undo.c revision 50471
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 2927963Ssteve#if 0 3020420Sstevestatic char * const rcsid = "@(#)undo.c,v 1.1 1994/02/01 00:34:44 alm Exp"; 3127963Ssteve#else 3227963Sstevestatic char * const rcsid = 3350471Speter "$FreeBSD: head/bin/ed/undo.c 50471 1999-08-27 23:15:48Z peter $"; 3427963Ssteve#endif 351057Salm#endif /* not lint */ 361057Salm 371057Salm#include "ed.h" 381057Salm 391057Salm 401057Salm#define USIZE 100 /* undo stack size */ 411057Salmundo_t *ustack = NULL; /* undo stack */ 421057Salmlong usize = 0; /* stack size variable */ 431057Salmlong u_p = 0; /* undo stack pointer */ 441057Salm 4546684Skris/* push_undo_stack: return pointer to initialized undo node */ 461057Salmundo_t * 471057Salmpush_undo_stack(type, from, to) 481057Salm int type; 491057Salm long from; 501057Salm long to; 511057Salm{ 521057Salm undo_t *t; 531057Salm 541057Salm#if defined(sun) || defined(NO_REALLOC_NULL) 551057Salm if (ustack == NULL && 561057Salm (ustack = (undo_t *) malloc((usize = USIZE) * sizeof(undo_t))) == NULL) { 571057Salm fprintf(stderr, "%s\n", strerror(errno)); 581057Salm sprintf(errmsg, "out of memory"); 591057Salm return NULL; 601057Salm } 611057Salm#endif 621057Salm t = ustack; 631057Salm if (u_p < usize || 641057Salm (t = (undo_t *) realloc(ustack, (usize += USIZE) * sizeof(undo_t))) != NULL) { 651057Salm ustack = t; 661057Salm ustack[u_p].type = type; 671057Salm ustack[u_p].t = get_addressed_line_node(to); 681057Salm ustack[u_p].h = get_addressed_line_node(from); 691057Salm return ustack + u_p++; 701057Salm } 711057Salm /* out of memory - release undo stack */ 721057Salm fprintf(stderr, "%s\n", strerror(errno)); 731057Salm sprintf(errmsg, "out of memory"); 741057Salm clear_undo_stack(); 751057Salm free(ustack); 761057Salm ustack = NULL; 771057Salm usize = 0; 781057Salm return NULL; 791057Salm} 801057Salm 811057Salm 821057Salm/* USWAP: swap undo nodes */ 831057Salm#define USWAP(x,y) { \ 841057Salm undo_t utmp; \ 851057Salm utmp = x, x = y, y = utmp; \ 861057Salm} 871057Salm 881057Salm 891057Salmlong u_current_addr = -1; /* if >= 0, undo enabled */ 901057Salmlong u_addr_last = -1; /* if >= 0, undo enabled */ 911057Salm 921057Salm/* pop_undo_stack: undo last change to the editor buffer */ 931057Salmint 941057Salmpop_undo_stack() 951057Salm{ 961057Salm long n; 971057Salm long o_current_addr = current_addr; 981057Salm long o_addr_last = addr_last; 991057Salm 1001057Salm if (u_current_addr == -1 || u_addr_last == -1) { 1011057Salm sprintf(errmsg, "nothing to undo"); 1021057Salm return ERR; 1031057Salm } else if (u_p) 1041057Salm modified = 1; 1051057Salm get_addressed_line_node(0); /* this get_addressed_line_node last! */ 1061057Salm SPL1(); 1071057Salm for (n = u_p; n-- > 0;) { 1081057Salm switch(ustack[n].type) { 1091057Salm case UADD: 1101057Salm REQUE(ustack[n].h->q_back, ustack[n].t->q_forw); 1111057Salm break; 1121057Salm case UDEL: 1131057Salm REQUE(ustack[n].h->q_back, ustack[n].h); 1141057Salm REQUE(ustack[n].t, ustack[n].t->q_forw); 1151057Salm break; 1161057Salm case UMOV: 1171057Salm case VMOV: 1181057Salm REQUE(ustack[n - 1].h, ustack[n].h->q_forw); 1191057Salm REQUE(ustack[n].t->q_back, ustack[n - 1].t); 1201057Salm REQUE(ustack[n].h, ustack[n].t); 1211057Salm n--; 1221057Salm break; 1231057Salm default: 1241057Salm /*NOTREACHED*/ 1251057Salm ; 1261057Salm } 1271057Salm ustack[n].type ^= 1; 1281057Salm } 1291057Salm /* reverse undo stack order */ 1301057Salm for (n = u_p; n-- > (u_p + 1)/ 2;) 1311057Salm USWAP(ustack[n], ustack[u_p - 1 - n]); 1321057Salm if (isglobal) 1331057Salm clear_active_list(); 1341057Salm current_addr = u_current_addr, u_current_addr = o_current_addr; 1351057Salm addr_last = u_addr_last, u_addr_last = o_addr_last; 1361057Salm SPL0(); 1371057Salm return 0; 1381057Salm} 1391057Salm 1401057Salm 1411057Salm/* clear_undo_stack: clear the undo stack */ 1421057Salmvoid 1431057Salmclear_undo_stack() 1441057Salm{ 1451057Salm line_t *lp, *ep, *tl; 1461057Salm 1471057Salm while (u_p--) 1481057Salm if (ustack[u_p].type == UDEL) { 1491057Salm ep = ustack[u_p].t->q_forw; 1501057Salm for (lp = ustack[u_p].h; lp != ep; lp = tl) { 1511057Salm unmark_line_node(lp); 1521057Salm tl = lp->q_forw; 1531057Salm free(lp); 1541057Salm } 1551057Salm } 1561057Salm u_p = 0; 1571057Salm u_current_addr = current_addr; 1581057Salm u_addr_last = addr_last; 1591057Salm} 160