Documentation/describe: improve one-line summary
[git.git] / diffcore-pickaxe.c
blob185f86b2840d3337eac9fb2b17b260ca0c53fbab
1 /*
2 * Copyright (C) 2005 Junio C Hamano
3 * Copyright (C) 2010 Google Inc.
4 */
5 #include "cache.h"
6 #include "diff.h"
7 #include "diffcore.h"
8 #include "xdiff-interface.h"
9 #include "kwset.h"
11 typedef int (*pickaxe_fn)(mmfile_t *one, mmfile_t *two,
12 struct diff_options *o,
13 regex_t *regexp, kwset_t kws);
15 struct diffgrep_cb {
16 regex_t *regexp;
17 int hit;
20 static void diffgrep_consume(void *priv, char *line, unsigned long len)
22 struct diffgrep_cb *data = priv;
23 regmatch_t regmatch;
24 int hold;
26 if (line[0] != '+' && line[0] != '-')
27 return;
28 if (data->hit)
30 * NEEDSWORK: we should have a way to terminate the
31 * caller early.
33 return;
34 /* Yuck -- line ought to be "const char *"! */
35 hold = line[len];
36 line[len] = '\0';
37 data->hit = !regexec(data->regexp, line + 1, 1, &regmatch, 0);
38 line[len] = hold;
41 static int diff_grep(mmfile_t *one, mmfile_t *two,
42 struct diff_options *o,
43 regex_t *regexp, kwset_t kws)
45 regmatch_t regmatch;
46 struct diffgrep_cb ecbdata;
47 xpparam_t xpp;
48 xdemitconf_t xecfg;
50 if (!one)
51 return !regexec(regexp, two->ptr, 1, &regmatch, 0);
52 if (!two)
53 return !regexec(regexp, one->ptr, 1, &regmatch, 0);
56 * We have both sides; need to run textual diff and see if
57 * the pattern appears on added/deleted lines.
59 memset(&xpp, 0, sizeof(xpp));
60 memset(&xecfg, 0, sizeof(xecfg));
61 ecbdata.regexp = regexp;
62 ecbdata.hit = 0;
63 xecfg.ctxlen = o->context;
64 xecfg.interhunkctxlen = o->interhunkcontext;
65 xdi_diff_outf(one, two, diffgrep_consume, &ecbdata,
66 &xpp, &xecfg);
67 return ecbdata.hit;
70 static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws)
72 unsigned int cnt;
73 unsigned long sz;
74 const char *data;
76 sz = mf->size;
77 data = mf->ptr;
78 cnt = 0;
80 if (regexp) {
81 regmatch_t regmatch;
82 int flags = 0;
84 assert(data[sz] == '\0');
85 while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
86 flags |= REG_NOTBOL;
87 data += regmatch.rm_eo;
88 if (*data && regmatch.rm_so == regmatch.rm_eo)
89 data++;
90 cnt++;
93 } else { /* Classic exact string match */
94 while (sz) {
95 struct kwsmatch kwsm;
96 size_t offset = kwsexec(kws, data, sz, &kwsm);
97 if (offset == -1)
98 break;
99 sz -= offset + kwsm.size[0];
100 data += offset + kwsm.size[0];
101 cnt++;
104 return cnt;
107 static int has_changes(mmfile_t *one, mmfile_t *two,
108 struct diff_options *o,
109 regex_t *regexp, kwset_t kws)
111 unsigned int one_contains = one ? contains(one, regexp, kws) : 0;
112 unsigned int two_contains = two ? contains(two, regexp, kws) : 0;
113 return one_contains != two_contains;
116 static int pickaxe_match(struct diff_filepair *p, struct diff_options *o,
117 regex_t *regexp, kwset_t kws, pickaxe_fn fn)
119 struct userdiff_driver *textconv_one = NULL;
120 struct userdiff_driver *textconv_two = NULL;
121 mmfile_t mf1, mf2;
122 int ret;
124 if (!o->pickaxe[0])
125 return 0;
127 /* ignore unmerged */
128 if (!DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two))
129 return 0;
131 if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
132 textconv_one = get_textconv(p->one);
133 textconv_two = get_textconv(p->two);
137 * If we have an unmodified pair, we know that the count will be the
138 * same and don't even have to load the blobs. Unless textconv is in
139 * play, _and_ we are using two different textconv filters (e.g.,
140 * because a pair is an exact rename with different textconv attributes
141 * for each side, which might generate different content).
143 if (textconv_one == textconv_two && diff_unmodified_pair(p))
144 return 0;
146 mf1.size = fill_textconv(textconv_one, p->one, &mf1.ptr);
147 mf2.size = fill_textconv(textconv_two, p->two, &mf2.ptr);
149 ret = fn(DIFF_FILE_VALID(p->one) ? &mf1 : NULL,
150 DIFF_FILE_VALID(p->two) ? &mf2 : NULL,
151 o, regexp, kws);
153 if (textconv_one)
154 free(mf1.ptr);
155 if (textconv_two)
156 free(mf2.ptr);
157 diff_free_filespec_data(p->one);
158 diff_free_filespec_data(p->two);
160 return ret;
163 static void pickaxe(struct diff_queue_struct *q, struct diff_options *o,
164 regex_t *regexp, kwset_t kws, pickaxe_fn fn)
166 int i;
167 struct diff_queue_struct outq;
169 DIFF_QUEUE_CLEAR(&outq);
171 if (o->pickaxe_opts & DIFF_PICKAXE_ALL) {
172 /* Showing the whole changeset if needle exists */
173 for (i = 0; i < q->nr; i++) {
174 struct diff_filepair *p = q->queue[i];
175 if (pickaxe_match(p, o, regexp, kws, fn))
176 return; /* do not munge the queue */
180 * Otherwise we will clear the whole queue by copying
181 * the empty outq at the end of this function, but
182 * first clear the current entries in the queue.
184 for (i = 0; i < q->nr; i++)
185 diff_free_filepair(q->queue[i]);
186 } else {
187 /* Showing only the filepairs that has the needle */
188 for (i = 0; i < q->nr; i++) {
189 struct diff_filepair *p = q->queue[i];
190 if (pickaxe_match(p, o, regexp, kws, fn))
191 diff_q(&outq, p);
192 else
193 diff_free_filepair(p);
197 free(q->queue);
198 *q = outq;
201 void diffcore_pickaxe(struct diff_options *o)
203 const char *needle = o->pickaxe;
204 int opts = o->pickaxe_opts;
205 regex_t regex, *regexp = NULL;
206 kwset_t kws = NULL;
208 if (opts & (DIFF_PICKAXE_REGEX | DIFF_PICKAXE_KIND_G)) {
209 int err;
210 int cflags = REG_EXTENDED | REG_NEWLINE;
211 if (DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE))
212 cflags |= REG_ICASE;
213 err = regcomp(&regex, needle, cflags);
214 if (err) {
215 /* The POSIX.2 people are surely sick */
216 char errbuf[1024];
217 regerror(err, &regex, errbuf, 1024);
218 regfree(&regex);
219 die("invalid regex: %s", errbuf);
221 regexp = &regex;
222 } else {
223 kws = kwsalloc(DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE)
224 ? tolower_trans_tbl : NULL);
225 kwsincr(kws, needle, strlen(needle));
226 kwsprep(kws);
229 /* Might want to warn when both S and G are on; I don't care... */
230 pickaxe(&diff_queued_diff, o, regexp, kws,
231 (opts & DIFF_PICKAXE_KIND_G) ? diff_grep : has_changes);
233 if (regexp)
234 regfree(regexp);
235 else
236 kwsfree(kws);
237 return;