Annotation of src/bin/ed/undo.c, Revision 1.5
1.5 ! msaitoh 1: /* $NetBSD: undo.c,v 1.4 2005/02/17 16:29:26 xtraeme Exp $ */
1.2 cgd 2:
1.1 alm 3: /* undo.c: This file contains the undo routines for the ed line editor */
4: /*-
5: * Copyright (c) 1993 Andrew Moore, Talke Studio.
6: * All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
16: *
17: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27: * SUCH DAMAGE.
28: */
29:
1.3 thorpej 30: #include <sys/cdefs.h>
1.1 alm 31: #ifndef lint
1.2 cgd 32: #if 0
1.1 alm 33: static char *rcsid = "@(#)undo.c,v 1.1 1994/02/01 00:34:44 alm Exp";
1.2 cgd 34: #else
1.5 ! msaitoh 35: __RCSID("$NetBSD: undo.c,v 1.4 2005/02/17 16:29:26 xtraeme Exp $");
1.2 cgd 36: #endif
1.1 alm 37: #endif /* not lint */
38:
39: #include "ed.h"
40:
41:
42: #define USIZE 100 /* undo stack size */
43: undo_t *ustack = NULL; /* undo stack */
44: long usize = 0; /* stack size variable */
45: long u_p = 0; /* undo stack pointer */
46:
1.5 ! msaitoh 47: /* push_undo_stack: return pointer to initialized undo node */
1.1 alm 48: undo_t *
1.4 xtraeme 49: push_undo_stack(int type, long from, long to)
1.1 alm 50: {
51: undo_t *t;
52:
53: #if defined(sun) || defined(NO_REALLOC_NULL)
54: if (ustack == NULL &&
55: (ustack = (undo_t *) malloc((usize = USIZE) * sizeof(undo_t))) == NULL) {
56: fprintf(stderr, "%s\n", strerror(errno));
57: sprintf(errmsg, "out of memory");
58: return NULL;
59: }
60: #endif
61: t = ustack;
62: if (u_p < usize ||
63: (t = (undo_t *) realloc(ustack, (usize += USIZE) * sizeof(undo_t))) != NULL) {
64: ustack = t;
65: ustack[u_p].type = type;
66: ustack[u_p].t = get_addressed_line_node(to);
67: ustack[u_p].h = get_addressed_line_node(from);
68: return ustack + u_p++;
69: }
70: /* out of memory - release undo stack */
71: fprintf(stderr, "%s\n", strerror(errno));
72: sprintf(errmsg, "out of memory");
73: clear_undo_stack();
74: free(ustack);
75: ustack = NULL;
76: usize = 0;
77: return NULL;
78: }
79:
80:
81: /* USWAP: swap undo nodes */
82: #define USWAP(x,y) { \
83: undo_t utmp; \
84: utmp = x, x = y, y = utmp; \
85: }
86:
87:
88: long u_current_addr = -1; /* if >= 0, undo enabled */
89: long u_addr_last = -1; /* if >= 0, undo enabled */
90:
91: /* pop_undo_stack: undo last change to the editor buffer */
92: int
1.4 xtraeme 93: pop_undo_stack(void)
1.1 alm 94: {
95: long n;
96: long o_current_addr = current_addr;
97: long o_addr_last = addr_last;
98:
99: if (u_current_addr == -1 || u_addr_last == -1) {
100: sprintf(errmsg, "nothing to undo");
101: return ERR;
102: } else if (u_p)
103: modified = 1;
104: get_addressed_line_node(0); /* this get_addressed_line_node last! */
105: SPL1();
106: for (n = u_p; n-- > 0;) {
107: switch(ustack[n].type) {
108: case UADD:
109: REQUE(ustack[n].h->q_back, ustack[n].t->q_forw);
110: break;
111: case UDEL:
112: REQUE(ustack[n].h->q_back, ustack[n].h);
113: REQUE(ustack[n].t, ustack[n].t->q_forw);
114: break;
115: case UMOV:
116: case VMOV:
117: REQUE(ustack[n - 1].h, ustack[n].h->q_forw);
118: REQUE(ustack[n].t->q_back, ustack[n - 1].t);
119: REQUE(ustack[n].h, ustack[n].t);
120: n--;
121: break;
122: default:
123: /*NOTREACHED*/
124: ;
125: }
126: ustack[n].type ^= 1;
127: }
128: /* reverse undo stack order */
129: for (n = u_p; n-- > (u_p + 1)/ 2;)
130: USWAP(ustack[n], ustack[u_p - 1 - n]);
131: if (isglobal)
132: clear_active_list();
133: current_addr = u_current_addr, u_current_addr = o_current_addr;
134: addr_last = u_addr_last, u_addr_last = o_addr_last;
135: SPL0();
136: return 0;
137: }
138:
139:
140: /* clear_undo_stack: clear the undo stack */
141: void
1.4 xtraeme 142: clear_undo_stack(void)
1.1 alm 143: {
144: line_t *lp, *ep, *tl;
145:
146: while (u_p--)
147: if (ustack[u_p].type == UDEL) {
148: ep = ustack[u_p].t->q_forw;
149: for (lp = ustack[u_p].h; lp != ep; lp = tl) {
150: unmark_line_node(lp);
151: tl = lp->q_forw;
152: free(lp);
153: }
154: }
155: u_p = 0;
156: u_current_addr = current_addr;
157: u_addr_last = addr_last;
158: }
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