-
Notifications
You must be signed in to change notification settings - Fork 385
Expand file tree
/
Copy pathTextInlineChange.cs
More file actions
306 lines (273 loc) · 11 KB
/
TextInlineChange.cs
File metadata and controls
306 lines (273 loc) · 11 KB
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
using System.Collections.Generic;
namespace SourceGit.Models
{
public class TextInlineChange(int dp, int dc, int ap, int ac)
{
public int DeletedStart { get; set; } = dp;
public int DeletedCount { get; set; } = dc;
public int AddedStart { get; set; } = ap;
public int AddedCount { get; set; } = ac;
private class Chunk(int hash, int start, int size)
{
public readonly int Hash = hash;
public readonly int Start = start;
public readonly int Size = size;
public bool Modified;
}
private enum Edit
{
None,
DeletedRight,
DeletedLeft,
AddedRight,
AddedLeft,
}
private class EditResult
{
public Edit State;
public int DeleteStart;
public int DeleteEnd;
public int AddStart;
public int AddEnd;
}
public static List<TextInlineChange> Compare(string oldValue, string newValue)
{
var hashes = new Dictionary<string, int>();
var chunksOld = MakeChunks(hashes, oldValue);
var chunksNew = MakeChunks(hashes, newValue);
var sizeOld = chunksOld.Count;
var sizeNew = chunksNew.Count;
var max = sizeOld + sizeNew + 2;
var forward = new int[max];
var reverse = new int[max];
CheckModified(chunksOld, 0, sizeOld, chunksNew, 0, sizeNew, forward, reverse);
var ret = new List<TextInlineChange>();
var posOld = 0;
var posNew = 0;
TextInlineChange last = null;
do
{
while (posOld < sizeOld && posNew < sizeNew && !chunksOld[posOld].Modified && !chunksNew[posNew].Modified)
{
posOld++;
posNew++;
}
var beginOld = posOld;
var beginNew = posNew;
var countOld = 0;
var countNew = 0;
for (; posOld < sizeOld && chunksOld[posOld].Modified; posOld++)
countOld += chunksOld[posOld].Size;
for (; posNew < sizeNew && chunksNew[posNew].Modified; posNew++)
countNew += chunksNew[posNew].Size;
if (countOld + countNew == 0)
continue;
var diff = new TextInlineChange(
countOld > 0 ? chunksOld[beginOld].Start : 0,
countOld,
countNew > 0 ? chunksNew[beginNew].Start : 0,
countNew);
if (last != null)
{
var midSizeOld = diff.DeletedStart - last.DeletedStart - last.DeletedCount;
var midSizeNew = diff.AddedStart - last.AddedStart - last.AddedCount;
if (midSizeOld == 1 && midSizeNew == 1)
{
last.DeletedCount += (1 + countOld);
last.AddedCount += (1 + countNew);
continue;
}
}
last = diff;
ret.Add(diff);
} while (posOld < sizeOld && posNew < sizeNew);
return ret;
}
private static List<Chunk> MakeChunks(Dictionary<string, int> hashes, string text)
{
var start = 0;
var size = text.Length;
var chunks = new List<Chunk>();
var delims = new HashSet<char>(" \t+-*/=!,:;.'\"/?|&#@%`<>()[]{}\\".ToCharArray());
for (int i = 0; i < size; i++)
{
var ch = text[i];
if (delims.Contains(ch))
{
if (start != i)
AddChunk(chunks, hashes, text.Substring(start, i - start), start);
AddChunk(chunks, hashes, text.Substring(i, 1), i);
start = i + 1;
}
}
if (start < size)
AddChunk(chunks, hashes, text.Substring(start), start);
return chunks;
}
private static void CheckModified(List<Chunk> chunksOld, int startOld, int endOld, List<Chunk> chunksNew, int startNew, int endNew, int[] forward, int[] reverse)
{
while (startOld < endOld && startNew < endNew && chunksOld[startOld].Hash == chunksNew[startNew].Hash)
{
startOld++;
startNew++;
}
while (startOld < endOld && startNew < endNew && chunksOld[endOld - 1].Hash == chunksNew[endNew - 1].Hash)
{
endOld--;
endNew--;
}
var lenOld = endOld - startOld;
var lenNew = endNew - startNew;
if (lenOld > 0 && lenNew > 0)
{
var rs = CheckModifiedEdit(chunksOld, startOld, endOld, chunksNew, startNew, endNew, forward, reverse);
if (rs.State == Edit.None)
return;
if (rs.State == Edit.DeletedRight && rs.DeleteStart - 1 > startOld)
{
chunksOld[--rs.DeleteStart].Modified = true;
}
else if (rs.State == Edit.DeletedLeft && rs.DeleteEnd < endOld)
{
chunksOld[rs.DeleteEnd++].Modified = true;
}
else if (rs.State == Edit.AddedRight && rs.AddStart - 1 > startNew)
{
chunksNew[--rs.AddStart].Modified = true;
}
else if (rs.State == Edit.AddedLeft && rs.AddEnd < endNew)
{
chunksNew[rs.AddEnd++].Modified = true;
}
CheckModified(chunksOld, startOld, rs.DeleteStart, chunksNew, startNew, rs.AddStart, forward, reverse);
CheckModified(chunksOld, rs.DeleteEnd, endOld, chunksNew, rs.AddEnd, endNew, forward, reverse);
}
else if (lenOld > 0)
{
for (int i = startOld; i < endOld; i++)
chunksOld[i].Modified = true;
}
else if (lenNew > 0)
{
for (int i = startNew; i < endNew; i++)
chunksNew[i].Modified = true;
}
}
private static EditResult CheckModifiedEdit(List<Chunk> chunksOld, int startOld, int endOld, List<Chunk> chunksNew, int startNew, int endNew, int[] forward, int[] reverse)
{
var lenOld = endOld - startOld;
var lenNew = endNew - startNew;
var max = lenOld + lenNew + 1;
var half = max / 2;
var delta = lenOld - lenNew;
var deltaEven = delta % 2 == 0;
var rs = new EditResult() { State = Edit.None };
forward[1 + half] = 0;
reverse[1 + half] = lenOld + 1;
for (int i = 0; i <= half; i++)
{
for (int j = -i; j <= i; j += 2)
{
var idx = j + half;
int o;
if (j == -i || (j != i && forward[idx - 1] < forward[idx + 1]))
{
o = forward[idx + 1];
rs.State = Edit.AddedRight;
}
else
{
o = forward[idx - 1] + 1;
rs.State = Edit.DeletedRight;
}
var n = o - j;
var startX = o;
var startY = n;
while (o < lenOld && n < lenNew && chunksOld[o + startOld].Hash == chunksNew[n + startNew].Hash)
{
o++;
n++;
}
forward[idx] = o;
if (!deltaEven && j - delta >= -i + 1 && j - delta <= i - 1)
{
var revIdx = (j - delta) + half;
var revOld = reverse[revIdx];
int revNew = revOld - j;
if (revOld <= o && revNew <= n)
{
if (i == 0)
{
rs.State = Edit.None;
}
else
{
rs.DeleteStart = startX + startOld;
rs.DeleteEnd = o + startOld;
rs.AddStart = startY + startNew;
rs.AddEnd = n + startNew;
}
return rs;
}
}
}
for (int j = -i; j <= i; j += 2)
{
var idx = j + half;
int o;
if (j == -i || (j != i && reverse[idx + 1] <= reverse[idx - 1]))
{
o = reverse[idx + 1] - 1;
rs.State = Edit.DeletedLeft;
}
else
{
o = reverse[idx - 1];
rs.State = Edit.AddedLeft;
}
var n = o - (j + delta);
var endX = o;
var endY = n;
while (o > 0 && n > 0 && chunksOld[startOld + o - 1].Hash == chunksNew[startNew + n - 1].Hash)
{
o--;
n--;
}
reverse[idx] = o;
if (deltaEven && j + delta >= -i && j + delta <= i)
{
var forIdx = (j + delta) + half;
var forOld = forward[forIdx];
int forNew = forOld - (j + delta);
if (forOld >= o && forNew >= n)
{
if (i == 0)
{
rs.State = Edit.None;
}
else
{
rs.DeleteStart = o + startOld;
rs.DeleteEnd = endX + startOld;
rs.AddStart = n + startNew;
rs.AddEnd = endY + startNew;
}
return rs;
}
}
}
}
rs.State = Edit.None;
return rs;
}
private static void AddChunk(List<Chunk> chunks, Dictionary<string, int> hashes, string data, int start)
{
if (!hashes.TryGetValue(data, out var hash))
{
hash = hashes.Count;
hashes.Add(data, hash);
}
chunks.Add(new Chunk(hash, start, data.Length));
}
}
}