org.apache.tephra.DefaultTransactionExecutor Maven / Gradle / Ivy
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* 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.tephra;
import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.MoreExecutors;
import com.google.inject.Inject;
import com.google.inject.assistedinject.Assisted;
import java.util.Arrays;
import java.util.Collection;
import java.util.concurrent.Callable;
import java.util.concurrent.TimeUnit;
/**
* Utility class that encapsulates the transaction life cycle over a given set of
* transaction-aware datasets. The executor can be reused across multiple invocations
* of the execute() method. However, it is not thread-safe for concurrent execution.
*
* Transaction execution will be retries according to specified in constructor {@link RetryStrategy}.
* By default {@link RetryOnConflictStrategy} is used with max 20 retries and 100 ms between retries.
*
*/
public class DefaultTransactionExecutor extends AbstractTransactionExecutor {
private final Collection txAwares;
private final TransactionSystemClient txClient;
private final RetryStrategy retryStrategy;
/**
* Convenience constructor, has same affect as {@link #DefaultTransactionExecutor(TransactionSystemClient, Iterable)}
*/
public DefaultTransactionExecutor(TransactionSystemClient txClient, TransactionAware... txAwares) {
this(txClient, Arrays.asList(txAwares));
}
public DefaultTransactionExecutor(TransactionSystemClient txClient,
Iterable txAwares,
RetryStrategy retryStrategy) {
super(MoreExecutors.sameThreadExecutor());
this.txAwares = ImmutableList.copyOf(txAwares);
this.txClient = txClient;
this.retryStrategy = retryStrategy;
}
/**
* Constructor for a transaction executor.
*/
@Inject
public DefaultTransactionExecutor(TransactionSystemClient txClient, @Assisted Iterable txAwares) {
this(txClient, txAwares, RetryStrategies.retryOnConflict(20, 100));
}
@Override
public O execute(Function function, I input) throws TransactionFailureException, InterruptedException {
return executeWithRetry(function, input);
}
@Override
public void execute(final Procedure procedure, I input)
throws TransactionFailureException, InterruptedException {
execute(new Function() {
@Override
public Void apply(I input) throws Exception {
procedure.apply(input);
return null;
}
}, input);
}
@Override
public O execute(final Callable callable) throws TransactionFailureException, InterruptedException {
return execute(new Function() {
@Override
public O apply(Void input) throws Exception {
return callable.call();
}
}, null);
}
@Override
public void execute(final Subroutine subroutine) throws TransactionFailureException, InterruptedException {
execute(new Function() {
@Override
public Void apply(Void input) throws Exception {
subroutine.apply();
return null;
}
}, null);
}
private O executeWithRetry(Function function, I input)
throws TransactionFailureException, InterruptedException {
int retries = 0;
while (true) {
try {
return executeOnce(function, input);
} catch (TransactionFailureException e) {
long delay = retryStrategy.nextRetry(e, ++retries);
if (delay < 0) {
throw e;
}
if (delay > 0) {
TimeUnit.MILLISECONDS.sleep(delay);
}
}
}
}
private O executeOnce(Function function, I input) throws TransactionFailureException {
TransactionContext txContext = new TransactionContext(txClient, txAwares);
txContext.start();
O o = null;
try {
o = function.apply(input);
} catch (Throwable e) {
txContext.abort(new TransactionFailureException("Transaction function failure for transaction. ", e));
// abort will throw
}
// will throw if smth goes wrong
txContext.finish();
return o;
}
}
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