git/diffcore-pickaxe.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #include "cache.h"
   5 #include "diff.h"
   6 #include "diffcore.h"
   7
   8 static unsigned int contains(struct diff_filespec *one,
   9                              const char *needle, unsigned long len,
  10                              regex_t *regexp)
  11 {
  12         unsigned int cnt;
  13         unsigned long offset, sz;
  14         const char *data;
  15         if (diff_populate_filespec(one, 0))
  16                 return 0;
  17         if (!len)
  18                 return 0;
  19
  20         sz = one->size;
  21         data = one->data;
  22         cnt = 0;
  23
  24         if (regexp) {
  25                 regmatch_t regmatch;
  26                 int flags = 0;
  27
  28                 while (*data && !regexec(regexp, data, 1, &regmatch, flags)) {
  29                         flags |= REG_NOTBOL;
  30                         data += regmatch.rm_so;
  31                         if (*data) data++;
  32                         cnt++;
  33                 }
  34
  35         } else { /* Classic exact string match */
  36                 /* Yes, I've heard of strstr(), but the thing is *data may
  37                  * not be NUL terminated.  Sue me.
  38                  */
  39                 for (offset = 0; offset + len <= sz; offset++) {
  40                         /* we count non-overlapping occurrences of needle */
  41                         if (!memcmp(needle, data + offset, len)) {
  42                                 offset += len - 1;
  43                                 cnt++;
  44                         }
  45                 }
  46         }
  47         diff_free_filespec_data(one);
  48         return cnt;
  49 }
  50
  51 void diffcore_pickaxe(const char *needle, int opts)
  52 {
  53         struct diff_queue_struct *q = &diff_queued_diff;
  54         unsigned long len = strlen(needle);
  55         int i, has_changes;
  56         regex_t regex, *regexp = NULL;
  57         struct diff_queue_struct outq;
  58         outq.queue = NULL;
  59         outq.nr = outq.alloc = 0;
  60
  61         if (opts & DIFF_PICKAXE_REGEX) {
  62                 int err;
  63                 err = regcomp(&regex, needle, REG_EXTENDED | REG_NEWLINE);
  64                 if (err) {
  65                         /* The POSIX.2 people are surely sick */
  66                         char errbuf[1024];
  67                         regerror(err, &regex, errbuf, 1024);
  68                         regfree(&regex);
  69                         die("invalid pickaxe regex: %s", errbuf);
  70                 }
  71                 regexp = &regex;
  72         }
  73
  74         if (opts & DIFF_PICKAXE_ALL) {
  75                 /* Showing the whole changeset if needle exists */
  76                 for (i = has_changes = 0; !has_changes && i < q->nr; i++) {
  77                         struct diff_filepair *p = q->queue[i];
  78                         if (!DIFF_FILE_VALID(p->one)) {
  79                                 if (!DIFF_FILE_VALID(p->two))
  80                                         continue; /* ignore unmerged */
  81                                 /* created */
  82                                 if (contains(p->two, needle, len, regexp))
  83                                         has_changes++;
  84                         }
  85                         else if (!DIFF_FILE_VALID(p->two)) {
  86                                 if (contains(p->one, needle, len, regexp))
  87                                         has_changes++;
  88                         }
  89                         else if (!diff_unmodified_pair(p) &&
  90                                  contains(p->one, needle, len, regexp) !=
  91                                  contains(p->two, needle, len, regexp))
  92                                 has_changes++;
  93                 }
  94                 if (has_changes)
  95                         return; /* not munge the queue */
  96
  97                 /* otherwise we will clear the whole queue
  98                  * by copying the empty outq at the end of this
  99                  * function, but first clear the current entries
 100                  * in the queue.
 101                  */
 102                 for (i = 0; i < q->nr; i++)
 103                         diff_free_filepair(q->queue[i]);
 104         }
 105         else
 106                 /* Showing only the filepairs that has the needle */
 107                 for (i = 0; i < q->nr; i++) {
 108                         struct diff_filepair *p = q->queue[i];
 109                         has_changes = 0;
 110                         if (!DIFF_FILE_VALID(p->one)) {
 111                                 if (!DIFF_FILE_VALID(p->two))
 112                                         ; /* ignore unmerged */
 113                                 /* created */
 114                                 else if (contains(p->two, needle, len, regexp))
 115                                         has_changes = 1;
 116                         }
 117                         else if (!DIFF_FILE_VALID(p->two)) {
 118                                 if (contains(p->one, needle, len, regexp))
 119                                         has_changes = 1;
 120                         }
 121                         else if (!diff_unmodified_pair(p) &&
 122                                  contains(p->one, needle, len, regexp) !=
 123                                  contains(p->two, needle, len, regexp))
 124                                 has_changes = 1;
 125
 126                         if (has_changes)
 127                                 diff_q(&outq, p);
 128                         else
 129                                 diff_free_filepair(p);
 130                 }
 131
 132         if (opts & DIFF_PICKAXE_REGEX) {
 133                 regfree(&regex);
 134         }
 135
 136         free(q->queue);
 137         *q = outq;
 138         return;
 139 }