Contiki 2.6
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00001 /* 00002 * Copyright (c) 2004, Swedish Institute of Computer Science. 00003 * All rights reserved. 00004 * 00005 * Redistribution and use in source and binary forms, with or without 00006 * modification, are permitted provided that the following conditions 00007 * are met: 00008 * 1. Redistributions of source code must retain the above copyright 00009 * notice, this list of conditions and the following disclaimer. 00010 * 2. Redistributions in binary form must reproduce the above copyright 00011 * notice, this list of conditions and the following disclaimer in the 00012 * documentation and/or other materials provided with the distribution. 00013 * 3. Neither the name of the Institute nor the names of its contributors 00014 * may be used to endorse or promote products derived from this software 00015 * without specific prior written permission. 00016 * 00017 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 00018 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00019 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00020 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 00021 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 00022 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 00023 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 00024 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00025 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 00026 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 00027 * SUCH DAMAGE. 00028 * 00029 * This file is part of the Contiki operating system. 00030 * 00031 * Author: Adam Dunkels <adam@sics.se> 00032 * 00033 * $Id: cfs-ram.c,v 1.10 2009/02/27 14:25:38 nvt-se Exp $ 00034 */ 00035 00036 #include <string.h> 00037 00038 #include "cfs/cfs.h" 00039 00040 struct filestate { 00041 int flag; 00042 #define FLAG_FILE_CLOSED 0 00043 #define FLAG_FILE_OPEN 1 00044 int fileptr; 00045 int filesize; 00046 }; 00047 00048 #ifdef CFS_RAM_CONF_SIZE 00049 #define CFS_RAM_SIZE CFS_RAM_CONF_SIZE 00050 #else 00051 #define CFS_RAM_SIZE 4096 00052 #endif 00053 00054 static struct filestate file; 00055 static char filemem[CFS_RAM_SIZE]; 00056 00057 /*---------------------------------------------------------------------------*/ 00058 int 00059 cfs_open(const char *n, int f) 00060 { 00061 if(file.flag == FLAG_FILE_CLOSED) { 00062 file.flag = FLAG_FILE_OPEN; 00063 if(f & CFS_READ) { 00064 file.fileptr = 0; 00065 } 00066 if(f & CFS_WRITE){ 00067 if(f & CFS_APPEND) { 00068 file.fileptr = file.filesize; 00069 } else { 00070 file.fileptr = 0; 00071 file.filesize = 0; 00072 } 00073 } 00074 return 1; 00075 } else { 00076 return -1; 00077 } 00078 } 00079 /*---------------------------------------------------------------------------*/ 00080 void 00081 cfs_close(int f) 00082 { 00083 file.flag = FLAG_FILE_CLOSED; 00084 } 00085 /*---------------------------------------------------------------------------*/ 00086 int 00087 cfs_read(int f, void *buf, unsigned int len) 00088 { 00089 if(file.fileptr + len > sizeof(filemem)) { 00090 len = sizeof(filemem) - file.fileptr; 00091 } 00092 00093 if(file.fileptr + len > file.filesize) { 00094 len = file.filesize - file.fileptr; 00095 } 00096 00097 if(f == 1) { 00098 memcpy(buf, &filemem[file.fileptr], len); 00099 file.fileptr += len; 00100 return len; 00101 } else { 00102 return -1; 00103 } 00104 } 00105 /*---------------------------------------------------------------------------*/ 00106 int 00107 cfs_write(int f, const void *buf, unsigned int len) 00108 { 00109 if(file.fileptr >= sizeof(filemem)) { 00110 return 0; 00111 } 00112 if(file.fileptr + len > sizeof(filemem)) { 00113 len = sizeof(filemem) - file.fileptr; 00114 } 00115 00116 if(file.fileptr + len > file.filesize) { 00117 /* Extend the size of the file. */ 00118 file.filesize = file.fileptr + len; 00119 } 00120 00121 if(f == 1) { 00122 memcpy(&filemem[file.fileptr], buf, len); 00123 file.fileptr += len; 00124 return len; 00125 } else { 00126 return -1; 00127 } 00128 } 00129 /*---------------------------------------------------------------------------*/ 00130 cfs_offset_t 00131 cfs_seek(int f, cfs_offset_t o, int w) 00132 { 00133 if(w == CFS_SEEK_SET && f == 1) { 00134 if(o > file.filesize) { 00135 o = file.filesize; 00136 } 00137 file.fileptr = o; 00138 return o; 00139 } 00140 return (cfs_offset_t)-1; 00141 } 00142 /*---------------------------------------------------------------------------*/ 00143 int 00144 cfs_remove(const char *name) 00145 { 00146 return -1; 00147 } 00148 /*---------------------------------------------------------------------------*/ 00149 int 00150 cfs_opendir(struct cfs_dir *p, const char *n) 00151 { 00152 return -1; 00153 } 00154 /*---------------------------------------------------------------------------*/ 00155 int 00156 cfs_readdir(struct cfs_dir *p, struct cfs_dirent *e) 00157 { 00158 return -1; 00159 } 00160 /*---------------------------------------------------------------------------*/ 00161 void 00162 cfs_closedir(struct cfs_dir *p) 00163 { 00164 } 00165 /*---------------------------------------------------------------------------*/