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 "m_name.h"
  11 #include "seq_list.h"
  12 #include "seq_getnum.h"
  13 #include "h/utils.h"
  14
  15 /* allocate this much buffer space at a time */
  16 #define MAXBUFFER 1024
  17
  18 /* static buffer to collect the sequence line */
  19 static char *buffer = NULL;
  20 static int len = 0;
  21
  22
  23 char *
  24 seq_list(struct msgs *mp, char *seqname)
  25 {
  26     int i, j, seqnum;
  27     char *bp;
  28
  29     /* On first invocation, allocate initial buffer space */
  30     if (!buffer) {
  31         len = MAXBUFFER;
  32         buffer = mh_xmalloc ((size_t) len);
  33     }
  34
  35     /*
  36      * Special processing for "cur" sequence.  We assume that the
  37      * "cur" sequence and mp->curmsg are in sync (see seq_add.c).
  38      * This is returned, even if message doesn't exist or the
  39      * folder is empty.
  40      */
  41     if (!strcmp (current, seqname)) {
  42         if (mp->curmsg) {
  43             snprintf(buffer, len, "%s", m_name(mp->curmsg));
  44             return buffer;
  45         }
  46         return NULL;
  47     }
  48
  49     /* If the folder is empty, just return NULL */
  50     if (mp->nummsg == 0)
  51         return NULL;
  52
  53     /* Get the index of the sequence */
  54     if ((seqnum = seq_getnum (mp, seqname)) == -1)
  55         return NULL;
  56
  57     bp = buffer;
  58
  59     for (i = mp->lowmsg; i <= mp->hghmsg; ++i) {
  60         /*
  61          * If message doesn't exist, or isn't in
  62          * the sequence, then continue.
  63          */
  64         if (!does_exist(mp, i) || !in_sequence(mp, seqnum, i))
  65             continue;
  66
  67         /*
  68          * See if we need to enlarge buffer.  Since we don't know
  69          * exactly how many character this particular message range
  70          * will need, we enlarge the buffer if we are within
  71          * 50 characters of the end.
  72          */
  73         if (bp - buffer > len - 50) {
  74             char *newbuf;
  75
  76             len += MAXBUFFER;
  77             newbuf = mh_xrealloc (buffer, (size_t) len);
  78             bp = newbuf + (bp - buffer);
  79             buffer = newbuf;
  80         }
  81
  82         /*
  83          * If this is not the first message range in
  84          * the list, first add a space.
  85          */
  86         if (bp > buffer)
  87             *bp++ = ' ';
  88
  89         strcpy(bp, m_name(i));
  90         bp += strlen(bp);
  91         j = i;                  /* Remember beginning of message range */
  92
  93         /*
  94          * Scan to the end of this message range
  95          */
  96         for (++i; i <= mp->hghmsg && does_exist(mp, i) && in_sequence(mp, seqnum, i);
  97              ++i)
  98             ;
  99
 100         if (i - j > 1) {
 101             *bp++ = '-';
 102             strcpy(bp, m_name(i - 1));
 103             bp += strlen(bp);
 104         }
 105     }
 106     return bp > buffer ? buffer : NULL;
 107 }