com.google.bitcoin.store

Class SPVBlockStore

java.lang.Object

com.google.bitcoin.store.SPVBlockStore

All Implemented Interfaces:

BlockStore

public class SPVBlockStore
extends Object
implements BlockStore

An SPVBlockStore holds a limited number of block headers in a memory mapped ring buffer. With such a store, you may not be able to process very deep re-orgs and could be disconnected from the chain (requiring a replay), but as they are virtually unheard of this is not a significant risk.

Field Summary

Fields

Modifier and Type	Field and Description
protected LinkedHashMap<Sha256Hash,StoredBlock>	blockCache
protected MappedByteBuffer	buffer
static int	DEFAULT_NUM_HEADERS The default number of headers that will be stored in the ring buffer.
protected static int	FILE_PROLOGUE_BYTES
protected FileLock	fileLock
static String	HEADER_MAGIC
protected StoredBlock	lastChainHead
protected ReentrantLock	lock
protected LinkedHashMap<Sha256Hash,Object>	notFoundCache
protected static Object	notFoundMarker
protected int	numHeaders
protected NetworkParameters	params
protected RandomAccessFile	randomAccessFile
protected static int	RECORD_SIZE

Constructor Summary

Constructors

Constructor and Description
SPVBlockStore(NetworkParameters params, File file) Creates and initializes an SPV block store.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Closes the store.
StoredBlock	get(Sha256Hash hash) Returns the StoredBlock given a hash.
StoredBlock	getChainHead() Returns the StoredBlock that represents the top of the chain of greatest total work.
int	getFileSize() Returns the size in bytes of the file that is used to store the chain with the current parameters.
void	put(StoredBlock block) Saves the given block header+extra data.
void	setChainHead(StoredBlock chainHead) Sets the StoredBlock that represents the top of the chain of greatest total work.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_NUM_HEADERS

public static final int DEFAULT_NUM_HEADERS

The default number of headers that will be stored in the ring buffer.

See Also:

Constant Field Values

HEADER_MAGIC

public static final String HEADER_MAGIC

See Also:

Constant Field Values

buffer

protected volatile MappedByteBuffer buffer

numHeaders

protected int numHeaders

params

protected NetworkParameters params

lock

protected ReentrantLock lock

blockCache

protected LinkedHashMap<Sha256Hash,StoredBlock> blockCache

notFoundMarker

protected static final Object notFoundMarker

notFoundCache

protected LinkedHashMap<Sha256Hash,Object> notFoundCache

fileLock

protected FileLock fileLock

randomAccessFile

protected RandomAccessFile randomAccessFile

lastChainHead

protected StoredBlock lastChainHead

RECORD_SIZE

protected static final int RECORD_SIZE

See Also:

Constant Field Values

FILE_PROLOGUE_BYTES

protected static final int FILE_PROLOGUE_BYTES

See Also:

Constant Field Values

Constructor Detail

SPVBlockStore

public SPVBlockStore(NetworkParameters params,
             File file)
              throws BlockStoreException

Creates and initializes an SPV block store. Will create the given file if it's missing. This operation will block on disk.

Throws:

BlockStoreException

Method Detail

getFileSize

public int getFileSize()

Returns the size in bytes of the file that is used to store the chain with the current parameters.

put

public void put(StoredBlock block)
         throws BlockStoreException

Description copied from 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.

Specified by:

put in interface BlockStore

Throws:

BlockStoreException

get

@Nullable
public StoredBlock get(Sha256Hash hash)
                throws BlockStoreException

Description copied from interface: BlockStore

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.

Specified by:

get in interface BlockStore

Throws:

BlockStoreException

getChainHead

public StoredBlock getChainHead()
                         throws BlockStoreException

Description copied from interface: BlockStore

Returns the StoredBlock that represents the top of the chain of greatest total work. Note that this can be arbitrarily expensive, you probably should use AbstractBlockChain.getChainHead() or perhaps AbstractBlockChain.getBestChainHeight() which will run in constant time and not take any heavyweight locks.

Specified by:

getChainHead in interface BlockStore

Throws:

BlockStoreException

setChainHead

public void setChainHead(StoredBlock chainHead)
                  throws BlockStoreException

Description copied from interface: BlockStore

Sets the StoredBlock that represents the top of the chain of greatest total work.

Specified by:

setChainHead in interface BlockStore

Throws:

BlockStoreException

close

public void close()
           throws BlockStoreException

Description copied from interface: BlockStore

Closes the store.

Specified by:

close in interface BlockStore

Throws:

BlockStoreException