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"
26 #include "stringfile.h"
27 #include "undostack.h"
30 UndoStack::UndoStack() : List<UndoStackItem>()
35 UndoStack::~UndoStack()
39 UndoStackItem* UndoStack::push()
41 // current is only 0 if before first undo
43 current = insert_after(current);
45 current = insert_before(first);
47 // delete future undos if necessary
48 if(current && current->next)
50 while(current->next) remove(last);
53 // delete oldest 2 undos if necessary
54 if(total() > UNDOLEVELS)
56 for(int i = 0; i < 2; i++)
58 UndoStackItem *second = first->next;
64 temp_data = second->get_data();
68 // Convert new first to key buffer.
71 second->set_data(temp_data);
80 void UndoStack::pull()
82 if(current) current = PREVIOUS;
85 UndoStackItem* UndoStack::pull_next()
87 // use first entry if none
91 // use next entry if there is a next entry
94 // don't change current if there is no next entry
102 void UndoStack::dump(FILE *fp)
104 fprintf(fp,"UndoStack::dump\n");
105 UndoStackItem *current = last;
108 while(current && i < 10)
110 fprintf(fp," %d %p %s %c\n",
113 current->get_description(),
114 current == this->current ? '*' : ' ');
137 // These difference routines are straight out of the Heroinediff/Heroinepatch
145 // We didn't want to use the diff program because that isn't efficient enough
146 // to compress EDL's. This program also handles binary data.
149 // Search from beginning for first difference.
150 // Count everything up to first difference as equal.
151 // Determine length of different block by searching for transposition with most
152 // similar characters.
153 // For every byte in different block, search for occurrence of
154 // transposed copy longer than a record header in remaining old buffer.
155 // If no match is found, add 1 to the different block length and try the next
156 // byte. Once the most similar match is found, store the changed data leading up to it in the
157 // difference record.
158 // This can be real slow if there is a large transposition early in the file.
161 // Search backwards from end of both files for last difference.
162 // Count all data from last same bytes as a transposition.
163 // Search forwards from start of both files until last same bytes
173 // Minimum size of transposed block.
174 // Smaller transpositions should be included in the same difference record.
177 // Format for difference records.
178 // The first 4 bytes are the offset of the change.
179 // The next 4 bytes are the number of bytes of new data.
180 // The next 4 bytes are the number of bytes of old data replaced.
181 // The new data follows.
182 static void append_record(unsigned char **result,
184 unsigned char *new_data,
189 if(new_size || old_size)
191 int record_size = new_size + 12;
192 unsigned char *new_result = new unsigned char[(*result_size) + record_size];
193 memcpy(new_result, (*result), (*result_size));
196 unsigned char *new_result_ptr = new_result + (*result_size);
197 *(int32_t*)new_result_ptr = new_offset;
199 *(int32_t*)new_result_ptr = new_size;
201 *(int32_t*)new_result_ptr = old_size;
204 memcpy(new_result_ptr, new_data, new_size);
205 (*result_size) += record_size;
206 (*result) = new_result;
212 static unsigned char* get_difference_fast(unsigned char *before,
214 unsigned char *after,
219 unsigned char *result = new unsigned char[4];
222 // Store size of new buffer
223 *(int32_t*)result = after_len;
227 // Get last different bytes
228 unsigned char *last_difference_after = after + after_len - 1;
229 unsigned char *last_difference_before = before + before_len - 1;
232 if(last_difference_after < after ||
233 last_difference_before < before) break;
234 if(*last_difference_after != *last_difference_before)
238 last_difference_after--;
239 last_difference_before--;
241 last_difference_after++;
242 last_difference_before++;
250 unsigned char *before_ptr = before;
251 unsigned char *after_ptr = after;
252 unsigned char *before_end = before + before_len;
253 unsigned char *after_end = after + after_len;
255 // Scan forward for first difference
258 if(before_ptr < before_end &&
259 after_ptr < after_end)
261 // Both characters equal
262 if(*before_ptr == *after_ptr &&
263 before_ptr < last_difference_before &&
264 after_ptr < last_difference_after)
272 // Get length of difference.
273 unsigned char *before_difference_start = before_ptr;
274 unsigned char *after_difference_start = after_ptr;
277 while(*before_ptr != *after_ptr &&
278 before_ptr < last_difference_before &&
279 after_ptr < last_difference_after)
285 // Finished comparing if either pointer hits its last difference
286 if(before_ptr >= last_difference_before ||
287 after_ptr >= last_difference_after)
290 before_ptr = last_difference_before;
291 after_ptr = last_difference_after;
296 int after_start = after_difference_start - after;
297 int before_start = before_difference_start - before;
298 int after_len = after_ptr - after_difference_start;
299 int before_len = before_ptr - before_difference_start;
304 memcpy(string, after_difference_start, MIN(after_len, 40));
305 string[MIN(after_len, 40)] = 0;
306 printf("after_offset=0x%x before_offset=0x%x after_size=%d before_size=%d \"%s\"\n",
315 // Create difference record
316 append_record(&result,
318 after_difference_start,
338 static void get_record(unsigned char **patch_ptr,
339 unsigned char *patch_end,
340 unsigned char **after_data,
346 if((*patch_ptr) < patch_end)
348 (*after_offset) = *(int32_t*)(*patch_ptr);
350 (*after_size) = *(int32_t*)(*patch_ptr);
352 (*before_size) = *(int32_t*)(*patch_ptr);
355 (*after_data) = (*patch_ptr);
356 (*patch_ptr) += (*after_size);
364 static unsigned char* apply_difference(unsigned char *before,
366 unsigned char *patch,
370 unsigned char *patch_ptr = patch;
371 *result_len = *(int32_t*)patch_ptr;
373 unsigned char *patch_end = patch + patch_len;
374 //unsigned char *before_end = before + before_len;
376 unsigned char *result = new unsigned char[*result_len];
377 unsigned char *result_ptr = result;
378 unsigned char *result_end = result + *result_len;
379 unsigned char *before_ptr = before;
384 unsigned char *after_data;
389 get_record(&patch_ptr,
398 int result_offset = result_ptr - result;
399 if(after_offset > result_offset)
401 int skip_size = after_offset - result_offset;
402 memcpy(result_ptr, before_ptr, skip_size);
403 result_ptr += skip_size;
404 before_ptr += skip_size;
406 memcpy(result_ptr, after_data, after_size);
407 result_ptr += after_size;
408 before_ptr += before_size;
412 // All data from before_ptr to end of result buffer is identical
413 if(result_end - result_ptr > 0)
414 memcpy(result_ptr, before_ptr, result_end - result_ptr);
431 UndoStackItem::UndoStackItem()
432 : ListItem<UndoStackItem>()
434 description = data = 0;
438 session_filename = 0;
441 UndoStackItem::~UndoStackItem()
443 delete [] description;
445 if( session_filename ) free( (void*)session_filename );
448 void UndoStackItem::set_description(char *description)
450 delete [] this->description;
451 this->description= 0;
452 this->description = new char[strlen(description) + 1];
453 strcpy(this->description, description);
456 void UndoStackItem::set_filename(char *filename)
458 if( session_filename ) free( (void*)session_filename );
459 this->session_filename = strdup(filename);
462 char* UndoStackItem::get_filename()
464 return session_filename;
468 const char* UndoStackItem::get_description()
476 int UndoStackItem::has_data()
478 return data_size ? 1 : 0;
481 void UndoStackItem::set_data(char *data)
483 delete [] this->data;
487 // Search for key buffer within interval
489 UndoStackItem *current = this;
491 for(int i = 0; i < UNDO_KEY_INTERVAL && current; i++)
493 if(current->key && current->has_data())
502 int new_size = strlen(data) + 1;
506 // Reconstruct previous data for difference
507 char *prev_buffer = previous->get_data();
508 int prev_size = prev_buffer ? strlen(prev_buffer) + 1 : 0;
511 // printf("UndoStackItem::set_data 1\n");
512 this->data = (char*)get_difference_fast((unsigned char*)prev_buffer,
514 (unsigned char*)data,
518 //printf("UndoStackItem::set_data 2 " _LD "\n", timer.get_difference());
521 // FILE *test1 = fopen("/tmp/undo1", "w");
522 // fwrite(prev_buffer, prev_size, 1, test1);
524 // FILE *test2 = fopen("/tmp/undo2", "w");
525 // fwrite(data, new_size, 1, test2);
527 // FILE *test3 = fopen("/tmp/undo2.diff", "w");
528 // fwrite(this->data, this->data_size, 1, test3);
531 //printf("UndoStackItem::set_data 3 %d %d\n", new_size, this->data_size);
533 // Diff was bigger than original.
534 // Happens if a lot of tiny changes happened and the record headers
535 // took more space than the changes.
536 if(this->data_size > new_size)
538 delete [] this->data;
544 // Reconstruct current data from difference
546 char *test_buffer = (char*)apply_difference((unsigned char*)prev_buffer,
548 (unsigned char*)this->data,
551 if(test_size != new_size ||
552 memcmp(test_buffer, data, test_size))
554 // FILE *test1 = fopen("/tmp/undo1", "w");
555 // fwrite(prev_buffer, prev_size, 1, test1);
557 // FILE *test2 = fopen("/tmp/undo2", "w");
558 // fwrite(data, new_size, 1, test2);
560 // FILE *test3 = fopen("/tmp/undo2.diff", "w");
561 // fwrite(this->data, this->data_size, 1, test3);
563 // FILE *test4 = fopen("/tmp/undo3", "w");
564 // fwrite(test_buffer, test_size, 1, test4);
567 printf("UndoStackItem::set_data: incremental undo failed!\n");
569 delete [] this->data;
573 delete [] test_buffer;
578 delete [] prev_buffer;
584 this->data_size = new_size;
585 this->data = new char[this->data_size];
586 memcpy(this->data, data, this->data_size);
593 char* UndoStackItem::get_incremental_data()
598 int UndoStackItem::get_incremental_size()
603 int UndoStackItem::get_size()
608 char* UndoStackItem::get_data()
610 // Find latest key buffer
611 UndoStackItem *current = this;
612 while(current && !current->key)
616 printf("UndoStackItem::get_data: no key buffer found!\n");
620 // This is the key buffer
623 char *result = new char[data_size];
624 memcpy(result, data, data_size);
629 char *current_data = current->get_data();
630 int current_size = current->get_size();
634 // Do incremental updates
636 char *new_data = (char*)apply_difference((unsigned char*)current_data,
638 (unsigned char*)current->get_incremental_data(),
639 current->get_incremental_size(),
641 delete [] current_data;
647 current_data = new_data;
648 current_size = new_size;
653 // Never hit this object.
654 delete [] current_data;
655 printf("UndoStackItem::get_data: lost starting object!\n");
662 int UndoStackItem::is_key()
667 void UndoStackItem::set_flags(uint64_t flags)
669 this->load_flags = flags;
672 uint64_t UndoStackItem::get_flags()
677 void UndoStackItem::set_creator(void *creator)
679 this->creator = creator;
682 void* UndoStackItem::get_creator()