com.bah.culvert.adapter.TableAdapter.java Source code

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Here is the source code for com.bah.culvert.adapter.TableAdapter.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.adapter;

import java.io.Closeable;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.Collection;
import java.util.List;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Writable;

import com.bah.culvert.iterators.SeekingCurrentIterator;
import com.bah.culvert.transactions.Get;
import com.bah.culvert.transactions.Put;
import com.bah.culvert.util.BaseConfigurable;

/**
 * Connect to a table. This is the top level interface that used to run a query.
 * 
 * @see HBaseTableAdapter
 */
public abstract class TableAdapter extends BaseConfigurable implements Closeable, Writable {

    /** Configuration key for the table name the adapter should to connect to */
    public static final String TABLE_NAME_SETTING_KEY = "culvert.adapter.tablename";

    /**
     * Create a table adapter with this table name. The name is stored in the
     * configuration, so any changes to the configuration could alter the behavior
     * of this table if you don't ensure the table names are the same across
     * configurations.
     * @param tableName
     * @see #TABLE_NAME_SETTING_KEY
     */
    public TableAdapter(String tableName) {
        this.setTableName(tableName);
    }

    /**
     * Create a table adapter based on a configuration where the table name is
     * already set.
     * @param conf Replaces any other configuration already set for the table
     */
    public TableAdapter(Configuration conf) {
        this.setConf(conf);
    }

    public void setTableName(String tableName) {
        getConf().set(TABLE_NAME_SETTING_KEY, tableName);
    }

    /**
     * Get the table name that this adapter connects to
     * 
     * @return name of the table
     */
    public String getTableName() {
        return getConf().get(TABLE_NAME_SETTING_KEY);
    }

    /**
     * Do a put on the table
     * 
     * @param put to put
     * @throws TableException on general table failure
     * @throws RuntimeException if the write is not valid
     */
    public abstract void put(Put put);

    /**
     * Do a get on the local table. Gets all the CFs and CQ in the specified row.
     * 
     * @param get to perform
     * @return the results from that get
     */
    public abstract SeekingCurrentIterator get(Get get);

    /**
     * Execute a {@link ConfigurableCallable} remotely on database shards starting
     * with <tt>startKeys</tt> using the provided {@link Configuration} .
     * 
     * @param <T>
     * @param rangeKeys
     * @param conf
     * @param remoteCallable
     * @return
     */
    public abstract <T> List<T> remoteExec(byte[] startKey, byte[] endKey,
            Class<? extends RemoteOp<T>> remoteCallable, Object... array);

    @Override
    public void close() {
        // default is no-op
    }

    /**
     * Pairs with {@link #getEndKeys()} 1-to-1 (1st start key matches with first
     * end key
     * @return the start keys for all servers
     */
    public abstract byte[][] getStartKeys();

    /**
     * Pairs with {@link #getStartKeys()} 1-to-1 (1st start key matches with first
     * end key
     * @return the end keys for all servers.
     */
    public abstract byte[][] getEndKeys();

    /**
     * Get the hosts that this table is running over. Mostly used for MapReduce
     * integration.
     * @return the servers addresses hosting this table
     */
    public abstract Collection<String> getHosts();

    public static void setTableName(Configuration conf, String tableName) {
        conf.set(TableAdapter.TABLE_NAME_SETTING_KEY, tableName);
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        Configuration conf = new Configuration();
        conf.readFields(in);
        setConf(conf);
    }

    @Override
    public void write(DataOutput out) throws IOException {
        getConf().write(out);
    }
}