com.bigdata.bop.solutions

Class SolutionSetStream

java.lang.Object

com.bigdata.stream.Stream

com.bigdata.bop.solutions.SolutionSetStream

All Implemented Interfaces:

ISolutionSet, ICheckpointProtocol, IReadWriteLockManager, ISimpleIndexAccess, ICounterSetAccess, ICommitter

public final class SolutionSetStream
extends Stream
implements ISolutionSet

A persistence capable solution set stored using a stream oriented API. The order of the solutions on playback is their write order. This data structure provides fast read/write performance, but does not provide key-based access into the solution sets. TODO Test performance with and without gzip. Extract into the CREATE schema / IndexMetadata so we can do this declaratively.

Nested Class Summary

Nested classes/interfaces inherited from class com.bigdata.stream.Stream

Stream.CompressionEnum, Stream.StreamIndexMetadata

Field Summary

Fields inherited from class com.bigdata.stream.Stream

entryCount, error, ERROR_CLOSED, ERROR_ERROR_STATE, ERROR_READ_ONLY, metadata, open, rootAddr

Constructor Summary

Constructors

Constructor and Description
SolutionSetStream(IRawStore store, Checkpoint checkpoint, IndexMetadata metadata, boolean readOnly) Required constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	clear()
static SolutionSetStream	create(IRawStore store, Stream.StreamIndexMetadata metadata) Create a stream for an ordered solution set.
BaseIndexStats	dumpPages(boolean recursive, boolean visitLeaves) Reports statistics for the index.
protected void	flush() Hook to flush anything which is dirty to the backing store.
ICloseableIterator<IBindingSet[]>	get() Return an ICloseableIterator reading the solutions from the stream.
ISolutionSetStats	getStats() Return the ISolutionSetStats for the saved solution set.
long	getStatsAddr() Return the address of the ISolutionSetStats to be written into the next Checkpoint record.
protected boolean	needsCheckpoint() Return true iff changes would be lost unless the Stream is flushed to the backing store using Stream.writeCheckpoint().
void	put(ICloseableIterator<IBindingSet[]> src2) Replace the contents of the stream with the solutions read from the source.
ICloseableIterator<IBindingSet>	scan() Visit all entries in the index in the natural order of the index (dereferencing visited tuples to the application objects stored within those tuples).
protected void	setCheckpoint(Checkpoint checkpoint) Sets the Stream.checkpoint and initializes the mutable fields from the checkpoint record.
void	write(ICloseableIterator<?> src) Write entries onto the stream.

Methods inherited from class com.bigdata.stream.Stream

assertNotReadOnly, assertNotTransient, close, fireDirtyEvent, getCheckpoint, getCounters, getDirtyListener, getIndexMetadata, getLastCommitTime, getMetadataAddr, getReadLockCount, getRecordVersion, getRootAddr, getStore, handleCommit, invalidate, isOpen, isReadOnly, load, rangeCount, readLock, recycle, removeAll, reopen, setDirtyListener, setLastCommitTime, wrapInputStream, wrapOutputStream, writeCheckpoint, writeCheckpoint2, writeLock

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.bigdata.btree.ICheckpointProtocol

close, getCheckpoint, getDirtyListener, getIndexMetadata, getLastCommitTime, getMetadataAddr, getRecordVersion, getRootAddr, isOpen, reopen, setDirtyListener, setLastCommitTime, writeCheckpoint, writeCheckpoint2

Methods inherited from interface com.bigdata.journal.ICommitter

handleCommit, invalidate

Methods inherited from interface com.bigdata.counters.ICounterSetAccess

getCounters

Methods inherited from interface com.bigdata.btree.ISimpleIndexAccess

getStore, rangeCount, removeAll

Methods inherited from interface com.bigdata.btree.IReadWriteLockManager

getReadLockCount, isReadOnly, readLock, writeLock

Constructor Detail

SolutionSetStream

public SolutionSetStream(IRawStore store,
                 Checkpoint checkpoint,
                 IndexMetadata metadata,
                 boolean readOnly)

Required constructor. This constructor is used both to create a new named solution set, and to load an existing named solution set from the store using a Checkpoint record.

Parameters:

store - The store.

checkpoint - The Checkpoint record.

metadata - The metadata record.

readOnly - When true the view will be immutable.

See Also:

Stream.create(IRawStore, StreamIndexMetadata), Stream.load(IRawStore, long, boolean)

Method Detail

create

public static SolutionSetStream create(IRawStore store,
                       Stream.StreamIndexMetadata metadata)

Create a stream for an ordered solution set.

FIXME GIST : This is not setting the SolutionSetStream class when invoked by Checkpoint.create(IRawStore, IndexMetadata) since Stream.create() is being invoked rather than SolutionSetStream.create().

See Also:

GIST

getStats

public ISolutionSetStats getStats()

Return the ISolutionSetStats for the saved solution set.

Specified by:

getStats in interface ISolutionSet

Returns:

The ISolutionSetStats.

getStatsAddr

public long getStatsAddr()

Return the address of the ISolutionSetStats to be written into the next Checkpoint record. The caller must have flush() the SolutionSetStream as a pre-condition (to ensure that the stats have been written out). If the ISolutionSetStats are not loaded, then the address from the last Checkpoint record is returned.

get

public ICloseableIterator<IBindingSet[]> get()

Description copied from interface: ISolutionSet

Return an ICloseableIterator reading the solutions from the stream.

Specified by:

get in interface ISolutionSet

put

public void put(ICloseableIterator<IBindingSet[]> src2)

Description copied from interface: ISolutionSet

Replace the contents of the stream with the solutions read from the source.

Specified by:

put in interface ISolutionSet

Parameters:

src2 - The source.

scan

public ICloseableIterator<IBindingSet> scan()

Description copied from interface: ISimpleIndexAccess

Visit all entries in the index in the natural order of the index (dereferencing visited tuples to the application objects stored within those tuples).

Specified by:

scan in interface ISolutionSet

Specified by:

scan in interface ISimpleIndexAccess

Specified by:

scan in class Stream

clear

public void clear()

Overrides:

clear in class Stream

needsCheckpoint

protected boolean needsCheckpoint()

Description copied from class: Stream

Return true iff changes would be lost unless the Stream is flushed to the backing store using Stream.writeCheckpoint().

Overrides:

needsCheckpoint in class Stream

Returns:

true true iff changes would be lost unless the Stream was flushed to the backing store using Stream.writeCheckpoint().

flush

protected void flush()

Description copied from class: Stream

Hook to flush anything which is dirty to the backing store. This is invoked by Stream._writeCheckpoint2().

Overrides:

flush in class Stream

setCheckpoint

protected void setCheckpoint(Checkpoint checkpoint)

Sets the Stream.checkpoint and initializes the mutable fields from the checkpoint record. In order for this operation to be atomic, the caller must be synchronized on the BTree or otherwise guaranteed to have exclusive access, e.g., during the ctor or when the BTree is mutable and access is therefore required to be single-threaded.

Extended to persist the ISolutionSetStats.

Overrides:

setCheckpoint in class Stream

write

public void write(ICloseableIterator<?> src)

Description copied from class: Stream

Write entries onto the stream.

Specified by:

write in class Stream

Parameters:

src - An iterator visiting the entries.

dumpPages

public BaseIndexStats dumpPages(boolean recursive,
                       boolean visitLeaves)

Description copied from interface: ICheckpointProtocol

Reports statistics for the index.

Specified by:

dumpPages in interface ICheckpointProtocol

Parameters:

recursive - When true, also collects statistics on the pages (nodes and leaves) using a low-level approach.

visitLeaves - When true and recursive:=true then the leaves of the index are also visited.

Returns:

Some interesting statistics about the index (and optionally the pages in that index) which the caller can print out.

See Also:

pre-heat the journal on startup