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         bvector_t *v;
  44         size_t old_size = mp->num_msgstats;
  45         size_t new_size = hi - lo + 1;
  46         size_t i;
  47
  48         /*
  49          * We are just extending (or shrinking) the end of message
  50          * status array.  So we don't have to move anything and can
  51          * just realloc the message status array.
  52          */
  53
  54         for (i = old_size, v = &mp->msgstats[old_size-1]; i > new_size;
  55              --i, --v) {
  56             bvector_free (*v);
  57         }
  58         mp->num_msgstats = MSGSTATNUM (lo, hi);
  59         mp->msgstats =
  60             mh_xrealloc (mp->msgstats, MSGSTATSIZE(mp));
  61         for (i = old_size, v = &mp->msgstats[old_size]; i < new_size;
  62              ++i, ++v) {
  63             *v = bvector_create (0);
  64         }
  65     } else {
  66         /*
  67          * We are changing the offset of the message status
  68          * array.  So we will need to shift everything.
  69          */
  70         bvector_t *tmpstats, *t;
  71         size_t i;
  72
  73         /* first allocate the new message status space */
  74         mp->num_msgstats = MSGSTATNUM (lo, hi);
  75         tmpstats = mh_xmalloc (MSGSTATSIZE(mp));
  76         for (i = 0, t = tmpstats; i < mp->num_msgstats; ++i, ++t) {
  77             *t = bvector_create (0);
  78         }
  79
  80         /* then copy messages status array with shift */
  81         if (mp->nummsg > 0) {
  82             for (msgnum = mp->lowmsg; msgnum <= mp->hghmsg; msgnum++)
  83                 bvector_copy (tmpstats[msgnum - lo], msgstat (mp, msgnum));
  84         }
  85         free(mp->msgstats);
  86         mp->msgstats = tmpstats;
  87     }
  88
  89     mp->lowoff = lo;
  90     mp->hghoff = hi;
  91
  92     /*
  93      * Clear all the flags for entries outside
  94      * the current message range for this folder.
  95      */
  96     if (mp->nummsg > 0) {
  97         for (msgnum = mp->lowoff; msgnum < mp->lowmsg; msgnum++)
  98             clear_msg_flags (mp, msgnum);
  99         for (msgnum = mp->hghmsg + 1; msgnum <= mp->hghoff; msgnum++)
 100             clear_msg_flags (mp, msgnum);
 101     } else {
 102         /* no messages, so clear entire range */
 103         for (msgnum = mp->lowoff; msgnum <= mp->hghoff; msgnum++)
 104             clear_msg_flags (mp, msgnum);
 105     }
 106
 107     return mp;
 108 }