shift.overflow.c

if (p->bytes_used == 0) {
	size_t max_overflow = 0;
	for (size_t j = 0; j < MAX_CHAIN_LENGTH; j++) {
		if (b->pieces[(piece_idx + i + j) % NUMBER_OF_HASH_BUCKET_PIECES].overflowed)
			max_overflow++;
	}
	// we scan keys as far as possible first, to move them closer to their ideal location
	for (size_t j = max_overflow - 1; j >= 0; j--)
	{
		hash_bucket_piece_t* cur = &b->pieces[(piece_idx + i + j) % NUMBER_OF_HASH_BUCKET_PIECES];
		buf = cur->data;
		end = buf + cur->bytes_used;
		while (buf < end) {
			cur_buf_start = buf;
			varint_decode(&buf, &k);
			varint_decode(&buf, &v);
			if (k % NUMBER_OF_HASH_BUCKET_PIECES == piece_idx) {
				diff = buf - cur_buf_start;
				if (diff + p->bytes_used <= PIECE_BUCKET_BUFFER_SIZE) {
					memmove(p->data + p->bytes_used, cur_buf_start, diff);
					memmove(cur_buf_start, buf, end - buf);
					cur->bytes_used -= (uint8_t)diff;
					p->bytes_used += (uint8_t)diff;
					end -= diff;
				}
			}
		}

	}
}