Andrew's git - gitweb.git/blob - 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
  10static 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
  50void 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}