1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
/* $OpenBSD: undo.c,v 1.12 2014/05/18 16:36:42 espie Exp $ */
/* $NetBSD: undo.c,v 1.2 1995/03/21 09:04:52 cgd Exp $ */
/* undo.c: This file contains the undo routines for the ed line editor */
/*-
* Copyright (c) 1993 Andrew Moore, Talke Studio.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "ed.h"
#define USIZE 100 /* undo stack size */
undo_t *ustack = NULL; /* undo stack */
int usize = 0; /* stack size variable */
int u_p = 0; /* undo stack pointer */
/* push_undo_stack: return pointer to initialized undo node */
undo_t *
push_undo_stack(int type, int from, int to)
{
undo_t *t;
t = ustack;
if (u_p < usize ||
(t = reallocarray(ustack, (usize += USIZE), sizeof(undo_t))) != NULL) {
ustack = t;
ustack[u_p].type = type;
ustack[u_p].t = get_addressed_line_node(to);
ustack[u_p].h = get_addressed_line_node(from);
return ustack + u_p++;
}
/* out of memory - release undo stack */
perror(NULL);
seterrmsg("out of memory");
clear_undo_stack();
free(ustack);
ustack = NULL;
usize = 0;
return NULL;
}
/* USWAP: swap undo nodes */
#define USWAP(x,y) { \
undo_t utmp; \
utmp = x, x = y, y = utmp; \
}
int u_current_addr = -1; /* if >= 0, undo enabled */
int u_addr_last = -1; /* if >= 0, undo enabled */
/* pop_undo_stack: undo last change to the editor buffer */
int
pop_undo_stack(void)
{
int n;
int o_current_addr = current_addr;
int o_addr_last = addr_last;
if (u_current_addr == -1 || u_addr_last == -1) {
seterrmsg("nothing to undo");
return ERR;
} else if (u_p)
modified = 1;
get_addressed_line_node(0); /* this get_addressed_line_node last! */
SPL1();
for (n = u_p; n-- > 0;) {
switch(ustack[n].type) {
case UADD:
REQUE(ustack[n].h->q_back, ustack[n].t->q_forw);
break;
case UDEL:
REQUE(ustack[n].h->q_back, ustack[n].h);
REQUE(ustack[n].t, ustack[n].t->q_forw);
break;
case UMOV:
case VMOV:
REQUE(ustack[n - 1].h, ustack[n].h->q_forw);
REQUE(ustack[n].t->q_back, ustack[n - 1].t);
REQUE(ustack[n].h, ustack[n].t);
n--;
break;
default:
/*NOTREACHED*/
;
}
ustack[n].type ^= 1;
}
/* reverse undo stack order */
for (n = u_p; n-- > (u_p + 1)/ 2;)
USWAP(ustack[n], ustack[u_p - 1 - n]);
if (isglobal)
clear_active_list();
current_addr = u_current_addr, u_current_addr = o_current_addr;
addr_last = u_addr_last, u_addr_last = o_addr_last;
SPL0();
return 0;
}
/* clear_undo_stack: clear the undo stack */
void
clear_undo_stack(void)
{
line_t *lp, *ep, *tl;
while (u_p--)
if (ustack[u_p].type == UDEL) {
ep = ustack[u_p].t->q_forw;
for (lp = ustack[u_p].h; lp != ep; lp = tl) {
unmark_line_node(lp);
tl = lp->q_forw;
free(lp);
}
}
u_p = 0;
u_current_addr = current_addr;
u_addr_last = addr_last;
}
|
