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 2899109Sobrien#include <sys/cdefs.h> 2999109Sobrien__FBSDID("$FreeBSD$"); 301057Salm 311057Salm#include "ed.h" 321057Salm 331057Salm 341057Salm#define USIZE 100 /* undo stack size */ 35241720Sedstatic undo_t *ustack = NULL; /* undo stack */ 36241720Sedstatic long usize = 0; /* stack size variable */ 37241720Sedstatic long u_p = 0; /* undo stack pointer */ 381057Salm 3946684Skris/* push_undo_stack: return pointer to initialized undo node */ 401057Salmundo_t * 4190109Simppush_undo_stack(int type, long from, long to) 421057Salm{ 431057Salm undo_t *t; 441057Salm 451057Salm#if defined(sun) || defined(NO_REALLOC_NULL) 461057Salm if (ustack == NULL && 471057Salm (ustack = (undo_t *) malloc((usize = USIZE) * sizeof(undo_t))) == NULL) { 481057Salm fprintf(stderr, "%s\n", strerror(errno)); 4981220Smike errmsg = "out of memory"; 501057Salm return NULL; 511057Salm } 521057Salm#endif 531057Salm t = ustack; 541057Salm if (u_p < usize || 551057Salm (t = (undo_t *) realloc(ustack, (usize += USIZE) * sizeof(undo_t))) != NULL) { 561057Salm ustack = t; 571057Salm ustack[u_p].type = type; 581057Salm ustack[u_p].t = get_addressed_line_node(to); 591057Salm ustack[u_p].h = get_addressed_line_node(from); 601057Salm return ustack + u_p++; 611057Salm } 621057Salm /* out of memory - release undo stack */ 631057Salm fprintf(stderr, "%s\n", strerror(errno)); 6481220Smike errmsg = "out of memory"; 651057Salm clear_undo_stack(); 661057Salm free(ustack); 671057Salm ustack = NULL; 681057Salm usize = 0; 691057Salm return NULL; 701057Salm} 711057Salm 721057Salm 731057Salm/* USWAP: swap undo nodes */ 741057Salm#define USWAP(x,y) { \ 751057Salm undo_t utmp; \ 761057Salm utmp = x, x = y, y = utmp; \ 771057Salm} 781057Salm 791057Salm 801057Salmlong u_current_addr = -1; /* if >= 0, undo enabled */ 811057Salmlong u_addr_last = -1; /* if >= 0, undo enabled */ 821057Salm 831057Salm/* pop_undo_stack: undo last change to the editor buffer */ 841057Salmint 8590109Simppop_undo_stack(void) 861057Salm{ 871057Salm long n; 881057Salm long o_current_addr = current_addr; 891057Salm long o_addr_last = addr_last; 901057Salm 911057Salm if (u_current_addr == -1 || u_addr_last == -1) { 9281220Smike errmsg = "nothing to undo"; 931057Salm return ERR; 941057Salm } else if (u_p) 951057Salm modified = 1; 961057Salm get_addressed_line_node(0); /* this get_addressed_line_node last! */ 971057Salm SPL1(); 981057Salm for (n = u_p; n-- > 0;) { 991057Salm switch(ustack[n].type) { 1001057Salm case UADD: 1011057Salm REQUE(ustack[n].h->q_back, ustack[n].t->q_forw); 1021057Salm break; 1031057Salm case UDEL: 1041057Salm REQUE(ustack[n].h->q_back, ustack[n].h); 1051057Salm REQUE(ustack[n].t, ustack[n].t->q_forw); 1061057Salm break; 1071057Salm case UMOV: 1081057Salm case VMOV: 1091057Salm REQUE(ustack[n - 1].h, ustack[n].h->q_forw); 1101057Salm REQUE(ustack[n].t->q_back, ustack[n - 1].t); 1111057Salm REQUE(ustack[n].h, ustack[n].t); 1121057Salm n--; 1131057Salm break; 1141057Salm default: 1151057Salm /*NOTREACHED*/ 1161057Salm ; 1171057Salm } 1181057Salm ustack[n].type ^= 1; 1191057Salm } 1201057Salm /* reverse undo stack order */ 1211057Salm for (n = u_p; n-- > (u_p + 1)/ 2;) 1221057Salm USWAP(ustack[n], ustack[u_p - 1 - n]); 1231057Salm if (isglobal) 1241057Salm clear_active_list(); 1251057Salm current_addr = u_current_addr, u_current_addr = o_current_addr; 1261057Salm addr_last = u_addr_last, u_addr_last = o_addr_last; 1271057Salm SPL0(); 1281057Salm return 0; 1291057Salm} 1301057Salm 1311057Salm 1321057Salm/* clear_undo_stack: clear the undo stack */ 1331057Salmvoid 13490109Simpclear_undo_stack(void) 1351057Salm{ 1361057Salm line_t *lp, *ep, *tl; 1371057Salm 1381057Salm while (u_p--) 1391057Salm if (ustack[u_p].type == UDEL) { 1401057Salm ep = ustack[u_p].t->q_forw; 1411057Salm for (lp = ustack[u_p].h; lp != ep; lp = tl) { 1421057Salm unmark_line_node(lp); 1431057Salm tl = lp->q_forw; 1441057Salm free(lp); 1451057Salm } 1461057Salm } 1471057Salm u_p = 0; 1481057Salm u_current_addr = current_addr; 1491057Salm u_addr_last = addr_last; 1501057Salm} 151