1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
|
/*
* Copyright (C) 2011, Google Inc.
* and other copyright owners as documented in the project's IP log.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Distribution License v1.0 which
* accompanies this distribution, is reproduced below, and is
* available at http://www.eclipse.org/org/documents/edl-v10.php
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* - Neither the name of the Eclipse Foundation, Inc. nor the
* names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.eclipse.jgit.blame;
import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
import static org.eclipse.jgit.lib.FileMode.TYPE_FILE;
import java.io.IOException;
import java.util.Collection;
import java.util.Collections;
import org.eclipse.jgit.blame.Candidate.BlobCandidate;
import org.eclipse.jgit.blame.Candidate.ReverseCandidate;
import org.eclipse.jgit.blame.ReverseWalk.ReverseCommit;
import org.eclipse.jgit.diff.DiffAlgorithm;
import org.eclipse.jgit.diff.DiffEntry;
import org.eclipse.jgit.diff.DiffEntry.ChangeType;
import org.eclipse.jgit.diff.EditList;
import org.eclipse.jgit.diff.HistogramDiff;
import org.eclipse.jgit.diff.RawText;
import org.eclipse.jgit.diff.RawTextComparator;
import org.eclipse.jgit.diff.RenameDetector;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.MutableObjectId;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectLoader;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevFlag;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.treewalk.TreeWalk;
import org.eclipse.jgit.treewalk.filter.AndTreeFilter;
import org.eclipse.jgit.treewalk.filter.PathFilter;
import org.eclipse.jgit.treewalk.filter.TreeFilter;
/**
* Generate author information for lines based on a provided file.
* <p>
* Applications that want a simple one-shot computation of blame for a file
* should use {@link #computeBlameResult()} to prepare the entire result in one
* method call. This may block for significant time as the history of the
* repository must be traversed until information is gathered for every line.
* <p>
* Applications that want more incremental update behavior may use either the
* raw {@link #next()} streaming approach supported by this class, or construct
* a {@link BlameResult} using {@link BlameResult#create(BlameGenerator)} and
* incrementally construct the result with {@link BlameResult#computeNext()}.
* <p>
* This class is not thread-safe.
* <p>
* An instance of BlameGenerator can only be used once. To blame multiple files
* the application must create a new BlameGenerator.
* <p>
* During blame processing there are two files involved:
* <ul>
* <li>result - The file whose lines are being examined. This is the revision
* the user is trying to view blame/annotation information alongside of.</li>
* <li>source - The file that was blamed with supplying one or more lines of
* data into result. The source may be a different file path (due to copy or
* rename). Source line numbers may differ from result line numbers due to lines
* being added/removed in intermediate revisions.</li>
* </ul>
* <p>
* The blame algorithm is implemented by initially assigning responsibility for
* all lines of the result to the starting commit. A difference against the
* commit's ancestor is computed, and responsibility is passed to the ancestor
* commit for any lines that are common. The starting commit is blamed only for
* the lines that do not appear in the ancestor, if any. The loop repeats using
* the ancestor, until there are no more lines to acquire information on, or the
* file's creation point is discovered in history.
*/
public class BlameGenerator {
private final Repository repository;
private final PathFilter resultPath;
private final MutableObjectId idBuf;
/** Revision pool used to acquire commits from. */
private RevWalk revPool;
/** Indicates the commit was put into the queue at least once. */
private RevFlag SEEN;
private ObjectReader reader;
private TreeWalk treeWalk;
private DiffAlgorithm diffAlgorithm = new HistogramDiff();
private RawTextComparator textComparator = RawTextComparator.DEFAULT;
private RenameDetector renameDetector;
/** Potential candidates, sorted by commit time descending. */
private Candidate queue;
/** Number of lines that still need to be discovered. */
private int remaining;
/** Blame is currently assigned to this source. */
private Candidate outCandidate;
private Region outRegion;
/**
* Create a blame generator for the repository and path (relative to
* repository)
*
* @param repository
* repository to access revision data from.
* @param path
* initial path of the file to start scanning (relative to the
* repository).
*/
public BlameGenerator(Repository repository, String path) {
this.repository = repository;
this.resultPath = PathFilter.create(path);
idBuf = new MutableObjectId();
setFollowFileRenames(true);
initRevPool(false);
remaining = -1;
}
private void initRevPool(boolean reverse) {
if (queue != null)
throw new IllegalStateException();
if (revPool != null)
revPool.release();
if (reverse)
revPool = new ReverseWalk(getRepository());
else
revPool = new RevWalk(getRepository());
revPool.setRetainBody(true);
SEEN = revPool.newFlag("SEEN"); //$NON-NLS-1$
reader = revPool.getObjectReader();
treeWalk = new TreeWalk(reader);
treeWalk.setRecursive(true);
}
/** @return repository being scanned for revision history. */
public Repository getRepository() {
return repository;
}
/** @return path file path being processed. */
public String getResultPath() {
return resultPath.getPath();
}
/**
* Difference algorithm to use when comparing revisions.
*
* @param algorithm
* @return {@code this}
*/
public BlameGenerator setDiffAlgorithm(DiffAlgorithm algorithm) {
diffAlgorithm = algorithm;
return this;
}
/**
* Text comparator to use when comparing revisions.
*
* @param comparator
* @return {@code this}
*/
public BlameGenerator setTextComparator(RawTextComparator comparator) {
textComparator = comparator;
return this;
}
/**
* Enable (or disable) following file renames, on by default.
* <p>
* If true renames are followed using the standard FollowFilter behavior
* used by RevWalk (which matches {@code git log --follow} in the C
* implementation). This is not the same as copy/move detection as
* implemented by the C implementation's of {@code git blame -M -C}.
*
* @param follow
* enable following.
* @return {@code this}
*/
public BlameGenerator setFollowFileRenames(boolean follow) {
if (follow)
renameDetector = new RenameDetector(getRepository());
else
renameDetector = null;
return this;
}
/**
* Obtain the RenameDetector if {@code setFollowFileRenames(true)}.
*
* @return the rename detector, allowing the application to configure its
* settings for rename score and breaking behavior.
*/
public RenameDetector getRenameDetector() {
return renameDetector;
}
/**
* Push a candidate blob onto the generator's traversal stack.
* <p>
* Candidates should be pushed in history order from oldest-to-newest.
* Applications should push the starting commit first, then the index
* revision (if the index is interesting), and finally the working tree
* copy (if the working tree is interesting).
*
* @param description
* description of the blob revision, such as "Working Tree".
* @param contents
* contents of the file.
* @return {@code this}
* @throws IOException
* the repository cannot be read.
*/
public BlameGenerator push(String description, byte[] contents)
throws IOException {
return push(description, new RawText(contents));
}
/**
* Push a candidate blob onto the generator's traversal stack.
* <p>
* Candidates should be pushed in history order from oldest-to-newest.
* Applications should push the starting commit first, then the index
* revision (if the index is interesting), and finally the working tree copy
* (if the working tree is interesting).
*
* @param description
* description of the blob revision, such as "Working Tree".
* @param contents
* contents of the file.
* @return {@code this}
* @throws IOException
* the repository cannot be read.
*/
public BlameGenerator push(String description, RawText contents)
throws IOException {
if (description == null)
description = JGitText.get().blameNotCommittedYet;
BlobCandidate c = new BlobCandidate(description, resultPath);
c.sourceText = contents;
c.regionList = new Region(0, 0, contents.size());
remaining = contents.size();
push(c);
return this;
}
/**
* Push a candidate object onto the generator's traversal stack.
* <p>
* Candidates should be pushed in history order from oldest-to-newest.
* Applications should push the starting commit first, then the index
* revision (if the index is interesting), and finally the working tree copy
* (if the working tree is interesting).
*
* @param description
* description of the blob revision, such as "Working Tree".
* @param id
* may be a commit or a blob.
* @return {@code this}
* @throws IOException
* the repository cannot be read.
*/
public BlameGenerator push(String description, AnyObjectId id)
throws IOException {
ObjectLoader ldr = reader.open(id);
if (ldr.getType() == OBJ_BLOB) {
if (description == null)
description = JGitText.get().blameNotCommittedYet;
BlobCandidate c = new BlobCandidate(description, resultPath);
c.sourceBlob = id.toObjectId();
c.sourceText = new RawText(ldr.getCachedBytes(Integer.MAX_VALUE));
c.regionList = new Region(0, 0, c.sourceText.size());
remaining = c.sourceText.size();
push(c);
return this;
}
RevCommit commit = revPool.parseCommit(id);
if (!find(commit, resultPath))
return this;
Candidate c = new Candidate(commit, resultPath);
c.sourceBlob = idBuf.toObjectId();
c.loadText(reader);
c.regionList = new Region(0, 0, c.sourceText.size());
remaining = c.sourceText.size();
push(c);
return this;
}
/**
* Configure the generator to compute reverse blame (history of deletes).
* <p>
* This method is expensive as it immediately runs a RevWalk over the
* history spanning the expression {@code start..end} (end being more recent
* than start) and then performs the equivalent operation as
* {@link #push(String, AnyObjectId)} to begin blame traversal from the
* commit named by {@code start} walking forwards through history until
* {@code end} blaming line deletions.
* <p>
* A reverse blame may produce multiple sources for the same result line,
* each of these is a descendant commit that removed the line, typically
* this occurs when the same deletion appears in multiple side branches such
* as due to a cherry-pick. Applications relying on reverse should use
* {@link BlameResult} as it filters these duplicate sources and only
* remembers the first (oldest) deletion.
*
* @param start
* oldest commit to traverse from. The result file will be loaded
* from this commit's tree.
* @param end
* most recent commit to stop traversal at. Usually an active
* branch tip, tag, or HEAD.
* @return {@code this}
* @throws IOException
* the repository cannot be read.
*/
public BlameGenerator reverse(AnyObjectId start, AnyObjectId end)
throws IOException {
return reverse(start, Collections.singleton(end.toObjectId()));
}
/**
* Configure the generator to compute reverse blame (history of deletes).
* <p>
* This method is expensive as it immediately runs a RevWalk over the
* history spanning the expression {@code start..end} (end being more recent
* than start) and then performs the equivalent operation as
* {@link #push(String, AnyObjectId)} to begin blame traversal from the
* commit named by {@code start} walking forwards through history until
* {@code end} blaming line deletions.
* <p>
* A reverse blame may produce multiple sources for the same result line,
* each of these is a descendant commit that removed the line, typically
* this occurs when the same deletion appears in multiple side branches such
* as due to a cherry-pick. Applications relying on reverse should use
* {@link BlameResult} as it filters these duplicate sources and only
* remembers the first (oldest) deletion.
*
* @param start
* oldest commit to traverse from. The result file will be loaded
* from this commit's tree.
* @param end
* most recent commits to stop traversal at. Usually an active
* branch tip, tag, or HEAD.
* @return {@code this}
* @throws IOException
* the repository cannot be read.
*/
public BlameGenerator reverse(AnyObjectId start,
Collection<? extends ObjectId> end) throws IOException {
initRevPool(true);
ReverseCommit result = (ReverseCommit) revPool.parseCommit(start);
if (!find(result, resultPath))
return this;
revPool.markUninteresting(result);
for (ObjectId id : end)
revPool.markStart(revPool.parseCommit(id));
while (revPool.next() != null) {
// just pump the queue
}
ReverseCandidate c = new ReverseCandidate(result, resultPath);
c.sourceBlob = idBuf.toObjectId();
c.loadText(reader);
c.regionList = new Region(0, 0, c.sourceText.size());
remaining = c.sourceText.size();
push(c);
return this;
}
/**
* Allocate a new RevFlag for use by the caller.
*
* @param name
* unique name of the flag in the blame context.
* @return the newly allocated flag.
* @since 3.4
*/
public RevFlag newFlag(String name) {
return revPool.newFlag(name);
}
/**
* Execute the generator in a blocking fashion until all data is ready.
*
* @return the complete result. Null if no file exists for the given path.
* @throws IOException
* the repository cannot be read.
*/
public BlameResult computeBlameResult() throws IOException {
try {
BlameResult r = BlameResult.create(this);
if (r != null)
r.computeAll();
return r;
} finally {
release();
}
}
/**
* Step the blame algorithm one iteration.
*
* @return true if the generator has found a region's source. The getSource*
* and {@link #getResultStart()}, {@link #getResultEnd()} methods
* can be used to inspect the region found. False if there are no
* more regions to describe.
* @throws IOException
* repository cannot be read.
*/
public boolean next() throws IOException {
// If there is a source still pending, produce the next region.
if (outRegion != null) {
Region r = outRegion;
remaining -= r.length;
if (r.next != null) {
outRegion = r.next;
return true;
}
if (outCandidate.queueNext != null)
return result(outCandidate.queueNext);
outCandidate = null;
outRegion = null;
}
// If there are no lines remaining, the entire result is done,
// even if there are revisions still available for the path.
if (remaining == 0)
return done();
for (;;) {
Candidate n = pop();
if (n == null)
return done();
int pCnt = n.getParentCount();
if (pCnt == 1) {
if (processOne(n))
return true;
} else if (1 < pCnt) {
if (processMerge(n))
return true;
} else if (n instanceof ReverseCandidate) {
// Do not generate a tip of a reverse. The region
// survives and should not appear to be deleted.
} else /* if (pCnt == 0) */{
// Root commit, with at least one surviving region.
// Assign the remaining blame here.
return result(n);
}
}
}
private boolean done() {
release();
return false;
}
private boolean result(Candidate n) throws IOException {
n.beginResult(revPool);
outCandidate = n;
outRegion = n.regionList;
return true;
}
private boolean reverseResult(Candidate parent, Candidate source)
throws IOException {
// On a reverse blame present the application the parent
// (as this is what did the removals), however the region
// list to enumerate is the source's surviving list.
Candidate res = parent.copy(parent.sourceCommit);
res.regionList = source.regionList;
return result(res);
}
private Candidate pop() {
Candidate n = queue;
if (n != null) {
queue = n.queueNext;
n.queueNext = null;
}
return n;
}
private void push(BlobCandidate toInsert) {
Candidate c = queue;
if (c != null) {
c.remove(SEEN); // will be pushed by toInsert
c.regionList = null;
toInsert.parent = c;
}
queue = toInsert;
}
private void push(Candidate toInsert) {
if (toInsert.has(SEEN)) {
// We have already added a Candidate for this commit to the queue,
// this can happen if the commit is a merge base for two or more
// parallel branches that were merged together.
//
// It is likely the candidate was not yet processed. The queue
// sorts descending by commit time and usually descendant commits
// have higher timestamps than the ancestors.
//
// Find the existing candidate and merge the new candidate's
// region list into it.
for (Candidate p = queue; p != null; p = p.queueNext) {
if (p.canMergeRegions(toInsert)) {
p.mergeRegions(toInsert);
return;
}
}
}
toInsert.add(SEEN);
// Insert into the queue using descending commit time, so
// the most recent commit will pop next.
int time = toInsert.getTime();
Candidate n = queue;
if (n == null || time >= n.getTime()) {
toInsert.queueNext = n;
queue = toInsert;
return;
}
for (Candidate p = n;; p = n) {
n = p.queueNext;
if (n == null || time >= n.getTime()) {
toInsert.queueNext = n;
p.queueNext = toInsert;
return;
}
}
}
private boolean processOne(Candidate n) throws IOException {
RevCommit parent = n.getParent(0);
if (parent == null)
return split(n.getNextCandidate(0), n);
revPool.parseHeaders(parent);
if (n.sourceCommit != null && n.recursivePath) {
treeWalk.setFilter(AndTreeFilter.create(n.sourcePath, ID_DIFF));
treeWalk.reset(n.sourceCommit.getTree(), parent.getTree());
if (!treeWalk.next())
return blameEntireRegionOnParent(n, parent);
if (isFile(treeWalk.getRawMode(1))) {
treeWalk.getObjectId(idBuf, 1);
return splitBlameWithParent(n, parent);
}
} else if (find(parent, n.sourcePath)) {
if (idBuf.equals(n.sourceBlob))
return blameEntireRegionOnParent(n, parent);
return splitBlameWithParent(n, parent);
}
if (n.sourceCommit == null)
return result(n);
DiffEntry r = findRename(parent, n.sourceCommit, n.sourcePath);
if (r == null)
return result(n);
if (0 == r.getOldId().prefixCompare(n.sourceBlob)) {
// A 100% rename without any content change can also
// skip directly to the parent.
n.sourceCommit = parent;
n.setSourcePath(PathFilter.create(r.getOldPath()));
push(n);
return false;
}
Candidate next = n.create(parent, PathFilter.create(r.getOldPath()));
next.sourceBlob = r.getOldId().toObjectId();
next.renameScore = r.getScore();
next.loadText(reader);
return split(next, n);
}
private boolean blameEntireRegionOnParent(Candidate n, RevCommit parent) {
// File was not modified, blame parent.
n.sourceCommit = parent;
push(n);
return false;
}
private boolean splitBlameWithParent(Candidate n, RevCommit parent)
throws IOException {
Candidate next = n.create(parent, n.sourcePath);
next.sourceBlob = idBuf.toObjectId();
next.loadText(reader);
return split(next, n);
}
private boolean split(Candidate parent, Candidate source)
throws IOException {
EditList editList = diffAlgorithm.diff(textComparator,
parent.sourceText, source.sourceText);
if (editList.isEmpty()) {
// Ignoring whitespace (or some other special comparator) can
// cause non-identical blobs to have an empty edit list. In
// a case like this push the parent alone.
parent.regionList = source.regionList;
push(parent);
return false;
}
parent.takeBlame(editList, source);
if (parent.regionList != null)
push(parent);
if (source.regionList != null) {
if (source instanceof ReverseCandidate)
return reverseResult(parent, source);
return result(source);
}
return false;
}
private boolean processMerge(Candidate n) throws IOException {
int pCnt = n.getParentCount();
// If any single parent exactly matches the merge, follow only
// that one parent through history.
ObjectId[] ids = null;
for (int pIdx = 0; pIdx < pCnt; pIdx++) {
RevCommit parent = n.getParent(pIdx);
revPool.parseHeaders(parent);
if (!find(parent, n.sourcePath))
continue;
if (!(n instanceof ReverseCandidate) && idBuf.equals(n.sourceBlob))
return blameEntireRegionOnParent(n, parent);
if (ids == null)
ids = new ObjectId[pCnt];
ids[pIdx] = idBuf.toObjectId();
}
// If rename detection is enabled, search for any relevant names.
DiffEntry[] renames = null;
if (renameDetector != null) {
renames = new DiffEntry[pCnt];
for (int pIdx = 0; pIdx < pCnt; pIdx++) {
RevCommit parent = n.getParent(pIdx);
if (ids != null && ids[pIdx] != null)
continue;
DiffEntry r = findRename(parent, n.sourceCommit, n.sourcePath);
if (r == null)
continue;
if (n instanceof ReverseCandidate) {
if (ids == null)
ids = new ObjectId[pCnt];
ids[pCnt] = r.getOldId().toObjectId();
} else if (0 == r.getOldId().prefixCompare(n.sourceBlob)) {
// A 100% rename without any content change can also
// skip directly to the parent. Note this bypasses an
// earlier parent that had the path (above) but did not
// have an exact content match. For performance reasons
// we choose to follow the one parent over trying to do
// possibly both parents.
n.setSourcePath(PathFilter.create(r.getOldPath()));
return blameEntireRegionOnParent(n, parent);
}
renames[pIdx] = r;
}
}
// Construct the candidate for each parent.
Candidate[] parents = new Candidate[pCnt];
for (int pIdx = 0; pIdx < pCnt; pIdx++) {
RevCommit parent = n.getParent(pIdx);
Candidate p;
if (renames != null && renames[pIdx] != null) {
p = n.create(parent,
PathFilter.create(renames[pIdx].getOldPath()));
p.renameScore = renames[pIdx].getScore();
p.sourceBlob = renames[pIdx].getOldId().toObjectId();
} else if (ids != null && ids[pIdx] != null) {
p = n.create(parent, n.sourcePath);
p.sourceBlob = ids[pIdx];
} else {
continue;
}
EditList editList;
if (n instanceof ReverseCandidate
&& p.sourceBlob.equals(n.sourceBlob)) {
// This special case happens on ReverseCandidate forks.
p.sourceText = n.sourceText;
editList = new EditList(0);
} else {
p.loadText(reader);
editList = diffAlgorithm.diff(textComparator,
p.sourceText, n.sourceText);
}
if (editList.isEmpty()) {
// Ignoring whitespace (or some other special comparator) can
// cause non-identical blobs to have an empty edit list. In
// a case like this push the parent alone.
if (n instanceof ReverseCandidate) {
parents[pIdx] = p;
continue;
}
p.regionList = n.regionList;
push(p);
return false;
}
p.takeBlame(editList, n);
// Only remember this parent candidate if there is at least
// one region that was blamed on the parent.
if (p.regionList != null) {
// Reverse blame requires inverting the regions. This puts
// the regions the parent deleted from us into the parent,
// and retains the common regions to look at other parents
// for deletions.
if (n instanceof ReverseCandidate) {
Region r = p.regionList;
p.regionList = n.regionList;
n.regionList = r;
}
parents[pIdx] = p;
}
}
if (n instanceof ReverseCandidate) {
// On a reverse blame report all deletions found in the children,
// and pass on to them a copy of our region list.
Candidate resultHead = null;
Candidate resultTail = null;
for (int pIdx = 0; pIdx < pCnt; pIdx++) {
Candidate p = parents[pIdx];
if (p == null)
continue;
if (p.regionList != null) {
Candidate r = p.copy(p.sourceCommit);
if (resultTail != null) {
resultTail.queueNext = r;
resultTail = r;
} else {
resultHead = r;
resultTail = r;
}
}
if (n.regionList != null) {
p.regionList = n.regionList.deepCopy();
push(p);
}
}
if (resultHead != null)
return result(resultHead);
return false;
}
// Push any parents that are still candidates.
for (int pIdx = 0; pIdx < pCnt; pIdx++) {
if (parents[pIdx] != null)
push(parents[pIdx]);
}
if (n.regionList != null)
return result(n);
return false;
}
/**
* Get the revision blamed for the current region.
* <p>
* The source commit may be null if the line was blamed to an uncommitted
* revision, such as the working tree copy, or during a reverse blame if the
* line survives to the end revision (e.g. the branch tip).
*
* @return current revision being blamed.
*/
public RevCommit getSourceCommit() {
return outCandidate.sourceCommit;
}
/** @return current author being blamed. */
public PersonIdent getSourceAuthor() {
return outCandidate.getAuthor();
}
/** @return current committer being blamed. */
public PersonIdent getSourceCommitter() {
RevCommit c = getSourceCommit();
return c != null ? c.getCommitterIdent() : null;
}
/** @return path of the file being blamed. */
public String getSourcePath() {
return outCandidate.sourcePath.getPath();
}
/** @return rename score if a rename occurred in {@link #getSourceCommit}. */
public int getRenameScore() {
return outCandidate.renameScore;
}
/**
* @return first line of the source data that has been blamed for the
* current region. This is line number of where the region was added
* during {@link #getSourceCommit()} in file
* {@link #getSourcePath()}.
*/
public int getSourceStart() {
return outRegion.sourceStart;
}
/**
* @return one past the range of the source data that has been blamed for
* the current region. This is line number of where the region was
* added during {@link #getSourceCommit()} in file
* {@link #getSourcePath()}.
*/
public int getSourceEnd() {
Region r = outRegion;
return r.sourceStart + r.length;
}
/**
* @return first line of the result that {@link #getSourceCommit()} has been
* blamed for providing. Line numbers use 0 based indexing.
*/
public int getResultStart() {
return outRegion.resultStart;
}
/**
* @return one past the range of the result that {@link #getSourceCommit()}
* has been blamed for providing. Line numbers use 0 based indexing.
* Because a source cannot be blamed for an empty region of the
* result, {@link #getResultEnd()} is always at least one larger
* than {@link #getResultStart()}.
*/
public int getResultEnd() {
Region r = outRegion;
return r.resultStart + r.length;
}
/**
* @return number of lines in the current region being blamed to
* {@link #getSourceCommit()}. This is always the value of the
* expression {@code getResultEnd() - getResultStart()}, but also
* {@code getSourceEnd() - getSourceStart()}.
*/
public int getRegionLength() {
return outRegion.length;
}
/**
* @return complete contents of the source file blamed for the current
* output region. This is the contents of {@link #getSourcePath()}
* within {@link #getSourceCommit()}. The source contents is
* temporarily available as an artifact of the blame algorithm. Most
* applications will want the result contents for display to users.
*/
public RawText getSourceContents() {
return outCandidate.sourceText;
}
/**
* @return complete file contents of the result file blame is annotating.
* This value is accessible only after being configured and only
* immediately before the first call to {@link #next()}. Returns
* null if the path does not exist.
* @throws IOException
* repository cannot be read.
* @throws IllegalStateException
* {@link #next()} has already been invoked.
*/
public RawText getResultContents() throws IOException {
return queue != null ? queue.sourceText : null;
}
/** Release the current blame session. */
public void release() {
revPool.release();
queue = null;
outCandidate = null;
outRegion = null;
}
private boolean find(RevCommit commit, PathFilter path) throws IOException {
treeWalk.setFilter(path);
treeWalk.reset(commit.getTree());
if (treeWalk.next() && isFile(treeWalk.getRawMode(0))) {
treeWalk.getObjectId(idBuf, 0);
return true;
}
return false;
}
private static final boolean isFile(int rawMode) {
return (rawMode & TYPE_FILE) == TYPE_FILE;
}
private DiffEntry findRename(RevCommit parent, RevCommit commit,
PathFilter path) throws IOException {
if (renameDetector == null)
return null;
treeWalk.setFilter(TreeFilter.ANY_DIFF);
treeWalk.reset(parent.getTree(), commit.getTree());
renameDetector.reset();
renameDetector.addAll(DiffEntry.scan(treeWalk));
for (DiffEntry ent : renameDetector.compute()) {
if (isRename(ent) && ent.getNewPath().equals(path.getPath()))
return ent;
}
return null;
}
private static boolean isRename(DiffEntry ent) {
return ent.getChangeType() == ChangeType.RENAME
|| ent.getChangeType() == ChangeType.COPY;
}
private static final TreeFilter ID_DIFF = new TreeFilter() {
@Override
public boolean include(TreeWalk tw) {
return !tw.idEqual(0, 1);
}
@Override
public boolean shouldBeRecursive() {
return false;
}
@Override
public TreeFilter clone() {
return this;
}
@Override
public String toString() {
return "ID_DIFF"; //$NON-NLS-1$
}
};
}
|