| /* |
| * 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.tinkerpop.gremlin.structure.io.gryo; |
| |
| import org.apache.tinkerpop.gremlin.structure.Vertex; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.FilterInputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.OutputStream; |
| import java.nio.ByteBuffer; |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| import java.util.List; |
| |
| /** |
| * An {@link InputStream} implementation that can independently process a Gryo file written with |
| * {@link GryoWriter#writeVertices(OutputStream, Iterator)}. |
| * |
| * @author Stephen Mallette (http://stephen.genoprime.com) |
| */ |
| public final class VertexByteArrayInputStream extends FilterInputStream { |
| |
| private static final byte[] vertexTerminatorClass = new byte[]{15, 1, 1, 9}; |
| private static final byte[] pattern = ByteBuffer.allocate(vertexTerminatorClass.length + 8).put(vertexTerminatorClass).putLong(4185403236219066774L).array(); |
| |
| public VertexByteArrayInputStream(final InputStream inputStream) { |
| super(inputStream); |
| } |
| |
| /** |
| * Read the bytes of the next {@link Vertex} in the stream. The returned |
| * stream can then be passed to {@link GryoReader#readVertex(java.io.InputStream, java.util.function.Function)}. |
| */ |
| public ByteArrayOutputStream readVertexBytes() throws IOException { |
| final ByteArrayOutputStream stream = new ByteArrayOutputStream(); |
| final LinkedList<Byte> buffer = new LinkedList<>(); |
| |
| int current = read(); |
| while (current > -1 && (buffer.size() < 12 || !isMatch(buffer))) { |
| stream.write(current); |
| |
| current = read(); |
| if (buffer.size() > 11) |
| buffer.removeFirst(); |
| |
| buffer.addLast((byte) current); |
| } |
| |
| stream.write(current); |
| return stream; |
| } |
| |
| private static boolean isMatch(final List<Byte> input) { |
| for (int i = 0; i < pattern.length; i++) { |
| if (pattern[i] != input.get(i)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| } |