Function note_tree_insert

notes.c:253–327

* To insert a leaf_node: * Search to the tree location appropriate for the given leaf_node's key: * - If location is unused (NULL), store the tweaked pointer directly there * - If location holds a note entry that matches the note-to-be-inserted, then * combine the two notes (by calling the given combine_notes function). * - If location holds a note entry that matches the subtree-to-be-inser

 *   node-to-be-inserted, and store the new int_node into the location.
 */
static int note_tree_insert(struct notes_tree *t, struct int_node *tree,
		unsigned char n, struct leaf_node *entry, unsigned char type,
		combine_notes_fn combine_notes)
{
	struct int_node *new_node;
	struct leaf_node *l;
	void **p = note_tree_search(t, &tree, &n, entry->key_oid.hash);
	int ret = 0;

	assert(GET_PTR_TYPE(entry) == 0); /* no type bits set */
	l = (struct leaf_node *) CLR_PTR_TYPE(*p);
	switch (GET_PTR_TYPE(*p)) {
	case PTR_TYPE_NULL:
		assert(!*p);
		if (is_null_oid(&entry->val_oid))
			free(entry);
		else
			*p = SET_PTR_TYPE(entry, type);
		return 0;
	case PTR_TYPE_NOTE:
		switch (type) {
		case PTR_TYPE_NOTE:
			if (oideq(&l->key_oid, &entry->key_oid)) {
				/* skip concatenation if l == entry */
				if (oideq(&l->val_oid, &entry->val_oid)) {
					free(entry);
					return 0;
				}

				ret = combine_notes(&l->val_oid,
						    &entry->val_oid);
				if (!ret && is_null_oid(&l->val_oid))
					note_tree_remove(t, tree, n, entry);
				free(entry);
				return ret;
			}
			break;
		case PTR_TYPE_SUBTREE:
			if (!SUBTREE_SHA1_PREFIXCMP(l->key_oid.hash,
						    entry->key_oid.hash)) {
				/* unpack 'entry' */
				load_subtree(t, entry, tree, n);
				free(entry);
				return 0;
			}
			break;
		}
		break;
	case PTR_TYPE_SUBTREE:
		if (!SUBTREE_SHA1_PREFIXCMP(entry->key_oid.hash, l->key_oid.hash)) {
			/* unpack 'l' and restart insert */
			*p = NULL;
			load_subtree(t, l, tree, n);
			free(l);
			return note_tree_insert(t, tree, n, entry, type,
						combine_notes);
		}
		break;