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 10.12 1996/10/23 09:30:49 bostic Exp $ (Berkeley) $Date: 1996/10/23 09:30:49 $";
  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(sp, fm, tm, lmode)
  36         SCR *sp;
  37         MARK *fm, *tm;
  38         int lmode;
  39 {
  40         recno_t lno;
  41         size_t blen, len, nlen, tlen;
  42         char *bp, *p;
  43         int eof, rval;
  44
  45         bp = NULL;
  46
  47         /* Case 1 -- delete in line mode. */
  48         if (lmode) {
  49                 for (lno = tm->lno; lno >= fm->lno; --lno) {
  50                         if (db_delete(sp, lno))
  51                                 return (1);
  52                         ++sp->rptlines[L_DELETED];
  53                         if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
  54                                 break;
  55                 }
  56                 goto done;
  57         }
  58
  59         /*
  60          * Case 2 -- delete to EOF.  This is a special case because it's
  61          * easier to pick it off than try and find it in the other cases.
  62          */
  63         if (db_last(sp, &lno))
  64                 return (1);
  65         if (tm->lno >= lno) {
  66                 if (tm->lno == lno) {
  67                         if (db_get(sp, lno, DBG_FATAL, &p, &len))
  68                                 return (1);
  69                         eof = tm->cno >= len ? 1 : 0;
  70                 } else
  71                         eof = 1;
  72                 if (eof) {
  73                         for (lno = tm->lno; lno > fm->lno; --lno) {
  74                                 if (db_delete(sp, lno))
  75                                         return (1);
  76                                 ++sp->rptlines[L_DELETED];
  77                                 if (lno %
  78                                     INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
  79                                         break;
  80                         }
  81                         if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
  82                                 return (1);
  83                         GET_SPACE_RET(sp, bp, blen, fm->cno);
  84                         memcpy(bp, p, fm->cno);
  85                         if (db_set(sp, fm->lno, bp, fm->cno))
  86                                 return (1);
  87                         goto done;
  88                 }
  89         }
  90
  91         /* Case 3 -- delete within a single line. */
  92         if (tm->lno == fm->lno) {
  93                 if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
  94                         return (1);
  95                 GET_SPACE_RET(sp, bp, blen, len);
  96                 if (fm->cno != 0)
  97                         memcpy(bp, p, fm->cno);
  98                 memcpy(bp + fm->cno, p + (tm->cno + 1), len - (tm->cno + 1));
  99                 if (db_set(sp, fm->lno,
 100                     bp, len - ((tm->cno - fm->cno) + 1)))
 101                         goto err;
 102                 goto done;
 103         }
 104
 105         /*
 106          * Case 4 -- delete over multiple lines.
 107          *
 108          * Copy the start partial line into place.
 109          */
 110         if ((tlen = fm->cno) != 0) {
 111                 if (db_get(sp, fm->lno, DBG_FATAL, &p, NULL))
 112                         return (1);
 113                 GET_SPACE_RET(sp, bp, blen, tlen + 256);
 114                 memcpy(bp, p, tlen);
 115         }
 116
 117         /* Copy the end partial line into place. */
 118         if (db_get(sp, tm->lno, DBG_FATAL, &p, &len))
 119                 goto err;
 120         if (len != 0 && tm->cno != len - 1) {
 121                 /*
 122                  * XXX
 123                  * We can overflow memory here, if the total length is greater
 124                  * than SIZE_T_MAX.  The only portable way I've found to test
 125                  * is depending on the overflow being less than the value.
 126                  */
 127                 nlen = (len - (tm->cno + 1)) + tlen;
 128                 if (tlen > nlen) {
 129                         msgq(sp, M_ERR, "002|Line length overflow");
 130                         goto err;
 131                 }
 132                 if (tlen == 0) {
 133                         GET_SPACE_RET(sp, bp, blen, nlen);
 134                 } else
 135                         ADD_SPACE_RET(sp, bp, blen, nlen);
 136
 137                 memcpy(bp + tlen, p + (tm->cno + 1), len - (tm->cno + 1));
 138                 tlen += len - (tm->cno + 1);
 139         }
 140
 141         /* Set the current line. */
 142         if (db_set(sp, fm->lno, bp, tlen))
 143                 goto err;
 144
 145         /* Delete the last and intermediate lines. */
 146         for (lno = tm->lno; lno > fm->lno; --lno) {
 147                 if (db_delete(sp, lno))
 148                         goto err;
 149                 ++sp->rptlines[L_DELETED];
 150                 if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
 151                         break;
 152         }
 153
 154 done:   rval = 0;
 155         if (0)
 156 err:            rval = 1;
 157         if (bp != NULL)
 158                 FREE_SPACE(sp, bp, blen);
 159         return (rval);
 160 }