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
13static const char sccsid[] = "$Id: delete.c,v 10.18 2012/02/11 15:52:33 zy Exp $";
14#endif /* not lint */
15
16#include <sys/types.h>
17#include <sys/queue.h>
18#include <sys/time.h>
19
20#include <bitstring.h>
21#include <errno.h>
22#include <limits.h>
23#include <stdio.h>
24#include <stdlib.h>
25#include <string.h>
26
27#include "common.h"
28
29/*
30 * del --
31 *	Delete a range of text.
32 *
33 * PUBLIC: int del(SCR *, MARK *, MARK *, int);
34 */
35int
36del(
37	SCR *sp,
38	MARK *fm,
39	MARK *tm,
40	int lmode)
41{
42	recno_t lno;
43	size_t blen, len, nlen, tlen;
44	CHAR_T *bp, *p;
45	int eof, rval;
46
47	bp = NULL;
48
49	/* Case 1 -- delete in line mode. */
50	if (lmode) {
51		for (lno = tm->lno; lno >= fm->lno; --lno) {
52			if (db_delete(sp, lno))
53				return (1);
54			++sp->rptlines[L_DELETED];
55			if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
56				break;
57		}
58		goto done;
59	}
60
61	/*
62	 * Case 2 -- delete to EOF.  This is a special case because it's
63	 * easier to pick it off than try and find it in the other cases.
64 	 */
65	if (db_last(sp, &lno))
66		return (1);
67	if (tm->lno >= lno) {
68		if (tm->lno == lno) {
69			if (db_get(sp, lno, DBG_FATAL, &p, &len))
70				return (1);
71			eof = tm->cno != ENTIRE_LINE && tm->cno >= len ? 1 : 0;
72		} else
73			eof = 1;
74		if (eof) {
75			for (lno = tm->lno; lno > fm->lno; --lno) {
76				if (db_delete(sp, lno))
77					return (1);
78				++sp->rptlines[L_DELETED];
79				if (lno %
80				    INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
81					break;
82			}
83			if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
84				return (1);
85			GET_SPACE_RETW(sp, bp, blen, fm->cno);
86			MEMCPY(bp, p, fm->cno);
87			if (db_set(sp, fm->lno, bp, fm->cno))
88				return (1);
89			goto done;
90		}
91	}
92
93	/* Case 3 -- delete within a single line. */
94	if (tm->lno == fm->lno) {
95		if (db_get(sp, fm->lno, DBG_FATAL, &p, &len))
96			return (1);
97		GET_SPACE_RETW(sp, bp, blen, len);
98		if (fm->cno != 0)
99			MEMCPY(bp, p, fm->cno);
100		MEMCPY(bp + fm->cno, p + (tm->cno + 1),
101			len - (tm->cno + 1));
102		if (db_set(sp, fm->lno,
103		    bp, len - ((tm->cno - fm->cno) + 1)))
104			goto err;
105		goto done;
106	}
107
108	/*
109	 * Case 4 -- delete over multiple lines.
110	 *
111	 * Copy the start partial line into place.
112	 */
113	if ((tlen = fm->cno) != 0) {
114		if (db_get(sp, fm->lno, DBG_FATAL, &p, NULL))
115			return (1);
116		GET_SPACE_RETW(sp, bp, blen, tlen + 256);
117		MEMCPY(bp, p, tlen);
118	}
119
120	/* Copy the end partial line into place. */
121	if (db_get(sp, tm->lno, DBG_FATAL, &p, &len))
122		goto err;
123	if (len != 0 && tm->cno != len - 1) {
124		/*
125		 * XXX
126		 * We can overflow memory here, if the total length is greater
127		 * than SIZE_T_MAX.  The only portable way I've found to test
128		 * is depending on the overflow being less than the value.
129		 */
130		nlen = (len - (tm->cno + 1)) + tlen;
131		if (tlen > nlen) {
132			msgq(sp, M_ERR, "002|Line length overflow");
133			goto err;
134		}
135		if (tlen == 0) {
136			GET_SPACE_RETW(sp, bp, blen, nlen);
137		} else
138			ADD_SPACE_RETW(sp, bp, blen, nlen);
139
140		MEMCPY(bp + tlen, p + (tm->cno + 1), len - (tm->cno + 1));
141		tlen += len - (tm->cno + 1);
142	}
143
144	/* Set the current line. */
145	if (db_set(sp, fm->lno, bp, tlen))
146		goto err;
147
148	/* Delete the last and intermediate lines. */
149	for (lno = tm->lno; lno > fm->lno; --lno) {
150		if (db_delete(sp, lno))
151			goto err;
152		++sp->rptlines[L_DELETED];
153		if (lno % INTERRUPT_CHECK == 0 && INTERRUPTED(sp))
154			break;
155	}
156
157done:	rval = 0;
158	if (0)
159err:		rval = 1;
160	if (bp != NULL)
161		FREE_SPACEW(sp, bp, blen);
162	return (rval);
163}
164