com.google.bitcoin.core.GetHeadersMessage Maven / Gradle / Ivy
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/*
* Copyright 2011 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.google.bitcoin.core;
import java.util.List;
/**
* The "getheaders" command is structurally identical to "getblocks", but has different meaning. On receiving this
* message a Bitcoin node returns matching blocks up to the limit, but without the bodies. It is useful as an
* optimization: when your wallet does not contain any keys created before a particular time, you don't have to download
* the bodies for those blocks because you know there are no relevant transactions.
*/
public class GetHeadersMessage extends GetBlocksMessage {
public GetHeadersMessage(NetworkParameters params, List locator, Sha256Hash stopHash) {
super(params, locator, stopHash);
}
public GetHeadersMessage(NetworkParameters params, byte[] msg) throws ProtocolException {
super(params, msg);
}
@Override
public String toString() {
StringBuffer b = new StringBuffer();
b.append("getheaders: ");
for (Sha256Hash hash : locator) {
b.append(hash.toString());
b.append(" ");
}
return b.toString();
}
/**
* Compares two getheaders messages. Note that even though they are structurally identical a GetHeadersMessage
* will not compare equal to a GetBlocksMessage containing the same data.
*/
@Override
public boolean equals(Object o) {
if (o == null || o.getClass() != getClass()) return false;
GetHeadersMessage other = (GetHeadersMessage) o;
return (other.version == version &&
locator.size() == other.locator.size() && locator.containsAll(other.locator) &&
stopHash.equals(other.stopHash));
}
@Override
public int hashCode() {
int hashCode = (int) version ^ "getheaders".hashCode();
for (Sha256Hash aLocator : locator) hashCode ^= aLocator.hashCode();
hashCode ^= stopHash.hashCode();
return hashCode;
}
}