org.apache.nutch.searcher.Hits.java Source code

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Here is the source code for org.apache.nutch.searcher.Hits.java

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/**
 * 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.nutch.searcher;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;

import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableComparable;
import org.apache.hadoop.io.Text;

/** A set of hits matching a query. */
public final class Hits implements Writable {

    private long total;
    private boolean totalIsExact = true;
    private Hit[] top;

    public Hits() {
    }

    public Hits(long total, Hit[] top) {
        this.total = total;
        this.top = top;
    }

    /** Returns the total number of hits for this query.  This may be an estimate
     * when (@link #totalIsExact()} is false. */
    public long getTotal() {
        return total;
    }

    /** True if {@link #getTotal()} gives the exact number of hits, or false if
     * it is only an estimate of the total number of hits. */
    public boolean totalIsExact() {
        return totalIsExact;
    }

    /** Set {@link #totalIsExact()}. */
    public void setTotalIsExact(boolean isExact) {
        totalIsExact = isExact;
    }

    /** Returns the number of hits included in this current listing. */
    public int getLength() {
        return top.length;
    }

    /** Returns the <code>i</code><sup>th</sup> hit in this list. */
    public Hit getHit(int i) {
        return top[i];
    }

    /** Returns a subset of the hit objects. */
    public Hit[] getHits(int start, int length) {
        Hit[] results = new Hit[length];
        for (int i = 0; i < length; i++) {
            results[i] = top[start + i];
        }
        return results;
    }

    public void write(DataOutput out) throws IOException {
        out.writeLong(total); // write total hits
        out.writeInt(top.length); // write hits returned
        if (top.length > 0) // write sort value class
            Text.writeString(out, top[0].getSortValue().getClass().getName());

        for (int i = 0; i < top.length; i++) {
            Hit h = top[i];
            out.writeInt(h.getIndexDocNo()); // write indexDocNo
            h.getSortValue().write(out); // write sortValue
            Text.writeString(out, h.getDedupValue()); // write dedupValue         
        }
    }

    public void readFields(DataInput in) throws IOException {
        total = in.readLong(); // read total hits
        top = new Hit[in.readInt()]; // read hits returned
        Class sortClass = null;
        if (top.length > 0) { // read sort value class
            try {
                sortClass = Class.forName(Text.readString(in));
            } catch (ClassNotFoundException e) {
                throw new IOException(e.toString());
            }
        }

        for (int i = 0; i < top.length; i++) {
            int indexDocNo = in.readInt(); // read indexDocNo

            WritableComparable sortValue = null;
            try {
                sortValue = (WritableComparable) sortClass.newInstance();
            } catch (Exception e) {
                throw new IOException(e.toString());
            }
            sortValue.readFields(in); // read sortValue
            String dedupValue = Text.readString(in); // read dedupValue

            top[i] = new Hit(indexDocNo, sortValue, dedupValue);
        }
    }

}