org.neo4j.gds.similarity.knn.KnnFactory Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of algo Show documentation
Neo4j Graph Data Science :: Algorithms
There is a newer version: 2.15.0
/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.gds.similarity.knn;

import org.neo4j.gds.GraphAlgorithmFactory;
import org.neo4j.gds.api.Graph;
import org.neo4j.gds.core.concurrency.DefaultPool;
import org.neo4j.gds.mem.MemoryEstimation;
import org.neo4j.gds.mem.MemoryRange;
import org.neo4j.gds.core.utils.progress.tasks.ProgressTracker;
import org.neo4j.gds.core.utils.progress.tasks.Task;
import org.neo4j.gds.core.utils.progress.tasks.Tasks;
import org.neo4j.gds.similarity.knn.metrics.SimilarityComputer;
import org.neo4j.gds.termination.TerminationFlag;

import java.util.List;

public class KnnFactory extends GraphAlgorithmFactory {

    private static final String KNN_BASE_TASK_NAME = "Knn";

    @Override
    public String taskName() {
        return KNN_BASE_TASK_NAME;
    }

    public Knn build(
        Graph graph,
        KnnParameters parameters,
        ProgressTracker progressTracker
    ) {
        return Knn.create(
            graph,
            parameters,
            SimilarityComputer.ofProperties(graph, parameters.nodePropertySpecs()),
            new KnnNeighborFilterFactory(graph.nodeCount()),
            ImmutableKnnContext
                .builder()
                .progressTracker(progressTracker)
                .executor(DefaultPool.INSTANCE)
                .build(),
            TerminationFlag.RUNNING_TRUE
        );
    }

    @Override
    public Knn build(
        Graph graph,
        CONFIG configuration,
        ProgressTracker progressTracker
    ) {
        var parameters = configuration.toParameters().finalize(graph.nodeCount());
        return build(graph, parameters, progressTracker);
    }

    @Override
    public MemoryEstimation memoryEstimation(CONFIG configuration) {
        return new KnnMemoryEstimateDefinition(configuration.toMemoryEstimationParameters()).memoryEstimation();
    }

    public static MemoryRange initialSamplerMemoryEstimation(KnnSampler.SamplerType samplerType, long boundedK) {
        switch(samplerType) {
            case UNIFORM: {
                return UniformKnnSampler.memoryEstimation(boundedK);
            }
            case RANDOMWALK: {
                return RandomWalkKnnSampler.memoryEstimation(boundedK);
            }
            default:
                throw new IllegalStateException("Invalid KnnSampler");
        }
    }

    @Override
    public Task progressTask(Graph graph, CONFIG config) {
        return knnTaskTree(graph.nodeCount(), config.maxIterations());
    }

    public static Task knnTaskTree(long nodeCount, int maxIterations) {
        return Tasks.task(
            KNN_BASE_TASK_NAME,
            Tasks.leaf("Initialize random neighbors", nodeCount),
            Tasks.iterativeDynamic(
                "Iteration",
                () -> List.of(
                    Tasks.leaf("Split old and new neighbors", nodeCount),
                    Tasks.leaf("Reverse old and new neighbors", nodeCount),
                    Tasks.leaf("Join neighbors", nodeCount)
                ),
                maxIterations
            )
        );
    }


}