/**
* Ivory: A Hadoop toolkit for Web-scale information retrieval
*
* 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 ivory.ptc.data;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.Iterator;
import edu.umd.cloud9.io.array.ArrayListOfIntsWritable;
import org.apache.hadoop.io.WritableComparable;
/**
* Data structure that holds a target document along with
* a list of (source) documents that point to the target
* document. In addition, a weight field is associated with
* the target document if necessary.
*
* The iterator method iterates over the source documents
* that point to the target document.
*
* @author Nima Asadi
*/
public class AnchorTextTarget implements WritableComparable<AnchorTextTarget>, Iterable<Integer> {
private ArrayListOfIntsWritable sources;
private int target;
private float weight;
/**
* Constructs a target with an empty source list.
*/
public AnchorTextTarget() {
sources = new ArrayListOfIntsWritable();
}
/**
* Constructs a target by cloning an existing target.
*
* @param at Existing target object.
*/
public AnchorTextTarget(AnchorTextTarget at) {
this();
target = at.target;
weight = at.weight;
addSources(at.sources);
}
/**
* Constructs a target object from scratch.
*
* @param trgt Document id of the target document.
* @param srcs Source documents that point to the target document.
* @param wt Weight for the target document.
*/
public AnchorTextTarget(int trgt, ArrayListOfIntsWritable srcs, float wt) {
this();
target = trgt;
weight = wt;
addSources(srcs);
}
@Override
public void readFields(DataInput in) throws IOException {
sources.clear();
sources.readFields(in);
target = in.readInt();
weight = in.readFloat();
}
@Override
public void write(DataOutput out) throws IOException {
sources.write(out);
out.writeInt(target);
out.writeFloat(weight);
}
/**
* Adds source documents to the list of source documents that
* point to the current target document.
*
* @param sources Source documents to be added.
*/
public void addSources(ArrayListOfIntsWritable sources) {
for (int i : sources) {
this.sources.add(i);
}
}
/**
* Resets the source list to the given list. Please note
* that this method removes the existing list with the given
* parameter; i.e., the source list will be reset and re-initialized.
*
* @param sources Source documents to be initialized with.
*/
public void setSources(ArrayListOfIntsWritable sources) {
this.sources = sources;
}
/**
* Retrieves the list of source documents.
*
* @return list of source documents.
*/
public ArrayListOfIntsWritable getSources() {
return sources;
}
/**
* Sets the target document.
*
* @param target New target document id.
*/
public void setTarget(int target) {
this.target = target;
}
/**
* Retrieves the target document id.
*
* @return document id of the target document.
*/
public int getTarget() {
return target;
}
/**
* Sets the weight for the current target document.
*
* @param wt Weight
*/
public void setWeight(float wt) {
this.weight = wt;
}
/**
* @return weight of the target document.
*/
public float getWeight() {
return weight;
}
@Override
public int compareTo(AnchorTextTarget at) {
if (weight < at.weight) {
return 1;
} else if (weight > at.weight) {
return -1;
} else if (target < at.target) {
return 1;
} else if (target > at.target) {
return -1;
}
return 0;
}
@Override
public boolean equals(Object o) {
AnchorTextTarget other = (AnchorTextTarget) o;
if (other.target != this.target) {
return false;
}
return this.weight == other.weight;
}
@Override
public int hashCode() {
return target;
}
@Override
public String toString() {
return "[ to=" + getTarget() + ", from=" + getSources() + ", weight="
+ getWeight() + " ]";
}
@Override
public Iterator<Integer> iterator() {
return sources.iterator();
}
}