diffcore-pickaxe.c

   1 // -*- c-basic-offset: 8; indent-tabs-mode: t -*-
   2 /*
   3  * Copyright (C) 2005 Junio C Hamano
   4  * Copyright (C) 2010 Google Inc.
   5  */
   6 #include "cache.h"
   7 #include "diff.h"
   8 #include "diffcore.h"
   9 #include "xdiff-interface.h"
  10
  11 struct diffgrep_cb {
  12         regex_t *regexp;
  13         int hit;
  14 };
  15
  16 static void diffgrep_consume(void *priv, char *line, unsigned long len)
  17 {
  18         struct diffgrep_cb *data = priv;
  19         regmatch_t regmatch;
  20         int hold;
  21
  22         if (line[0] != '+' && line[0] != '-')
  23                 return;
  24         if (data->hit)
  25                 /*
  26                  * NEEDSWORK: we should have a way to terminate the
  27                  * caller early.
  28                  */
  29                 return;
  30         /* Yuck -- line ought to be "const char *"! */
  31         hold = line[len];
  32         line[len] = '\0';
  33         data->hit = !regexec(data->regexp, line + 1, 1, &regmatch, 0);
  34         line[len] = hold;
  35 }
  36
  37 static void fill_one(struct diff_filespec *one,
  38                      mmfile_t *mf, struct userdiff_driver **textconv)
  39 {
  40         if (DIFF_FILE_VALID(one)) {
  41                 *textconv = get_textconv(one);
  42                 mf->size = fill_textconv(*textconv, one, &mf->ptr);
  43         } else {
  44                 memset(mf, 0, sizeof(*mf));
  45         }
  46 }
  47
  48 static int diff_grep(struct diff_filepair *p, regex_t *regexp, struct diff_options *o)
  49 {
  50         regmatch_t regmatch;
  51         struct userdiff_driver *textconv_one = NULL;
  52         struct userdiff_driver *textconv_two = NULL;
  53         mmfile_t mf1, mf2;
  54         int hit;
  55
  56         if (diff_unmodified_pair(p))
  57                 return 0;
  58
  59         fill_one(p->one, &mf1, &textconv_one);
  60         fill_one(p->two, &mf2, &textconv_two);
  61
  62         if (!mf1.ptr) {
  63                 if (!mf2.ptr)
  64                         return 0; /* ignore unmerged */
  65                 /* created "two" -- does it have what we are looking for? */
  66                 hit = !regexec(regexp, p->two->data, 1, &regmatch, 0);
  67         } else if (!mf2.ptr) {
  68                 /* removed "one" -- did it have what we are looking for? */
  69                 hit = !regexec(regexp, p->one->data, 1, &regmatch, 0);
  70         } else {
  71                 /*
  72                  * We have both sides; need to run textual diff and see if
  73                  * the pattern appears on added/deleted lines.
  74                  */
  75                 struct diffgrep_cb ecbdata;
  76                 xpparam_t xpp;
  77                 xdemitconf_t xecfg;
  78
  79                 memset(&xpp, 0, sizeof(xpp));
  80                 memset(&xecfg, 0, sizeof(xecfg));
  81                 ecbdata.regexp = regexp;
  82                 ecbdata.hit = 0;
  83                 xecfg.ctxlen = o->context;
  84                 xecfg.interhunkctxlen = o->interhunkcontext;
  85                 xdi_diff_outf(&mf1, &mf2, diffgrep_consume, &ecbdata,
  86                               &xpp, &xecfg);
  87                 hit = ecbdata.hit;
  88         }
  89         if (textconv_one)
  90                 free(mf1.ptr);
  91         if (textconv_two)
  92                 free(mf2.ptr);
  93         return hit;
  94 }
  95
  96 static void diffcore_pickaxe_grep(struct diff_options *o)
  97 {
  98         struct diff_queue_struct *q = &diff_queued_diff;
  99         int i, has_changes, err;
 100         regex_t regex;
 101         struct diff_queue_struct outq;
 102         outq.queue = NULL;
 103         outq.nr = outq.alloc = 0;
 104
 105         err = regcomp(&regex, o->pickaxe, REG_EXTENDED | REG_NEWLINE);
 106         if (err) {
 107                 char errbuf[1024];
 108                 regerror(err, &regex, errbuf, 1024);
 109                 regfree(&regex);
 110                 die("invalid log-grep regex: %s", errbuf);
 111         }
 112
 113         if (o->pickaxe_opts & DIFF_PICKAXE_ALL) {
 114                 /* Showing the whole changeset if needle exists */
 115                 for (i = has_changes = 0; !has_changes && i < q->nr; i++) {
 116                         struct diff_filepair *p = q->queue[i];
 117                         if (diff_grep(p, &regex, o))
 118                                 has_changes++;
 119                 }
 120                 if (has_changes)
 121                         return; /* do not munge the queue */
 122
 123                 /*
 124                  * Otherwise we will clear the whole queue by copying
 125                  * the empty outq at the end of this function, but
 126                  * first clear the current entries in the queue.
 127                  */
 128                 for (i = 0; i < q->nr; i++)
 129                         diff_free_filepair(q->queue[i]);
 130         } else {
 131                 /* Showing only the filepairs that has the needle */
 132                 for (i = 0; i < q->nr; i++) {
 133                         struct diff_filepair *p = q->queue[i];
 134                         if (diff_grep(p, &regex, o))
 135                                 diff_q(&outq, p);
 136                         else
 137                                 diff_free_filepair(p);
 138                 }
 139         }
 140
 141         regfree(&regex);
 142
 143         free(q->queue);
 144         *q = outq;
 145         return;
 146 }
 147
 148 struct needle {
 149     unsigned skip[256];
 150     unsigned long len;
 151     int use_regex;
 152     regex_t regex;
 153     unsigned char text[];
 154 };
 155
 156 static void bmh_init(struct needle *needle)
 157 {
 158     int i;
 159     for (i = 0; i < 256; i++)
 160         needle->skip[i] = needle->len;
 161
 162     // Last character in needle can not be a mismatch in last position */
 163     for (i = 0; i < needle->len - 1; i++)
 164         needle->skip[needle->text[i]] = needle->len - i - 1;
 165 }
 166
 167
 168 static unsigned bmh(const unsigned char *haystack, unsigned long hlen,
 169                     const struct needle *needle)
 170 {
 171     int i;
 172
 173     if (hlen < needle->len)
 174         return 0;
 175
 176     const unsigned char *end = haystack + hlen - needle->len;
 177     unsigned cnt = 0;
 178     while (haystack <= end) {
 179         while (haystack[needle->len - 1] != needle->text[needle->len - 1]) {
 180             haystack += needle->skip[haystack[needle->len - 1]];
 181             if (haystack > end)
 182                 return cnt;
 183         }
 184         for (i = 0; i < needle->len - 1; i++)
 185             if (haystack[i] != needle->text[i])
 186                 goto mismatch;
 187         cnt++;
 188         haystack += needle->len;
 189         continue;
 190     mismatch:
 191         haystack += needle->skip[haystack[needle->len - 1]];
 192     }
 193
 194     return cnt;
 195 }
 196
 197
 198 static unsigned int contains(struct diff_filespec *one,
 199                              struct needle *needle)
 200 {
 201         unsigned int cnt;
 202         unsigned long sz;
 203         const char *data;
 204         if (diff_populate_filespec(one, 0))
 205                 return 0;
 206         if (!needle->len)
 207                 return 0;
 208
 209         sz = one->size;
 210         data = one->data;
 211         cnt = 0;
 212
 213         if (needle->use_regex) {
 214                 regmatch_t regmatch;
 215                 int flags = 0;
 216
 217                 assert(data[sz] == '\0');
 218                 while (*data && !regexec(&needle->regex, data, 1, &regmatch, flags)) {
 219                         flags |= REG_NOTBOL;
 220                         data += regmatch.rm_eo;
 221                         if (*data && regmatch.rm_so == regmatch.rm_eo)
 222                                 data++;
 223                         cnt++;
 224                 }
 225
 226         } else
 227             cnt = bmh(data, sz, needle);
 228         diff_free_filespec_data(one);
 229         return cnt;
 230 }
 231
 232 static void diffcore_pickaxe_count(struct diff_options *o)
 233 {
 234         const char *needle_txt = o->pickaxe;
 235         int opts = o->pickaxe_opts;
 236         struct diff_queue_struct *q = &diff_queued_diff;
 237         unsigned long len = strlen(needle_txt);
 238         int i, has_changes;
 239         struct diff_queue_struct outq;
 240         DIFF_QUEUE_CLEAR(&outq);
 241         struct needle *needle = NULL;
 242
 243         if (opts & DIFF_PICKAXE_REGEX) {
 244                 needle = xcalloc(1, sizeof(*needle));
 245                 needle->use_regex = 1;
 246                 needle->len = len;
 247                 int err;
 248                 err = regcomp(&needle->regex, needle_txt, REG_EXTENDED | REG_NEWLINE);
 249                 if (err) {
 250                         /* The POSIX.2 people are surely sick */
 251                         char errbuf[1024];
 252                         regerror(err, &needle->regex, errbuf, 1024);
 253                         regfree(&needle->regex);
 254                         die("invalid pickaxe regex: %s", errbuf);
 255                 }
 256         }
 257         else {
 258                 needle = xcalloc(1, sizeof(*needle) + len);
 259                 memcpy(needle->text, needle_txt, len);
 260                 needle->len = len;
 261                 bmh_init(needle);
 262         }
 263
 264         if (opts & DIFF_PICKAXE_ALL) {
 265                 /* Showing the whole changeset if needle exists */
 266                 for (i = has_changes = 0; !has_changes && i < q->nr; i++) {
 267                         struct diff_filepair *p = q->queue[i];
 268                         if (!DIFF_FILE_VALID(p->one)) {
 269                                 if (!DIFF_FILE_VALID(p->two))
 270                                         continue; /* ignore unmerged */
 271                                 /* created */
 272                                 if (contains(p->two, needle))
 273                                         has_changes++;
 274                         }
 275                         else if (!DIFF_FILE_VALID(p->two)) {
 276                                 if (contains(p->one, needle))
 277                                         has_changes++;
 278                         }
 279                         else if (!diff_unmodified_pair(p) &&
 280                                  contains(p->one, needle) !=
 281                                  contains(p->two, needle))
 282                                 has_changes++;
 283                 }
 284                 if (has_changes)
 285                         return; /* not munge the queue */
 286
 287                 /* otherwise we will clear the whole queue
 288                  * by copying the empty outq at the end of this
 289                  * function, but first clear the current entries
 290                  * in the queue.
 291                  */
 292                 for (i = 0; i < q->nr; i++)
 293                         diff_free_filepair(q->queue[i]);
 294         }
 295         else
 296                 /* Showing only the filepairs that has the needle */
 297                 for (i = 0; i < q->nr; i++) {
 298                         struct diff_filepair *p = q->queue[i];
 299                         has_changes = 0;
 300                         if (!DIFF_FILE_VALID(p->one)) {
 301                                 if (!DIFF_FILE_VALID(p->two))
 302                                         ; /* ignore unmerged */
 303                                 /* created */
 304                                 else if (contains(p->two, needle))
 305                                         has_changes = 1;
 306                         }
 307                         else if (!DIFF_FILE_VALID(p->two)) {
 308                                 if (contains(p->one, needle))
 309                                         has_changes = 1;
 310                         }
 311                         else if (!diff_unmodified_pair(p) &&
 312                                  contains(p->one, needle) !=
 313                                  contains(p->two, needle))
 314                                 has_changes = 1;
 315
 316                         if (has_changes)
 317                                 diff_q(&outq, p);
 318                         else
 319                                 diff_free_filepair(p);
 320                 }
 321
 322         if (opts & DIFF_PICKAXE_REGEX)
 323                 regfree(&regex);
 324
 325         free(q->queue);
 326         *q = outq;
 327         return;
 328 }
 329
 330 void diffcore_pickaxe(struct diff_options *o)
 331 {
 332         /* Might want to warn when both S and G are on; I don't care... */
 333         if (o->pickaxe_opts & DIFF_PICKAXE_KIND_G)
 334                 diffcore_pickaxe_grep(o);
 335         else
 336                 diffcore_pickaxe_count(o);
 337 }