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 {
  11         unsigned int cnt;
  12         unsigned long offset, sz;
  13         const char *data;
  14         if (diff_populate_filespec(one, 0))
  15                 return 0;
  16
  17         sz = one->size;
  18         data = one->data;
  19         cnt = 0;
  20
  21         /* Yes, I've heard of strstr(), but the thing is *data may
  22          * not be NUL terminated.  Sue me.
  23          */
  24         for (offset = 0; offset + len <= sz; offset++) {
  25                 /* we count non-overlapping occurrences of needle */
  26                 if (!memcmp(needle, data + offset, len)) {
  27                         offset += len - 1;
  28                         cnt++;
  29                 }
  30         }
  31         return cnt;
  32 }
  33
  34 void diffcore_pickaxe(const char *needle, int opts)
  35 {
  36         struct diff_queue_struct *q = &diff_queued_diff;
  37         unsigned long len = strlen(needle);
  38         int i, has_changes;
  39         struct diff_queue_struct outq;
  40         outq.queue = NULL;
  41         outq.nr = outq.alloc = 0;
  42
  43         if (opts & DIFF_PICKAXE_ALL) {
  44                 /* Showing the whole changeset if needle exists */
  45                 for (i = has_changes = 0; !has_changes && i < q->nr; i++) {
  46                         struct diff_filepair *p = q->queue[i];
  47                         if (!DIFF_FILE_VALID(p->one)) {
  48                                 if (!DIFF_FILE_VALID(p->two))
  49                                         continue; /* ignore unmerged */
  50                                 /* created */
  51                                 if (contains(p->two, needle, len))
  52                                         has_changes++;
  53                         }
  54                         else if (!DIFF_FILE_VALID(p->two)) {
  55                                 if (contains(p->one, needle, len))
  56                                         has_changes++;
  57                         }
  58                         else if (!diff_unmodified_pair(p) &&
  59                                  contains(p->one, needle, len) !=
  60                                  contains(p->two, needle, len))
  61                                 has_changes++;
  62                 }
  63                 if (has_changes)
  64                         return; /* not munge the queue */
  65
  66                 /* otherwise we will clear the whole queue
  67                  * by copying the empty outq at the end of this
  68                  * function, but first clear the current entries
  69                  * in the queue.
  70                  */
  71                 for (i = 0; i < q->nr; i++)
  72                         diff_free_filepair(q->queue[i]);
  73         }
  74         else
  75                 /* Showing only the filepairs that has the needle */
  76                 for (i = 0; i < q->nr; i++) {
  77                         struct diff_filepair *p = q->queue[i];
  78                         has_changes = 0;
  79                         if (!DIFF_FILE_VALID(p->one)) {
  80                                 if (!DIFF_FILE_VALID(p->two))
  81                                         ; /* ignore unmerged */
  82                                 /* created */
  83                                 else if (contains(p->two, needle, len))
  84                                         has_changes = 1;
  85                         }
  86                         else if (!DIFF_FILE_VALID(p->two)) {
  87                                 if (contains(p->one, needle, len))
  88                                         has_changes = 1;
  89                         }
  90                         else if (!diff_unmodified_pair(p) &&
  91                                  contains(p->one, needle, len) !=
  92                                  contains(p->two, needle, len))
  93                                 has_changes = 1;
  94
  95                         if (has_changes)
  96                                 diff_q(&outq, p);
  97                         else
  98                                 diff_free_filepair(p);
  99                 }
 100
 101         free(q->queue);
 102         *q = outq;
 103         return;
 104 }