| /* |
| * 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.db.tries; |
| |
| import java.util.function.Function; |
| |
| import org.agrona.DirectBuffer; |
| |
| /** |
| * Simple utility class for dumping the structure of a trie to string. |
| */ |
| class TrieDumper<T> implements Trie.Walker<T, String> |
| { |
| private final StringBuilder b; |
| private final Function<T, String> contentToString; |
| int needsIndent = -1; |
| int currentLength = 0; |
| |
| public TrieDumper(Function<T, String> contentToString) |
| { |
| this.contentToString = contentToString; |
| this.b = new StringBuilder(); |
| } |
| |
| private void endLineAndSetIndent(int newIndent) |
| { |
| needsIndent = newIndent; |
| } |
| |
| @Override |
| public void resetPathLength(int newLength) |
| { |
| currentLength = newLength; |
| endLineAndSetIndent(newLength); |
| } |
| |
| private void maybeIndent() |
| { |
| if (needsIndent >= 0) |
| { |
| b.append('\n'); |
| for (int i = 0; i < needsIndent; ++i) |
| b.append(" "); |
| needsIndent = -1; |
| } |
| } |
| |
| @Override |
| public void addPathByte(int nextByte) |
| { |
| maybeIndent(); |
| ++currentLength; |
| b.append(String.format("%02x", nextByte)); |
| } |
| |
| @Override |
| public void addPathBytes(DirectBuffer buffer, int pos, int count) |
| { |
| maybeIndent(); |
| for (int i = 0; i < count; ++i) |
| b.append(String.format("%02x", buffer.getByte(pos + i) & 0xFF)); |
| currentLength += count; |
| } |
| |
| @Override |
| public void content(T content) |
| { |
| b.append(" -> "); |
| b.append(contentToString.apply(content)); |
| endLineAndSetIndent(currentLength); |
| } |
| |
| @Override |
| public String complete() |
| { |
| return b.toString(); |
| } |
| } |