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 #include <regex.h>
   9
  10 static unsigned int contains(struct diff_filespec *one,
  11                              const char *needle, unsigned long len,
  12                              regex_t *regexp)
  13 {
  14         unsigned int cnt;
  15         unsigned long offset, sz;
  16         const char *data;
  17         if (diff_populate_filespec(one, 0))
  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         return cnt;
  48 }
  49
  50 void diffcore_pickaxe(const char *needle, int opts)
  51 {
  52         struct diff_queue_struct *q = &diff_queued_diff;
  53         unsigned long len = strlen(needle);
  54         int i, has_changes;
  55         regex_t regex, *regexp = NULL;
  56         struct diff_queue_struct outq;
  57         outq.queue = NULL;
  58         outq.nr = outq.alloc = 0;
  59
  60         if (opts & DIFF_PICKAXE_REGEX) {
  61                 int err;
  62                 err = regcomp(&regex, needle, REG_EXTENDED | REG_NEWLINE);
  63                 if (err) {
  64                         /* The POSIX.2 people are surely sick */
  65                         char errbuf[1024];
  66                         regerror(err, &regex, errbuf, 1024);
  67                         regfree(&regex);
  68                         die("invalid pickaxe regex: %s", errbuf);
  69                 }
  70                 regexp = &regex;
  71         }
  72
  73         if (opts & DIFF_PICKAXE_ALL) {
  74                 /* Showing the whole changeset if needle exists */
  75                 for (i = has_changes = 0; !has_changes && i < q->nr; i++) {
  76                         struct diff_filepair *p = q->queue[i];
  77                         if (!DIFF_FILE_VALID(p->one)) {
  78                                 if (!DIFF_FILE_VALID(p->two))
  79                                         continue; /* ignore unmerged */
  80                                 /* created */
  81                                 if (contains(p->two, needle, len, regexp))
  82                                         has_changes++;
  83                         }
  84                         else if (!DIFF_FILE_VALID(p->two)) {
  85                                 if (contains(p->one, needle, len, regexp))
  86                                         has_changes++;
  87                         }
  88                         else if (!diff_unmodified_pair(p) &&
  89                                  contains(p->one, needle, len, regexp) !=
  90                                  contains(p->two, needle, len, regexp))
  91                                 has_changes++;
  92                 }
  93                 if (has_changes)
  94                         return; /* not munge the queue */
  95
  96                 /* otherwise we will clear the whole queue
  97                  * by copying the empty outq at the end of this
  98                  * function, but first clear the current entries
  99                  * in the queue.
 100                  */
 101                 for (i = 0; i < q->nr; i++)
 102                         diff_free_filepair(q->queue[i]);
 103         }
 104         else
 105                 /* Showing only the filepairs that has the needle */
 106                 for (i = 0; i < q->nr; i++) {
 107                         struct diff_filepair *p = q->queue[i];
 108                         has_changes = 0;
 109                         if (!DIFF_FILE_VALID(p->one)) {
 110                                 if (!DIFF_FILE_VALID(p->two))
 111                                         ; /* ignore unmerged */
 112                                 /* created */
 113                                 else if (contains(p->two, needle, len, regexp))
 114                                         has_changes = 1;
 115                         }
 116                         else if (!DIFF_FILE_VALID(p->two)) {
 117                                 if (contains(p->one, needle, len, regexp))
 118                                         has_changes = 1;
 119                         }
 120                         else if (!diff_unmodified_pair(p) &&
 121                                  contains(p->one, needle, len, regexp) !=
 122                                  contains(p->two, needle, len, regexp))
 123                                 has_changes = 1;
 124
 125                         if (has_changes)
 126                                 diff_q(&outq, p);
 127                         else
 128                                 diff_free_filepair(p);
 129                 }
 130
 131         if (opts & DIFF_PICKAXE_REGEX) {
 132                 regfree(&regex);
 133         }
 134
 135         free(q->queue);
 136         *q = outq;
 137         return;
 138 }