/**
* Copyright 2013 Google 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 com.matthewmitchell.nubitsj.testing;
import com.matthewmitchell.nubitsj.core.*;
import com.matthewmitchell.nubitsj.utils.Threading;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.SettableFuture;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.locks.ReentrantLock;
/**
* A mock transaction broadcaster can be used in unit tests as a stand-in for a PeerGroup. It catches any transactions
* broadcast through it and makes them available via the {@link #waitForTransaction()} method. Using that will cause
* the broadcast to be seen as if it never propagated though, so you may instead use {@link #waitForTxFuture()} and then
* set the returned future when you want the "broadcast" to be completed.
*/
public class MockTransactionBroadcaster implements TransactionBroadcaster {
private final ReentrantLock lock = Threading.lock("mock tx broadcaster");
private final Wallet wallet;
public static class TxFuturePair {
public final Transaction tx;
public final SettableFuture<Transaction> future;
public TxFuturePair(Transaction tx, SettableFuture<Transaction> future) {
this.tx = tx;
this.future = future;
}
/** Tells the broadcasting code that the broadcast was a success, just does future.set(tx) */
public void succeed() {
future.set(tx);
}
}
private final LinkedBlockingQueue<TxFuturePair> broadcasts = new LinkedBlockingQueue<TxFuturePair>();
/** Sets this mock broadcaster on the given wallet. */
public MockTransactionBroadcaster(Wallet wallet) {
// This code achieves nothing directly, but it sets up the broadcaster/peergroup > wallet lock ordering
// so inversions can be caught.
lock.lock();
try {
this.wallet = wallet;
wallet.setTransactionBroadcaster(this);
wallet.getPendingTransactions();
} finally {
lock.unlock();
}
}
@Override
public TransactionBroadcast broadcastTransaction(Transaction tx) {
// Use a lock just to catch lock ordering inversions e.g. wallet->broadcaster.
lock.lock();
try {
SettableFuture<Transaction> result = SettableFuture.create();
broadcasts.put(new TxFuturePair(tx, result));
Futures.addCallback(result, new FutureCallback<Transaction>() {
@Override
public void onSuccess(Transaction result) {
try {
wallet.receivePending(result, null);
} catch (VerificationException e) {
throw new RuntimeException(e);
}
}
@Override
public void onFailure(Throwable t) {
}
});
return TransactionBroadcast.createMockBroadcast(tx, result);
} catch (InterruptedException e) {
throw new RuntimeException(e);
} finally {
lock.unlock();
}
}
public Transaction waitForTransaction() {
return waitForTxFuture().tx;
}
public Transaction waitForTransactionAndSucceed() {
TxFuturePair pair = waitForTxFuture();
pair.succeed();
return pair.tx;
}
public TxFuturePair waitForTxFuture() {
try {
return broadcasts.take();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
public int size() {
return broadcasts.size();
}
}