mdw@git.distorted.org.uk Git - disorder/blob - lib/trackorder.c

   1 /*
   2  * This file is part of DisOrder
   3  * Copyright (C) 2005, 2006, 2007 Richard Kettlewell
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file lib/trackorder.c
  19  * @brief Track ordering
  20  */
  21 #include "common.h"
  22
  23 #include <fnmatch.h>
  24
  25 #include "trackname.h"
  26 #include "log.h"
  27 #include "unicode.h"
  28
  29 /** @brief Compare two tracks
  30  * @param sa First sort key
  31  * @param sb Second sort key
  32  * @param da First display string
  33  * @param db Second display string
  34  * @param ta First raw track
  35  * @param tb Second raw track
  36  * @return -ve, 0 or +ve for a <, = or > b
  37  *
  38  * Tries the following comparisons until a difference is found:
  39  * - case-independent comparison of sort keys
  40  * - case-dependent comparison of sort keys
  41  * - case-independent comparison of display strings
  42  * - case-dependent comparison of display strings
  43  * - case-dependent comparison of paths (see compare_path())
  44  */
  45 int compare_tracks(const char *sa, const char *sb,
  46                    const char *da, const char *db,
  47                    const char *ta, const char *tb) {
  48   int c;
  49
  50   if((c = strcmp(utf8_casefold_canon(sa, strlen(sa), 0),
  51                  utf8_casefold_canon(sb, strlen(sb), 0))))
  52     return c;
  53   if((c = strcmp(sa, sb))) return c;
  54   if((c = strcmp(utf8_casefold_canon(da, strlen(da), 0),
  55                  utf8_casefold_canon(db, strlen(db), 0))))
  56     return c;
  57   if((c = strcmp(da, db))) return c;
  58   return compare_path(ta, tb);
  59 }
  60
  61 /** @brief Compare two paths
  62  * @param ap First path
  63  * @param an Length of @p ap
  64  * @param bp Second path
  65  * @param bn Length @p bp
  66  * @return -ve, 0 or +ve for ap <, = or > bp
  67  *
  68  * Sorts files within a directory together.
  69  *
  70  * See also compare_path().
  71  */
  72 int compare_path_raw(const unsigned char *ap, size_t an,
  73                      const unsigned char *bp, size_t bn) {
  74   /* Don't change this function!  The database sort order depends on it */
  75   while(an > 0 && bn > 0) {
  76     if(*ap == *bp) {
  77       ap++;
  78       bp++;
  79       an--;
  80       bn--;
  81     } else if(*ap == '/') {
  82       return -1;                /* /a/b < /aa/ */
  83     } else if(*bp == '/') {
  84       return 1;                 /* /aa > /a/b */
  85     } else
  86       return *ap - *bp;
  87   }
  88   if(an > 0)
  89     return 1;                   /* /a/b > /a and /ab > /a */
  90   else if(bn > 0)
  91     return -1;                  /* /a < /ab and /a < /a/b */
  92   else
  93     return 0;
  94 }
  95
  96 /*
  97 Local Variables:
  98 c-basic-offset:2
  99 comment-column:40
 100 fill-column:79
 101 End:
 102 */