io.virtdata.random.RandomLineToString Maven / Gradle / Ivy
/*
*
* Copyright 2015 Jonathan Shook
*
* Licensed 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 io.virtdata.random;
import io.virtdata.annotations.DeprecatedFunction;
import io.virtdata.util.VirtDataResources;
import org.apache.commons.math3.distribution.IntegerDistribution;
import org.apache.commons.math3.distribution.UniformIntegerDistribution;
import org.apache.commons.math3.random.MersenneTwister;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.List;
import java.util.function.LongFunction;
/**
* TODO: Redo this a functional with murmur3F
*/
@DeprecatedFunction("random mappers are not deterministic. They will be replaced with hash-based functions.")
public class RandomLineToString implements LongFunction {
private final static Logger logger = LoggerFactory.getLogger(RandomLineToString.class);
private List lines = new ArrayList<>();
private final MersenneTwister rng;
private final IntegerDistribution itemDistribution;
private final String filename;
public RandomLineToString(String filename) {
this.rng = new MersenneTwister(System.nanoTime());
this.filename = filename;
this.lines = VirtDataResources.readDataFileLines(filename);
itemDistribution= new UniformIntegerDistribution(rng, 0, lines.size()-2);
}
public RandomLineToString(String filename, MersenneTwister rng) {
this.rng = rng;
this.filename = filename;
this.lines = VirtDataResources.readDataFileLines(filename);
this.lines = VirtDataResources.readDataFileLines(filename);
itemDistribution= new UniformIntegerDistribution(rng, 0, lines.size()-2);
}
public RandomLineToString(String filename, long seed) {
this.rng = new MersenneTwister(seed);
this.filename = filename;
this.lines = VirtDataResources.readDataFileLines(filename);
itemDistribution= new UniformIntegerDistribution(rng, 0, lines.size()-2);
}
public String toString() {
return getClass().getSimpleName() + ":" + filename;
}
@Override
public String apply(long operand) {
int itemIdx = itemDistribution.sample();
String item = lines.get(itemIdx);
return item;
}
}