| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.cassandra.io.tries; |
| |
| /** |
| * An abstraction of a node given to the trie serializer to write. |
| */ |
| public interface SerializationNode<VALUE> |
| { |
| /** |
| * The number of children of the node. |
| */ |
| int childCount(); |
| |
| /** |
| * The payload of the node if the node has any associated, otherwise null. |
| */ |
| VALUE payload(); |
| |
| /** |
| * The transition character for the child at position i. Must be an integer between 0 and 255. |
| */ |
| int transition(int i); |
| |
| /** |
| * Returns the distance between this node's position and the child at index i. |
| * Given as a difference calculation to be able to handle two different types of calls: |
| * - writing nodes where all children's positions are already completely determined |
| * - sizing and writing branches within a page where we don't know where we'll actually place |
| * the nodes, but we know how far backward the child nodes will end up |
| */ |
| long serializedPositionDelta(int i, long nodePosition); |
| |
| /** |
| * Returns the furthest distance that needs to be written to store this node, i.e. |
| * min(serializedPositionDelta(i, nodePosition) for 0 <= i < childCount()) |
| * Given separately as the loop above can be inefficient (e.g. when children are not yet written). |
| */ |
| long maxPositionDelta(long nodePosition); |
| } |