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

   1 /*
   2  * folder_realloc.c -- realloc a folder/msgs structure
   3  *
   4  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   5  * COPYRIGHT file in the root directory of the nmh distribution for
   6  * complete copyright information.
   7  */
   8
   9 #include <h/mh.h>
  10 #include <h/utils.h>
  11
  12 /*
  13  * Reallocate some of the space in the folder
  14  * structure (currently just message status array).
  15  *
  16  * Return pointer to new folder structure.
  17  * If error, return NULL.
  18  */
  19
  20 struct msgs *
  21 folder_realloc (struct msgs *mp, int lo, int hi)
  22 {
  23     int msgnum;
  24
  25     /* sanity checks */
  26     if (lo < 1)
  27         adios (NULL, "BUG: called folder_realloc with lo (%d) < 1", lo);
  28     if (hi < 1)
  29         adios (NULL, "BUG: called folder_realloc with hi (%d) < 1", hi);
  30     if (mp->nummsg > 0 && lo > mp->lowmsg)
  31         adios (NULL, "BUG: called folder_realloc with lo (%d) > mp->lowmsg (%d)",
  32                lo, mp->lowmsg);
  33     if (mp->nummsg > 0 && hi < mp->hghmsg)
  34         adios (NULL, "BUG: called folder_realloc with hi (%d) < mp->hghmsg (%d)",
  35                hi, mp->hghmsg);
  36
  37     /* Check if we really need to reallocate anything */
  38     if (lo == mp->lowoff && hi == mp->hghoff)
  39         return mp;
  40
  41     if (lo == mp->lowoff) {
  42         bvector_t *v;
  43         size_t old_size = mp->num_msgstats;
  44         size_t new_size = hi - lo + 1;
  45         size_t i;
  46
  47         /*
  48          * We are just extending (or shrinking) the end of message
  49          * status array.  So we don't have to move anything and can
  50          * just realloc the message status array.
  51          */
  52
  53         for (i = old_size, v = &mp->msgstats[old_size-1]; i > new_size;
  54              --i, --v) {
  55             bvector_free (*v);
  56         }
  57         mp->num_msgstats = MSGSTATNUM (lo, hi);
  58         mp->msgstats =
  59             mh_xrealloc (mp->msgstats, MSGSTATSIZE(mp));
  60         for (i = old_size, v = &mp->msgstats[old_size]; i < new_size;
  61              ++i, ++v) {
  62             *v = bvector_create (0);
  63         }
  64     } else {
  65         /*
  66          * We are changing the offset of the message status
  67          * array.  So we will need to shift everything.
  68          */
  69         bvector_t *tmpstats, *t;
  70         size_t i;
  71
  72         /* first allocate the new message status space */
  73         mp->num_msgstats = MSGSTATNUM (lo, hi);
  74         tmpstats = mh_xmalloc (MSGSTATSIZE(mp));
  75         for (i = 0, t = tmpstats; i < mp->num_msgstats; ++i, ++t) {
  76             *t = bvector_create (0);
  77         }
  78
  79         /* then copy messages status array with shift */
  80         if (mp->nummsg > 0) {
  81             for (msgnum = mp->lowmsg; msgnum <= mp->hghmsg; msgnum++)
  82                 bvector_copy (tmpstats[msgnum - lo], msgstat (mp, msgnum));
  83         }
  84         free(mp->msgstats);
  85         mp->msgstats = tmpstats;
  86     }
  87
  88     mp->lowoff = lo;
  89     mp->hghoff = hi;
  90
  91     /*
  92      * Clear all the flags for entries outside
  93      * the current message range for this folder.
  94      */
  95     if (mp->nummsg > 0) {
  96         for (msgnum = mp->lowoff; msgnum < mp->lowmsg; msgnum++)
  97             clear_msg_flags (mp, msgnum);
  98         for (msgnum = mp->hghmsg + 1; msgnum <= mp->hghoff; msgnum++)
  99             clear_msg_flags (mp, msgnum);
 100     } else {
 101         /* no messages, so clear entire range */
 102         for (msgnum = mp->lowoff; msgnum <= mp->hghoff; msgnum++)
 103             clear_msg_flags (mp, msgnum);
 104     }
 105
 106     return mp;
 107 }