutos 0:083111ae2a11 102 }
saloutos 0:083111ae2a11 103
saloutos 0:083111ae2a11 104 /** Get the file position of the file
saloutos 0:083111ae2a11 105 *
saloutos 0:083111ae2a11 106 * @note This is equivalent to seek(0, SEEK_CUR)
saloutos 0:083111ae2a11 107 *
saloutos 0:083111ae2a11 108 * @return The current offset in the file, negative error code on failure
saloutos 0:083111ae2a11 109 */
saloutos 0:083111ae2a11 110 virtual off_t tell()
saloutos 0:083111ae2a11 111 {
saloutos 0:083111ae2a11 112 return seek(0, SEEK_CUR);
saloutos 0:083111ae2a11 113 }
saloutos 0:083111ae2a11 114
saloutos 0:083111ae2a11 115 /** Rewind the file position to the beginning of the file
saloutos 0:083111ae2a11 116 *
saloutos 0:083111ae2a11 117 * @note This is equivalent to seek(0, SEEK_SET)
saloutos 0:083111ae2a11 118 */
saloutos 0:083111ae2a11 119 virtual void rewind()
saloutos 0:083111ae2a11 120 {
saloutos 0:083111ae2a11 121 seek(0, SEEK_SET);
saloutos 0:083111ae2a11 122 }
saloutos 0:083111ae2a11 123
saloutos 0:083111ae2a11 124 /** Get the size of the file
saloutos 0:083111ae2a11 125 *
saloutos 0:083111ae2a11 126 * @return Size of the file in bytes
saloutos 0:083111ae2a11 127 */
saloutos 0:083111ae2a11 128 virtual off_t size();
saloutos 0:083111ae2a11 129
saloutos 0:083111ae2a11 130 /** Move the file position to a given offset from a given location.
saloutos 0:083111ae2a11 131 *
saloutos 0:083111ae2a11 132 * @param offset The offset from whence to move to
saloutos 0:083111ae2a11 133 * @param whence SEEK_SET for the start of the file, SEEK_CUR for the
saloutos 0:083111ae2a11 134 * current file position, or SEEK_END for the end of the file.
saloutos 0:083111ae2a11 135 *
saloutos 0:083111ae2a11 136 * @returns
saloutos 0:083111ae2a11 137 * new file position on success,
saloutos 0:083111ae2a11 138 * -1 on failure or unsupported
saloutos 0:083111ae2a11 139 */
saloutos 0:083111ae2a11 140 MBED_DEPRECATED_SINCE("mbed-os-5.4", "Replaced by FileHandle::seek")
saloutos 0:083111ae2a11 141 virtual off_t lseek(off_t offset, int whence)
saloutos 0:083111ae2a11 142 {
saloutos 0:083111ae2a11 143 return seek(offset, whence);
saloutos 0:083111ae2a11 144 }
saloutos 0:083111ae2a11 145
saloutos 0:083111ae2a11 146 /** Flush any buffers associated with the FileHandle, ensuring it
saloutos 0:083111ae2a11 147 * is up to date on disk
saloutos 0:083111ae2a11 148 *
saloutos 0:083111ae2a11 149 * @returns
saloutos 0:083111ae2a11 150 * 0 on success or un-needed,
saloutos 0:083111ae2a11 151 * -1 on error
saloutos 0:083111ae2a11 152 */
saloutos 0:083111ae2a11 153 MBED_DEPRECATED_SINCE("mbed-os-5.4", "Replaced by FileHandle::sync")
saloutos 0:083111ae2a11 154 virtual int fsync()
saloutos 0:083111ae2a11 155 {
saloutos 0:083111ae2a11 156 return sync();
saloutos 0:083111ae2a11 157 }
saloutos 0:083111ae2a11 158
saloutos 0:083111ae2a11 159 /** Find the length of the file
saloutos 0:083111ae2a11 160 *
saloutos 0:083111ae2a11 161 * @returns
saloutos 0:083111ae2a11 162 * Length of the file
saloutos 0:083111ae2a11 163 */
saloutos 0:083111ae2a11 164 MBED_DEPRECATED_SINCE("mbed-os-5.4", "Replaced by FileHandle::size")
saloutos 0:083111ae2a11 165 virtual off_t flen()
saloutos 0:083111ae2a11 166 {
saloutos 0:083111ae2a11 167 return size();
saloutos 0:083111ae2a11 168 }
saloutos 0:083111ae2a11 169
saloutos 0:083111ae2a11 170 /** Set blocking or non-blocking mode of the file operation like read/write.
saloutos 0:083111ae2a11 171 * Definition depends upon the subclass implementing FileHandle.
saloutos 0:083111ae2a11 172 * The default is blocking.
saloutos 0:083111ae2a11 173 *
saloutos 0:083111ae2a11 174 * @param blocking true for blocking mode, false for non-blocking mode.
saloutos 0:083111ae2a11 175 *
saloutos 0:083111ae2a11 176 * @return 0 on success
saloutos 0:083111ae2a11 177 * @return Negative error code on failure
saloutos 0:083111ae2a11 178 */
saloutos 0:083111ae2a11 179 virtual int set_blocking(bool blocking)
saloutos 0:083111ae2a11 180 {
saloutos 0:083111ae2a11 181 return -1;
saloutos 0:083111ae2a11 182 }
saloutos 0:083111ae2a11 183
saloutos 0:083111ae2a11 184 /** Check for poll event flags
saloutos 0:083111ae2a11 185 * The input parameter can be used or ignored - the could always return all events,
saloutos 0:083111ae2a11 186 * or could check just the events listed in events.
saloutos 0:083111ae2a11 187 * Call is non-blocking - returns instantaneous state of events.
saloutos 0:083111ae2a11 188 * Whenever an event occurs, the derived class should call the sigio() callback).
saloutos 0:083111ae2a11 189 *
saloutos 0:083111ae2a11 190 * @param events bitmask of poll events we're interested in - POLLIN/POLLOUT etc.
saloutos 0:083111ae2a11 191 *
saloutos 0:083111ae2a11 192 * @returns bitmask of poll events that have occurred.
saloutos 0:083111ae2a11 193 */
saloutos 0:083111ae2a11 194 virtual short poll(short events) const
saloutos 0:083111ae2a11 195 {
saloutos 0:083111ae2a11 196 // Possible default for real files
saloutos 0:083111ae2a11 197 return POLLIN | POLLOUT;
saloutos 0:083111ae2a11 198 }
saloutos 0:083111ae2a11 199
saloutos 0:083111ae2a11 200 /** Definition depends upon the subclass implementing FileHandle.
saloutos 0:083111ae2a11 201 * For example, if the FileHandle is of type Stream, writable() could return
saloutos 0:083111ae2a11 202 * true when there is ample buffer space available for write() calls.
saloutos 0:083111ae2a11 203 *
saloutos 0:083111ae2a11 204 * @returns true if the FileHandle is writable.
saloutos 0:083111ae2a11 205 */
saloutos 0:083111ae2a11 206 bool writable() const
saloutos 0:083111ae2a11 207 {
saloutos 0:083111ae2a11 208 return poll(POLLOUT) & POLLOUT;
saloutos 0:083111ae2a11 209 }
saloutos 0:083111ae2a11 210
saloutos 0:083111ae2a11 211 /** Definition depends upon the subclass implementing FileHandle.
saloutos 0:083111ae2a11 212 * For example, if the FileHandle is of type Stream, readable() could return
saloutos 0:083111ae2a11 213 * true when there is something available to read.
saloutos 0:083111ae2a11 214 *
saloutos 0:083111ae2a11 215 * @returns true when there is something available to read.
saloutos 0:083111ae2a11 216 */
saloutos 0:083111ae2a11 217 bool readable() const
saloutos 0:083111ae2a11 218 {
saloutos 0:083111ae2a11 219 return poll(POLLIN) & POLLIN;
saloutos 0:083111ae2a11 220 }
saloutos 0:083111ae2a11 221
saloutos 0:083111ae2a11 222 /** Register a callback on state change of the file.
saloutos 0:083111ae2a11 223 *
saloutos 0:083111ae2a11 224 * The specified callback will be called on state changes such as when
saloutos 0:083111ae2a11 225 * the file can be written to or read from.
saloutos 0:083111ae2a11 226 *
saloutos 0:083111ae2a11 227 * The callback may be called in an interrupt context and should not
saloutos 0:083111ae2a11 228 * perform expensive operations.
saloutos 0:083111ae2a11 229 *
saloutos 0:083111ae2a11 230 * Note! This is not intended as an attach-like asynchronous api, but rather
saloutos 0:083111ae2a11 231 * as a building block for constructing such functionality.
saloutos 0:083111ae2a11 232 *
saloutos 0:083111ae2a11 233 * The exact timing of when the registered function
saloutos 0:083111ae2a11 234 * is called is not guaranteed and susceptible to change. It should be used
saloutos 0:083111ae2a11 235 * as a cue to make read/write/poll calls to find the current state.
saloutos 0:083111ae2a11 236 *
saloutos 0:083111ae2a11 237 * @param func Function to call on state change
saloutos 0:083111ae2a11 238 */
saloutos 0:083111ae2a11 239 virtual void sigio(Callback<void()> func)
saloutos 0:083111ae2a11 240 {
saloutos 0:083111ae2a11 241 //Default for real files. Do nothing for real files.
saloutos 0:083111ae2a11 242 }
saloutos 0:083111ae2a11 243 };
saloutos 0:083111ae2a11 244
saloutos 0:083111ae2a11 245 /** Not a member function
saloutos 0:083111ae2a11 246 * This call is equivalent to posix fdopen().
saloutos 0:083111ae2a11 247 * It associates a Stream to an already opened file descriptor (FileHandle)
saloutos 0:083111ae2a11 248 *
saloutos 0:083111ae2a11 249 * @param fh a pointer to an opened file descriptor
saloutos 0:083111ae2a11 250 * @param mode operation upon the file descriptor, e.g., 'wb+'
saloutos 0:083111ae2a11 251 *
saloutos 0:083111ae2a11 252 * @returns a pointer to std::FILE
saloutos 0:083111ae2a11 253 */
saloutos 0:083111ae2a11 254
saloutos 0:083111ae2a11 255 std::FILE *fdopen(FileHandle *fh, const char *mode);
saloutos 0:083111ae2a11 256
saloutos 0:083111ae2a11 257 } // namespace mbed
saloutos 0:083111ae2a11 258
saloutos 0:083111ae2a11 259 #endif