[unix-history] / bin / ed / undo.c

/* 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.
 */

#ifndef lint
static char *rcsid = "@(#)$Id: undo.c,v 1.2 1993/12/14 16:19:56 alm Exp $";
#endif /* not lint */

#include "ed.h"


#define USIZE 100				/* undo stack size */
undo_t *ustack = NULL;				/* undo stack */
long usize = 0;					/* stack size variable */
long u_p = 0;					/* undo stack pointer */

/* push_undo_stack: return pointer to intialized undo node */
undo_t *
push_undo_stack(type, from, to)
	int type;
	long from;
	long to;
{
	undo_t *t;

#if defined(sun) || defined(NO_REALLOC_NULL)
	if (ustack == NULL &&
	    (ustack = (undo_t *) malloc((usize = USIZE) * sizeof(undo_t))) == NULL) {
		fprintf(stderr, "%s\n", strerror(errno));
		sprintf(errmsg, "out of memory");
		return NULL;
	}
#endif
	t = ustack;
	if (u_p < usize ||
	    (t = (undo_t *) realloc(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 */
	fprintf(stderr, "%s\n", strerror(errno));
	sprintf(errmsg, "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; \
}


long u_current_addr = -1;	/* if >= 0, undo enabled */
long u_addr_last = -1;		/* if >= 0, undo enabled */

/* pop_undo_stack: undo last change to the editor buffer */
int
pop_undo_stack()
{
	long n;
	long o_current_addr = current_addr;
	long o_addr_last = addr_last;

	if (u_current_addr == -1 || u_addr_last == -1) {
		sprintf(errmsg, "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()
{
	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;
}
Commit	Line	Data
84ee7b23 AM	1	/* undo.c: This file contains the undo routines for the ed line editor */
	2	/*-
	3	* Copyright (c) 1993 Andrew Moore, Talke Studio.
	4	* All rights reserved.
	5	*
	6	* Redistribution and use in source and binary forms, with or without
	7	* modification, are permitted provided that the following conditions
	8	* are met:
	9	* 1. Redistributions of source code must retain the above copyright
	10	* notice, this list of conditions and the following disclaimer.
	11	* 2. Redistributions in binary form must reproduce the above copyright
	12	* notice, this list of conditions and the following disclaimer in the
	13	* documentation and/or other materials provided with the distribution.
	14	*
	15	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
	16	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	17	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	18	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
	19	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	20	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	21	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	22	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	23	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	24	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	25	* SUCH DAMAGE.
	26	*/
	27
	28	#ifndef lint
	29	static char *rcsid = "@(#)$Id: undo.c,v 1.2 1993/12/14 16:19:56 alm Exp $";
	30	#endif /* not lint */
	31
	32	#include "ed.h"
	33
	34
	35	#define USIZE 100 /* undo stack size */
	36	undo_t ustack = NULL; / undo stack */
	37	long usize = 0; /* stack size variable */
	38	long u_p = 0; /* undo stack pointer */
	39
	40	/* push_undo_stack: return pointer to intialized undo node */
	41	undo_t *
	42	push_undo_stack(type, from, to)
	43	int type;
	44	long from;
	45	long to;
	46	{
	47	undo_t *t;
	48
	49	#if defined(sun) \|\| defined(NO_REALLOC_NULL)
	50	if (ustack == NULL &&
	51	(ustack = (undo_t ) malloc((usize = USIZE) sizeof(undo_t))) == NULL) {
	52	fprintf(stderr, "%s\n", strerror(errno));
	53	sprintf(errmsg, "out of memory");
	54	return NULL;
	55	}
	56	#endif
	57	t = ustack;
	58	if (u_p < usize \|\|
	59	(t = (undo_t ) realloc(ustack, (usize += USIZE) sizeof(undo_t))) != NULL) {
	60	ustack = t;
	61	ustack[u_p].type = type;
	62	ustack[u_p].t = get_addressed_line_node(to);
	63	ustack[u_p].h = get_addressed_line_node(from);
	64	return ustack + u_p++;
65	}
66	/* out of memory - release undo stack */
67	fprintf(stderr, "%s\n", strerror(errno));
68	sprintf(errmsg, "out of memory");
69	clear_undo_stack();
70	free(ustack);
71	ustack = NULL;
72	usize = 0;
73	return NULL;
74	}
75
76
77	/* USWAP: swap undo nodes */
78	#define USWAP(x,y) { \
79	undo_t utmp; \
80	utmp = x, x = y, y = utmp; \
81	}
82
83
84	long u_current_addr = -1; /* if >= 0, undo enabled */
85	long u_addr_last = -1; /* if >= 0, undo enabled */
86
87	/* pop_undo_stack: undo last change to the editor buffer */
88	int
89	pop_undo_stack()
90	{
91	long n;
92	long o_current_addr = current_addr;
93	long o_addr_last = addr_last;
94
95	if (u_current_addr == -1 \|\| u_addr_last == -1) {
96	sprintf(errmsg, "nothing to undo");
97	return ERR;
98	} else if (u_p)
99	modified = 1;
100	get_addressed_line_node(0); /* this get_addressed_line_node last! */
101	SPL1();
102	for (n = u_p; n-- > 0;) {
103	switch(ustack[n].type) {
104	case UADD:
105	REQUE(ustack[n].h->q_back, ustack[n].t->q_forw);
106	break;
107	case UDEL:
108	REQUE(ustack[n].h->q_back, ustack[n].h);
109	REQUE(ustack[n].t, ustack[n].t->q_forw);
110	break;
111	case UMOV:
112	case VMOV:
113	REQUE(ustack[n - 1].h, ustack[n].h->q_forw);
114	REQUE(ustack[n].t->q_back, ustack[n - 1].t);
115	REQUE(ustack[n].h, ustack[n].t);
116	n--;
117	break;
118	default:
119	/NOTREACHED/
120	;
121	}
122	ustack[n].type ^= 1;
123	}
124	/* reverse undo stack order */
125	for (n = u_p; n-- > (u_p + 1)/ 2;)
126	USWAP(ustack[n], ustack[u_p - 1 - n]);
127	if (isglobal)
128	clear_active_list();
129	current_addr = u_current_addr, u_current_addr = o_current_addr;
130	addr_last = u_addr_last, u_addr_last = o_addr_last;
131	SPL0();
132	return 0;
133	}
134
135
136	/* clear_undo_stack: clear the undo stack */
137	void
138	clear_undo_stack()
139	{
140	line_t lp, ep, *tl;
141
142	while (u_p--)
143	if (ustack[u_p].type == UDEL) {
144	ep = ustack[u_p].t->q_forw;
145	for (lp = ustack[u_p].h; lp != ep; lp = tl) {
146	unmark_line_node(lp);
147	tl = lp->q_forw;
148	free(lp);
149	}
150	}
151	u_p = 0;
152	u_current_addr = current_addr;
153	u_addr_last = addr_last;
154	}