/*
* Copyright 2013 Google Inc.
* Copyright 2014 Andreas Schildbach
*
* 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.tools;
import com.matthewmitchell.nubitsj.core.*;
import com.matthewmitchell.nubitsj.params.MainNetParams;
import com.matthewmitchell.nubitsj.store.BlockStore;
import com.matthewmitchell.nubitsj.store.MemoryBlockStore;
import com.matthewmitchell.nubitsj.utils.BriefLogFormatter;
import com.matthewmitchell.nubitsj.utils.Threading;
import com.google.common.base.Charsets;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.nio.ByteBuffer;
import java.security.DigestOutputStream;
import java.security.MessageDigest;
import java.util.Date;
import java.util.TreeMap;
import static com.google.common.base.Preconditions.checkState;
/**
* Downloads and verifies a full chain from your local peer, emitting checkpoints at each difficulty transition period
* to a file which is then signed with your key.
*/
public class BuildCheckpoints {
private static final NetworkParameters PARAMS = MainNetParams.get();
private static final File PLAIN_CHECKPOINTS_FILE = new File("checkpoints");
private static final File TEXTUAL_CHECKPOINTS_FILE = new File("checkpoints.txt");
public static void main(String[] args) throws Exception {
BriefLogFormatter.initWithSilentNubitsJ();
// Sorted map of block height to StoredBlock object.
final TreeMap<Integer, StoredBlock> checkpoints = new TreeMap<Integer, StoredBlock>();
// Configure nubitsj to fetch only headers, not save them to disk, connect to a local fully synced/validated
// node and to save block headers that are on interval boundaries, as long as they are <1 month old.
final BlockStore store = new MemoryBlockStore(PARAMS);
final BlockChain chain = new BlockChain(PARAMS, store);
final PeerGroup peerGroup = new PeerGroup(PARAMS, chain);
final InetAddress peerAddress = InetAddress.getLocalHost();
System.out.println("Connecting to " + peerAddress + "...");
peerGroup.addAddress(peerAddress);
long now = new Date().getTime() / 1000;
peerGroup.setFastCatchupTimeSecs(now);
final long oneMonthAgo = now - (86400 * 30);
chain.addListener(new AbstractBlockChainListener() {
@Override
public void notifyNewBestBlock(StoredBlock block) throws VerificationException {
int height = block.getHeight();
if (height % PARAMS.getInterval() == 0 && block.getHeader().getTimeSeconds() <= oneMonthAgo) {
System.out.println(String.format("Checkpointing block %s at height %d",
block.getHeader().getHash(), block.getHeight()));
checkpoints.put(height, block);
}
}
}, Threading.SAME_THREAD);
peerGroup.start();
peerGroup.downloadBlockChain();
checkState(checkpoints.size() > 0);
// Write checkpoint data out.
writeBinaryCheckpoints(checkpoints, PLAIN_CHECKPOINTS_FILE);
writeTextualCheckpoints(checkpoints, TEXTUAL_CHECKPOINTS_FILE);
peerGroup.stop();
store.close();
// Sanity check the created files.
sanityCheck(PLAIN_CHECKPOINTS_FILE, checkpoints.size());
sanityCheck(TEXTUAL_CHECKPOINTS_FILE, checkpoints.size());
}
private static void writeBinaryCheckpoints(TreeMap<Integer, StoredBlock> checkpoints, File file) throws Exception {
final FileOutputStream fileOutputStream = new FileOutputStream(file, false);
MessageDigest digest = Sha256Hash.newDigest();
final DigestOutputStream digestOutputStream = new DigestOutputStream(fileOutputStream, digest);
digestOutputStream.on(false);
final DataOutputStream dataOutputStream = new DataOutputStream(digestOutputStream);
dataOutputStream.writeBytes("CHECKPOINTS 1");
dataOutputStream.writeInt(0); // Number of signatures to read. Do this later.
digestOutputStream.on(true);
dataOutputStream.writeInt(checkpoints.size());
ByteBuffer buffer = ByteBuffer.allocate(StoredBlock.COMPACT_SERIALIZED_SIZE);
for (StoredBlock block : checkpoints.values()) {
block.serializeCompact(buffer);
dataOutputStream.write(buffer.array());
buffer.position(0);
}
dataOutputStream.close();
Sha256Hash checkpointsHash = Sha256Hash.wrap(digest.digest());
System.out.println("Hash of checkpoints data is " + checkpointsHash);
digestOutputStream.close();
fileOutputStream.close();
System.out.println("Checkpoints written to '" + file.getCanonicalPath() + "'.");
}
private static void writeTextualCheckpoints(TreeMap<Integer, StoredBlock> checkpoints, File file) throws IOException {
PrintWriter writer = new PrintWriter(new OutputStreamWriter(new FileOutputStream(file), Charsets.US_ASCII));
writer.println("TXT CHECKPOINTS 1");
writer.println("0"); // Number of signatures to read. Do this later.
writer.println(checkpoints.size());
ByteBuffer buffer = ByteBuffer.allocate(StoredBlock.COMPACT_SERIALIZED_SIZE);
for (StoredBlock block : checkpoints.values()) {
block.serializeCompact(buffer);
writer.println(CheckpointManager.BASE64.encode(buffer.array()));
buffer.position(0);
}
writer.close();
System.out.println("Checkpoints written to '" + file.getCanonicalPath() + "'.");
}
private static void sanityCheck(File file, int expectedSize) throws IOException {
CheckpointManager manager = new CheckpointManager(PARAMS, new FileInputStream(file));
checkState(manager.numCheckpoints() == expectedSize);
if (PARAMS.getId().equals(NetworkParameters.ID_MAINNET)) {
StoredBlock test = manager.getCheckpointBefore(1390500000); // Thu Jan 23 19:00:00 CET 2014
checkState(test.getHeight() == 280224);
checkState(test.getHeader().getHashAsString()
.equals("00000000000000000b5d59a15f831e1c45cb688a4db6b0a60054d49a9997fa34"));
} else if (PARAMS.getId().equals(NetworkParameters.ID_TESTNET)) {
StoredBlock test = manager.getCheckpointBefore(1390500000); // Thu Jan 23 19:00:00 CET 2014
checkState(test.getHeight() == 167328);
checkState(test.getHeader().getHashAsString()
.equals("0000000000035ae7d5025c2538067fe7adb1cf5d5d9c31b024137d9090ed13a9"));
}
}
}