com.bigdata.journal
Class TransientBufferStrategy

java.lang.Object
  com.bigdata.rawstore.AbstractRawStore
      com.bigdata.rawstore.AbstractRawWormStore
          com.bigdata.journal.AbstractBufferStrategy
              com.bigdata.journal.BasicBufferStrategy
                  com.bigdata.journal.TransientBufferStrategy

All Implemented Interfaces:

ICounterSetAccess, IBufferStrategy, IAddressManager, IMRMW, IMROW, IRawStore, IWORM

public class TransientBufferStrategy
extends BasicBufferStrategy

Transient buffer strategy uses a direct buffer but never writes on disk.

Version:

$Id: TransientBufferStrategy.java 4069 2011-01-09 20:58:02Z thompsonbry $

Author:

Bryan Thompson

See Also:

BufferMode.Transient

Field Summary

Fields inherited from class com.bigdata.journal.BasicBufferStrategy

extent, userExtent

Fields inherited from class com.bigdata.journal.AbstractBufferStrategy

bufferMode, ERR_ADDRESS_IS_NULL, ERR_ADDRESS_NOT_WRITTEN, ERR_BAD_RECORD_SIZE, ERR_BUFFER_EMPTY, ERR_BUFFER_NULL, ERR_BUFFER_OVERRUN, ERR_INT32, ERR_NOT_OPEN, ERR_OPEN, ERR_READ_ONLY, ERR_RECORD_LENGTH_ZERO, ERR_TRUNCATE, initialExtent, log, maximumExtent, nextOffset, WARN

Fields inherited from class com.bigdata.rawstore.AbstractRawWormStore

am

Fields inherited from interface com.bigdata.rawstore.IAddressManager

NULL

Method Summary

void	deleteResources() Deletes the backing file(s) (if any) and clears any records for the store from the IGlobalLRU.
void	force(boolean metadata) Force the data to stable storage.
File	getFile() Always returns null.
int	getHeaderSize() There is no header.
boolean	isFullyBuffered() True iff the store is fully buffered (all reads are against memory).
boolean	isStable() True iff backed by stable storage.
ByteBuffer	readRootBlock(boolean rootBlock0) Read the specified root block from the backing file.
void	setNextOffset(long lastOffset) Protocol support for HAWrite
void	writeRootBlock(IRootBlockView rootBlock, ForceEnum forceOnCommit) Write the root block onto stable storage (ie, flush it through to disk).

Methods inherited from class com.bigdata.journal.BasicBufferStrategy

close, getBufferView, getCounters, getExtent, getUserExtent, read, transferTo, truncate, write

Methods inherited from class com.bigdata.journal.AbstractBufferStrategy

abort, assertOpen, closeForWrites, commit, delete, destroy, getBufferMode, getInitialExtent, getMaximumExtent, getMaxRecordSize, getMetaBitsAddr, getMetaStartAddr, getMinimumExtension, getNextOffset, getResourceMetadata, getUUID, isOpen, isReadOnly, overflow, requiresCommit, size, transferFromDiskTo, useChecksums

Methods inherited from class com.bigdata.rawstore.AbstractRawWormStore

getAddressManager, getByteCount, getOffset, getOffsetBits, getPhysicalAddress, toAddr, toString

Methods inherited from class com.bigdata.rawstore.AbstractRawStore

abortContext, delete, detachContext, write, write, write

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.bigdata.journal.IBufferStrategy

getAddressManager, getOffsetBits

Methods inherited from interface com.bigdata.rawstore.IRawStore

write

Methods inherited from interface com.bigdata.rawstore.IAddressManager

getByteCount, getOffset, getPhysicalAddress, toAddr, toString

Method Detail

deleteResources

public void deleteResources()

Description copied from interface: IRawStore

Deletes the backing file(s) (if any) and clears any records for the store from the IGlobalLRU.

force

public void force(boolean metadata)

Description copied from interface: IRawStore

Force the data to stable storage. While this is NOT sufficient to guarantee an atomic commit, the data must be forced to disk as part of an atomic commit protocol.

Parameters:

metadata - If true, then force both the file contents and the file metadata to disk.

getFile

public File getFile()

Always returns null.

isStable

public final boolean isStable()

Description copied from interface: IRawStore

True iff backed by stable storage.

isFullyBuffered

public boolean isFullyBuffered()

Description copied from interface: IRawStore

True iff the store is fully buffered (all reads are against memory). Implementations MAY change the value returned by this method over the life cycle of the store, e.g., to conserve memory a store may drop or decrease its buffer if it is backed by disk.

Note: This does not guarantee that the OS will not swap the buffer onto disk.

writeRootBlock

public void writeRootBlock(IRootBlockView rootBlock,
                           ForceEnum forceOnCommit)

Description copied from interface: IBufferStrategy

Write the root block onto stable storage (ie, flush it through to disk).

Parameters:

rootBlock - The root block. Which root block is indicated by IRootBlockView.isRootBlock0().

getHeaderSize

public final int getHeaderSize()

There is no header.

Returns:

ZERO (0).

readRootBlock

public ByteBuffer readRootBlock(boolean rootBlock0)

Description copied from interface: IBufferStrategy

Read the specified root block from the backing file.

setNextOffset

public void setNextOffset(long lastOffset)

Protocol support for HAWrite