org.bitcoinj.core.GetUTXOsMessage Maven / Gradle / Ivy
/*
* Copyright 2014 the bitcoinj authors
*
* 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 org.bitcoinj.core;
import com.google.common.base.Objects;
import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;
/**
* This command is supported only by Bitcoin XT nodes, which
* advertise themselves using the second service bit flag. It requests a query of the UTXO set keyed by a set of
* outpoints (i.e. tx hash and output index). The result contains a bitmap of spentness flags, and the contents of
* the associated outputs if they were found. The results aren't authenticated by anything, so the peer could lie,
* or a man in the middle could swap out its answer for something else. Please consult
* BIP 65 for more information on this
* message.
*
* Note that this message does not let you query the UTXO set by address, script or any other criteria. The
* reason is that Bitcoin nodes don't calculate the necessary database indexes to answer such queries, to save
* space and time. If you want to look up unspent outputs by address, you can either query a block explorer site,
* or you can use the {@link FullPrunedBlockChain} class to build the required indexes yourself. Bear in that it will
* be quite slow and disk intensive to do that!
*
* Instances of this class are not safe for use by multiple threads.
*/
public class GetUTXOsMessage extends Message {
public static final int MIN_PROTOCOL_VERSION = 70002;
/** Bitmask of service flags required for a node to support this command (0x3) */
public static final long SERVICE_FLAGS_REQUIRED = 3;
private boolean includeMempool;
private ImmutableList outPoints;
public GetUTXOsMessage(NetworkParameters params, List outPoints, boolean includeMempool) {
super(params);
this.outPoints = ImmutableList.copyOf(outPoints);
this.includeMempool = includeMempool;
}
public GetUTXOsMessage(NetworkParameters params, byte[] payloadBytes) {
super(params, payloadBytes, 0);
}
@Override
protected void parse() throws ProtocolException {
includeMempool = readBytes(1)[0] == 1;
long numOutpoints = readVarInt();
ImmutableList.Builder list = ImmutableList.builder();
for (int i = 0; i < numOutpoints; i++) {
TransactionOutPoint outPoint = new TransactionOutPoint(params, payload, cursor);
list.add(outPoint);
cursor += outPoint.getMessageSize();
}
outPoints = list.build();
length = cursor;
}
public boolean getIncludeMempool() {
return includeMempool;
}
public ImmutableList getOutPoints() {
return outPoints;
}
@Override
protected void bitcoinSerializeToStream(OutputStream stream) throws IOException {
stream.write(new byte[]{includeMempool ? (byte) 1 : 0}); // include mempool.
stream.write(new VarInt(outPoints.size()).encode());
for (TransactionOutPoint outPoint : outPoints) {
outPoint.bitcoinSerializeToStream(stream);
}
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
GetUTXOsMessage other = (GetUTXOsMessage) o;
return includeMempool == other.includeMempool && outPoints.equals(other.outPoints);
}
@Override
public int hashCode() {
return Objects.hashCode(includeMempool, outPoints);
}
}