org.bitcoinj.utils.BlockFileLoader Maven / Gradle / Ivy
/*
* Copyright 2012 Matt Corallo.
*
* 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.utils;
import static com.google.common.base.Preconditions.checkArgument;
import org.bitcoinj.core.Block;
import org.bitcoinj.core.NetworkParameters;
import org.bitcoinj.core.ProtocolException;
import org.bitcoinj.core.Utils;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.NoSuchElementException;
/**
* This class reads block files stored in the Dash Core format. This is simply a way to concatenate
* blocks together. Importing block data with this tool can be a lot faster than syncing over the network, if you
* have the files available.
*
* In order to comply with {@link Iterator}, this class swallows a lot of {@link IOException}s, which may result in a few
* blocks being missed followed by a huge set of orphan blocks.
*
* To blindly import all files which can be found in Dash Core (version 0.8 or higher) datadir automatically,
* try this code fragment:
* {@code
* BlockFileLoader loader = new BlockFileLoader(BlockFileLoader.getReferenceClientBlockFileList());
* for (Block block : loader) {
* try { chain.add(block); } catch (Exception e) { }
* }
* }
*/
public class BlockFileLoader implements Iterable, Iterator {
/**
* Gets the list of files which contain blocks from Dash Core.
*/
public static List getReferenceClientBlockFileList(File blocksDir) {
checkArgument(blocksDir.isDirectory(), "%s is not a directory", blocksDir);
List list = new LinkedList<>();
for (int i = 0; true; i++) {
File file = new File(blocksDir, String.format(Locale.US, "blk%05d.dat", i));
if (!file.exists())
break;
list.add(file);
}
return list;
}
public static List getReferenceClientBlockFileList() {
return getReferenceClientBlockFileList(defaultBlocksDir());
}
public static File defaultBlocksDir() {
final File defaultBlocksDir;
if (Utils.isWindows()) {
defaultBlocksDir = new File(System.getenv("APPDATA") + "\\DashCore\\blocks\\");
} else if (Utils.isMac()) {
defaultBlocksDir = new File(System.getProperty("user.home") + "/Library/Application Support/DashCore/blocks/");
} else if (Utils.isLinux()) {
defaultBlocksDir = new File(System.getProperty("user.home") + "/.dashcore/blocks/");
} else {
throw new RuntimeException("Unsupported system");
}
return defaultBlocksDir;
}
private Iterator fileIt;
private File file = null;
private FileInputStream currentFileStream = null;
private Block nextBlock = null;
private NetworkParameters params;
public BlockFileLoader(NetworkParameters params, File blocksDir) {
this(params, getReferenceClientBlockFileList(blocksDir));
}
public BlockFileLoader(NetworkParameters params, List files) {
fileIt = files.iterator();
this.params = params;
}
@Override
public boolean hasNext() {
if (nextBlock == null)
loadNextBlock();
return nextBlock != null;
}
@Override
public Block next() throws NoSuchElementException {
if (!hasNext())
throw new NoSuchElementException();
Block next = nextBlock;
nextBlock = null;
return next;
}
private void loadNextBlock() {
while (true) {
try {
if (!fileIt.hasNext() && (currentFileStream == null || currentFileStream.available() < 1))
break;
} catch (IOException e) {
currentFileStream = null;
if (!fileIt.hasNext())
break;
}
while (true) {
try {
if (currentFileStream != null && currentFileStream.available() > 0)
break;
} catch (IOException e1) {
currentFileStream = null;
}
if (!fileIt.hasNext()) {
nextBlock = null;
currentFileStream = null;
return;
}
file = fileIt.next();
try {
currentFileStream = new FileInputStream(file);
} catch (FileNotFoundException e) {
currentFileStream = null;
}
}
try {
int nextChar = currentFileStream.read();
while (nextChar != -1) {
if (nextChar != ((params.getPacketMagic() >>> 24) & 0xff)) {
nextChar = currentFileStream.read();
continue;
}
nextChar = currentFileStream.read();
if (nextChar != ((params.getPacketMagic() >>> 16) & 0xff))
continue;
nextChar = currentFileStream.read();
if (nextChar != ((params.getPacketMagic() >>> 8) & 0xff))
continue;
nextChar = currentFileStream.read();
if (nextChar == (params.getPacketMagic() & 0xff))
break;
}
byte[] bytes = new byte[4];
currentFileStream.read(bytes, 0, 4);
long size = Utils.readUint32BE(Utils.reverseBytes(bytes), 0);
// We allow larger than MAX_BLOCK_SIZE because test code uses this as well.
if (size > Block.MAX_BLOCK_SIZE*2 || size <= 0)
continue;
bytes = new byte[(int) size];
currentFileStream.read(bytes, 0, (int) size);
try {
nextBlock = params.getDefaultSerializer().makeBlock(bytes);
} catch (ProtocolException e) {
nextBlock = null;
continue;
} catch (Exception e) {
throw new RuntimeException("unexpected problem with block in " + file, e);
}
break;
} catch (IOException e) {
currentFileStream = null;
continue;
}
}
}
@Override
public void remove() throws UnsupportedOperationException {
throw new UnsupportedOperationException();
}
@Override
public Iterator iterator() {
return this;
}
}