4 * Copyright (C) 2008 Adam Williams <broadcast at earthling dot net>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include "bcsignals.h"
27 #include "undostack.h"
30 UndoStack::UndoStack() : List<UndoStackItem>()
35 UndoStack::~UndoStack()
39 UndoStackItem *UndoStack::get_current_undo()
41 UndoStackItem *item = current;
42 if( item && (number_of(item) & 1) ) item = item->previous;
43 if( item && !(number_of(item) & 1) ) item = item->previous;
47 UndoStackItem *UndoStack::get_current_redo()
49 UndoStackItem *item = current ? current : first;
50 if( item && (number_of(item) & 1) ) item = item->next;
51 if( item && !(number_of(item) & 1) ) item = item->next;
56 UndoStackItem* UndoStack::push()
58 // current is only 0 if before first undo
60 current = insert_after(current);
62 current = insert_before(first);
64 // delete future undos if necessary
65 if( current && current->next ) {
66 while( current->next ) remove(last);
69 // delete oldest 2 undos if necessary
70 if( total() > UNDOLEVELS ) {
71 for( int i=0; i<2; ++i ) {
72 UndoStackItem *second = first->next;
76 if( !second->is_key() ) {
77 temp_data = second->get_data();
81 // Convert new first to key buffer.
82 if( !second->is_key() ) {
83 second->set_data(temp_data);
92 UndoStackItem* UndoStack::pull_next()
94 // use first entry if none
98 // use next entry if there is a next entry
101 // don't change current if there is no next entry
109 void UndoStack::dump(FILE *fp)
111 fprintf(fp,"UndoStack::dump\n");
112 UndoStackItem *current = last;
114 for( int i=0; current && i<32; ++i,current=PREVIOUS ) {
115 fprintf(fp,"%c %2d %14p %-24s %8d %04jx %c\n", current->is_key() ? 'k' : ' ',
116 i, current, current->get_description(), current->get_size(),
117 current->get_flags(), current == this->current ? '*' : ' ');
118 //char fn[BCSTRLEN]; sprintf(fn,"/tmp/undo%d", i); FILE *fp = fopen(fn,"w");
119 //if( fp ) { char *cp=current->get_data(); fwrite(cp,strlen(cp),1,fp); fclose(fp); delete [] cp; }
123 // undo can be incremental or direct, from key to current
124 //#define UNDO_INCREMENTAL
133 static unsigned char* apply_difference(unsigned char *before, int before_len,
134 unsigned char *patch, int patch_len, int *result_len)
136 XMLBuffer xbfr((const char *)patch, patch_len, 0);
138 xbfr.read((char *)&len, sizeof(len));
139 char *result = new char[len];
140 char *rp = result, *bp = (char*)before;
142 while( xbfr.itell() < patch_len ) {
144 xbfr.read((char*)&urecd, sizeof(urecd));
145 int ofs = rp - result;
146 if( urecd.new_ofs > ofs ) {
147 int sz = urecd.new_ofs - ofs;
151 if( urecd.new_len > 0 )
152 xbfr.read(rp, urecd.new_len);
153 bp += urecd.old_len; rp += urecd.new_len;
156 // All data from before_ptr to end of result buffer is identical
157 int sz = bp - (char *)before;
158 if( (before_len-=sz) > 0 ) {
159 memcpy(rp, bp, before_len);
163 *result_len = rp - result;
164 return (unsigned char *)result;
167 UndoStackItem::UndoStackItem()
168 : ListItem<UndoStackItem>()
170 description = data = 0;
174 session_filename = 0;
177 UndoStackItem::~UndoStackItem()
179 delete [] description;
181 delete [] session_filename;
184 void UndoStackItem::set_description(char *description)
186 delete [] this->description;
187 this->description= 0;
188 this->description = new char[strlen(description) + 1];
189 strcpy(this->description, description);
192 void UndoStackItem::set_filename(char *filename)
194 delete [] session_filename;
195 this->session_filename = cstrdup(filename);
198 char* UndoStackItem::get_filename()
200 return session_filename;
204 const char* UndoStackItem::get_description()
214 UndoHash::UndoHash(char *txt, int len, UndoHash *nxt)
219 line[va] = line[vb] = -1;
220 occurs[va] = occurs[vb] = 0;
222 UndoHash::~UndoHash()
226 UndoHashTable::UndoHashTable()
228 for( int i=0; i<hash_sz; ++i ) table[i] = 0;
229 bof = new UndoHash(0, 0, 0);
230 eof = new UndoHash(0, 0, 0);
232 UndoHashTable::~UndoHashTable()
236 for( int i=0; i<hash_sz; ++i ) {
237 for( UndoHash *nxt=0, *hp=table[i]; hp; hp=nxt ) {
238 nxt = hp->nxt; delete hp;
243 UndoHash *UndoHashTable::add(char *txt, int len)
245 uint8_t *bp = (uint8_t *)txt;
247 for( int i=len; --i>=0; ++bp ) {
249 v = (v + (v>>hash_sz2)) & hash_sz1;
251 UndoHash *hp = table[v];
252 while( hp && strncmp(hp->txt,txt,len) ) hp = hp->nxt;
254 hp = new UndoHash(txt, len, table[v]);
260 UndoLine::UndoLine(UndoHash *hash, char *tp)
262 this->txt = tp; this->len = 0;
264 hash->occurs[va] = hash->occurs[vb] = 1;
267 UndoLine::UndoLine(UndoHashTable *hash, char *txt, int len)
269 this->txt = txt; this->len = len;
270 this->hash = hash->add(txt, len);
272 UndoLine::~UndoLine()
276 int UndoLine::eq(UndoLine *ln)
278 return hash == ln->hash ? 1 : 0;
281 void UndoVersion::scan_lines(UndoHashTable *hash, char *sp, char *ep)
283 for( int line=1; sp<ep; ++line ) {
285 while( sp<ep && *sp++ != '\n' );
286 UndoLine *ln = new UndoLine(hash, txt, sp-txt);
287 ln->hash->line[ver] = line;
288 ++ln->hash->occurs[ver];
294 void UndoStackItem::set_data(char *data)
296 delete [] this->data; this->data = 0;
297 this->data_size = 0; this->key = 0;
298 int data_size = strlen(data)+1;
300 UndoStackItem *current = this;
301 // Search for key buffer within interval
302 for( int i=UNDO_KEY_INTERVAL; --i>=0 && current && !current->key; current=PREVIOUS );
304 int need_key = current ? 0 : 1;
305 // setting need_key = 1 forces all undo data items to key (not diffd)
307 char *prev = 0; int prev_size = 0;
309 #ifdef UNDO_INCREMENTAL
310 prev = previous->get_data();
311 prev_size = prev ? strlen(prev)+1 : 0;
313 prev = current->data;
314 prev_size = current->data_size;
316 int min_size = data_size/16;
317 // if the previous is a sizable incremental diff
318 if( previous && !previous->key &&
319 previous->data_size > min_size ) {
320 // and this minimum diff distance is a lot different, need key
321 int dist = abs(data_size - prev_size);
322 if( abs(dist - previous->data_size) > min_size )
327 int bfr_size = BCTEXTLEN;
328 char *bfr = new char[bfr_size];
329 XMLBuffer xbfr(bfr_size, bfr, 1);
330 xbfr.write((char*)&data_size, sizeof(data_size));
332 UndoVersion alines(va), blines(vb);
333 char *asp = data, *aep = asp + data_size-1;
334 char *bsp = prev, *bep = bsp + prev_size-1;
335 alines.append(new UndoLine(hash.bof, asp));
336 blines.append(new UndoLine(hash.bof, bsp));
337 alines.scan_lines(&hash, asp, aep);
338 blines.scan_lines(&hash, bsp, bep);
339 int asz = alines.size(), bsz = blines.size();
340 // trim matching suffix
341 while( asz > 0 && bsz > 0 && alines[asz-1]->eq(blines[bsz-1]) ) {
342 aep = alines[--asz]->txt; alines.remove_object();
343 bep = blines[--bsz]->txt; blines.remove_object();
345 // include for matching last item
346 alines.append(new UndoLine(hash.eof, aep));
347 blines.append(new UndoLine(hash.eof, bep));
348 hash.eof->line[va] = asz++;
349 hash.eof->line[vb] = bsz++;
352 while( ai < asz || bi < bsz ) {
353 // skip running match
354 if( alines[ai]->eq(blines[bi]) ) { ++ai; ++bi; continue; }
355 char *adp = alines[ai]->txt, *bdp = blines[bi]->txt;
356 // find best unique match
357 int ma = asz, mb = bsz;
358 int mx = ma + mb + 1;
359 for( int ia=ai; ia<asz && ia-ai<mx; ++ia ) {
360 UndoHash *ah = alines[ia]->hash;
361 if( ah->occurs[va] != 1 || ah->occurs[vb] != 1 ) continue;
362 int m = (ah->line[va] - ai) + (ah->line[vb] - bi);
363 if( m >= mx ) continue;
364 ma = ah->line[va]; mb = ah->line[vb]; mx = m;
367 while( ma > 0 && mb > 0 && alines[ma-1]->eq(blines[mb-1]) ) { --ma; --mb; }
368 char *ap = alines[ma]->txt, *bp = blines[mb]->txt;
371 urecd.new_ofs = adp - data;
372 urecd.new_len = ap - adp;
373 urecd.old_len = bp - bdp;
374 xbfr.write((const char*)&urecd, sizeof(urecd));
375 xbfr.write((const char*)adp, urecd.new_len);
378 int64_t pos = xbfr.otell();
379 if( abs(data_size-prev_size) < pos/2 ) {
380 this->data = new char[this->data_size = pos];
382 xbfr.read(this->data, pos);
385 char *test_data = (char*)apply_difference(
386 (unsigned char *)prev, prev_size,
387 (unsigned char *)this->data, this->data_size,
389 if( test_size != data_size || memcmp(test_data, data, test_size) ) {
390 printf("UndoStackItem::set_data: *** incremental undo failed!\n");
391 delete [] this->data; this->data = 0; this->data_size = 0;
401 #ifdef UNDO_INCREMENTAL
406 this->data = new char[this->data_size = data_size];
407 memcpy(this->data, data, this->data_size);
411 char* UndoStackItem::get_data()
413 // Find latest key buffer
414 UndoStackItem *current = this;
415 while( current && !current->key )
418 printf("UndoStackItem::get_data: no key buffer found!\n");
422 // This is the key buffer
423 if( current == this ) {
424 char *result = new char[data_size];
425 memcpy(result, data, data_size);
428 #ifdef UNDO_INCREMENTAL
430 char *current_data = current->get_data();
431 int current_size = current->data_size;
434 // Do incremental updates
436 char *new_data = (char*)apply_difference(
437 (unsigned char*)current_data, current_size,
438 (unsigned char*)current->data, current->data_size,
440 delete [] current_data;
442 if( current == this )
444 current_data = new_data;
445 current_size = new_size;
448 // Never hit this object.
449 delete [] current_data;
450 printf("UndoStackItem::get_data: lost starting object!\n");
454 char *new_data = (char*)apply_difference(
455 (unsigned char*)current->data, current->data_size,
456 (unsigned char*)this->data, this->data_size, &new_size);
461 int UndoStackItem::is_key()
466 int UndoStackItem::get_size()
471 void UndoStackItem::set_flags(uint64_t flags)
473 this->load_flags = flags;
476 uint64_t UndoStackItem::get_flags()
481 void UndoStackItem::set_creator(void *creator)
483 this->creator = creator;
486 void* UndoStackItem::get_creator()
491 void UndoStackItem::save(FILE *fp)
493 fwrite(&key,1,sizeof(key),fp);
494 fwrite(&load_flags,1,sizeof(load_flags),fp);
495 fwrite(&data_size,1,sizeof(data_size),fp);
496 fwrite(data,1,data_size,fp);
497 for( char *bp=session_filename; *bp; ++bp ) fputc(*bp, fp);
499 for( char *bp=description; *bp; ++bp ) fputc(*bp, fp);
503 void UndoStackItem::load(FILE *fp)
505 fread(&key,1,sizeof(key),fp);
506 fread(&load_flags,1,sizeof(load_flags),fp);
507 fread(&data_size,1,sizeof(data_size),fp);
508 fread(data=new char[data_size],1,data_size,fp);
509 char filename[BCTEXTLEN], descr[BCTEXTLEN];
510 char *bp = filename, *ep = bp+sizeof(filename)-1;
511 for( int ch; bp<ep && (ch=fgetc(fp))>0; ++bp ) *bp = ch;
513 session_filename = cstrdup(filename);
514 bp = descr; ep = bp+sizeof(descr)-1;
515 for( int ch; bp<ep && (ch=fgetc(fp))>0; ++bp ) *bp = ch;
517 description = cstrdup(descr);
518 //printf("read undo key=%d,flags=%jx,data_size=%d,data=%p,file=%s,descr=%s\n",
519 // key, load_flags, data_size, data, session_filename, description);
522 void UndoStack::save(FILE *fp)
524 for( UndoStackItem *item=first; item; item=item->next ) {
525 int is_current = item == current ? 1 : 0;
526 fwrite(&is_current,1,sizeof(is_current),fp);
528 // if( item == current ) break; // stop at current
532 void UndoStack::load(FILE *fp)
534 while( last ) delete last;
536 UndoStackItem *current_item = 0;
538 while( fread(&is_current,1,sizeof(is_current),fp) == sizeof(is_current) ) {
539 UndoStackItem *item = push();
541 if( is_current ) current_item = item;
543 if( current_item ) current = current_item;