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 10.14 2000/06/27 17:19:04 skimo Exp $ (Berkeley) $Date: 2000/06/27 17:19:04 $";
  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         db_recno_t lno;
  41         size_t blen, len, nlen, tlen;
  42         char *bp;
  43         CHAR_T *p;
  44         int eof, rval;
  45
  46         bp = NULL;
  47
  48         /* Case 1 -- delete in line mode. */
  49         if (lmode) {
  50                 for (lno = tm->lno; lno >= fm->lno; --lno) {
  51                         if (db_delete(sp, lno))
  52                                 return (1);
  53                         ++sp->rptlines[L_DELETED];
  54                         if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
  55                                 break;
  56                 }
  57                 goto done;
  58         }
  59
  60         /*
  61          * Case 2 -- delete to EOF.  This is a special case because it's
  62          * easier to pick it off than try and find it in the other cases.
  63          */
  64         if (db_last(sp, &lno))
  65                 return (1);
  66         if (tm->lno >= lno) {
  67                 if (tm->lno == lno) {
  68                         if (db_get(sp, lno, DBG_FATAL, &p, &len))
  69                                 return (1);
  70                         eof = tm->cno >= len ? 1 : 0;
  71                 } else
  72                         eof = 1;
  73                 if (eof) {
  74                         for (lno = tm->lno; lno > fm->lno; --lno) {
  75                                 if (db_delete(sp, lno))
  76                                         return (1);
  77                                 ++sp->rptlines[L_DELETED];
  78                                 if (lno %
  79                                     INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
  80                                         break;
  81                         }
  82                         if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
  83                                 return (1);
  84                         GET_SPACE_RET(sp, bp, blen, fm->cno);
  85                         memcpy(bp, p, fm->cno);
  86                         if (db_set(sp, fm->lno, bp, fm->cno))
  87                                 return (1);
  88                         goto done;
  89                 }
  90         }
  91
  92         /* Case 3 -- delete within a single line. */
  93         if (tm->lno == fm->lno) {
  94                 if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
  95                         return (1);
  96                 GET_SPACE_RET(sp, bp, blen, len);
  97                 if (fm->cno != 0)
  98                         memcpy(bp, p, fm->cno);
  99                 memcpy(bp + fm->cno, p + (tm->cno + 1), len - (tm->cno + 1));
 100                 if (db_set(sp, fm->lno,
 101                     bp, len - ((tm->cno - fm->cno) + 1)))
 102                         goto err;
 103                 goto done;
 104         }
 105
 106         /*
 107          * Case 4 -- delete over multiple lines.
 108          *
 109          * Copy the start partial line into place.
 110          */
 111         if ((tlen = fm->cno) != 0) {
 112                 if (db_get(sp, fm->lno, DBG_FATAL, &p, NULL))
 113                         return (1);
 114                 GET_SPACE_RET(sp, bp, blen, tlen + 256);
 115                 memcpy(bp, p, tlen);
 116         }
 117
 118         /* Copy the end partial line into place. */
 119         if (db_get(sp, tm->lno, DBG_FATAL, &p, &len))
 120                 goto err;
 121         if (len != 0 && tm->cno != len - 1) {
 122                 /*
 123                  * XXX
 124                  * We can overflow memory here, if the total length is greater
 125                  * than SIZE_T_MAX.  The only portable way I've found to test
 126                  * is depending on the overflow being less than the value.
 127                  */
 128                 nlen = (len - (tm->cno + 1)) + tlen;
 129                 if (tlen > nlen) {
 130                         msgq(sp, M_ERR, "002|Line length overflow");
 131                         goto err;
 132                 }
 133                 if (tlen == 0) {
 134                         GET_SPACE_RET(sp, bp, blen, nlen);
 135                 } else
 136                         ADD_SPACE_RET(sp, bp, blen, nlen);
 137
 138                 memcpy(bp + tlen, p + (tm->cno + 1), len - (tm->cno + 1));
 139                 tlen += len - (tm->cno + 1);
 140         }
 141
 142         /* Set the current line. */
 143         if (db_set(sp, fm->lno, bp, tlen))
 144                 goto err;
 145
 146         /* Delete the last and intermediate lines. */
 147         for (lno = tm->lno; lno > fm->lno; --lno) {
 148                 if (db_delete(sp, lno))
 149                         goto err;
 150                 ++sp->rptlines[L_DELETED];
 151                 if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
 152                         break;
 153         }
 154
 155 done:   rval = 0;
 156         if (0)
 157 err:            rval = 1;
 158         if (bp != NULL)
 159                 FREE_SPACE(sp, bp, blen);
 160         return (rval);
 161 }