com.bah.culvert.data.Result.java Source code

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Here is the source code for com.bah.culvert.data.Result.java

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/**
 * Copyright 2011 Booz Allen Hamilton.
 * 
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership. Booz Allen Hamilton
 * 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 com.bah.culvert.data;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import javax.management.Query;

import org.apache.hadoop.io.Writable;

import com.bah.culvert.adapter.TableAdapter;
import com.bah.culvert.constraints.Constraint;
import com.bah.culvert.util.Bytes;
import com.google.common.collect.Iterables;

/**
 * Result of one record as record ID (key) and value, from doing a lookup in a
 * table.
 * <p>
 * NOTE: This class is <b>NOT</b> thread-safe
 * @see Query
 * @see Constraint
 * @see TableAdapter
 */
public class Result implements Writable {
    protected byte[] recordId;
    protected List<CKeyValue> values;

    /**
     * No args constructor for serialization
     */
    public Result() {
        this.recordId = new byte[0];
        this.values = new ArrayList<CKeyValue>();
    }

    /**
     * Create a Result with only a row id for the record
     * @param recordID row id of the record
     */
    public Result(byte[] recordID) {
        if (recordID == null) {
            throw new NullPointerException("recordID is not allowed to be null");
        }
        this.recordId = recordID;
        this.values = new ArrayList<CKeyValue>(0);
    }

    /**
     * Create a result with from a set of key values.
     * <p>
     * {@link CKeyValue}s must all have the same row ID, otherwise, results are
     * undefined.
     * @param rowId of the results returned
     * @param keyValues result returned
     */
    public Result(byte[] rowId, CKeyValue... keyValues) {
        if (rowId == null) {
            throw new NullPointerException("recordID is not allowed to be null");
        }
        if (keyValues == null) {
            throw new NullPointerException("keyValues is not allowed to be null");
        }

        this.recordId = rowId;
        // sort the list of incoming values
        List<CKeyValue> values = Arrays.asList(keyValues);
        Collections.sort(values, KeyComparator.INSTANCE);
        this.values = new ArrayList<CKeyValue>(values);
    }

    /**
     * Create a result with from a set of key values.
     * <p>
     * {@link CKeyValue}s must all have the same row ID, otherwise, results are
     * undefined.
     * @param keyValues result returned
     */
    public Result(CKeyValue... keyValues) {
        this(keyValues[0].getRowId(), keyValues);
    }

    /**
     * Create a result from the provided keyvalues iterable.
     * @param keyValues The keyvalues to put in this result.
     */
    public Result(Iterable<CKeyValue> keyValues) {
        this(Iterables.toArray(keyValues, CKeyValue.class));
    }

    /**
     * @return row key of the result
     */
    public byte[] getRecordId() {
        return this.recordId;
    }

    /**
     * @return value of the result record
     */
    public List<CKeyValue> getKeyValues() {
        return values;
    }

    /**
     * Find the value associated with the given family and qualifier
     * @param family for the value
     * @param qualifier qualifier for the value
     * @return the full {@link CKeyValue} for that value. If that family and
     *         qualifier are not present, returns <tt>null</tt>
     */
    public CKeyValue getValue(byte[] family, byte[] qualifier) {
        // quick failure case check
        if (this.values.size() == 0)
            return null;

        // since we know that they are sorted at this point, just do the lookup as a
        // binary search
        int index = Collections.binarySearch(values, new CKeyValue(this.recordId, family, qualifier),
                KeyComparator.INSTANCE);
        if (index < 0)
            return null;
        return values.get(index);
    }

    /**
     * @param recordId the recordId to set
     */
    public void setRecordId(byte[] recordId) {
        this.recordId = recordId;
    }

    /**
     * @param values the values to set
     */
    public void setValues(CKeyValue... values) {
        if (values == null)
            this.values = new ArrayList<CKeyValue>(0);
        else
            this.values = new ArrayList<CKeyValue>(Arrays.asList(values));
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        this.recordId = Bytes.readByteArray(in);
        int size = in.readInt();
        this.values = new ArrayList<CKeyValue>(size);
        for (int i = 0; i < size; i++) {
            CKeyValue kv = new CKeyValue();
            kv.readFields(in);
            values.add(kv);
        }

    }

    @Override
    public void write(DataOutput out) throws IOException {
        Bytes.writeByteArray(out, this.recordId);
        out.writeInt(this.values.size());
        for (CKeyValue kv : this.values)
            kv.write(out);

    }

    /**
     * Does a shallow copy of the specified result
     * @param result to copy
     */
    public void copy(Result result) {
        this.recordId = result.getRecordId();
        this.values = result.values;
    }

    /**
     * Add {@link CKeyValue} to this result.
     * <p>
     * NOTE: They must ALL have the same byte [] value for the key (Arrays
     * {@link #equals(Object)} must return true) or behavior is undefined.
     * @param kvs
     */
    public void addKeyValues(CKeyValue... kvs) {
        this.values.addAll(Arrays.asList(kvs));
    }

}