co.cask.cdap.data2.transaction.stream.inmemory.InMemoryStreamConsumerStateStore.java Source code

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Here is the source code for co.cask.cdap.data2.transaction.stream.inmemory.InMemoryStreamConsumerStateStore.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.inmemory;

import co.cask.cdap.api.common.Bytes;
import co.cask.cdap.api.dataset.table.Row;
import co.cask.cdap.data2.dataset2.lib.table.inmemory.InMemoryTable;
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 InMemoryStreamConsumerStateStore extends StreamConsumerStateStore {

    private final InMemoryTable table;

    protected InMemoryStreamConsumerStateStore(StreamConfig streamConfig, InMemoryTable table) {
        super(streamConfig);
        this.table = table;
    }

    @Override
    protected byte[] fetch(byte[] row, byte[] column) throws IOException {
        try {
            return table.get(row, column);
        } catch (Exception e) {
            throw new IOException(e);
        }
    }

    @Override
    protected void fetchAll(byte[] row, Map<byte[], byte[]> result) throws IOException {
        try {
            Row fetched = table.get(row);
            if (!fetched.isEmpty()) {
                result.putAll(fetched.getColumns());
            }
        } catch (Exception e) {
            throw new IOException(e);
        }
    }

    @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;
        }
        byte[][] columns = new byte[values.size()][];
        byte[][] vals = new byte[values.size()][];
        int i = 0;
        for (Map.Entry<byte[], byte[]> columnValue : values.entrySet()) {
            columns[i] = columnValue.getKey();
            vals[i] = columnValue.getValue().length > 0 ? columnValue.getValue() : null;
            i++;
        }

        try {
            table.put(row, columns, vals);
        } catch (Exception e) {
            throw new IOException(e);
        }
    }

    @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
        }
        byte[][] columnsArr = new byte[columns.size()][];
        int i = 0;
        for (byte[] column : columns) {
            columnsArr[i] = column;
            i++;
        }

        try {
            table.delete(row, columnsArr);
        } catch (Exception e) {
            throw new IOException(e);
        }
    }

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