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

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