1/*	$NetBSD: delete.c,v 1.4 2017/11/22 12:47:30 rin Exp $ */
2/*-
3 * Copyright (c) 1992, 1993, 1994
4 *	The Regents of the University of California.  All rights reserved.
5 * Copyright (c) 1992, 1993, 1994, 1995, 1996
6 *	Keith Bostic.  All rights reserved.
7 *
8 * See the LICENSE file for redistribution information.
9 */
10
11#include "config.h"
12
13#include <sys/cdefs.h>
14#if 0
15#ifndef lint
16static 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 ";
17#endif /* not lint */
18#else
19__RCSID("$NetBSD: delete.c,v 1.4 2017/11/22 12:47:30 rin Exp $");
20#endif
21
22#include <sys/types.h>
23#include <sys/queue.h>
24
25#include <bitstring.h>
26#include <errno.h>
27#include <limits.h>
28#include <stdio.h>
29#include <stdlib.h>
30#include <string.h>
31
32#include "common.h"
33
34/*
35 * del --
36 *	Delete a range of text.
37 *
38 * PUBLIC: int del __P((SCR *, MARK *, MARK *, int));
39 */
40int
41del(SCR *sp, MARK *fm, MARK *tm, int lmode)
42{
43	db_recno_t lno;
44	size_t blen, len, nlen, tlen;
45	CHAR_T *bp, *p;
46	int eof, rval;
47
48	bp = NULL;
49
50	/* Case 1 -- delete in line mode. */
51	if (lmode) {
52		for (lno = tm->lno; lno >= fm->lno; --lno) {
53			if (db_delete(sp, lno))
54				return (1);
55			++sp->rptlines[L_DELETED];
56			if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
57				break;
58		}
59		goto done;
60	}
61
62	/*
63	 * Case 2 -- delete to EOF.  This is a special case because it's
64	 * easier to pick it off than try and find it in the other cases.
65 	 */
66	if (db_last(sp, &lno))
67		return (1);
68	if (tm->lno >= lno) {
69		if (tm->lno == lno) {
70			if (db_get(sp, lno, DBG_FATAL, &p, &len))
71				return (1);
72			eof = tm->cno != ENTIRE_LINE && tm->cno >= len ? 1 : 0;
73		} else
74			eof = 1;
75		if (eof) {
76			for (lno = tm->lno; lno > fm->lno; --lno) {
77				if (db_delete(sp, lno))
78					return (1);
79				++sp->rptlines[L_DELETED];
80				if (lno %
81				    INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
82					break;
83			}
84			if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
85				return (1);
86			GET_SPACE_RETW(sp, bp, blen, fm->cno);
87			MEMCPYW(bp, p, fm->cno);
88			if (db_set(sp, fm->lno, bp, fm->cno))
89				return (1);
90			goto done;
91		}
92	}
93
94	/* Case 3 -- delete within a single line. */
95	if (tm->lno == fm->lno) {
96		if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
97			return (1);
98		if (len != 0) {
99			GET_SPACE_RETW(sp, bp, blen, len);
100			if (fm->cno != 0)
101				MEMCPYW(bp, p, fm->cno);
102			MEMCPYW(bp + fm->cno, p + (tm->cno + 1),
103				len - (tm->cno + 1));
104			if (db_set(sp, fm->lno,
105			    bp, len - ((tm->cno - fm->cno) + 1)))
106				goto err;
107		}
108		goto done;
109	}
110
111	/*
112	 * Case 4 -- delete over multiple lines.
113	 *
114	 * Copy the start partial line into place.
115	 */
116	if ((tlen = fm->cno) != 0) {
117		if (db_get(sp, fm->lno, DBG_FATAL, &p, NULL))
118			return (1);
119		GET_SPACE_RETW(sp, bp, blen, tlen + 256);
120		MEMCPYW(bp, p, tlen);
121	}
122
123	/* Copy the end partial line into place. */
124	if (db_get(sp, tm->lno, DBG_FATAL, &p, &len))
125		goto err;
126	if (len != 0 && tm->cno != len - 1) {
127		/*
128		 * XXX
129		 * We can overflow memory here, if the total length is greater
130		 * than SIZE_T_MAX.  The only portable way I've found to test
131		 * is depending on the overflow being less than the value.
132		 */
133		nlen = (len - (tm->cno + 1)) + tlen;
134		if (tlen > nlen) {
135			msgq(sp, M_ERR, "002|Line length overflow");
136			goto err;
137		}
138		if (tlen == 0) {
139			GET_SPACE_RETW(sp, bp, blen, nlen);
140		} else
141			ADD_SPACE_RETW(sp, bp, blen, nlen);
142
143		MEMCPYW(bp + tlen, p + (tm->cno + 1), len - (tm->cno + 1));
144		tlen += len - (tm->cno + 1);
145	}
146
147	/* Set the current line. */
148	if (db_set(sp, fm->lno, bp, tlen))
149		goto err;
150
151	/* Delete the last and intermediate lines. */
152	for (lno = tm->lno; lno > fm->lno; --lno) {
153		if (db_delete(sp, lno))
154			goto err;
155		++sp->rptlines[L_DELETED];
156		if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
157			break;
158	}
159
160done:	rval = 0;
161	if (0)
162err:		rval = 1;
163	if (bp != NULL)
164		FREE_SPACEW(sp, bp, blen);
165	return (rval);
166}
167