undo.c revision 81220
11057Salm/* undo.c: This file contains the undo routines for the ed line editor */ 21057Salm/*- 31057Salm * Copyright (c) 1993 Andrew Moore, Talke Studio. 41057Salm * All rights reserved. 51057Salm * 61057Salm * Redistribution and use in source and binary forms, with or without 71057Salm * modification, are permitted provided that the following conditions 81057Salm * are met: 91057Salm * 1. Redistributions of source code must retain the above copyright 101057Salm * notice, this list of conditions and the following disclaimer. 111057Salm * 2. Redistributions in binary form must reproduce the above copyright 121057Salm * notice, this list of conditions and the following disclaimer in the 131057Salm * documentation and/or other materials provided with the distribution. 141057Salm * 151057Salm * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 161057Salm * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 171057Salm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 181057Salm * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 191057Salm * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 201057Salm * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 211057Salm * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 221057Salm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 231057Salm * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 241057Salm * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 251057Salm * SUCH DAMAGE. 261057Salm */ 271057Salm 281057Salm#ifndef lint 2981220Smikestatic const char rcsid[] = 3050471Speter "$FreeBSD: head/bin/ed/undo.c 81220 2001-08-06 22:01:31Z mike $"; 311057Salm#endif /* not lint */ 321057Salm 331057Salm#include "ed.h" 341057Salm 351057Salm 361057Salm#define USIZE 100 /* undo stack size */ 371057Salmundo_t *ustack = NULL; /* undo stack */ 381057Salmlong usize = 0; /* stack size variable */ 391057Salmlong u_p = 0; /* undo stack pointer */ 401057Salm 4146684Skris/* push_undo_stack: return pointer to initialized undo node */ 421057Salmundo_t * 431057Salmpush_undo_stack(type, from, to) 441057Salm int type; 451057Salm long from; 461057Salm long to; 471057Salm{ 481057Salm undo_t *t; 491057Salm 501057Salm#if defined(sun) || defined(NO_REALLOC_NULL) 511057Salm if (ustack == NULL && 521057Salm (ustack = (undo_t *) malloc((usize = USIZE) * sizeof(undo_t))) == NULL) { 531057Salm fprintf(stderr, "%s\n", strerror(errno)); 5481220Smike errmsg = "out of memory"; 551057Salm return NULL; 561057Salm } 571057Salm#endif 581057Salm t = ustack; 591057Salm if (u_p < usize || 601057Salm (t = (undo_t *) realloc(ustack, (usize += USIZE) * sizeof(undo_t))) != NULL) { 611057Salm ustack = t; 621057Salm ustack[u_p].type = type; 631057Salm ustack[u_p].t = get_addressed_line_node(to); 641057Salm ustack[u_p].h = get_addressed_line_node(from); 651057Salm return ustack + u_p++; 661057Salm } 671057Salm /* out of memory - release undo stack */ 681057Salm fprintf(stderr, "%s\n", strerror(errno)); 6981220Smike errmsg = "out of memory"; 701057Salm clear_undo_stack(); 711057Salm free(ustack); 721057Salm ustack = NULL; 731057Salm usize = 0; 741057Salm return NULL; 751057Salm} 761057Salm 771057Salm 781057Salm/* USWAP: swap undo nodes */ 791057Salm#define USWAP(x,y) { \ 801057Salm undo_t utmp; \ 811057Salm utmp = x, x = y, y = utmp; \ 821057Salm} 831057Salm 841057Salm 851057Salmlong u_current_addr = -1; /* if >= 0, undo enabled */ 861057Salmlong u_addr_last = -1; /* if >= 0, undo enabled */ 871057Salm 881057Salm/* pop_undo_stack: undo last change to the editor buffer */ 891057Salmint 901057Salmpop_undo_stack() 911057Salm{ 921057Salm long n; 931057Salm long o_current_addr = current_addr; 941057Salm long o_addr_last = addr_last; 951057Salm 961057Salm if (u_current_addr == -1 || u_addr_last == -1) { 9781220Smike errmsg = "nothing to undo"; 981057Salm return ERR; 991057Salm } else if (u_p) 1001057Salm modified = 1; 1011057Salm get_addressed_line_node(0); /* this get_addressed_line_node last! */ 1021057Salm SPL1(); 1031057Salm for (n = u_p; n-- > 0;) { 1041057Salm switch(ustack[n].type) { 1051057Salm case UADD: 1061057Salm REQUE(ustack[n].h->q_back, ustack[n].t->q_forw); 1071057Salm break; 1081057Salm case UDEL: 1091057Salm REQUE(ustack[n].h->q_back, ustack[n].h); 1101057Salm REQUE(ustack[n].t, ustack[n].t->q_forw); 1111057Salm break; 1121057Salm case UMOV: 1131057Salm case VMOV: 1141057Salm REQUE(ustack[n - 1].h, ustack[n].h->q_forw); 1151057Salm REQUE(ustack[n].t->q_back, ustack[n - 1].t); 1161057Salm REQUE(ustack[n].h, ustack[n].t); 1171057Salm n--; 1181057Salm break; 1191057Salm default: 1201057Salm /*NOTREACHED*/ 1211057Salm ; 1221057Salm } 1231057Salm ustack[n].type ^= 1; 1241057Salm } 1251057Salm /* reverse undo stack order */ 1261057Salm for (n = u_p; n-- > (u_p + 1)/ 2;) 1271057Salm USWAP(ustack[n], ustack[u_p - 1 - n]); 1281057Salm if (isglobal) 1291057Salm clear_active_list(); 1301057Salm current_addr = u_current_addr, u_current_addr = o_current_addr; 1311057Salm addr_last = u_addr_last, u_addr_last = o_addr_last; 1321057Salm SPL0(); 1331057Salm return 0; 1341057Salm} 1351057Salm 1361057Salm 1371057Salm/* clear_undo_stack: clear the undo stack */ 1381057Salmvoid 1391057Salmclear_undo_stack() 1401057Salm{ 1411057Salm line_t *lp, *ep, *tl; 1421057Salm 1431057Salm while (u_p--) 1441057Salm if (ustack[u_p].type == UDEL) { 1451057Salm ep = ustack[u_p].t->q_forw; 1461057Salm for (lp = ustack[u_p].h; lp != ep; lp = tl) { 1471057Salm unmark_line_node(lp); 1481057Salm tl = lp->q_forw; 1491057Salm free(lp); 1501057Salm } 1511057Salm } 1521057Salm u_p = 0; 1531057Salm u_current_addr = current_addr; 1541057Salm u_addr_last = addr_last; 1551057Salm} 156