/**
* 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.io.*;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;
/**
* Keeps {@link StoredBlock}s in memory. Used primarily for unit testing.
*/
public class MemoryBlockStore implements BlockStore {
// We use a ByteBuffer to hold hashes here because the Java array equals()/hashcode() methods do not operate on
// the contents of the array but just inherit the default Object behavior. ByteBuffer provides the functionality
// needed to act as a key in a map.
//
// The StoredBlocks are also stored as serialized objects to ensure we don't have assumptions that would make
// things harder for disk based implementations.
private Map<ByteBuffer, byte[]> blockMap;
private StoredBlock chainHead;
public MemoryBlockStore(NetworkParameters params) {
blockMap = new HashMap<ByteBuffer, byte[]>();
// Insert the genesis block.
try {
Block genesisHeader = params.genesisBlock.cloneAsHeader();
StoredBlock storedGenesis = new StoredBlock(genesisHeader, genesisHeader.getWork(), 0);
put(storedGenesis);
setChainHead(storedGenesis);
} catch (BlockStoreException e) {
throw new RuntimeException(e); // Cannot happen.
} catch (VerificationException e) {
throw new RuntimeException(e); // Cannot happen.
}
}
public synchronized void put(StoredBlock block) throws BlockStoreException {
byte[] hash = block.getHeader().getHash();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
ObjectOutputStream oos = new ObjectOutputStream(bos);
oos.writeObject(block);
oos.close();
blockMap.put(ByteBuffer.wrap(hash), bos.toByteArray());
} catch (IOException e) {
throw new BlockStoreException(e);
}
}
public synchronized StoredBlock get(byte[] hash) throws BlockStoreException {
try {
byte[] serializedBlock = blockMap.get(ByteBuffer.wrap(hash));
if (serializedBlock == null)
return null;
ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(serializedBlock));
StoredBlock storedBlock = (StoredBlock) ois.readObject();
return storedBlock;
} catch (IOException e) {
throw new BlockStoreException(e);
} catch (ClassNotFoundException e) {
throw new BlockStoreException(e);
}
}
public StoredBlock getChainHead() {
return chainHead;
}
public void setChainHead(StoredBlock chainHead) throws BlockStoreException {
this.chainHead = chainHead;
}
}