com.bigdata.rawstore

Class AbstractRawWormStore

java.lang.Object

com.bigdata.rawstore.AbstractRawStore

com.bigdata.rawstore.AbstractRawWormStore

All Implemented Interfaces:

ICounterSetAccess, IAddressManager, IRawStore, IStreamStore, IWORM

Direct Known Subclasses:

AbstractBufferStrategy, SimpleFileRawStore, 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:

$Id$

Author:

Bryan Thompson

See Also:

WormAddressManager

Field Summary

Fields

Modifier and Type	Field and Description
protected WormAddressManager	am The object that knows how to encode, decode, and (de-)serialize addresses.

Fields inherited from interface com.bigdata.rawstore.IAddressManager

NULL

Constructor Summary

Constructors

Constructor and Description
AbstractRawWormStore(int offsetBits)

Method Summary

Methods

Modifier and Type	Method and Description
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.
long	getPhysicalAddress(long addr) Determine the unencoded physical address
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.

Methods inherited from class com.bigdata.rawstore.AbstractRawStore

delete, getInputStream, getOutputStream

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, getFile, getResourceMetadata, getUUID, isFullyBuffered, isOpen, isReadOnly, isStable, read, size, write

Methods inherited from interface com.bigdata.counters.ICounterSetAccess

getCounters

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.

getPhysicalAddress

public final long getPhysicalAddress(long addr)

Description copied from interface: IAddressManager

Determine the unencoded physical address

Specified by:

getPhysicalAddress in interface IAddressManager

Parameters:

addr - The encoded address

Returns:

an unencoded address offset

getByteCount

public final int getByteCount(long addr)

Description copied from interface: IAddressManager

The length of the datum in bytes. This must be the actual length of the record on the disk, not the length of the caller's byte[]. This is necessary in order to support transparent checksums and/or compression for records in the IRawStore.

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.

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.