@recaptime-dev's working patches + fork for Phorge, a community fork of Phabricator. (Upstream dev and stable branches are at upstream/main and upstream/stable respectively.)
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phorge
phabricator
In prose diffs, use hash-and-diff for coarse "level 0" diffing to scale better
Summary: Depends on D20838. Fixes T13414. Instead of doing coarse diffing with "PhutilEditDistanceMatrix", use hash-and-diff with "DocumentEngine".
Test Plan:
- On a large document (~3K top level blocks), saw a more sensible diff, instead of the whole thing falling back to "everything changed" mode.
- On a small document, still saw a sensible granular diff.
{F6888249}
Maniphest Tasks: T13414
Differential Revision: https://secure.phabricator.com/D20839
+130
-48
+1
-1
src/__phutil_library_map__.php
+1
-1
src/__phutil_library_map__.php
···
12402
12402
'PhutilPHPCodeSnippetContextFreeGrammar' => 'PhutilCLikeCodeSnippetContextFreeGrammar',
12403
12403
'PhutilPhabricatorAuthAdapter' => 'PhutilOAuthAuthAdapter',
12404
12404
'PhutilProseDiff' => 'Phobject',
12405
-
'PhutilProseDiffTestCase' => 'PhutilTestCase',
12405
+
'PhutilProseDiffTestCase' => 'PhabricatorTestCase',
12406
12406
'PhutilProseDifferenceEngine' => 'Phobject',
12407
12407
'PhutilQueryString' => 'Phobject',
12408
12408
'PhutilRealNameContextFreeGrammar' => 'PhutilContextFreeGrammar',
+19
-4
src/applications/files/diff/PhabricatorDocumentEngineBlocks.php
+19
-4
src/applications/files/diff/PhabricatorDocumentEngineBlocks.php
···
50
50
51
51
if ($old_line) {
52
52
$old_hash = rtrim($old_line['text'], "\n");
53
-
$old_block = array_shift($old_map[$old_hash]);
54
-
$old_block->setDifferenceType($old_line['type']);
53
+
if (!strlen($old_hash)) {
54
+
// This can happen when one of the sources has no blocks.
55
+
$old_block = null;
56
+
} else {
57
+
$old_block = array_shift($old_map[$old_hash]);
58
+
$old_block->setDifferenceType($old_line['type']);
59
+
}
55
60
} else {
56
61
$old_block = null;
57
62
}
58
63
59
64
if ($new_line) {
60
65
$new_hash = rtrim($new_line['text'], "\n");
61
-
$new_block = array_shift($new_map[$new_hash]);
62
-
$new_block->setDifferenceType($new_line['type']);
66
+
if (!strlen($new_hash)) {
67
+
$new_block = null;
68
+
} else {
69
+
$new_block = array_shift($new_map[$new_hash]);
70
+
$new_block->setDifferenceType($new_line['type']);
71
+
}
63
72
} else {
64
73
$new_block = null;
74
+
}
75
+
76
+
// If both lists are empty, we may generate a row which has two empty
77
+
// blocks.
78
+
if (!$old_block && !$new_block) {
79
+
continue;
65
80
}
66
81
67
82
$rows[] = array(
+108
-42
src/infrastructure/diff/prose/PhutilProseDifferenceEngine.php
+108
-42
src/infrastructure/diff/prose/PhutilProseDifferenceEngine.php
···
10
10
$u_parts = $this->splitCorpus($u, $level);
11
11
$v_parts = $this->splitCorpus($v, $level);
12
12
13
-
$matrix = id(new PhutilEditDistanceMatrix())
14
-
->setMaximumLength(128)
15
-
->setSequences($u_parts, $v_parts)
16
-
->setComputeString(true);
17
-
18
-
// For word-level and character-level changes, smooth the output string
19
-
// to reduce the choppiness of the diff.
20
-
if ($level > 1) {
21
-
$matrix->setApplySmoothing(PhutilEditDistanceMatrix::SMOOTHING_FULL);
22
-
}
23
-
24
-
$u_pos = 0;
25
-
$v_pos = 0;
26
-
27
-
$edits = $matrix->getEditString();
28
-
$edits_length = strlen($edits);
29
-
30
-
$diff = new PhutilProseDiff();
31
-
for ($ii = 0; $ii < $edits_length; $ii++) {
32
-
$c = $edits[$ii];
33
-
if ($c == 's') {
34
-
$diff->addPart('=', $u_parts[$u_pos]);
35
-
$u_pos++;
36
-
$v_pos++;
37
-
} else if ($c == 'd') {
38
-
$diff->addPart('-', $u_parts[$u_pos]);
39
-
$u_pos++;
40
-
} else if ($c == 'i') {
41
-
$diff->addPart('+', $v_parts[$v_pos]);
42
-
$v_pos++;
43
-
} else if ($c == 'x') {
44
-
$diff->addPart('-', $u_parts[$u_pos]);
45
-
$diff->addPart('+', $v_parts[$v_pos]);
46
-
$u_pos++;
47
-
$v_pos++;
48
-
} else {
49
-
throw new Exception(
50
-
pht(
51
-
'Unexpected character ("%s") in edit string.',
52
-
$c));
53
-
}
13
+
if ($level === 0) {
14
+
$diff = $this->newHashDiff($u_parts, $v_parts);
15
+
$too_large = false;
16
+
} else {
17
+
list($diff, $too_large) = $this->newEditDistanceMatrixDiff(
18
+
$u_parts,
19
+
$v_parts,
20
+
$level);
54
21
}
55
22
56
23
$diff->reorderParts();
···
119
86
} else if (!strlen($new)) {
120
87
$result->addPart('-', $old);
121
88
} else {
122
-
if ($matrix->didReachMaximumLength()) {
89
+
if ($too_large) {
123
90
// If this text was too big to diff, don't try to subdivide it.
124
91
$result->addPart('-', $old);
125
92
$result->addPart('+', $new);
···
204
171
}
205
172
206
173
return $results;
174
+
}
175
+
176
+
private function newEditDistanceMatrixDiff(
177
+
array $u_parts,
178
+
array $v_parts,
179
+
$level) {
180
+
181
+
$matrix = id(new PhutilEditDistanceMatrix())
182
+
->setMaximumLength(128)
183
+
->setSequences($u_parts, $v_parts)
184
+
->setComputeString(true);
185
+
186
+
// For word-level and character-level changes, smooth the output string
187
+
// to reduce the choppiness of the diff.
188
+
if ($level > 1) {
189
+
$matrix->setApplySmoothing(PhutilEditDistanceMatrix::SMOOTHING_FULL);
190
+
}
191
+
192
+
$u_pos = 0;
193
+
$v_pos = 0;
194
+
195
+
$edits = $matrix->getEditString();
196
+
$edits_length = strlen($edits);
197
+
198
+
$diff = new PhutilProseDiff();
199
+
for ($ii = 0; $ii < $edits_length; $ii++) {
200
+
$c = $edits[$ii];
201
+
if ($c == 's') {
202
+
$diff->addPart('=', $u_parts[$u_pos]);
203
+
$u_pos++;
204
+
$v_pos++;
205
+
} else if ($c == 'd') {
206
+
$diff->addPart('-', $u_parts[$u_pos]);
207
+
$u_pos++;
208
+
} else if ($c == 'i') {
209
+
$diff->addPart('+', $v_parts[$v_pos]);
210
+
$v_pos++;
211
+
} else if ($c == 'x') {
212
+
$diff->addPart('-', $u_parts[$u_pos]);
213
+
$diff->addPart('+', $v_parts[$v_pos]);
214
+
$u_pos++;
215
+
$v_pos++;
216
+
} else {
217
+
throw new Exception(
218
+
pht(
219
+
'Unexpected character ("%s") in edit string.',
220
+
$c));
221
+
}
222
+
}
223
+
224
+
return array($diff, $matrix->didReachMaximumLength());
225
+
}
226
+
227
+
private function newHashDiff(array $u_parts, array $v_parts) {
228
+
229
+
$u_ref = new PhabricatorDocumentRef();
230
+
$v_ref = new PhabricatorDocumentRef();
231
+
232
+
$u_blocks = $this->newDocumentEngineBlocks($u_parts);
233
+
$v_blocks = $this->newDocumentEngineBlocks($v_parts);
234
+
235
+
$rows = id(new PhabricatorDocumentEngineBlocks())
236
+
->addBlockList($u_ref, $u_blocks)
237
+
->addBlockList($v_ref, $v_blocks)
238
+
->newTwoUpLayout();
239
+
240
+
$diff = new PhutilProseDiff();
241
+
foreach ($rows as $row) {
242
+
list($u_block, $v_block) = $row;
243
+
244
+
if ($u_block && $v_block) {
245
+
if ($u_block->getDifferenceType() === '-') {
246
+
$diff->addPart('-', $u_block->getContent());
247
+
$diff->addPart('+', $v_block->getContent());
248
+
} else {
249
+
$diff->addPart('=', $u_block->getContent());
250
+
}
251
+
} else if ($u_block) {
252
+
$diff->addPart('-', $u_block->getContent());
253
+
} else {
254
+
$diff->addPart('+', $v_block->getContent());
255
+
}
256
+
}
257
+
258
+
return $diff;
259
+
}
260
+
261
+
private function newDocumentEngineBlocks(array $parts) {
262
+
$blocks = array();
263
+
264
+
foreach ($parts as $part) {
265
+
$hash = PhabricatorHash::digestForIndex($part);
266
+
267
+
$blocks[] = id(new PhabricatorDocumentEngineBlock())
268
+
->setContent($part)
269
+
->setDifferenceHash($hash);
270
+
}
271
+
272
+
return $blocks;
207
273
}
208
274
209
275
}
+2
-1
src/infrastructure/diff/prose/__tests__/PhutilProseDiffTestCase.php
+2
-1
src/infrastructure/diff/prose/__tests__/PhutilProseDiffTestCase.php