undo.c revision 90109
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 90109 2002-02-02 06:36:49Z imp $"; 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 * 4390109Simppush_undo_stack(int type, long from, long to) 441057Salm{ 451057Salm undo_t *t; 461057Salm 471057Salm#if defined(sun) || defined(NO_REALLOC_NULL) 481057Salm if (ustack == NULL && 491057Salm (ustack = (undo_t *) malloc((usize = USIZE) * sizeof(undo_t))) == NULL) { 501057Salm fprintf(stderr, "%s\n", strerror(errno)); 5181220Smike errmsg = "out of memory"; 521057Salm return NULL; 531057Salm } 541057Salm#endif 551057Salm t = ustack; 561057Salm if (u_p < usize || 571057Salm (t = (undo_t *) realloc(ustack, (usize += USIZE) * sizeof(undo_t))) != NULL) { 581057Salm ustack = t; 591057Salm ustack[u_p].type = type; 601057Salm ustack[u_p].t = get_addressed_line_node(to); 611057Salm ustack[u_p].h = get_addressed_line_node(from); 621057Salm return ustack + u_p++; 631057Salm } 641057Salm /* out of memory - release undo stack */ 651057Salm fprintf(stderr, "%s\n", strerror(errno)); 6681220Smike errmsg = "out of memory"; 671057Salm clear_undo_stack(); 681057Salm free(ustack); 691057Salm ustack = NULL; 701057Salm usize = 0; 711057Salm return NULL; 721057Salm} 731057Salm 741057Salm 751057Salm/* USWAP: swap undo nodes */ 761057Salm#define USWAP(x,y) { \ 771057Salm undo_t utmp; \ 781057Salm utmp = x, x = y, y = utmp; \ 791057Salm} 801057Salm 811057Salm 821057Salmlong u_current_addr = -1; /* if >= 0, undo enabled */ 831057Salmlong u_addr_last = -1; /* if >= 0, undo enabled */ 841057Salm 851057Salm/* pop_undo_stack: undo last change to the editor buffer */ 861057Salmint 8790109Simppop_undo_stack(void) 881057Salm{ 891057Salm long n; 901057Salm long o_current_addr = current_addr; 911057Salm long o_addr_last = addr_last; 921057Salm 931057Salm if (u_current_addr == -1 || u_addr_last == -1) { 9481220Smike errmsg = "nothing to undo"; 951057Salm return ERR; 961057Salm } else if (u_p) 971057Salm modified = 1; 981057Salm get_addressed_line_node(0); /* this get_addressed_line_node last! */ 991057Salm SPL1(); 1001057Salm for (n = u_p; n-- > 0;) { 1011057Salm switch(ustack[n].type) { 1021057Salm case UADD: 1031057Salm REQUE(ustack[n].h->q_back, ustack[n].t->q_forw); 1041057Salm break; 1051057Salm case UDEL: 1061057Salm REQUE(ustack[n].h->q_back, ustack[n].h); 1071057Salm REQUE(ustack[n].t, ustack[n].t->q_forw); 1081057Salm break; 1091057Salm case UMOV: 1101057Salm case VMOV: 1111057Salm REQUE(ustack[n - 1].h, ustack[n].h->q_forw); 1121057Salm REQUE(ustack[n].t->q_back, ustack[n - 1].t); 1131057Salm REQUE(ustack[n].h, ustack[n].t); 1141057Salm n--; 1151057Salm break; 1161057Salm default: 1171057Salm /*NOTREACHED*/ 1181057Salm ; 1191057Salm } 1201057Salm ustack[n].type ^= 1; 1211057Salm } 1221057Salm /* reverse undo stack order */ 1231057Salm for (n = u_p; n-- > (u_p + 1)/ 2;) 1241057Salm USWAP(ustack[n], ustack[u_p - 1 - n]); 1251057Salm if (isglobal) 1261057Salm clear_active_list(); 1271057Salm current_addr = u_current_addr, u_current_addr = o_current_addr; 1281057Salm addr_last = u_addr_last, u_addr_last = o_addr_last; 1291057Salm SPL0(); 1301057Salm return 0; 1311057Salm} 1321057Salm 1331057Salm 1341057Salm/* clear_undo_stack: clear the undo stack */ 1351057Salmvoid 13690109Simpclear_undo_stack(void) 1371057Salm{ 1381057Salm line_t *lp, *ep, *tl; 1391057Salm 1401057Salm while (u_p--) 1411057Salm if (ustack[u_p].type == UDEL) { 1421057Salm ep = ustack[u_p].t->q_forw; 1431057Salm for (lp = ustack[u_p].h; lp != ep; lp = tl) { 1441057Salm unmark_line_node(lp); 1451057Salm tl = lp->q_forw; 1461057Salm free(lp); 1471057Salm } 1481057Salm } 1491057Salm u_p = 0; 1501057Salm u_current_addr = current_addr; 1511057Salm u_addr_last = addr_last; 1521057Salm} 153