com.google.bitcoin.store.BlockStore Maven / Gradle / Ivy
/**
* 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.store;
import com.google.bitcoin.core.Sha256Hash;
import com.google.bitcoin.core.StoredBlock;
/**
* An implementor of BlockStore saves StoredBlock objects to disk. Different implementations store them in
* different ways. An in-memory implementation (MemoryBlockStore) exists for unit testing but real apps will want to
* use implementations that save to disk.
*
* A BlockStore is a map of hashes to StoredBlock. The hash is the double digest of the BitCoin serialization
* of the block header, not the header with the extra data as well.
*
* BlockStores are thread safe.
*/
public interface BlockStore {
/**
* Saves the given block header+extra data. The key isn't specified explicitly as it can be calculated from the
* StoredBlock directly. Can throw if there is a problem with the underlying storage layer such as running out of
* disk space.
*/
void put(StoredBlock block) throws BlockStoreException;
/**
* Returns the StoredBlock given a hash. The returned values block.getHash() method will be equal to the
* parameter. If no such block is found, returns null.
*/
StoredBlock get(Sha256Hash hash) throws BlockStoreException;
/**
* Returns the {@link StoredBlock} that represents the top of the chain of greatest total work. Note that this
* can be arbitrarily expensive, you probably should use {@link com.google.bitcoin.core.BlockChain#getChainHead()}
* or perhaps {@link com.google.bitcoin.core.BlockChain#getBestChainHeight()} which will run in constant time and
* not take any heavyweight locks.
*/
StoredBlock getChainHead() throws BlockStoreException;
/**
* Sets the {@link StoredBlock} that represents the top of the chain of greatest total work.
*/
void setChainHead(StoredBlock chainHead) throws BlockStoreException;
/** Closes the store. */
void close() throws BlockStoreException;
}