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 strncpy(buf2, buf1, len);
107 buf2[len] = '\0';
108 res = atoi(buf2);
109 free(buf2);
110 return res;
111}
112
113static char *replace_tabs(char *line)
114{
115 char *prev_buf = line;
116 char *cur_buf;
117 size_t linelen = strlen(line);
118 int n_tabs = 0;
119 int i;
120 char *result;
121
122 if (linelen == 0) {
123 result = xmalloc(1);
124 result[0] = '\0';
125 return result;
126 }
127
128 for (i = 0; i < linelen; i++) {
129 if (line[i] == '\t')
130 n_tabs += 1;
131 }
132 result = xmalloc(linelen + n_tabs * 8 + 1);
133 result[0] = '\0';
134
135 for (;;) {
136 cur_buf = strchr(prev_buf, '\t');
137 if (!cur_buf) {
138 strcat(result, prev_buf);
139 break;
140 } else {
141 strncat(result, prev_buf, cur_buf - prev_buf);
142 linelen = strlen(result);
143 memset(&result[linelen], ' ', 8 - (linelen % 8));
144 result[linelen + 8 - (linelen % 8)] = '\0';
145 }
146 prev_buf = cur_buf + 1;
147 }
148 return result;
149}
150
151static int calc_deferred_lines(struct deferred_lines *start)
152{
153 struct deferred_lines *item = start;
154 int result = 0;
155 while (item) {
156 result += 1;
157 item = item->next;
158 }
159 return result;
160}
161
162static void deferred_old_add(char *line, int line_no)
163{
164 struct deferred_lines *item = xmalloc(sizeof(struct deferred_lines));
165 item->line = xstrdup(line);
166 item->line_no = line_no;
167 item->next = NULL;
168 if (deferred_old) {
169 deferred_old_last->next = item;
170 deferred_old_last = item;
171 } else {
172 deferred_old = deferred_old_last = item;
173 }
174}
175
176static void deferred_new_add(char *line, int line_no)
177{
178 struct deferred_lines *item = xmalloc(sizeof(struct deferred_lines));
179 item->line = xstrdup(line);
180 item->line_no = line_no;
181 item->next = NULL;
182 if (deferred_new) {
183 deferred_new_last->next = item;
184 deferred_new_last = item;
185 } else {
186 deferred_new = deferred_new_last = item;
187 }
188}
189
190static void print_part_with_lcs(char *class, char *line, char *lcs)
191{
192 int line_len = strlen(line);
193 int i, j;
194 char c[2] = " ";
195 int same = 1;
196
197 j = 0;
198 for (i = 0; i < line_len; i++) {
199 c[0] = line[i];
200 if (same) {
201 if (line[i] == lcs[j])
202 j += 1;
203 else {
204 same = 0;
205 htmlf("<span class='%s'>", class);
206 }
207 } else if (line[i] == lcs[j]) {
208 same = 1;
209 htmlf("</span>");
210 j += 1;
211 }
212 html_txt(c);
213 }
214}
215
216static void print_ssdiff_line(char *class,
217 int old_line_no,
218 char *old_line,
219 int new_line_no,
220 char *new_line, int individual_chars)
221{
222 char *lcs = NULL;
223
224 if (old_line)
225 old_line = replace_tabs(old_line + 1);
226 if (new_line)
227 new_line = replace_tabs(new_line + 1);
228 if (individual_chars && old_line && new_line)
229 lcs = longest_common_subsequence(old_line, new_line);
230 html("<tr>\n");
231 if (old_line_no > 0) {
232 struct diff_filespec *old_file = cgit_get_current_old_file();
233 char *lineno_str = fmt("n%d", old_line_no);
234 char *id_str = fmt("id=%s#%s", is_null_oid(&old_file->oid)?"HEAD":oid_to_hex(old_rev_oid), lineno_str);
235 char *fileurl = cgit_fileurl(ctx.repo->url, "tree", old_file->path, id_str);
236 html("<td class='lineno'><a href='");
237 html(fileurl);
238 htmlf("' id='%s'>%s</a>", lineno_str, lineno_str + 1);
239 html("</td>");
240 htmlf("<td class='%s'>", class);
241 free(fileurl);
242 } else if (old_line)
243 htmlf("<td class='lineno'></td><td class='%s'>", class);
244 else
245 htmlf("<td class='lineno'></td><td class='%s_dark'>", class);
246 if (old_line) {
247 if (lcs)
248 print_part_with_lcs("del", old_line, lcs);
249 else
250 html_txt(old_line);
251 }
252
253 html("</td>\n");
254 if (new_line_no > 0) {
255 struct diff_filespec *new_file = cgit_get_current_new_file();
256 char *lineno_str = fmt("n%d", new_line_no);
257 char *id_str = fmt("id=%s#%s", is_null_oid(&new_file->oid)?"HEAD":oid_to_hex(new_rev_oid), lineno_str);
258 char *fileurl = cgit_fileurl(ctx.repo->url, "tree", new_file->path, id_str);
259 html("<td class='lineno'><a href='");
260 html(fileurl);
261 htmlf("' id='%s'>%s</a>", lineno_str, lineno_str + 1);
262 html("</td>");
263 htmlf("<td class='%s'>", class);
264 free(fileurl);
265 } else if (new_line)
266 htmlf("<td class='lineno'></td><td class='%s'>", class);
267 else
268 htmlf("<td class='lineno'></td><td class='%s_dark'>", class);
269 if (new_line) {
270 if (lcs)
271 print_part_with_lcs("add", new_line, lcs);
272 else
273 html_txt(new_line);
274 }
275
276 html("</td></tr>");
277 if (lcs)
278 free(lcs);
279 if (new_line)
280 free(new_line);
281 if (old_line)
282 free(old_line);
283}
284
285static void print_deferred_old_lines(void)
286{
287 struct deferred_lines *iter_old, *tmp;
288 iter_old = deferred_old;
289 while (iter_old) {
290 print_ssdiff_line("del", iter_old->line_no,
291 iter_old->line, -1, NULL, 0);
292 tmp = iter_old->next;
293 free(iter_old);
294 iter_old = tmp;
295 }
296}
297
298static void print_deferred_new_lines(void)
299{
300 struct deferred_lines *iter_new, *tmp;
301 iter_new = deferred_new;
302 while (iter_new) {
303 print_ssdiff_line("add", -1, NULL,
304 iter_new->line_no, iter_new->line, 0);
305 tmp = iter_new->next;
306 free(iter_new);
307 iter_new = tmp;
308 }
309}
310
311static void print_deferred_changed_lines(void)
312{
313 struct deferred_lines *iter_old, *iter_new, *tmp;
314 int n_old_lines = calc_deferred_lines(deferred_old);
315 int n_new_lines = calc_deferred_lines(deferred_new);
316 int individual_chars = (n_old_lines == n_new_lines ? 1 : 0);
317
318 iter_old = deferred_old;
319 iter_new = deferred_new;
320 while (iter_old || iter_new) {
321 if (iter_old && iter_new)
322 print_ssdiff_line("changed", iter_old->line_no,
323 iter_old->line,
324 iter_new->line_no, iter_new->line,
325 individual_chars);
326 else if (iter_old)
327 print_ssdiff_line("changed", iter_old->line_no,
328 iter_old->line, -1, NULL, 0);
329 else if (iter_new)
330 print_ssdiff_line("changed", -1, NULL,
331 iter_new->line_no, iter_new->line, 0);
332 if (iter_old) {
333 tmp = iter_old->next;
334 free(iter_old);
335 iter_old = tmp;
336 }
337
338 if (iter_new) {
339 tmp = iter_new->next;
340 free(iter_new);
341 iter_new = tmp;
342 }
343 }
344}
345
346void cgit_ssdiff_print_deferred_lines(void)
347{
348 if (!deferred_old && !deferred_new)
349 return;
350 if (deferred_old && !deferred_new)
351 print_deferred_old_lines();
352 else if (!deferred_old && deferred_new)
353 print_deferred_new_lines();
354 else
355 print_deferred_changed_lines();
356 deferred_old = deferred_old_last = NULL;
357 deferred_new = deferred_new_last = NULL;
358}
359
360/*
361 * print a single line returned from xdiff
362 */
363void cgit_ssdiff_line_cb(char *line, int len)
364{
365 char c = line[len - 1];
366 line[len - 1] = '\0';
367 if (line[0] == '@') {
368 current_old_line = line_from_hunk(line, '-');
369 current_new_line = line_from_hunk(line, '+');
370 }
371
372 if (line[0] == ' ') {
373 if (deferred_old || deferred_new)
374 cgit_ssdiff_print_deferred_lines();
375 print_ssdiff_line("ctx", current_old_line, line,
376 current_new_line, line, 0);
377 current_old_line += 1;
378 current_new_line += 1;
379 } else if (line[0] == '+') {
380 deferred_new_add(line, current_new_line);
381 current_new_line += 1;
382 } else if (line[0] == '-') {
383 deferred_old_add(line, current_old_line);
384 current_old_line += 1;
385 } else if (line[0] == '@') {
386 html("<tr><td colspan='4' class='hunk'>");
387 html_txt(line);
388 html("</td></tr>");
389 } else {
390 html("<tr><td colspan='4' class='ctx'>");
391 html_txt(line);
392 html("</td></tr>");
393 }
394 line[len - 1] = c;
395}
396
397void cgit_ssdiff_header_begin(void)
398{
399 current_old_line = -1;
400 current_new_line = -1;
401 html("<tr><td class='space' colspan='4'><div></div></td></tr>");
402 html("<tr><td class='head' colspan='4'>");
403}
404
405void cgit_ssdiff_header_end(void)
406{
407 html("</td><tr>");
408}
409
410void cgit_ssdiff_footer(void)
411{
412 if (deferred_old || deferred_new)
413 cgit_ssdiff_print_deferred_lines();
414 html("<tr><td class='foot' colspan='4'></td></tr>");
415}