co.cask.cdap.data2.transaction.stream.leveldb.LevelDBStreamConsumerStateStore.java Source code

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Here is the source code for co.cask.cdap.data2.transaction.stream.leveldb.LevelDBStreamConsumerStateStore.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.transaction.stream.leveldb;

import co.cask.cdap.api.common.Bytes;
import co.cask.cdap.data2.dataset2.lib.table.leveldb.LevelDBTableCore;
import co.cask.cdap.data2.transaction.stream.StreamConfig;
import co.cask.cdap.data2.transaction.stream.StreamConsumerStateStore;
import com.google.common.collect.ImmutableSortedMap;
import com.google.common.collect.Maps;

import java.io.IOException;
import java.util.Map;
import java.util.Set;

/**
 *
 */
public final class LevelDBStreamConsumerStateStore extends StreamConsumerStateStore {

    private final LevelDBTableCore tableCore;

    protected LevelDBStreamConsumerStateStore(StreamConfig streamConfig, LevelDBTableCore tableCore) {
        super(streamConfig);
        this.tableCore = tableCore;
    }

    @Override
    protected byte[] fetch(byte[] row, byte[] column) throws IOException {
        return tableCore.getRow(row, new byte[][] { column }, null, null, -1, null).get(column);
    }

    @Override
    protected void fetchAll(byte[] row, Map<byte[], byte[]> result) throws IOException {
        result.putAll(tableCore.getRow(row, null, null, null, -1, null));
    }

    @Override
    protected void fetchAll(byte[] row, byte[] columnPrefix, Map<byte[], byte[]> result) throws IOException {
        // Ignore the column prefix. Parent class would handle it.
        fetchAll(row, result);
    }

    @Override
    protected void store(byte[] row, byte[] column, byte[] value) throws IOException {
        store(row, ImmutableSortedMap.<byte[], byte[]>orderedBy(Bytes.BYTES_COMPARATOR).put(column, value).build());
    }

    @Override
    protected void store(byte[] row, Map<byte[], byte[]> values) throws IOException {
        if (values.isEmpty()) {
            return;
        }
        Map<byte[], Map<byte[], byte[]>> changes = ImmutableSortedMap
                .<byte[], Map<byte[], byte[]>>orderedBy(Bytes.BYTES_COMPARATOR).put(row, values).build();

        tableCore.persist(changes, Long.MAX_VALUE);
    }

    @Override
    protected void delete(byte[] row, Set<byte[]> columns) throws IOException {
        if (columns.isEmpty()) {
            return;
        }
        Map<byte[], byte[]> deleteColumns = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
        for (byte[] column : columns) {
            deleteColumns.put(column, Bytes.EMPTY_BYTE_ARRAY); // Value doesn't matter
        }
        Map<byte[], Map<byte[], byte[]>> undoes = ImmutableSortedMap
                .<byte[], Map<byte[], byte[]>>orderedBy(Bytes.BYTES_COMPARATOR).put(row, deleteColumns).build();

        tableCore.undo(undoes, Long.MAX_VALUE);
    }

    @Override
    public void close() throws IOException {
        // No-op
    }
}