text: /*
   * 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 <adam@sics.se>
   *
   */
  #ifndef __FS_H__
  #define __FS_H__
  
  #include "lwip/opt.h"
  
  /** Set this to 1 and provide the functions:
   * - "int fs_open_custom(struct fs_file *file, const char *name)"
   *    Called first for every opened file to allow opening files
   *    that are not included in fsdata(_custom).c
   * - "void fs_close_custom(struct fs_file *file)"
   *    Called to free resources allocated by fs_open_custom().
   */
  #ifndef LWIP_HTTPD_CUSTOM_FILES
  #define LWIP_HTTPD_CUSTOM_FILES       0
  #endif
  
  /** Set this to 1 to include an application state argument per file
   * that is opened. This allows to keep a state per connection/file.
   */
  #ifndef LWIP_HTTPD_FILE_STATE
  #define LWIP_HTTPD_FILE_STATE         0
  #endif
  
  /** HTTPD_PRECALCULATED_CHECKSUM==1: include precompiled checksums for
   * predefined (MSS-sized) chunks of the files to prevent having to calculate
   * the checksums at runtime. */
  #ifndef HTTPD_PRECALCULATED_CHECKSUM
  #define HTTPD_PRECALCULATED_CHECKSUM  0
  #endif
  
  #if HTTPD_PRECALCULATED_CHECKSUM
  struct fsdata_chksum {
    u32_t offset;
    u16_t chksum;
    u16_t len;
  };
  #endif /* HTTPD_PRECALCULATED_CHECKSUM */
  
  struct fs_file {
    const char *data;
    int len;
    int index;
    void *pextension;
  #if HTTPD_PRECALCULATED_CHECKSUM
    const struct fsdata_chksum *chksum;
    u16_t chksum_count;
  #endif /* HTTPD_PRECALCULATED_CHECKSUM */
    u8_t http_header_included;
  #if LWIP_HTTPD_CUSTOM_FILES
    u8_t is_custom_file;
  #endif /* LWIP_HTTPD_CUSTOM_FILES */
  #if LWIP_HTTPD_FILE_STATE
    void *state;
  #endif /* LWIP_HTTPD_FILE_STATE */
  };
  
  struct fs_file *fs_open(const char *name);
  void fs_close(struct fs_file *file);
  int fs_read(struct fs_file *file, char *buffer, int count);
  int fs_bytes_left(struct fs_file *file);
  
  #if LWIP_HTTPD_FILE_STATE
  /** This user-defined function is called when a file is opened. */
  void *fs_state_init(struct fs_file *file, const char *name);
  /** This user-defined function is called when a file is closed. */
  void fs_state_free(struct fs_file *file, void *state);
  #endif /* #if LWIP_HTTPD_FILE_STATE */
  
  #endif /* __FS_H__ */
  