fiftyone.mobile.detection.entities.stream.Node Maven / Gradle / Ivy
/* *********************************************************************
* This Source Code Form is copyright of 51Degrees Mobile Experts Limited.
* Copyright © 2017 51Degrees Mobile Experts Limited, 5 Charlotte Close,
* Caversham, Reading, Berkshire, United Kingdom RG4 7BY
*
* This Source Code Form is the subject of the following patents and patent
* applications, owned by 51Degrees Mobile Experts Limited of 5 Charlotte
* Close, Caversham, Reading, Berkshire, United Kingdom RG4 7BY:
* European Patent No. 2871816;
* European Patent Application No. 17184134.9;
* United States Patent Nos. 9,332,086 and 9,350,823; and
* United States Patent Application No. 15/686,066.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0.
*
* If a copy of the MPL was not distributed with this file, You can obtain
* one at http://mozilla.org/MPL/2.0/.
*
* This Source Code Form is "Incompatible With Secondary Licenses", as
* defined by the Mozilla Public License, v. 2.0.
* ********************************************************************* */
package fiftyone.mobile.detection.entities.stream;
import fiftyone.mobile.detection.IndirectDataset;
import fiftyone.mobile.detection.entities.NodeNumericIndex;
import fiftyone.mobile.detection.readers.BinaryReader;
import java.io.IOException;
/**
* Represents a Entities.Node which can be used with the
* Stream data set. NumericChidren and RankedSignatureIndexes are not loaded
* into memory when the entity is constructed, they're only loaded from the
* data source when requested.
*
* Objects of this class should not be created directly as they are part of the
* internal logic.
*/
public abstract class Node extends fiftyone.mobile.detection.entities.Node {
/**
* The position in the data set where the NumericChildren start.
*/
protected int numericChildrenPosition;
/**
* Pool used to load NumericChildren and RankedSignatureIndexes.
*/
protected final Pool pool;
/**
* Constructs a new instance of Node.
*
* @param dataSet The data set the node is contained within.
* @param offset The offset in the data structure to the node.
* @param reader Reader connected to the source data structure and
* positioned to start reading.
* @throws java.io.IOException if there was a problem accessing data file.
*/
public Node(IndirectDataset dataSet, int offset, BinaryReader reader)
throws IOException {
super(dataSet, offset, reader);
this.pool = dataSet.pool;
}
/**
* An array of all the numeric children.
*
* @return array of all the numeric children.
* @throws java.io.IOException if there was a problem accessing data file.
*/
@Override
@SuppressWarnings("DoubleCheckedLocking")
public final NodeNumericIndex[] getNumericChildren() throws IOException {
NodeNumericIndex[] result = numericChildren;
if(result == null) {
synchronized(this) {
result = numericChildren;
if(result == null) {
BinaryReader reader = pool.getReader();
try {
reader.setPos(numericChildrenPosition);
result = numericChildren = readNodeNumericIndexes(
dataSet, reader, numericChildrenCount);
}
finally {
pool.release(reader);
}
}
}
}
return result;
}
@SuppressWarnings("VolatileArrayField")
protected volatile NodeNumericIndex[] numericChildren;
}