www.pudn.com > lwip-1.3.0.rar > fs.c

/* 
 * Copyright (c) 2001-2003 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. The name of the author may not be used to endorse or promote products 
 *    derived from this software without specific prior written permission.  
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 lwIP TCP/IP stack. 
 *  
 * Author: Adam Dunkels  
 * 
 */ 
#include "lwip/def.h" 
#include "fs.h" 
#include "fsdata.h" 
#include "fsdata.c" 
#include  
 
/*-----------------------------------------------------------------------------------*/ 
/* Define the number of open files that we can support. */ 
#ifndef LWIP_MAX_OPEN_FILES 
#define LWIP_MAX_OPEN_FILES     10 
#endif 
 
/* Define the file system memory allocation structure. */ 
struct fs_table { 
  struct fs_file file; 
  int inuse; 
}; 
 
/* Allocate file system memory */ 
struct fs_table fs_memory[LWIP_MAX_OPEN_FILES]; 
 
/*-----------------------------------------------------------------------------------*/ 
static struct fs_file * 
fs_malloc(void) 
{ 
  int i; 
  for(i = 0; i < LWIP_MAX_OPEN_FILES; i++) { 
    if(fs_memory[i].inuse == 0) { 
      fs_memory[i].inuse = 1; 
      return(&fs_memory[i].file); 
    } 
  } 
  return(NULL); 
} 
 
/*-----------------------------------------------------------------------------------*/ 
static void 
fs_free(struct fs_file *file) 
{ 
  int i; 
  for(i = 0; i < LWIP_MAX_OPEN_FILES; i++) { 
    if(&fs_memory[i].file == file) { 
      fs_memory[i].inuse = 0; 
      break; 
    } 
  } 
  return; 
} 
 
/*-----------------------------------------------------------------------------------*/ 
struct fs_file * 
fs_open(char *name) 
{ 
  struct fs_file *file; 
  const struct fsdata_file *f; 
 
  file = fs_malloc(); 
  if(file == NULL) { 
    return NULL; 
  } 
 
  for(f = FS_ROOT; f != NULL; f = f->next) { 
    if (!strcmp(name, (char *)f->name)) { 
      file->data = (char *)f->data; 
      file->len = f->len; 
      file->index = f->len; 
      file->pextension = NULL; 
      return file; 
    } 
  } 
  fs_free(file); 
  return NULL; 
} 
 
/*-----------------------------------------------------------------------------------*/ 
void 
fs_close(struct fs_file *file) 
{ 
  fs_free(file); 
} 
/*-----------------------------------------------------------------------------------*/ 
int 
fs_read(struct fs_file *file, char *buffer, int count) 
{ 
  int read; 
 
  if(file->index == file->len) { 
    return -1; 
  } 
 
  read = file->len - file->index; 
  if(read > count) { 
    read = count; 
  } 
 
  memcpy(buffer, (file->data + file->index), read); 
  file->index += read; 
 
  return(read); 
}