ui-ssdiff.c (view raw)
1#include "cgit.h"
2#include "ui-ssdiff.h"
3#include "html.h"
4#include "ui-shared.h"
5#include "ui-diff.h"
6
7extern int use_ssdiff;
8
9static int current_old_line, current_new_line;
10static int **L = NULL;
11
12struct deferred_lines {
13 int line_no;
14 char *line;
15 struct deferred_lines *next;
16};
17
18static struct deferred_lines *deferred_old, *deferred_old_last;
19static struct deferred_lines *deferred_new, *deferred_new_last;
20
21static void create_or_reset_lcs_table(void)
22{
23 int i;
24
25 if (L != NULL) {
26 memset(*L, 0, sizeof(int) * MAX_SSDIFF_SIZE);
27 return;
28 }
29
30 // xcalloc will die if we ran out of memory;
31 // not very helpful for debugging
32 L = (int**)xcalloc(MAX_SSDIFF_M, sizeof(int *));
33 *L = (int*)xcalloc(MAX_SSDIFF_SIZE, sizeof(int));
34
35 for (i = 1; i < MAX_SSDIFF_M; i++) {
36 L[i] = *L + i * MAX_SSDIFF_N;
37 }
38}
39
40static char *longest_common_subsequence(char *A, char *B)
41{
42 int i, j, ri;
43 int m = strlen(A);
44 int n = strlen(B);
45 int tmp1, tmp2;
46 int lcs_length;
47 char *result;
48
49 // We bail if the lines are too long
50 if (m >= MAX_SSDIFF_M || n >= MAX_SSDIFF_N)
51 return NULL;
52
53 create_or_reset_lcs_table();
54
55 for (i = m; i >= 0; i--) {
56 for (j = n; j >= 0; j--) {
57 if (A[i] == '\0' || B[j] == '\0') {
58 L[i][j] = 0;
59 } else if (A[i] == B[j]) {
60 L[i][j] = 1 + L[i + 1][j + 1];
61 } else {
62 tmp1 = L[i + 1][j];
63 tmp2 = L[i][j + 1];
64 L[i][j] = (tmp1 > tmp2 ? tmp1 : tmp2);
65 }
66 }
67 }
68
69 lcs_length = L[0][0];
70 result = xmalloc(lcs_length + 2);
71 memset(result, 0, sizeof(*result) * (lcs_length + 2));
72
73 ri = 0;
74 i = 0;
75 j = 0;
76 while (i < m && j < n) {
77 if (A[i] == B[j]) {
78 result[ri] = A[i];
79 ri += 1;
80 i += 1;
81 j += 1;
82 } else if (L[i + 1][j] >= L[i][j + 1]) {
83 i += 1;
84 } else {
85 j += 1;
86 }
87 }
88
89 return result;
90}
91
92static int line_from_hunk(char *line, char type)
93{
94 char *buf1, *buf2;
95 int len, res;
96
97 buf1 = strchr(line, type);
98 if (buf1 == NULL)
99 return 0;
100 buf1 += 1;
101 buf2 = strchr(buf1, ',');
102 if (buf2 == NULL)
103 return 0;
104 len = buf2 - buf1;
105 buf2 = xmalloc(len + 1);
106 strlcpy(buf2, buf1, len + 1);
107 res = atoi(buf2);
108 free(buf2);
109 return res;
110}
111
112static char *replace_tabs(char *line)
113{
114 char *prev_buf = line;
115 char *cur_buf;
116 size_t linelen = strlen(line);
117 int n_tabs = 0;
118 int i;
119 char *result;
120
121 if (linelen == 0) {
122 result = xmalloc(1);
123 result[0] = '\0';
124 return result;
125 }
126
127 for (i = 0; i < linelen; i++) {
128 if (line[i] == '\t')
129 n_tabs += 1;
130 }
131 result = xmalloc(linelen + n_tabs * 8 + 1);
132 result[0] = '\0';
133
134 for (;;) {
135 cur_buf = strchr(prev_buf, '\t');
136 if (!cur_buf) {
137 strcat(result, prev_buf);
138 break;
139 } else {
140 strncat(result, prev_buf, cur_buf - prev_buf);
141 linelen = strlen(result);
142 memset(&result[linelen], ' ', 8 - (linelen % 8));
143 result[linelen + 8 - (linelen % 8)] = '\0';
144 }
145 prev_buf = cur_buf + 1;
146 }
147 return result;
148}
149
150static int calc_deferred_lines(struct deferred_lines *start)
151{
152 struct deferred_lines *item = start;
153 int result = 0;
154 while (item) {
155 result += 1;
156 item = item->next;
157 }
158 return result;
159}
160
161static void deferred_old_add(char *line, int line_no)
162{
163 struct deferred_lines *item = xmalloc(sizeof(struct deferred_lines));
164 item->line = xstrdup(line);
165 item->line_no = line_no;
166 item->next = NULL;
167 if (deferred_old) {
168 deferred_old_last->next = item;
169 deferred_old_last = item;
170 } else {
171 deferred_old = deferred_old_last = item;
172 }
173}
174
175static void deferred_new_add(char *line, int line_no)
176{
177 struct deferred_lines *item = xmalloc(sizeof(struct deferred_lines));
178 item->line = xstrdup(line);
179 item->line_no = line_no;
180 item->next = NULL;
181 if (deferred_new) {
182 deferred_new_last->next = item;
183 deferred_new_last = item;
184 } else {
185 deferred_new = deferred_new_last = item;
186 }
187}
188
189static void print_part_with_lcs(char *class, char *line, char *lcs)
190{
191 int line_len = strlen(line);
192 int i, j;
193 char c[2] = " ";
194 int same = 1;
195
196 j = 0;
197 for (i = 0; i < line_len; i++) {
198 c[0] = line[i];
199 if (same) {
200 if (line[i] == lcs[j])
201 j += 1;
202 else {
203 same = 0;
204 htmlf("<span class='%s'>", class);
205 }
206 } else if (line[i] == lcs[j]) {
207 same = 1;
208 htmlf("</span>");
209 j += 1;
210 }
211 html_txt(c);
212 }
213}
214
215static void print_ssdiff_line(char *class,
216 int old_line_no,
217 char *old_line,
218 int new_line_no,
219 char *new_line, int individual_chars)
220{
221 char *lcs = NULL;
222
223 if (old_line)
224 old_line = replace_tabs(old_line + 1);
225 if (new_line)
226 new_line = replace_tabs(new_line + 1);
227 if (individual_chars && old_line && new_line)
228 lcs = longest_common_subsequence(old_line, new_line);
229 html("<tr>\n");
230 if (old_line_no > 0) {
231 struct diff_filespec *old_file = cgit_get_current_old_file();
232 char *lineno_str = fmt("n%d", old_line_no);
233 char *id_str = fmt("id=%s#%s", is_null_oid(&old_file->oid)?"HEAD":oid_to_hex(old_rev_oid), lineno_str);
234 char *fileurl = cgit_fileurl(ctx.repo->url, "tree", old_file->path, id_str);
235 html("<td class='lineno'><a href='");
236 html(fileurl);
237 htmlf("' id='%s'>%s</a>", lineno_str, lineno_str + 1);
238 html("</td>");
239 htmlf("<td class='%s'>", class);
240 free(fileurl);
241 } else if (old_line)
242 htmlf("<td class='lineno'></td><td class='%s'>", class);
243 else
244 htmlf("<td class='lineno'></td><td class='%s_dark'>", class);
245 if (old_line) {
246 if (lcs)
247 print_part_with_lcs("del", old_line, lcs);
248 else
249 html_txt(old_line);
250 }
251
252 html("</td>\n");
253 if (new_line_no > 0) {
254 struct diff_filespec *new_file = cgit_get_current_new_file();
255 char *lineno_str = fmt("n%d", new_line_no);
256 char *id_str = fmt("id=%s#%s", is_null_oid(&new_file->oid)?"HEAD":oid_to_hex(new_rev_oid), lineno_str);
257 char *fileurl = cgit_fileurl(ctx.repo->url, "tree", new_file->path, id_str);
258 html("<td class='lineno'><a href='");
259 html(fileurl);
260 htmlf("' id='%s'>%s</a>", lineno_str, lineno_str + 1);
261 html("</td>");
262 htmlf("<td class='%s'>", class);
263 free(fileurl);
264 } else if (new_line)
265 htmlf("<td class='lineno'></td><td class='%s'>", class);
266 else
267 htmlf("<td class='lineno'></td><td class='%s_dark'>", class);
268 if (new_line) {
269 if (lcs)
270 print_part_with_lcs("add", new_line, lcs);
271 else
272 html_txt(new_line);
273 }
274
275 html("</td></tr>");
276 if (lcs)
277 free(lcs);
278 if (new_line)
279 free(new_line);
280 if (old_line)
281 free(old_line);
282}
283
284static void print_deferred_old_lines(void)
285{
286 struct deferred_lines *iter_old, *tmp;
287 iter_old = deferred_old;
288 while (iter_old) {
289 print_ssdiff_line("del", iter_old->line_no,
290 iter_old->line, -1, NULL, 0);
291 tmp = iter_old->next;
292 free(iter_old);
293 iter_old = tmp;
294 }
295}
296
297static void print_deferred_new_lines(void)
298{
299 struct deferred_lines *iter_new, *tmp;
300 iter_new = deferred_new;
301 while (iter_new) {
302 print_ssdiff_line("add", -1, NULL,
303 iter_new->line_no, iter_new->line, 0);
304 tmp = iter_new->next;
305 free(iter_new);
306 iter_new = tmp;
307 }
308}
309
310static void print_deferred_changed_lines(void)
311{
312 struct deferred_lines *iter_old, *iter_new, *tmp;
313 int n_old_lines = calc_deferred_lines(deferred_old);
314 int n_new_lines = calc_deferred_lines(deferred_new);
315 int individual_chars = (n_old_lines == n_new_lines ? 1 : 0);
316
317 iter_old = deferred_old;
318 iter_new = deferred_new;
319 while (iter_old || iter_new) {
320 if (iter_old && iter_new)
321 print_ssdiff_line("changed", iter_old->line_no,
322 iter_old->line,
323 iter_new->line_no, iter_new->line,
324 individual_chars);
325 else if (iter_old)
326 print_ssdiff_line("changed", iter_old->line_no,
327 iter_old->line, -1, NULL, 0);
328 else if (iter_new)
329 print_ssdiff_line("changed", -1, NULL,
330 iter_new->line_no, iter_new->line, 0);
331 if (iter_old) {
332 tmp = iter_old->next;
333 free(iter_old);
334 iter_old = tmp;
335 }
336
337 if (iter_new) {
338 tmp = iter_new->next;
339 free(iter_new);
340 iter_new = tmp;
341 }
342 }
343}
344
345void cgit_ssdiff_print_deferred_lines(void)
346{
347 if (!deferred_old && !deferred_new)
348 return;
349 if (deferred_old && !deferred_new)
350 print_deferred_old_lines();
351 else if (!deferred_old && deferred_new)
352 print_deferred_new_lines();
353 else
354 print_deferred_changed_lines();
355 deferred_old = deferred_old_last = NULL;
356 deferred_new = deferred_new_last = NULL;
357}
358
359/*
360 * print a single line returned from xdiff
361 */
362void cgit_ssdiff_line_cb(char *line, int len)
363{
364 char c = line[len - 1];
365 line[len - 1] = '\0';
366 if (line[0] == '@') {
367 current_old_line = line_from_hunk(line, '-');
368 current_new_line = line_from_hunk(line, '+');
369 }
370
371 if (line[0] == ' ') {
372 if (deferred_old || deferred_new)
373 cgit_ssdiff_print_deferred_lines();
374 print_ssdiff_line("ctx", current_old_line, line,
375 current_new_line, line, 0);
376 current_old_line += 1;
377 current_new_line += 1;
378 } else if (line[0] == '+') {
379 deferred_new_add(line, current_new_line);
380 current_new_line += 1;
381 } else if (line[0] == '-') {
382 deferred_old_add(line, current_old_line);
383 current_old_line += 1;
384 } else if (line[0] == '@') {
385 html("<tr><td colspan='4' class='hunk'>");
386 html_txt(line);
387 html("</td></tr>");
388 } else {
389 html("<tr><td colspan='4' class='ctx'>");
390 html_txt(line);
391 html("</td></tr>");
392 }
393 line[len - 1] = c;
394}
395
396void cgit_ssdiff_header_begin(void)
397{
398 current_old_line = -1;
399 current_new_line = -1;
400 html("<tr><td class='space' colspan='4'><div></div></td></tr>");
401 html("<tr><td class='head' colspan='4'>");
402}
403
404void cgit_ssdiff_header_end(void)
405{
406 html("</td><tr>");
407}
408
409void cgit_ssdiff_footer(void)
410{
411 if (deferred_old || deferred_new)
412 cgit_ssdiff_print_deferred_lines();
413 html("<tr><td class='foot' colspan='4'></td></tr>");
414}