apps/plugins/dict.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2005 Tomas Salfischberger
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 #include "plugin.h"
  23 #include "lib/simple_viewer.h"
  24
  25
  26
  27 #define MIN_DESC_BUF_SIZE 0x400 /* arbitrary minimum size for description */
  28
  29 /* Some lenghts */
  30 #define WORDLEN 32 /* has to be the same in rdf2binary.c */
  31
  32 /* Struct packing */
  33 #ifdef __GNUC__
  34 #define STRUCT_PACKED __attribute__((packed))
  35 #else
  36 #define STRUCT_PACKED
  37 #pragma pack (push, 2)
  38 #endif
  39
  40 /* The word struct :) */
  41 struct stWord
  42 {
  43     char word[WORDLEN];
  44     long offset;
  45 } STRUCT_PACKED;
  46
  47 /* for endian problems */
  48 #ifdef ROCKBOX_BIG_ENDIAN
  49 #define reverse(x) x
  50 #else
  51 long reverse (long N) {
  52     unsigned char B[4];
  53     B[0] = (N & 0x000000FF) >> 0;
  54     B[1] = (N & 0x0000FF00) >> 8;
  55     B[2] = (N & 0x00FF0000) >> 16;
  56     B[3] = (N & 0xFF000000) >> 24;
  57     return ((B[0] << 24) | (B[1] << 16) | (B[2] << 8) | (B[3] << 0));
  58 }
  59 #endif
  60
  61
  62 /* data files */
  63 #define DICT_INDEX PLUGIN_APPS_DIR "/dict.index"
  64 #define DICT_DESC PLUGIN_APPS_DIR "/dict.desc"
  65
  66 /* the main plugin function */
  67 enum plugin_status plugin_start(const void* parameter)
  68 {
  69     char searchword[WORDLEN]; /* word to search for */
  70     char *description; /* pointer to description buffer */
  71     struct stWord word; /* the struct to read into */
  72     int fIndex, fData; /* files */
  73     int filesize, high, low, probe;
  74     char *buffer;
  75     size_t buffer_size;
  76
  77     /* plugin stuff */
  78     (void)parameter;
  79
  80     /* allocate buffer. */
  81     buffer = rb->plugin_get_buffer(&buffer_size);
  82     if (buffer == NULL || buffer_size < MIN_DESC_BUF_SIZE)
  83     {
  84         DEBUGF("Err: Failed to allocate buffer.\n");
  85         rb->splash(HZ*2, "Failed to allocate buffer.");
  86         return PLUGIN_ERROR;
  87     }
  88
  89     description = buffer;
  90
  91     /* "clear" input buffer */
  92     searchword[0] = '\0';
  93
  94     /* get the word to search */
  95     if (rb->kbd_input(searchword, sizeof(searchword)) < 0)
  96         return PLUGIN_OK; /* input cancelled */
  97
  98     fIndex = rb->open(DICT_INDEX, O_RDONLY); /* index file */
  99     if (fIndex < 0)
 100     {
 101         DEBUGF("Err: Failed to open index file.\n");
 102         rb->splash(HZ*2, "Failed to open index.");
 103         return PLUGIN_ERROR;
 104     }
 105
 106     filesize = rb->filesize(fIndex); /* get filesize */
 107
 108     DEBUGF("Filesize: %d bytes = %d words \n", filesize,
 109            (filesize / (int)sizeof(struct stWord)));
 110
 111     /* for the searching algorithm */
 112     high = filesize / sizeof( struct stWord );
 113     low = -1;
 114
 115     while (high - low > 1)
 116     {
 117         probe = (high + low) / 2;
 118
 119         /* Jump to word pointed by probe, and read it. */
 120         rb->lseek(fIndex, sizeof(struct stWord) * probe, SEEK_SET);
 121         rb->read(fIndex, &word, sizeof(struct stWord));
 122
 123         /* jump according to the found word. */
 124         if (rb->strcasecmp(searchword, word.word) < 0)
 125         {
 126             high = probe;
 127         }
 128         else
 129         {
 130             low = probe;
 131         }
 132     }
 133
 134     /* read in the word */
 135     rb->lseek(fIndex, sizeof(struct stWord) * low, SEEK_SET);
 136     rb->read(fIndex, &word, sizeof(struct stWord));
 137     rb->close(fIndex);
 138
 139     /* Check if we found something */
 140     if (low == -1 || rb->strcasecmp(searchword, word.word) != 0)
 141     {
 142         DEBUGF("Not found.\n");
 143         rb->splash(HZ*2, "Not found.");
 144         return PLUGIN_OK;
 145     }
 146
 147     DEBUGF("Found %s at offset %ld\n", word.word, reverse(word.offset));
 148
 149     /* now open the description file */
 150     fData = rb->open(DICT_DESC, O_RDONLY);
 151     if (fData < 0)
 152     {
 153         DEBUGF("Err: Failed to open description file.\n");
 154         rb->splash(HZ*2, "Failed to open descriptions.");
 155         return PLUGIN_ERROR;
 156     }
 157
 158     /* seek to the right offset */
 159     rb->lseek(fData, (off_t)reverse(word.offset), SEEK_SET);
 160
 161     /* Read in the description */
 162     rb->read_line(fData, description, buffer_size);
 163
 164     /* And print it to debug. */
 165     DEBUGF("Description: %s\n", description);
 166
 167     rb->close(fData);
 168
 169     /* display description. */
 170     view_text(searchword, description);
 171
 172     return PLUGIN_OK;
 173 }