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

   1 /* seq_list.c -- Get all messages in a sequence and return them
   2  *            -- as a space separated list of message ranges.
   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 /* allocate this much buffer space at a time */
  13 #define MAXBUFFER 1024
  14
  15 /* static buffer to collect the sequence line */
  16 static char *buffer = NULL;
  17 static int len = 0;
  18
  19
  20 char *
  21 seq_list(struct msgs *mp, char *seqname)
  22 {
  23     int i, j, seqnum;
  24     char *bp;
  25
  26     /* On first invocation, allocate initial buffer space */
  27     if (!buffer) {
  28         len = MAXBUFFER;
  29         buffer = mh_xmalloc ((size_t) len);
  30     }
  31
  32     /*
  33      * Special processing for "cur" sequence.  We assume that the
  34      * "cur" sequence and mp->curmsg are in sync (see seq_add.c).
  35      * This is returned, even if message doesn't exist or the
  36      * folder is empty.
  37      */
  38     if (!strcmp (current, seqname)) {
  39         if (mp->curmsg) {
  40             snprintf(buffer, len, "%s", m_name(mp->curmsg));
  41             return buffer;
  42         }
  43         return NULL;
  44     }
  45
  46     /* If the folder is empty, just return NULL */
  47     if (mp->nummsg == 0)
  48         return NULL;
  49
  50     /* Get the index of the sequence */
  51     if ((seqnum = seq_getnum (mp, seqname)) == -1)
  52         return NULL;
  53
  54     bp = buffer;
  55
  56     for (i = mp->lowmsg; i <= mp->hghmsg; ++i) {
  57         /*
  58          * If message doesn't exist, or isn't in
  59          * the sequence, then continue.
  60          */
  61         if (!does_exist(mp, i) || !in_sequence(mp, seqnum, i))
  62             continue;
  63
  64         /*
  65          * See if we need to enlarge buffer.  Since we don't know
  66          * exactly how many character this particular message range
  67          * will need, we enlarge the buffer if we are within
  68          * 50 characters of the end.
  69          */
  70         if (bp - buffer > len - 50) {
  71             char *newbuf;
  72
  73             len += MAXBUFFER;
  74             newbuf = mh_xrealloc (buffer, (size_t) len);
  75             bp = newbuf + (bp - buffer);
  76             buffer = newbuf;
  77         }
  78
  79         /*
  80          * If this is not the first message range in
  81          * the list, first add a space.
  82          */
  83         if (bp > buffer)
  84             *bp++ = ' ';
  85
  86         strcpy(bp, m_name(i));
  87         bp += strlen(bp);
  88         j = i;                  /* Remember beginning of message range */
  89
  90         /*
  91          * Scan to the end of this message range
  92          */
  93         for (++i; i <= mp->hghmsg && does_exist(mp, i) && in_sequence(mp, seqnum, i);
  94              ++i)
  95             ;
  96
  97         if (i - j > 1) {
  98             *bp++ = '-';
  99             strcpy(bp, m_name(i - 1));
 100             bp += strlen(bp);
 101         }
 102     }
 103     return bp > buffer ? buffer : NULL;
 104 }