xor-filter

How to use

plugins {
 id 'java'
}
sourceCompatibility = 11
repositories {
 mavenCentral()
 maven {
 url "https://dl.bintray.com/komiya-atsushi/maven"
 }
}
dependencies {
 implementation 'com.google.guava:guava:28.2-jre'
 implementation 'me.k11i:xor-filter:0.1.1'
}

package me.k11i.demo;
import com.google.common.hash.Funnels;
import me.k11i.xorfilter.XorFilter;
import java.io.*;
import java.nio.charset.StandardCharsets;
import java.util.List;
@SuppressWarnings("UnstableApiUsage")
public class XorFilterDemo {
 public static void main(String[] args) throws IOException {
 List<String> strings = List.of(
 "1235df54-e42e-457b-9d9d-de0c46ecdfe7",
 "4ea534e3-6552-4975-b520-196ac5124423",
 "8b0fbde6-aaab-4a53-a546-be4cccdae3e9",
 "82570f67-7378-4772-ada2-ac7f1b44dbcf"
 );
 // Build Xor filter from the collection.
 XorFilter<String> filter = XorFilter.build(
 Funnels.stringFunnel(StandardCharsets.UTF_8),
 strings,
 XorFilter.Strategy.MURMUR128_XOR8);
 // Query whether the filter contains the element.
 boolean result = filter.mightContain(strings.get(0));
 System.out.println(result); // => true
 // XorFilter implements java.util.function.Predicate interface.
 result = filter.test("8d05d410-1a0c-467b-9554-89c453a5");
 System.out.println(result); // => false
 // Serialize the filter.
 byte[] serialized;
 try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
 filter.writeTo(out);
 serialized = out.toByteArray();
 }
 // Deserialize and use the filter.
 XorFilter<String> deserialized = XorFilter.readFrom(
 new ByteArrayInputStream(serialized),
 Funnels.stringFunnel(StandardCharsets.UTF_8));
 System.out.println(filter.mightContain(strings.get(0))); // => true
 System.out.println(filter.mightContain("8d05d410-1a0c-467b-9554-89c453a5")); // => false
 }
}

Benchmark

Throughput (queries/ms)

Serialization size