diplodocus.org Git - nmh/blob - sbr/crawl_folders.c

   1
   2 /*
   3  * crawl_folders.c -- crawl folder hierarchy
   4  *
   5  * This code is Copyright (c) 2008, by the authors of nmh.  See the
   6  * COPYRIGHT file in the root directory of the nmh distribution for
   7  * complete copyright information.
   8  */
   9
  10 #include <h/mh.h>
  11 #include <h/crawl_folders.h>
  12 #include <h/utils.h>
  13
  14 struct crawl_context {
  15     int max;                    /* how many folders we currently can hold in
  16                                  * the array `folders', increased by
  17                                  * CRAWL_NUMFOLDERS at a time */
  18     char **folders;             /* the array of folders */
  19     int start;
  20     int foldp;
  21 };
  22
  23 /*
  24  * Add the folder name into the
  25  * list in a sorted fashion.
  26  */
  27
  28 static void
  29 add_folder (char *fold, struct crawl_context *crawl)
  30 {
  31     int i, j;
  32
  33     /* if necessary, reallocate the space for folder names */
  34     if (crawl->foldp >= crawl->max) {
  35         crawl->max += CRAWL_NUMFOLDERS;
  36         crawl->folders = mh_xrealloc (crawl->folders,
  37                                       crawl->max * sizeof(char *));
  38     }
  39
  40     for (i = crawl->start; i < crawl->foldp; i++)
  41         if (strcmp (fold, crawl->folders[i]) < 0) {
  42             for (j = crawl->foldp - 1; j >= i; j--)
  43                 crawl->folders[j + 1] = crawl->folders[j];
  44             crawl->foldp++;
  45             crawl->folders[i] = fold;
  46             return;
  47         }
  48
  49     crawl->folders[crawl->foldp++] = fold;
  50 }
  51
  52 static void
  53 add_children (char *name, struct crawl_context *crawl)
  54 {
  55     char *prefix, *child;
  56     struct stat st;
  57     struct dirent *dp;
  58     DIR * dd;
  59     int child_is_folder;
  60
  61     if (!(dd = opendir (name))) {
  62         admonish (name, "unable to read directory ");
  63         return;
  64     }
  65
  66     if (strcmp (name, ".") == 0) {
  67         prefix = mh_xstrdup("");
  68     } else {
  69         prefix = concat (name, "/", (void *)NULL);
  70     }
  71
  72     while ((dp = readdir (dd))) {
  73         /* If the system supports it, try to skip processing of children we
  74          * know are not directories or symlinks. */
  75         child_is_folder = -1;
  76 #if defined(HAVE_STRUCT_DIRENT_D_TYPE)
  77         if (dp->d_type == DT_DIR) {
  78             child_is_folder = 1;
  79         } else if (dp->d_type != DT_LNK && dp->d_type != DT_UNKNOWN) {
  80             continue;
  81         }
  82 #endif
  83         if (!strcmp (dp->d_name, ".") || !strcmp (dp->d_name, "..")) {
  84             continue;
  85         }
  86         child = concat (prefix, dp->d_name, (void *)NULL);
  87         /* If we have no d_type or d_type is DT_LNK or DT_UNKNOWN, stat the
  88          * child to see what it is. */
  89         if (child_is_folder == -1) {
  90             child_is_folder = (stat (child, &st) != -1 && S_ISDIR(st.st_mode));
  91         }
  92         if (child_is_folder) {
  93             /* add_folder saves child in the list, don't free it */
  94             add_folder (child, crawl);
  95         } else {
  96             free (child);
  97         }
  98     }
  99
 100     closedir (dd);
 101     free(prefix);
 102 }
 103
 104 static void
 105 crawl_folders_body (struct crawl_context *crawl,
 106                     char *dir, crawl_callback_t *callback, void *baton)
 107 {
 108     int i;
 109     int os = crawl->start;
 110     int of = crawl->foldp;
 111
 112     crawl->start = crawl->foldp;
 113
 114     add_children (dir, crawl);
 115
 116     for (i = crawl->start; i < crawl->foldp; i++) {
 117         char *fold = crawl->folders[i];
 118         int crawl_children = 1;
 119
 120         if (callback != NULL) {
 121             crawl_children = callback (fold, baton);
 122         }
 123
 124         if (crawl_children) {
 125             crawl_folders_body (crawl, fold, callback, baton);
 126         }
 127     }
 128
 129     crawl->start = os;
 130     crawl->foldp = of;
 131 }
 132
 133 void
 134 crawl_folders (char *dir, crawl_callback_t *callback, void *baton)
 135 {
 136     struct crawl_context *crawl;
 137     NEW(crawl);
 138     crawl->max = CRAWL_NUMFOLDERS;
 139     crawl->start = crawl->foldp = 0;
 140     crawl->folders = mh_xmalloc (crawl->max * sizeof(*crawl->folders));
 141
 142     crawl_folders_body (crawl, dir, callback, baton);
 143
 144     /* Note that we "leak" the folder names, on the assumption that the caller
 145      * is using them. */
 146     free (crawl->folders);
 147     free (crawl);
 148 }