mbed library sources. Supersedes mbed-src.
Dependents: LPCXpresso1769_blinky
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Diff: api/FileHandle.h
- Revision:
- 0:9b334a45a8ff
- Child:
- 144:ef7eb2e8f9f7
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/api/FileHandle.h Thu Oct 01 15:25:22 2015 +0300 @@ -0,0 +1,119 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2013 ARM Limited + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#ifndef MBED_FILEHANDLE_H +#define MBED_FILEHANDLE_H + +typedef int FILEHANDLE; + +#include <stdio.h> + +#if defined(__ARMCC_VERSION) || defined(__ICCARM__) +typedef int ssize_t; +typedef long off_t; + +#else +# include <sys/types.h> +#endif + +namespace mbed { + +/** An OO equivalent of the internal FILEHANDLE variable + * and associated _sys_* functions. + * + * FileHandle is an abstract class, needing at least sys_write and + * sys_read to be implmented for a simple interactive device. + * + * No one ever directly tals to/instanciates a FileHandle - it gets + * created by FileSystem, and wrapped up by stdio. + */ +class FileHandle { + +public: + /** Write the contents of a buffer to the file + * + * @param buffer the buffer to write from + * @param length the number of characters to write + * + * @returns + * The number of characters written (possibly 0) on success, -1 on error. + */ + virtual ssize_t write(const void* buffer, size_t length) = 0; + + /** Close the file + * + * @returns + * Zero on success, -1 on error. + */ + virtual int close() = 0; + + /** Function read + * Reads the contents of the file into a buffer + * + * @param buffer the buffer to read in to + * @param length the number of characters to read + * + * @returns + * The number of characters read (zero at end of file) on success, -1 on error. + */ + virtual ssize_t read(void* buffer, size_t length) = 0; + + /** Check if the handle is for a interactive terminal device. + * If so, line buffered behaviour is used by default + * + * @returns + * 1 if it is a terminal, + * 0 otherwise + */ + virtual int isatty() = 0; + + /** Move the file position to a given offset from a given location. + * + * @param offset The offset from whence to move to + * @param whence SEEK_SET for the start of the file, SEEK_CUR for the + * current file position, or SEEK_END for the end of the file. + * + * @returns + * new file position on success, + * -1 on failure or unsupported + */ + virtual off_t lseek(off_t offset, int whence) = 0; + + /** Flush any buffers associated with the FileHandle, ensuring it + * is up to date on disk + * + * @returns + * 0 on success or un-needed, + * -1 on error + */ + virtual int fsync() = 0; + + virtual off_t flen() { + /* remember our current position */ + off_t pos = lseek(0, SEEK_CUR); + if(pos == -1) return -1; + /* seek to the end to get the file length */ + off_t res = lseek(0, SEEK_END); + /* return to our old position */ + lseek(pos, SEEK_SET); + return res; + } + + virtual ~FileHandle(); +}; + +} // namespace mbed + +#endif