co.cask.cdap.data2.dataset2.lib.table.leveldb.LevelDBOrderedTable.java Source code

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Here is the source code for co.cask.cdap.data2.dataset2.lib.table.leveldb.LevelDBOrderedTable.java

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/*
 * Copyright  2014 Cask Data, Inc.
 *
 * 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 co.cask.cdap.data2.dataset2.lib.table.leveldb;

import co.cask.cdap.api.common.Bytes;
import co.cask.cdap.api.dataset.table.ConflictDetection;
import co.cask.cdap.api.dataset.table.Scanner;
import co.cask.cdap.data2.dataset2.lib.table.ordered.BufferingOrderedTable;
import co.cask.cdap.data2.dataset2.lib.table.ordered.IncrementValue;
import co.cask.cdap.data2.dataset2.lib.table.ordered.PutValue;
import co.cask.cdap.data2.dataset2.lib.table.ordered.Update;
import co.cask.tephra.Transaction;
import com.google.common.collect.Maps;

import java.io.IOException;
import java.util.Map;
import java.util.NavigableMap;
import javax.annotation.Nullable;

/**
 * A table client based on LevelDB.
 */
public class LevelDBOrderedTable extends BufferingOrderedTable {

    private final LevelDBOrderedTableCore core;
    private Transaction tx;
    private long persistedVersion;

    public LevelDBOrderedTable(String tableName, ConflictDetection level, LevelDBOrderedTableService service)
            throws IOException {
        super(tableName, level);
        this.core = new LevelDBOrderedTableCore(tableName, service);
    }

    // TODO this is the same for all OcTableClient implementations -> promote to base class
    @Override
    public void startTx(Transaction tx) {
        super.startTx(tx);
        this.tx = tx;
    }

    @Override
    public void increment(byte[] row, byte[][] columns, long[] amounts) throws Exception {
        // for local operation with leveldb, we don't worry about the cost of reads
        incrementAndGet(row, columns, amounts);
    }

    @Override
    protected void persist(NavigableMap<byte[], NavigableMap<byte[], Update>> changes) throws Exception {
        persistedVersion = tx == null ? System.currentTimeMillis() : tx.getWritePointer();

        NavigableMap<byte[], NavigableMap<byte[], byte[]>> puts = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
        NavigableMap<byte[], NavigableMap<byte[], Long>> increments = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
        for (Map.Entry<byte[], NavigableMap<byte[], Update>> rowEntry : changes.entrySet()) {
            for (Map.Entry<byte[], Update> colEntry : rowEntry.getValue().entrySet()) {
                Update val = colEntry.getValue();
                if (val instanceof IncrementValue) {
                    NavigableMap<byte[], Long> incrCols = increments.get(rowEntry.getKey());
                    if (incrCols == null) {
                        incrCols = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
                        increments.put(rowEntry.getKey(), incrCols);
                    }
                    incrCols.put(colEntry.getKey(), ((IncrementValue) val).getValue());
                } else if (val instanceof PutValue) {
                    NavigableMap<byte[], byte[]> putCols = puts.get(rowEntry.getKey());
                    if (putCols == null) {
                        putCols = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
                        puts.put(rowEntry.getKey(), putCols);
                    }
                    putCols.put(colEntry.getKey(), ((PutValue) val).getValue());
                }
            }
        }
        for (Map.Entry<byte[], NavigableMap<byte[], Long>> incEntry : increments.entrySet()) {
            core.increment(incEntry.getKey(), incEntry.getValue());
        }
        core.persist(puts, persistedVersion);
    }

    @Override
    protected void undo(NavigableMap<byte[], NavigableMap<byte[], Update>> persisted) throws Exception {
        core.undo(persisted, persistedVersion);
    }

    @Override
    protected NavigableMap<byte[], byte[]> getPersisted(byte[] row, @Nullable byte[][] columns) throws Exception {
        return core.getRow(row, columns, null, null, columns == null ? Integer.MAX_VALUE : columns.length, tx);
    }

    @Override
    protected NavigableMap<byte[], byte[]> getPersisted(byte[] row, byte[] startColumn, byte[] stopColumn,
            int limit) throws Exception {
        return core.getRow(row, null, startColumn, stopColumn, limit, tx);
    }

    @Override
    protected Scanner scanPersisted(byte[] startRow, byte[] stopRow) throws Exception {
        return core.scan(startRow, stopRow, null, null, tx);
    }
}