/*
* 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.api.dataset.table.Row;
import co.cask.cdap.api.dataset.table.Scanner;
import co.cask.cdap.common.conf.CConfiguration;
import co.cask.cdap.data.file.FileReader;
import co.cask.cdap.data.file.ReadFilter;
import co.cask.cdap.data.stream.StreamEventOffset;
import co.cask.cdap.data.stream.StreamFileOffset;
import co.cask.cdap.data2.dataset2.lib.table.leveldb.KeyValue;
import co.cask.cdap.data2.dataset2.lib.table.leveldb.LevelDBOrderedTableCore;
import co.cask.cdap.data2.queue.ConsumerConfig;
import co.cask.cdap.data2.transaction.stream.AbstractStreamFileConsumer;
import co.cask.cdap.data2.transaction.stream.StreamConfig;
import co.cask.cdap.data2.transaction.stream.StreamConsumerState;
import co.cask.cdap.data2.transaction.stream.StreamConsumerStateStore;
import co.cask.tephra.Transaction;
import com.google.common.collect.Maps;
import java.io.IOException;
import java.util.Arrays;
import java.util.Map;
import java.util.NavigableMap;
import javax.annotation.Nullable;
/**
*
*/
public final class LevelDBStreamFileConsumer extends AbstractStreamFileConsumer {
// used for undoing state. The value does not matter, but the OcTable interface was written to expect some value.
private static final byte[] DUMMY_STATE_CONTENT = { };
private final LevelDBOrderedTableCore tableCore;
private final Object dbLock;
private final NavigableMap<byte[], NavigableMap<byte[], byte[]>> rowMapForClaim;
private final NavigableMap<byte[], byte[]> colMapForClaim;
/**
* @param streamConfig Stream configuration.
* @param consumerConfig Consumer configuration.
* @param reader For reading stream events. This class is responsible for closing the reader.
*/
public LevelDBStreamFileConsumer(CConfiguration cConf,
StreamConfig streamConfig, ConsumerConfig consumerConfig,
FileReader<StreamEventOffset, Iterable<StreamFileOffset>> reader,
StreamConsumerStateStore stateStore, StreamConsumerState beginConsumerState,
@Nullable ReadFilter extraFilter,
LevelDBOrderedTableCore tableCore, Object dbLock) {
super(cConf, streamConfig, consumerConfig, reader, stateStore, beginConsumerState, extraFilter);
this.tableCore = tableCore;
this.dbLock = dbLock;
this.rowMapForClaim = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
this.colMapForClaim = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
}
@Override
protected boolean claimFifoEntry(byte[] row, byte[] value, byte[] oldValue) throws IOException {
synchronized (dbLock) {
Map<byte[], byte[]> values =
tableCore.getRow(row, new byte[][] { stateColumnName }, null, null, -1, Transaction.ALL_VISIBLE_LATEST);
if (!Arrays.equals(values.get(stateColumnName), oldValue)) {
return false;
}
rowMapForClaim.clear();
colMapForClaim.clear();
colMapForClaim.put(stateColumnName, value);
rowMapForClaim.put(row, colMapForClaim);
tableCore.persist(rowMapForClaim, KeyValue.LATEST_TIMESTAMP);
return true;
}
}
@Override
protected void updateState(Iterable<byte[]> rows, int size, byte[] value) throws IOException {
NavigableMap<byte[], NavigableMap<byte[], byte[]>> changes = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
for (byte[] row : rows) {
NavigableMap<byte[], byte[]> values = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
values.put(stateColumnName, value);
changes.put(row, values);
}
tableCore.persist(changes, KeyValue.LATEST_TIMESTAMP);
}
@Override
protected void undoState(Iterable<byte[]> rows, int size) throws IOException {
NavigableMap<byte[], NavigableMap<byte[], byte[]>> changes = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
for (byte[] row : rows) {
NavigableMap<byte[], byte[]> values = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
values.put(stateColumnName, DUMMY_STATE_CONTENT);
changes.put(row, values);
}
tableCore.undo(changes, KeyValue.LATEST_TIMESTAMP);
}
@Override
protected StateScanner scanStates(byte[] startRow, byte[] stopRow) throws IOException {
final Scanner scanner = tableCore.scan(startRow, stopRow, null, null, Transaction.ALL_VISIBLE_LATEST);
return new StateScanner() {
private Row pair;
@Override
public boolean nextStateRow() throws IOException {
pair = scanner.next();
return pair != null;
}
@Override
public byte[] getRow() {
return pair.getRow();
}
@Override
public byte[] getState() {
return pair.getColumns().get(stateColumnName);
}
@Override
public void close() throws IOException {
scanner.close();
}
};
}
}