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

   1
   2 /*
   3  * folder_realloc.c -- realloc a folder/msgs structure
   4  *
   5  * $Id$
   6  *
   7  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   8  * COPYRIGHT file in the root directory of the nmh distribution for
   9  * complete copyright information.
  10  */
  11
  12 #include <h/mh.h>
  13 #include <h/utils.h>
  14
  15 /*
  16  * Reallocate some of the space in the folder
  17  * structure (currently just message status array).
  18  *
  19  * Return pointer to new folder structure.
  20  * If error, return NULL.
  21  */
  22
  23 struct msgs *
  24 folder_realloc (struct msgs *mp, int lo, int hi)
  25 {
  26     int msgnum;
  27
  28     /* sanity checks */
  29     if (lo < 1)
  30         adios (NULL, "BUG: called folder_realloc with lo (%d) < 1", lo);
  31     if (hi < 1)
  32         adios (NULL, "BUG: called folder_realloc with hi (%d) < 1", hi);
  33     if (mp->nummsg > 0 && lo > mp->lowmsg)
  34         adios (NULL, "BUG: called folder_realloc with lo (%d) > mp->lowmsg (%d)",
  35                lo, mp->lowmsg);
  36     if (mp->nummsg > 0 && hi < mp->hghmsg)
  37         adios (NULL, "BUG: called folder_realloc with hi (%d) < mp->hghmsg (%d)",
  38                hi, mp->hghmsg);
  39
  40     /* Check if we really need to reallocate anything */
  41     if (lo == mp->lowoff && hi == mp->hghoff)
  42         return mp;
  43
  44     if (lo == mp->lowoff) {
  45         /*
  46          * We are just extending (or shrinking) the end of message
  47          * status array.  So we don't have to move anything and can
  48          * just realloc the message status array.
  49          */
  50         mp->msgstats = mh_xrealloc (mp->msgstats, MSGSTATSIZE(mp, lo, hi));
  51     } else {
  52         /*
  53          * We are changing the offset of the message status
  54          * array.  So we will need to shift everything.
  55          */
  56         seqset_t *tmpstats;
  57
  58         /* first allocate the new message status space */
  59         tmpstats = mh_xmalloc (MSGSTATSIZE(mp, lo, hi));
  60
  61         /* then copy messages status array with shift */
  62         if (mp->nummsg > 0) {
  63             for (msgnum = mp->lowmsg; msgnum <= mp->hghmsg; msgnum++)
  64                 tmpstats[msgnum - lo] = mp->msgstats[msgnum - mp->lowoff];
  65         }
  66         free(mp->msgstats);
  67         mp->msgstats = tmpstats;
  68     }
  69
  70     mp->lowoff = lo;
  71     mp->hghoff = hi;
  72
  73     /*
  74      * Clear all the flags for entries outside
  75      * the current message range for this folder.
  76      */
  77     if (mp->nummsg > 0) {
  78         for (msgnum = mp->lowoff; msgnum < mp->lowmsg; msgnum++)
  79             clear_msg_flags (mp, msgnum);
  80         for (msgnum = mp->hghmsg + 1; msgnum <= mp->hghoff; msgnum++)
  81             clear_msg_flags (mp, msgnum);
  82     } else {
  83         /* no messages, so clear entire range */
  84         for (msgnum = mp->lowoff; msgnum <= mp->hghoff; msgnum++)
  85             clear_msg_flags (mp, msgnum);
  86     }
  87
  88     return mp;
  89 }