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

   1
   2 /*
   3  * folder_realloc.c -- realloc a folder/msgs structure
   4  *
   5  * This code is Copyright (c) 2002, 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/utils.h>
  12
  13 /*
  14  * Reallocate some of the space in the folder
  15  * structure (currently just message status array).
  16  *
  17  * Return pointer to new folder structure.
  18  * If error, return NULL.
  19  */
  20
  21 struct msgs *
  22 folder_realloc (struct msgs *mp, int lo, int hi)
  23 {
  24     int msgnum;
  25
  26     /* sanity checks */
  27     if (lo < 1)
  28         adios (NULL, "BUG: called folder_realloc with lo (%d) < 1", lo);
  29     if (hi < 1)
  30         adios (NULL, "BUG: called folder_realloc with hi (%d) < 1", hi);
  31     if (mp->nummsg > 0 && lo > mp->lowmsg)
  32         adios (NULL, "BUG: called folder_realloc with lo (%d) > mp->lowmsg (%d)",
  33                lo, mp->lowmsg);
  34     if (mp->nummsg > 0 && hi < mp->hghmsg)
  35         adios (NULL, "BUG: called folder_realloc with hi (%d) < mp->hghmsg (%d)",
  36                hi, mp->hghmsg);
  37
  38     /* Check if we really need to reallocate anything */
  39     if (lo == mp->lowoff && hi == mp->hghoff)
  40         return mp;
  41
  42     if (lo == mp->lowoff) {
  43         /*
  44          * We are just extending (or shrinking) the end of message
  45          * status array.  So we don't have to move anything and can
  46          * just realloc the message status array.
  47          */
  48         mp->msgstats = mh_xrealloc (mp->msgstats, MSGSTATSIZE(mp, lo, hi));
  49     } else {
  50         /*
  51          * We are changing the offset of the message status
  52          * array.  So we will need to shift everything.
  53          */
  54         seqset_t *tmpstats;
  55
  56         /* first allocate the new message status space */
  57         tmpstats = mh_xmalloc (MSGSTATSIZE(mp, lo, hi));
  58
  59         /* then copy messages status array with shift */
  60         if (mp->nummsg > 0) {
  61             for (msgnum = mp->lowmsg; msgnum <= mp->hghmsg; msgnum++)
  62                 tmpstats[msgnum - lo] = mp->msgstats[msgnum - mp->lowoff];
  63         }
  64         free(mp->msgstats);
  65         mp->msgstats = tmpstats;
  66     }
  67
  68     mp->lowoff = lo;
  69     mp->hghoff = hi;
  70
  71     /*
  72      * Clear all the flags for entries outside
  73      * the current message range for this folder.
  74      */
  75     if (mp->nummsg > 0) {
  76         for (msgnum = mp->lowoff; msgnum < mp->lowmsg; msgnum++)
  77             clear_msg_flags (mp, msgnum);
  78         for (msgnum = mp->hghmsg + 1; msgnum <= mp->hghoff; msgnum++)
  79             clear_msg_flags (mp, msgnum);
  80     } else {
  81         /* no messages, so clear entire range */
  82         for (msgnum = mp->lowoff; msgnum <= mp->hghoff; msgnum++)
  83             clear_msg_flags (mp, msgnum);
  84     }
  85
  86     return mp;
  87 }