common/delete.c

   1 /*-
   2  * Copyright (c) 1992, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
   5  *      Keith Bostic.  All rights reserved.
   6  *
   7  * See the LICENSE file for redistribution information.
   8  */
   9
  10 #include "config.h"
  11
  12 #ifndef lint
  13 static const char sccsid[] = "$Id: delete.c,v 10.17 2001/06/25 15:19:09 skimo Exp $ (Berkeley) $Date: 2001/06/25 15:19:09 $";
  14 #endif /* not lint */
  15
  16 #include <sys/types.h>
  17 #include <sys/queue.h>
  18
  19 #include <bitstring.h>
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include "common.h"
  27
  28 /*
  29  * del --
  30  *      Delete a range of text.
  31  *
  32  * PUBLIC: int del __P((SCR *, MARK *, MARK *, int));
  33  */
  34 int
  35 del(SCR *sp, MARK *fm, MARK *tm, int lmode)
  36 {
  37         db_recno_t lno;
  38         size_t blen, len, nlen, tlen;
  39         CHAR_T *bp, *p;
  40         int eof, rval;
  41
  42         bp = NULL;
  43
  44         /* Case 1 -- delete in line mode. */
  45         if (lmode) {
  46                 for (lno = tm->lno; lno >= fm->lno; --lno) {
  47                         if (db_delete(sp, lno))
  48                                 return (1);
  49                         ++sp->rptlines[L_DELETED];
  50                         if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
  51                                 break;
  52                 }
  53                 goto done;
  54         }
  55
  56         /*
  57          * Case 2 -- delete to EOF.  This is a special case because it's
  58          * easier to pick it off than try and find it in the other cases.
  59          */
  60         if (db_last(sp, &lno))
  61                 return (1);
  62         if (tm->lno >= lno) {
  63                 if (tm->lno == lno) {
  64                         if (db_get(sp, lno, DBG_FATAL, &p, &len))
  65                                 return (1);
  66                         eof = tm->cno >= len ? 1 : 0;
  67                 } else
  68                         eof = 1;
  69                 if (eof) {
  70                         for (lno = tm->lno; lno > fm->lno; --lno) {
  71                                 if (db_delete(sp, lno))
  72                                         return (1);
  73                                 ++sp->rptlines[L_DELETED];
  74                                 if (lno %
  75                                     INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
  76                                         break;
  77                         }
  78                         if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
  79                                 return (1);
  80                         GET_SPACE_RETW(sp, bp, blen, fm->cno);
  81                         MEMCPYW(bp, p, fm->cno);
  82                         if (db_set(sp, fm->lno, bp, fm->cno))
  83                                 return (1);
  84                         goto done;
  85                 }
  86         }
  87
  88         /* Case 3 -- delete within a single line. */
  89         if (tm->lno == fm->lno) {
  90                 if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
  91                         return (1);
  92                 GET_SPACE_RETW(sp, bp, blen, len);
  93                 if (fm->cno != 0)
  94                         MEMCPYW(bp, p, fm->cno);
  95                 MEMCPYW(bp + fm->cno, p + (tm->cno + 1),
  96                         len - (tm->cno + 1));
  97                 if (db_set(sp, fm->lno,
  98                     bp, len - ((tm->cno - fm->cno) + 1)))
  99                         goto err;
 100                 goto done;
 101         }
 102
 103         /*
 104          * Case 4 -- delete over multiple lines.
 105          *
 106          * Copy the start partial line into place.
 107          */
 108         if ((tlen = fm->cno) != 0) {
 109                 if (db_get(sp, fm->lno, DBG_FATAL, &p, NULL))
 110                         return (1);
 111                 GET_SPACE_RETW(sp, bp, blen, tlen + 256);
 112                 MEMCPYW(bp, p, tlen);
 113         }
 114
 115         /* Copy the end partial line into place. */
 116         if (db_get(sp, tm->lno, DBG_FATAL, &p, &len))
 117                 goto err;
 118         if (len != 0 && tm->cno != len - 1) {
 119                 /*
 120                  * XXX
 121                  * We can overflow memory here, if the total length is greater
 122                  * than SIZE_T_MAX.  The only portable way I've found to test
 123                  * is depending on the overflow being less than the value.
 124                  */
 125                 nlen = (len - (tm->cno + 1)) + tlen;
 126                 if (tlen > nlen) {
 127                         msgq(sp, M_ERR, "002|Line length overflow");
 128                         goto err;
 129                 }
 130                 if (tlen == 0) {
 131                         GET_SPACE_RETW(sp, bp, blen, nlen);
 132                 } else
 133                         ADD_SPACE_RETW(sp, bp, blen, nlen);
 134
 135                 MEMCPYW(bp + tlen, p + (tm->cno + 1), len - (tm->cno + 1));
 136                 tlen += len - (tm->cno + 1);
 137         }
 138
 139         /* Set the current line. */
 140         if (db_set(sp, fm->lno, bp, tlen))
 141                 goto err;
 142
 143         /* Delete the last and intermediate lines. */
 144         for (lno = tm->lno; lno > fm->lno; --lno) {
 145                 if (db_delete(sp, lno))
 146                         goto err;
 147                 ++sp->rptlines[L_DELETED];
 148                 if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
 149                         break;
 150         }
 151
 152 done:   rval = 0;
 153         if (0)
 154 err:            rval = 1;
 155         if (bp != NULL)
 156                 FREE_SPACEW(sp, bp, blen);
 157         return (rval);
 158 }