Function find_deltas

builtin/pack-objects.c:2972–3112

}

static void find_deltas(struct object_entry **list, unsigned *list_size,
			int window, int depth, unsigned *processed)
{
	uint32_t i, idx = 0, count = 0;
	struct unpacked *array;
	unsigned long mem_usage = 0;

	CALLOC_ARRAY(array, window);

	for (;;) {
		struct object_entry *entry;
		struct unpacked *n = array + idx;
		int j, max_depth, best_base = -1;

		progress_lock();
		if (!*list_size) {
			progress_unlock();
			break;
		}
		entry = *list++;
		(*list_size)--;
		if (!entry->preferred_base) {
			(*processed)++;
			display_progress(progress_state, *processed);
		}
		progress_unlock();

		mem_usage -= free_unpacked(n);
		n->entry = entry;

		while (window_memory_limit &&
		       mem_usage > window_memory_limit &&
		       count > 1) {
			const uint32_t tail = (idx + window - count) % window;
			mem_usage -= free_unpacked(array + tail);
			count--;
		}

		/* We do not compute delta to *create* objects we are not
		 * going to pack.
		 */
		if (entry->preferred_base)
			goto next;

		/*
		 * If the current object is at pack edge, take the depth the
		 * objects that depend on the current object into account
		 * otherwise they would become too deep.
		 */
		max_depth = depth;
		if (DELTA_CHILD(entry)) {
			max_depth -= check_delta_limit(entry, 0);
			if (max_depth <= 0)
				goto next;
		}

		j = window;
		while (--j > 0) {