+
+ if (last_index != (uint64_t) -1) {
+ assert(last_index <= right);
+
+ /* If we cached the last index we
+ * looked at, let's try to not to jump
+ * too wildly around and see if we can
+ * limit the range to look at early to
+ * the immediate neighbors of the last
+ * index we looked at. */
+
+ if (last_index > 0) {
+ uint64_t x = last_index - 1;
+
+ p = le64toh(array->entry_array.items[x]);
+ if (p <= 0)
+ return -EBADMSG;
+
+ r = test_object(f, p, needle);
+ if (r < 0)
+ return r;
+
+ if (r == TEST_FOUND)
+ r = direction == DIRECTION_DOWN ? TEST_RIGHT : TEST_LEFT;
+
+ if (r == TEST_RIGHT)
+ right = x;
+ else
+ left = x + 1;
+ }
+
+ if (last_index < right) {
+ uint64_t y = last_index + 1;
+
+ p = le64toh(array->entry_array.items[y]);
+ if (p <= 0)
+ return -EBADMSG;
+
+ r = test_object(f, p, needle);
+ if (r < 0)
+ return r;
+
+ if (r == TEST_FOUND)
+ r = direction == DIRECTION_DOWN ? TEST_RIGHT : TEST_LEFT;
+
+ if (r == TEST_RIGHT)
+ right = y;
+ else
+ left = y + 1;
+ }
+
+ last_index = (uint64_t) -1;
+ }
+