Vladimir Vana / mbed

pro vyuku PSS v Jecne

FileHandle.h@0:23d1f73bf130, 2017-09-24 (annotated)

Committer:
vladvana
Date:
Sun Sep 24 12:31:52 2017 +0000
Revision:
0:23d1f73bf130
podklady pro cviceni z PSS

Who changed what in which revision?

UserRevisionLine numberNew contents of line
vladvana 0:23d1f73bf130 1 /* mbed Microcontroller Library
vladvana 0:23d1f73bf130 2 * Copyright (c) 2006-2013 ARM Limited
vladvana 0:23d1f73bf130 3 *
vladvana 0:23d1f73bf130 4 * Licensed under the Apache License, Version 2.0 (the "License");
vladvana 0:23d1f73bf130 5 * you may not use this file except in compliance with the License.
vladvana 0:23d1f73bf130 6 * You may obtain a copy of the License at
vladvana 0:23d1f73bf130 7 *
vladvana 0:23d1f73bf130 8 * http://www.apache.org/licenses/LICENSE-2.0
vladvana 0:23d1f73bf130 9 *
vladvana 0:23d1f73bf130 10 * Unless required by applicable law or agreed to in writing, software
vladvana 0:23d1f73bf130 11 * distributed under the License is distributed on an "AS IS" BASIS,
vladvana 0:23d1f73bf130 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
vladvana 0:23d1f73bf130 13 * See the License for the specific language governing permissions and
vladvana 0:23d1f73bf130 14 * limitations under the License.
vladvana 0:23d1f73bf130 15 */
vladvana 0:23d1f73bf130 16 #ifndef MBED_FILEHANDLE_H
vladvana 0:23d1f73bf130 17 #define MBED_FILEHANDLE_H
vladvana 0:23d1f73bf130 18
vladvana 0:23d1f73bf130 19 typedef int FILEHANDLE;
vladvana 0:23d1f73bf130 20
vladvana 0:23d1f73bf130 21 #include <stdio.h>
vladvana 0:23d1f73bf130 22
vladvana 0:23d1f73bf130 23 #if defined(__ARMCC_VERSION) || defined(__ICCARM__)
vladvana 0:23d1f73bf130 24 typedef int ssize_t;
vladvana 0:23d1f73bf130 25 typedef long off_t;
vladvana 0:23d1f73bf130 26
vladvana 0:23d1f73bf130 27 #else
vladvana 0:23d1f73bf130 28 # include <sys/types.h>
vladvana 0:23d1f73bf130 29 #endif
vladvana 0:23d1f73bf130 30
vladvana 0:23d1f73bf130 31 namespace mbed {
vladvana 0:23d1f73bf130 32
vladvana 0:23d1f73bf130 33 /** An OO equivalent of the internal FILEHANDLE variable
vladvana 0:23d1f73bf130 34 * and associated _sys_* functions.
vladvana 0:23d1f73bf130 35 *
vladvana 0:23d1f73bf130 36 * FileHandle is an abstract class, needing at least sys_write and
vladvana 0:23d1f73bf130 37 * sys_read to be implmented for a simple interactive device.
vladvana 0:23d1f73bf130 38 *
vladvana 0:23d1f73bf130 39 * No one ever directly tals to/instanciates a FileHandle - it gets
vladvana 0:23d1f73bf130 40 * created by FileSystem, and wrapped up by stdio.
vladvana 0:23d1f73bf130 41 */
vladvana 0:23d1f73bf130 42 class FileHandle {
vladvana 0:23d1f73bf130 43
vladvana 0:23d1f73bf130 44 public:
vladvana 0:23d1f73bf130 45 /** Write the contents of a buffer to the file
vladvana 0:23d1f73bf130 46 *
vladvana 0:23d1f73bf130 47 * @param buffer the buffer to write from
vladvana 0:23d1f73bf130 48 * @param length the number of characters to write
vladvana 0:23d1f73bf130 49 *
vladvana 0:23d1f73bf130 50 * @returns
vladvana 0:23d1f73bf130 51 * The number of characters written (possibly 0) on success, -1 on error.
vladvana 0:23d1f73bf130 52 */
vladvana 0:23d1f73bf130 53 virtual ssize_t write(const void* buffer, size_t length) = 0;
vladvana 0:23d1f73bf130 54
vladvana 0:23d1f73bf130 55 /** Close the file
vladvana 0:23d1f73bf130 56 *
vladvana 0:23d1f73bf130 57 * @returns
vladvana 0:23d1f73bf130 58 * Zero on success, -1 on error.
vladvana 0:23d1f73bf130 59 */
vladvana 0:23d1f73bf130 60 virtual int close() = 0;
vladvana 0:23d1f73bf130 61
vladvana 0:23d1f73bf130 62 /** Function read
vladvana 0:23d1f73bf130 63 * Reads the contents of the file into a buffer
vladvana 0:23d1f73bf130 64 *
vladvana 0:23d1f73bf130 65 * @param buffer the buffer to read in to
vladvana 0:23d1f73bf130 66 * @param length the number of characters to read
vladvana 0:23d1f73bf130 67 *
vladvana 0:23d1f73bf130 68 * @returns
vladvana 0:23d1f73bf130 69 * The number of characters read (zero at end of file) on success, -1 on error.
vladvana 0:23d1f73bf130 70 */
vladvana 0:23d1f73bf130 71 virtual ssize_t read(void* buffer, size_t length) = 0;
vladvana 0:23d1f73bf130 72
vladvana 0:23d1f73bf130 73 /** Check if the handle is for a interactive terminal device.
vladvana 0:23d1f73bf130 74 * If so, line buffered behaviour is used by default
vladvana 0:23d1f73bf130 75 *
vladvana 0:23d1f73bf130 76 * @returns
vladvana 0:23d1f73bf130 77 * 1 if it is a terminal,
vladvana 0:23d1f73bf130 78 * 0 otherwise
vladvana 0:23d1f73bf130 79 */
vladvana 0:23d1f73bf130 80 virtual int isatty() = 0;
vladvana 0:23d1f73bf130 81
vladvana 0:23d1f73bf130 82 /** Move the file position to a given offset from a given location.
vladvana 0:23d1f73bf130 83 *
vladvana 0:23d1f73bf130 84 * @param offset The offset from whence to move to
vladvana 0:23d1f73bf130 85 * @param whence SEEK_SET for the start of the file, SEEK_CUR for the
vladvana 0:23d1f73bf130 86 * current file position, or SEEK_END for the end of the file.
vladvana 0:23d1f73bf130 87 *
vladvana 0:23d1f73bf130 88 * @returns
vladvana 0:23d1f73bf130 89 * new file position on success,
vladvana 0:23d1f73bf130 90 * -1 on failure or unsupported
vladvana 0:23d1f73bf130 91 */
vladvana 0:23d1f73bf130 92 virtual off_t lseek(off_t offset, int whence) = 0;
vladvana 0:23d1f73bf130 93
vladvana 0:23d1f73bf130 94 /** Flush any buffers associated with the FileHandle, ensuring it
vladvana 0:23d1f73bf130 95 * is up to date on disk
vladvana 0:23d1f73bf130 96 *
vladvana 0:23d1f73bf130 97 * @returns
vladvana 0:23d1f73bf130 98 * 0 on success or un-needed,
vladvana 0:23d1f73bf130 99 * -1 on error
vladvana 0:23d1f73bf130 100 */
vladvana 0:23d1f73bf130 101 virtual int fsync() = 0;
vladvana 0:23d1f73bf130 102
vladvana 0:23d1f73bf130 103 virtual off_t flen() {
vladvana 0:23d1f73bf130 104 /* remember our current position */
vladvana 0:23d1f73bf130 105 off_t pos = lseek(0, SEEK_CUR);
vladvana 0:23d1f73bf130 106 if(pos == -1) return -1;
vladvana 0:23d1f73bf130 107 /* seek to the end to get the file length */
vladvana 0:23d1f73bf130 108 off_t res = lseek(0, SEEK_END);
vladvana 0:23d1f73bf130 109 /* return to our old position */
vladvana 0:23d1f73bf130 110 lseek(pos, SEEK_SET);
vladvana 0:23d1f73bf130 111 return res;
vladvana 0:23d1f73bf130 112 }
vladvana 0:23d1f73bf130 113
vladvana 0:23d1f73bf130 114 virtual ~FileHandle();
vladvana 0:23d1f73bf130 115 };
vladvana 0:23d1f73bf130 116
vladvana 0:23d1f73bf130 117 } // namespace mbed
vladvana 0:23d1f73bf130 118
vladvana 0:23d1f73bf130 119 #endif