/* * Copyright (c) 2004, Swedish Institute of Computer Science. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * This file is part of the Contiki operating system. * * Author: Adam Dunkels <adam@sics.se> * */ #include <string.h> #include "cfs/cfs.h" struct filestate { int flag; #define FLAG_FILE_CLOSED 0 #define FLAG_FILE_OPEN 1 int fileptr; int filesize; }; #ifdef CFS_RAM_CONF_SIZE #define CFS_RAM_SIZE CFS_RAM_CONF_SIZE #else #define CFS_RAM_SIZE 4096 #endif static struct filestate file; static char filemem[CFS_RAM_SIZE]; /*---------------------------------------------------------------------------*/ int cfs_open(const char *n, int f) { if(file.flag == FLAG_FILE_CLOSED) { file.flag = FLAG_FILE_OPEN; if(f & CFS_READ) { file.fileptr = 0; } if(f & CFS_WRITE){ if(f & CFS_APPEND) { file.fileptr = file.filesize; } else { file.fileptr = 0; file.filesize = 0; } } return 1; } else { return -1; } } /*---------------------------------------------------------------------------*/ void cfs_close(int f) { file.flag = FLAG_FILE_CLOSED; } /*---------------------------------------------------------------------------*/ int cfs_read(int f, void *buf, unsigned int len) { if(file.fileptr + len > sizeof(filemem)) { len = sizeof(filemem) - file.fileptr; } if(file.fileptr + len > file.filesize) { len = file.filesize - file.fileptr; } if(f == 1) { memcpy(buf, &filemem[file.fileptr], len); file.fileptr += len; return len; } else { return -1; } } /*---------------------------------------------------------------------------*/ int cfs_write(int f, const void *buf, unsigned int len) { if(file.fileptr >= sizeof(filemem)) { return 0; } if(file.fileptr + len > sizeof(filemem)) { len = sizeof(filemem) - file.fileptr; } if(file.fileptr + len > file.filesize) { /* Extend the size of the file. */ file.filesize = file.fileptr + len; } if(f == 1) { memcpy(&filemem[file.fileptr], buf, len); file.fileptr += len; return len; } else { return -1; } } /*---------------------------------------------------------------------------*/ cfs_offset_t cfs_seek(int f, cfs_offset_t o, int w) { if(w == CFS_SEEK_SET && f == 1) { if(o > file.filesize) { o = file.filesize; } file.fileptr = o; return o; } return (cfs_offset_t)-1; } /*---------------------------------------------------------------------------*/ int cfs_remove(const char *name) { return -1; } /*---------------------------------------------------------------------------*/ int cfs_opendir(struct cfs_dir *p, const char *n) { return -1; } /*---------------------------------------------------------------------------*/ int cfs_readdir(struct cfs_dir *p, struct cfs_dirent *e) { return -1; } /*---------------------------------------------------------------------------*/ void cfs_closedir(struct cfs_dir *p) { } /*---------------------------------------------------------------------------*/