/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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 org.apache.hive.hcatalog.streaming;
import java.util.Collection;
/**
* Represents a set of Transactions returned by Hive. Supports opening, writing to
* and commiting/aborting each transaction. The interface is designed to ensure
* transactions in a batch are used up sequentially. To stream to the same HiveEndPoint
* concurrently, create separate StreamingConnections.
*
* Note on thread safety: At most 2 threads can run through a given TransactionBatch at the same
* time. One thread may call {@link #heartbeat()} and the other all other methods.
* Violating this may result in "out of sequence response".
*
*/
public interface TransactionBatch {
public enum TxnState {INACTIVE, OPEN, COMMITTED, ABORTED }
/**
* Activate the next available transaction in the current transaction batch
* @throws StreamingException if not able to switch to next Txn
* @throws InterruptedException if call in interrupted
*/
public void beginNextTransaction() throws StreamingException, InterruptedException;
/**
* Get Id of currently open transaction
* @return transaction id
*/
public Long getCurrentTxnId();
/**
* get state of current transaction
*/
public TxnState getCurrentTransactionState();
/**
* Commit the currently open transaction
* @throws StreamingException if there are errors committing
* @throws InterruptedException if call in interrupted
*/
public void commit() throws StreamingException, InterruptedException;
/**
* Abort the currently open transaction
* @throws StreamingException if there are errors
* @throws InterruptedException if call in interrupted
*/
public void abort() throws StreamingException, InterruptedException;
/**
* Remaining transactions are the ones that are not committed or aborted or open.
* Current open transaction is not considered part of remaining txns.
* @return number of transactions remaining this batch.
*/
public int remainingTransactions();
/**
* Write record using RecordWriter
* @param record the data to be written
* @throws StreamingException if there are errors when writing
* @throws InterruptedException if call in interrupted
*/
public void write(byte[] record) throws StreamingException, InterruptedException;
/**
* Write records using RecordWriter
* @throws StreamingException if there are errors when writing
* @throws InterruptedException if call in interrupted
*/
public void write(Collection<byte[]> records) throws StreamingException, InterruptedException;
/**
* Issues a heartbeat to hive metastore on the current and remaining txn ids
* to keep them from expiring
* @throws StreamingException if there are errors
*/
public void heartbeat() throws StreamingException;
/**
* Close the TransactionBatch
* @throws StreamingException if there are errors closing batch
* @throws InterruptedException if call in interrupted
*/
public void close() throws StreamingException, InterruptedException;
public boolean isClosed();
}