/*
* 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.giraph.aggregators.matrix.sparse;
import it.unimi.dsi.fastutil.ints.Int2FloatMap;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import it.unimi.dsi.fastutil.ints.Int2FloatOpenHashMap;
import it.unimi.dsi.fastutil.objects.ObjectIterator;
import org.apache.hadoop.io.Writable;
/**
* The float vector holds the values of a particular row.
*/
public class FloatSparseVector implements Writable {
/**
* The entries of the vector are (key, value) pairs of the form (row, value)
*/
private Int2FloatOpenHashMap entries = null;
/**
* Create a new vector with default size.
*/
public FloatSparseVector() {
initialize(Int2FloatOpenHashMap.DEFAULT_INITIAL_SIZE);
}
/**
* Create a new vector with given size.
*
* @param size the size of the vector
*/
public FloatSparseVector(int size) {
initialize(size);
}
/**
* Initialize the values of the vector. The default value is 0.0
*
* @param size the size of the vector
*/
private void initialize(int size) {
entries = new Int2FloatOpenHashMap(size);
entries.defaultReturnValue(0.0f);
}
/**
* Get a particular entry of the vector.
*
* @param i the entry
* @return the value of the entry.
*/
public float get(int i) {
return entries.get(i);
}
/**
* Set the given value to the entry specified.
*
* @param i the entry
* @param value the value to set to the entry
*/
public void set(int i, float value) {
entries.put(i, value);
}
/**
* Clear the contents of the vector.
*/
public void clear() {
entries.clear();
}
/**
* Add the vector specified. This is a vector addition that does an
* element-by-element addition.
*
* @param other the vector to add.
*/
public void add(FloatSparseVector other) {
ObjectIterator<Int2FloatMap.Entry> iter =
other.entries.int2FloatEntrySet().fastIterator();
while (iter.hasNext()) {
Int2FloatMap.Entry entry = iter.next();
entries.addTo(entry.getIntKey(), entry.getFloatValue());
}
}
@Override
public void write(DataOutput out) throws IOException {
out.writeInt(entries.size());
ObjectIterator<Int2FloatMap.Entry> iter =
entries.int2FloatEntrySet().fastIterator();
while (iter.hasNext()) {
Int2FloatMap.Entry entry = iter.next();
out.writeInt(entry.getIntKey());
out.writeFloat(entry.getFloatValue());
}
}
@Override
public void readFields(DataInput in) throws IOException {
int size = in.readInt();
initialize(size);
for (int i = 0; i < size; ++i) {
int row = in.readInt();
float value = in.readFloat();
entries.put(row, value);
}
}
}