Andrew's git - gitweb.git/blob - diffcore-pickaxe.c

   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"
  10
  11typedef int (*pickaxe_fn)(mmfile_t *one, mmfile_t *two,
  12                          struct diff_options *o,
  13                          regex_t *regexp, kwset_t kws);
  14
  15static int pickaxe_match(struct diff_filepair *p, struct diff_options *o,
  16                         regex_t *regexp, kwset_t kws, pickaxe_fn fn);
  17
  18static void pickaxe(struct diff_queue_struct *q, struct diff_options *o,
  19                    regex_t *regexp, kwset_t kws, pickaxe_fn fn)
  20{
  21        int i;
  22        struct diff_queue_struct outq;
  23
  24        DIFF_QUEUE_CLEAR(&outq);
  25
  26        if (o->pickaxe_opts & DIFF_PICKAXE_ALL) {
  27                /* Showing the whole changeset if needle exists */
  28                for (i = 0; i < q->nr; i++) {
  29                        struct diff_filepair *p = q->queue[i];
  30                        if (pickaxe_match(p, o, regexp, kws, fn))
  31                                return; /* do not munge the queue */
  32                }
  33
  34                /*
  35                 * Otherwise we will clear the whole queue by copying
  36                 * the empty outq at the end of this function, but
  37                 * first clear the current entries in the queue.
  38                 */
  39                for (i = 0; i < q->nr; i++)
  40                        diff_free_filepair(q->queue[i]);
  41        } else {
  42                /* Showing only the filepairs that has the needle */
  43                for (i = 0; i < q->nr; i++) {
  44                        struct diff_filepair *p = q->queue[i];
  45                        if (pickaxe_match(p, o, regexp, kws, fn))
  46                                diff_q(&outq, p);
  47                        else
  48                                diff_free_filepair(p);
  49                }
  50        }
  51
  52        free(q->queue);
  53        *q = outq;
  54}
  55
  56struct diffgrep_cb {
  57        regex_t *regexp;
  58        int hit;
  59};
  60
  61static void diffgrep_consume(void *priv, char *line, unsigned long len)
  62{
  63        struct diffgrep_cb *data = priv;
  64        regmatch_t regmatch;
  65        int hold;
  66
  67        if (line[0] != '+' && line[0] != '-')
  68                return;
  69        if (data->hit)
  70                /*
  71                 * NEEDSWORK: we should have a way to terminate the
  72                 * caller early.
  73                 */
  74                return;
  75        /* Yuck -- line ought to be "const char *"! */
  76        hold = line[len];
  77        line[len] = '\0';
  78        data->hit = !regexec(data->regexp, line + 1, 1, &regmatch, 0);
  79        line[len] = hold;
  80}
  81
  82static int diff_grep(mmfile_t *one, mmfile_t *two,
  83                     struct diff_options *o,
  84                     regex_t *regexp, kwset_t kws)
  85{
  86        regmatch_t regmatch;
  87        struct diffgrep_cb ecbdata;
  88        xpparam_t xpp;
  89        xdemitconf_t xecfg;
  90
  91        if (!one)
  92                return !regexec(regexp, two->ptr, 1, &regmatch, 0);
  93        if (!two)
  94                return !regexec(regexp, one->ptr, 1, &regmatch, 0);
  95
  96        /*
  97         * We have both sides; need to run textual diff and see if
  98         * the pattern appears on added/deleted lines.
  99         */
 100        memset(&xpp, 0, sizeof(xpp));
 101        memset(&xecfg, 0, sizeof(xecfg));
 102        ecbdata.regexp = regexp;
 103        ecbdata.hit = 0;
 104        xecfg.ctxlen = o->context;
 105        xecfg.interhunkctxlen = o->interhunkcontext;
 106        xdi_diff_outf(one, two, diffgrep_consume, &ecbdata,
 107                      &xpp, &xecfg);
 108        return ecbdata.hit;
 109}
 110
 111static void diffcore_pickaxe_grep(struct diff_options *o)
 112{
 113        int err;
 114        regex_t regex;
 115        int cflags = REG_EXTENDED | REG_NEWLINE;
 116
 117        if (DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE))
 118                cflags |= REG_ICASE;
 119
 120        err = regcomp(&regex, o->pickaxe, cflags);
 121        if (err) {
 122                char errbuf[1024];
 123                regerror(err, &regex, errbuf, 1024);
 124                regfree(&regex);
 125                die("invalid regex: %s", errbuf);
 126        }
 127
 128        pickaxe(&diff_queued_diff, o, &regex, NULL, diff_grep);
 129
 130        regfree(&regex);
 131        return;
 132}
 133
 134static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws)
 135{
 136        unsigned int cnt;
 137        unsigned long sz;
 138        const char *data;
 139
 140        sz = mf->size;
 141        data = mf->ptr;
 142        cnt = 0;
 143
 144        if (regexp) {
 145                regmatch_t regmatch;
 146                int flags = 0;
 147
 148                assert(data[sz] == '\0');
 149                while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
 150                        flags |= REG_NOTBOL;
 151                        data += regmatch.rm_eo;
 152                        if (*data && regmatch.rm_so == regmatch.rm_eo)
 153                                data++;
 154                        cnt++;
 155                }
 156
 157        } else { /* Classic exact string match */
 158                while (sz) {
 159                        struct kwsmatch kwsm;
 160                        size_t offset = kwsexec(kws, data, sz, &kwsm);
 161                        const char *found;
 162                        if (offset == -1)
 163                                break;
 164                        else
 165                                found = data + offset;
 166                        sz -= found - data + kwsm.size[0];
 167                        data = found + kwsm.size[0];
 168                        cnt++;
 169                }
 170        }
 171        return cnt;
 172}
 173
 174static int has_changes(mmfile_t *one, mmfile_t *two,
 175                       struct diff_options *o,
 176                       regex_t *regexp, kwset_t kws)
 177{
 178        unsigned int one_contains = one ? contains(one, regexp, kws) : 0;
 179        unsigned int two_contains = two ? contains(two, regexp, kws) : 0;
 180        return one_contains != two_contains;
 181}
 182
 183static int pickaxe_match(struct diff_filepair *p, struct diff_options *o,
 184                         regex_t *regexp, kwset_t kws, pickaxe_fn fn)
 185{
 186        struct userdiff_driver *textconv_one = NULL;
 187        struct userdiff_driver *textconv_two = NULL;
 188        mmfile_t mf1, mf2;
 189        int ret;
 190
 191        if (!o->pickaxe[0])
 192                return 0;
 193
 194        /* ignore unmerged */
 195        if (!DIFF_FILE_VALID(p->one) && !DIFF_FILE_VALID(p->two))
 196                return 0;
 197
 198        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
 199                textconv_one = get_textconv(p->one);
 200                textconv_two = get_textconv(p->two);
 201        }
 202
 203        /*
 204         * If we have an unmodified pair, we know that the count will be the
 205         * same and don't even have to load the blobs. Unless textconv is in
 206         * play, _and_ we are using two different textconv filters (e.g.,
 207         * because a pair is an exact rename with different textconv attributes
 208         * for each side, which might generate different content).
 209         */
 210        if (textconv_one == textconv_two && diff_unmodified_pair(p))
 211                return 0;
 212
 213        mf1.size = fill_textconv(textconv_one, p->one, &mf1.ptr);
 214        mf2.size = fill_textconv(textconv_two, p->two, &mf2.ptr);
 215
 216        ret = fn(DIFF_FILE_VALID(p->one) ? &mf1 : NULL,
 217                 DIFF_FILE_VALID(p->two) ? &mf2 : NULL,
 218                 o, regexp, kws);
 219
 220        if (textconv_one)
 221                free(mf1.ptr);
 222        if (textconv_two)
 223                free(mf2.ptr);
 224        diff_free_filespec_data(p->one);
 225        diff_free_filespec_data(p->two);
 226
 227        return ret;
 228}
 229
 230static void diffcore_pickaxe_count(struct diff_options *o)
 231{
 232        const char *needle = o->pickaxe;
 233        int opts = o->pickaxe_opts;
 234        unsigned long len = strlen(needle);
 235        regex_t regex, *regexp = NULL;
 236        kwset_t kws = NULL;
 237
 238        if (opts & DIFF_PICKAXE_REGEX) {
 239                int err;
 240                err = regcomp(&regex, needle, REG_EXTENDED | REG_NEWLINE);
 241                if (err) {
 242                        /* The POSIX.2 people are surely sick */
 243                        char errbuf[1024];
 244                        regerror(err, &regex, errbuf, 1024);
 245                        regfree(&regex);
 246                        die("invalid regex: %s", errbuf);
 247                }
 248                regexp = &regex;
 249        } else {
 250                kws = kwsalloc(DIFF_OPT_TST(o, PICKAXE_IGNORE_CASE)
 251                               ? tolower_trans_tbl : NULL);
 252                kwsincr(kws, needle, len);
 253                kwsprep(kws);
 254        }
 255
 256        pickaxe(&diff_queued_diff, o, regexp, kws, has_changes);
 257
 258        if (opts & DIFF_PICKAXE_REGEX)
 259                regfree(&regex);
 260        else
 261                kwsfree(kws);
 262        return;
 263}
 264
 265void diffcore_pickaxe(struct diff_options *o)
 266{
 267        /* Might want to warn when both S and G are on; I don't care... */
 268        if (o->pickaxe_opts & DIFF_PICKAXE_KIND_G)
 269                diffcore_pickaxe_grep(o);
 270        else
 271                diffcore_pickaxe_count(o);
 272}