Extract helper bits from c-merge-recursive work

[git.git] / path-list.c

diff --git a/path-list.c b/path-list.c
new file mode 100644 (file)
index 0000000..f15a10d
--- /dev/null
+++ b/path-list.c
@@ -0,0 +1,105 @@
+#include <stdio.h>
+#include "cache.h"
+#include "path-list.h"
+
+/* if there is no exact match, point to the index where the entry could be
+ * inserted */
+static int get_entry_index(const struct path_list *list, const char *path,
+               int *exact_match)
+{
+       int left = -1, right = list->nr;
+
+       while (left + 1 < right) {
+               int middle = (left + right) / 2;
+               int compare = strcmp(path, list->items[middle].path);
+               if (compare < 0)
+                       right = middle;
+               else if (compare > 0)
+                       left = middle;
+               else {
+                       *exact_match = 1;
+                       return middle;
+               }
+       }
+
+       *exact_match = 0;
+       return right;
+}
+
+/* returns -1-index if already exists */
+static int add_entry(struct path_list *list, const char *path)
+{
+       int exact_match;
+       int index = get_entry_index(list, path, &exact_match);
+
+       if (exact_match)
+               return -1 - index;
+
+       if (list->nr + 1 >= list->alloc) {
+               list->alloc += 32;
+               list->items = xrealloc(list->items, list->alloc
+                               * sizeof(struct path_list_item));
+       }
+       if (index < list->nr)
+               memmove(list->items + index + 1, list->items + index,
+                               (list->nr - index)
+                               * sizeof(struct path_list_item));
+       list->items[index].path = list->strdup_paths ?
+               strdup(path) : (char *)path;
+       list->items[index].util = NULL;
+       list->nr++;
+
+       return index;
+}
+
+struct path_list_item *path_list_insert(const char *path, struct path_list *list)
+{
+       int index = add_entry(list, path);
+
+       if (index < 0)
+               index = 1 - index;
+
+       return list->items + index;
+}
+
+int path_list_has_path(const struct path_list *list, const char *path)
+{
+       int exact_match;
+       get_entry_index(list, path, &exact_match);
+       return exact_match;
+}
+
+struct path_list_item *path_list_lookup(const char *path, struct path_list *list)
+{
+       int exact_match, i = get_entry_index(list, path, &exact_match);
+       if (!exact_match)
+               return NULL;
+       return list->items + i;
+}
+
+void path_list_clear(struct path_list *list, int free_items)
+{
+       if (list->items) {
+               int i;
+               if (free_items)
+                       for (i = 0; i < list->nr; i++) {
+                               if (list->strdup_paths)
+                                       free(list->items[i].path);
+                               if (list->items[i].util)
+                                       free(list->items[i].util);
+                       }
+               free(list->items);
+       }
+       list->items = NULL;
+       list->nr = list->alloc = 0;
+}
+
+void print_path_list(const char *text, const struct path_list *p)
+{
+       int i;
+       if ( text )
+               printf("%s\n", text);
+       for (i = 0; i < p->nr; i++)
+               printf("%s:%p\n", p->items[i].path, p->items[i].util);
+}
+