com.bigdata.rawstore
Class AbstractRawWormStore

java.lang.Object
  com.bigdata.rawstore.AbstractRawStore
      com.bigdata.rawstore.AbstractRawWormStore

All Implemented Interfaces:

IAddressManager, IRawStore, IStoreSerializer, IWORM

Direct Known Subclasses:

AbstractBufferStrategy, SimpleMemoryRawStore, TemporaryRawStore

public abstract class AbstractRawWormStore
extends AbstractRawStore
implements IWORM

An abstract base class for IRawStore implementations that use an append only (Write Once, Read Many) strategy. The IAddressManager interface is delegated to an WormAddressManager allowing flexible configuration of the use of bits to represent the byte offset of a record in the store and the bits used to represent the size of a record in the store.

Version:

$Id: AbstractRawWormStore.java 2265 2009-10-26 12:51:06Z thompsonbry $

Author:

Bryan Thompson

See Also:

WormAddressManager

Field Summary

protected WormAddressManager

am The object that knows how to encode, decode, and (de-)serialize addresses.

Fields inherited from class com.bigdata.rawstore.AbstractRawStore

serializer

Fields inherited from interface com.bigdata.rawstore.IAddressManager

NULL

Constructor Summary

AbstractRawWormStore(int offsetBits)

Method Summary

WormAddressManager	getAddressManager() The object that knows how to encode, decode, and (de-)serialize addresses.
int	getByteCount(long addr) The length of the datum in bytes.
long	getOffset(long addr) The offset on the store at which the datum is stored.
int	getOffsetBits() The #of bits out of a 64-bit long integer that are used to encode the byte offset as an unsigned integer.
void	packAddr(DataOutput out, long addr) Pack the address onto the output stream.
long	toAddr(int nbytes, long offset) Converts a byte count and offset into a long integer.
String	toString(long addr) A human readable representation of the address.
long	unpackAddr(DataInput in) Unpack the address from the input stream.

Methods inherited from class com.bigdata.rawstore.AbstractRawStore

deserialize, deserialize, deserialize, serialize

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.bigdata.rawstore.IRawStore

close, deleteResources, destroy, force, getCounters, getFile, getResourceMetadata, getUUID, isFullyBuffered, isOpen, isReadOnly, isStable, read, size, write

Field Detail

am

protected final WormAddressManager am

The object that knows how to encode, decode, and (de-)serialize addresses.

Constructor Detail

AbstractRawWormStore

public AbstractRawWormStore(int offsetBits)

Parameters:

offsetBits - The #of bits that will be used to represent the byte offset in the 64-bit long integer addresses for the store. See WormAddressManager.

Method Detail

getAddressManager

public final WormAddressManager getAddressManager()

The object that knows how to encode, decode, and (de-)serialize addresses.

Specified by:

getAddressManager in class AbstractRawStore

getOffsetBits

public final int getOffsetBits()

The #of bits out of a 64-bit long integer that are used to encode the byte offset as an unsigned integer. The remaining bits are used to encode the byte count (aka record length) as an unsigned integer.

toAddr

public final long toAddr(int nbytes,
                         long offset)

Description copied from interface: IAddressManager

Converts a byte count and offset into a long integer.

Specified by:

toAddr in interface IAddressManager

Parameters:

nbytes - The byte count.

offset - The byte offset.

Returns:

The long integer.

getOffset

public final long getOffset(long addr)

Description copied from interface: IAddressManager

The offset on the store at which the datum is stored. While this is often the offset of a byte into a file on disk, implementations MAY assign offsets using other strategies.

Specified by:

getOffset in interface IAddressManager

Parameters:

addr - The opaque identifier that is the within store locator for some datum.

Returns:

The offset of that datum.

getByteCount

public final int getByteCount(long addr)

Description copied from interface: IAddressManager

The length of the datum in bytes.

Specified by:

getByteCount in interface IAddressManager

Parameters:

addr - The opaque identifier that is the within store locator for some datum.

Returns:

The offset of that datum.

packAddr

public final void packAddr(DataOutput out,
                           long addr)
                    throws IOException

Description copied from interface: IAddressManager

Pack the address onto the output stream.

Specified by:

packAddr in interface IAddressManager

Parameters:

out - The output stream.

addr - The opaque identifier that is the within store locator for some datum.

Throws:

IOException

unpackAddr

public final long unpackAddr(DataInput in)
                      throws IOException

Description copied from interface: IAddressManager

Unpack the address from the input stream.

Specified by:

unpackAddr in interface IAddressManager

Parameters:

in - The input stream.

Returns:

The opaque identifier that is the within store locator for some datum.

Throws:

IOException

toString

public final String toString(long addr)

Description copied from interface: IAddressManager

A human readable representation of the address.

Specified by:

toString in interface IAddressManager

Parameters:

addr - The opaque identifier that is the within store locator for some datum.

Returns:

A human readable representation.