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 "undostack.h"
29 UndoStack::UndoStack() : List<UndoStackItem>()
34 UndoStack::~UndoStack()
38 UndoStackItem* UndoStack::push()
40 // current is only 0 if before first undo
42 current = insert_after(current);
44 current = insert_before(first);
46 // delete future undos if necessary
47 if(current && current->next)
49 while(current->next) remove(last);
52 // delete oldest 2 undos if necessary
53 if(total() > UNDOLEVELS)
55 for(int i = 0; i < 2; i++)
57 UndoStackItem *second = first->next;
63 temp_data = second->get_data();
67 // Convert new first to key buffer.
70 second->set_data(temp_data);
79 void UndoStack::pull()
81 if(current) current = PREVIOUS;
84 UndoStackItem* UndoStack::pull_next()
86 // use first entry if none
90 // use next entry if there is a next entry
93 // don't change current if there is no next entry
101 void UndoStack::dump(FILE *fp)
103 fprintf(fp,"UndoStack::dump\n");
104 UndoStackItem *current = last;
107 while(current && i < 10)
109 fprintf(fp," %d %p %s %c\n",
112 current->get_description(),
113 current == this->current ? '*' : ' ');
136 // These difference routines are straight out of the Heroinediff/Heroinepatch
144 // We didn't want to use the diff program because that isn't efficient enough
145 // to compress EDL's. This program also handles binary data.
148 // Search from beginning for first difference.
149 // Count everything up to first difference as equal.
150 // Determine length of different block by searching for transposition with most
151 // similar characters.
152 // For every byte in different block, search for occurrence of
153 // transposed copy longer than a record header in remaining old buffer.
154 // If no match is found, add 1 to the different block length and try the next
155 // byte. Once the most similar match is found, store the changed data leading up to it in the
156 // difference record.
157 // This can be real slow if there is a large transposition early in the file.
160 // Search backwards from end of both files for last difference.
161 // Count all data from last same bytes as a transposition.
162 // Search forwards from start of both files until last same bytes
172 // Minimum size of transposed block.
173 // Smaller transpositions should be included in the same difference record.
176 // Format for difference records.
177 // The first 4 bytes are the offset of the change.
178 // The next 4 bytes are the number of bytes of new data.
179 // The next 4 bytes are the number of bytes of old data replaced.
180 // The new data follows.
181 static void append_record(unsigned char **result,
183 unsigned char *new_data,
188 if(new_size || old_size)
190 int record_size = new_size + 12;
191 unsigned char *new_result = new unsigned char[(*result_size) + record_size];
192 memcpy(new_result, (*result), (*result_size));
195 unsigned char *new_result_ptr = new_result + (*result_size);
196 *(int32_t*)new_result_ptr = new_offset;
198 *(int32_t*)new_result_ptr = new_size;
200 *(int32_t*)new_result_ptr = old_size;
203 memcpy(new_result_ptr, new_data, new_size);
204 (*result_size) += record_size;
205 (*result) = new_result;
211 static unsigned char* get_difference_fast(unsigned char *before,
213 unsigned char *after,
218 unsigned char *result = new unsigned char[4];
221 // Store size of new buffer
222 *(int32_t*)result = after_len;
226 // Get last different bytes
227 unsigned char *last_difference_after = after + after_len - 1;
228 unsigned char *last_difference_before = before + before_len - 1;
231 if(last_difference_after < after ||
232 last_difference_before < before) break;
233 if(*last_difference_after != *last_difference_before)
237 last_difference_after--;
238 last_difference_before--;
240 last_difference_after++;
241 last_difference_before++;
249 unsigned char *before_ptr = before;
250 unsigned char *after_ptr = after;
251 unsigned char *before_end = before + before_len;
252 unsigned char *after_end = after + after_len;
254 // Scan forward for first difference
257 if(before_ptr < before_end &&
258 after_ptr < after_end)
260 // Both characters equal
261 if(*before_ptr == *after_ptr &&
262 before_ptr < last_difference_before &&
263 after_ptr < last_difference_after)
271 // Get length of difference.
272 unsigned char *before_difference_start = before_ptr;
273 unsigned char *after_difference_start = after_ptr;
276 while(*before_ptr != *after_ptr &&
277 before_ptr < last_difference_before &&
278 after_ptr < last_difference_after)
284 // Finished comparing if either pointer hits its last difference
285 if(before_ptr >= last_difference_before ||
286 after_ptr >= last_difference_after)
289 before_ptr = last_difference_before;
290 after_ptr = last_difference_after;
295 int after_start = after_difference_start - after;
296 int before_start = before_difference_start - before;
297 int after_len = after_ptr - after_difference_start;
298 int before_len = before_ptr - before_difference_start;
303 memcpy(string, after_difference_start, MIN(after_len, 40));
304 string[MIN(after_len, 40)] = 0;
305 printf("after_offset=0x%x before_offset=0x%x after_size=%d before_size=%d \"%s\"\n",
314 // Create difference record
315 append_record(&result,
317 after_difference_start,
337 static void get_record(unsigned char **patch_ptr,
338 unsigned char *patch_end,
339 unsigned char **after_data,
345 if((*patch_ptr) < patch_end)
347 (*after_offset) = *(int32_t*)(*patch_ptr);
349 (*after_size) = *(int32_t*)(*patch_ptr);
351 (*before_size) = *(int32_t*)(*patch_ptr);
354 (*after_data) = (*patch_ptr);
355 (*patch_ptr) += (*after_size);
363 static unsigned char* apply_difference(unsigned char *before,
365 unsigned char *patch,
369 unsigned char *patch_ptr = patch;
370 *result_len = *(int32_t*)patch_ptr;
372 unsigned char *patch_end = patch + patch_len;
373 //unsigned char *before_end = before + before_len;
375 unsigned char *result = new unsigned char[*result_len];
376 unsigned char *result_ptr = result;
377 unsigned char *result_end = result + *result_len;
378 unsigned char *before_ptr = before;
383 unsigned char *after_data;
388 get_record(&patch_ptr,
397 int result_offset = result_ptr - result;
398 if(after_offset > result_offset)
400 int skip_size = after_offset - result_offset;
401 memcpy(result_ptr, before_ptr, skip_size);
402 result_ptr += skip_size;
403 before_ptr += skip_size;
405 memcpy(result_ptr, after_data, after_size);
406 result_ptr += after_size;
407 before_ptr += before_size;
411 // All data from before_ptr to end of result buffer is identical
412 if(result_end - result_ptr > 0)
413 memcpy(result_ptr, before_ptr, result_end - result_ptr);
422 UndoStackItem::UndoStackItem()
423 : ListItem<UndoStackItem>()
425 description = data = 0;
429 session_filename = 0;
432 UndoStackItem::~UndoStackItem()
434 delete [] description;
436 delete [] session_filename;
439 void UndoStackItem::set_description(char *description)
441 delete [] this->description;
442 this->description= 0;
443 this->description = new char[strlen(description) + 1];
444 strcpy(this->description, description);
447 void UndoStackItem::set_filename(char *filename)
449 delete [] session_filename;
450 this->session_filename = cstrdup(filename);
453 char* UndoStackItem::get_filename()
455 return session_filename;
459 const char* UndoStackItem::get_description()
467 int UndoStackItem::has_data()
469 return data_size ? 1 : 0;
472 void UndoStackItem::set_data(char *data)
474 delete [] this->data;
478 // Search for key buffer within interval
480 UndoStackItem *current = this;
482 for(int i = 0; i < UNDO_KEY_INTERVAL && current; i++)
484 if(current->key && current->has_data())
493 int new_size = strlen(data) + 1;
497 // Reconstruct previous data for difference
498 char *prev_buffer = previous->get_data();
499 int prev_size = prev_buffer ? strlen(prev_buffer) + 1 : 0;
502 // printf("UndoStackItem::set_data 1\n");
503 this->data = (char*)get_difference_fast((unsigned char*)prev_buffer,
505 (unsigned char*)data,
509 //printf("UndoStackItem::set_data 2 " _LD "\n", timer.get_difference());
512 // FILE *test1 = fopen("/tmp/undo1", "w");
513 // fwrite(prev_buffer, prev_size, 1, test1);
515 // FILE *test2 = fopen("/tmp/undo2", "w");
516 // fwrite(data, new_size, 1, test2);
518 // FILE *test3 = fopen("/tmp/undo2.diff", "w");
519 // fwrite(this->data, this->data_size, 1, test3);
522 //printf("UndoStackItem::set_data 3 %d %d\n", new_size, this->data_size);
524 // Diff was bigger than original.
525 // Happens if a lot of tiny changes happened and the record headers
526 // took more space than the changes.
527 if(this->data_size > new_size)
529 delete [] this->data;
535 // Reconstruct current data from difference
537 char *test_buffer = (char*)apply_difference((unsigned char*)prev_buffer,
539 (unsigned char*)this->data,
542 if(test_size != new_size ||
543 memcmp(test_buffer, data, test_size))
545 // FILE *test1 = fopen("/tmp/undo1", "w");
546 // fwrite(prev_buffer, prev_size, 1, test1);
548 // FILE *test2 = fopen("/tmp/undo2", "w");
549 // fwrite(data, new_size, 1, test2);
551 // FILE *test3 = fopen("/tmp/undo2.diff", "w");
552 // fwrite(this->data, this->data_size, 1, test3);
554 // FILE *test4 = fopen("/tmp/undo3", "w");
555 // fwrite(test_buffer, test_size, 1, test4);
558 printf("UndoStackItem::set_data: incremental undo failed!\n");
560 delete [] this->data;
564 delete [] test_buffer;
569 delete [] prev_buffer;
575 this->data_size = new_size;
576 this->data = new char[this->data_size];
577 memcpy(this->data, data, this->data_size);
584 char* UndoStackItem::get_incremental_data()
589 int UndoStackItem::get_incremental_size()
594 int UndoStackItem::get_size()
599 char* UndoStackItem::get_data()
601 // Find latest key buffer
602 UndoStackItem *current = this;
603 while(current && !current->key)
607 printf("UndoStackItem::get_data: no key buffer found!\n");
611 // This is the key buffer
614 char *result = new char[data_size];
615 memcpy(result, data, data_size);
620 char *current_data = current->get_data();
621 int current_size = current->get_size();
625 // Do incremental updates
627 char *new_data = (char*)apply_difference((unsigned char*)current_data,
629 (unsigned char*)current->get_incremental_data(),
630 current->get_incremental_size(),
632 delete [] current_data;
638 current_data = new_data;
639 current_size = new_size;
644 // Never hit this object.
645 delete [] current_data;
646 printf("UndoStackItem::get_data: lost starting object!\n");
653 int UndoStackItem::is_key()
658 void UndoStackItem::set_flags(uint64_t flags)
660 this->load_flags = flags;
663 uint64_t UndoStackItem::get_flags()
668 void UndoStackItem::set_creator(void *creator)
670 this->creator = creator;
673 void* UndoStackItem::get_creator()