com.bigdata.service

Class CacheOnceMetadataIndex

java.lang.Object

com.bigdata.service.CacheOnceMetadataIndex

All Implemented Interfaces:

IRangeQuery, IMetadataIndex

Direct Known Subclasses:

CachingMetadataIndex

public class CacheOnceMetadataIndex
extends Object
implements IMetadataIndex

Implementation caches all locators but does not allow stale locators. This is useful for read-historical index views since locators can not become stale for a historical view.

Version:

$Id$

Author:

Bryan Thompson

Field Summary

Fields

Modifier and Type	Field and Description
protected AbstractScaleOutFederation<?>	fed The federation.
protected static org.apache.log4j.Logger	log
protected MetadataIndex.MetadataIndexMetadata	mdmd Cached metadata record for the metadata index.
protected String	name Name of the scale-out index.
protected long	timestamp Timestamp of the view.

Fields inherited from interface com.bigdata.btree.IRangeQuery

ALL, CURSOR, DEFAULT, DELETED, FIXED_LENGTH_SUCCESSOR, KEYS, NONE, PARALLEL, READONLY, REMOVEALL, REVERSE, VALS

Constructor Summary

Constructors

Constructor and Description
CacheOnceMetadataIndex(AbstractScaleOutFederation<?> fed, String name, long timestamp, MetadataIndex.MetadataIndexMetadata mdmd) Caches the index partition locators.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	cacheLocators(byte[] fromKey, byte[] toKey) Bulk copy the partition definitions for the scale-out index into the client.
PartitionLocator	find(byte[] key) Find and return the partition spanning the given key.
PartitionLocator	get(byte[] key) The partition with that separator key or null (exact match on the separator key).
MetadataIndex.MetadataIndexMetadata	getIndexMetadata() The metadata for the metadata index itself.
IndexMetadata	getScaleOutIndexMetadata() The metadata template for the scale-out index managed by this metadata index.
long	rangeCount() Return the #of tuples in the index.
long	rangeCount(byte[] fromKey, byte[] toKey) Return the #of tuples in a half-open key range.
long	rangeCountExact(byte[] fromKey, byte[] toKey) Return the exact #of tuples in a half-open key range.
long	rangeCountExactWithDeleted(byte[] fromKey, byte[] toKey) Return the exact #of tuples in a half-open key range, including any deleted tuples.
ITupleIterator	rangeIterator() Visits all tuples in key order.
ITupleIterator	rangeIterator(byte[] fromKey, byte[] toKey) Return an iterator that visits the entries in a half-open key range.
ITupleIterator	rangeIterator(byte[] fromKey, byte[] toKey, int capacity, int flags, IFilter filter) Designated variant (the one that gets overridden) for an iterator that visits the entries in a half-open key range.
void	staleLocator(PartitionLocator locator) Notification that a locator is stale.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final org.apache.log4j.Logger log

fed

protected final AbstractScaleOutFederation<?> fed

The federation.

name

protected final String name

Name of the scale-out index.

timestamp

protected final long timestamp

Timestamp of the view.

mdmd

protected final MetadataIndex.MetadataIndexMetadata mdmd

Cached metadata record for the metadata index.

Constructor Detail

CacheOnceMetadataIndex

public CacheOnceMetadataIndex(AbstractScaleOutFederation<?> fed,
                      String name,
                      long timestamp,
                      MetadataIndex.MetadataIndexMetadata mdmd)

Caches the index partition locators.

Parameters:

name - The name of the scale-out index.

Method Detail

toString

public String toString()

Overrides:

toString in class Object

cacheLocators

protected void cacheLocators(byte[] fromKey,
                 byte[] toKey)

Bulk copy the partition definitions for the scale-out index into the client.

Note: This assumes that the metadata index is NOT partitioned and DOES NOT support delete markers.

staleLocator

public void staleLocator(PartitionLocator locator)

Description copied from interface: IMetadataIndex

Notification that a locator is stale. Caching implementations of this interface will use this notice to update their state from the authoritative metadata index. Non-caching and authoritative implementations just ignore this message.

Specified by:

staleLocator in interface IMetadataIndex

Parameters:

locator - The locator.

Throws:

UnsupportedOperationException - stale locators should not occur for read-historical views!

getIndexMetadata

public final MetadataIndex.MetadataIndexMetadata getIndexMetadata()

Description copied from interface: IMetadataIndex

The metadata for the metadata index itself. Note that the MetadataIndex.MetadataIndexMetadata.getManagedIndexMetadata() returns the template IndexMetadata for the scale-out index partitions.

Specified by:

getIndexMetadata in interface IMetadataIndex

See Also:

IMetadataIndex.getScaleOutIndexMetadata()

getScaleOutIndexMetadata

public final IndexMetadata getScaleOutIndexMetadata()

Description copied from interface: IMetadataIndex

The metadata template for the scale-out index managed by this metadata index.

Specified by:

getScaleOutIndexMetadata in interface IMetadataIndex

get

public PartitionLocator get(byte[] key)

Description copied from interface: IMetadataIndex

The partition with that separator key or null (exact match on the separator key).

Specified by:

get in interface IMetadataIndex

Parameters:

key - The separator key (the first key that would go into that partition).

Returns:

The partition with that separator key or null.

find

public PartitionLocator find(byte[] key)

Description copied from interface: IMetadataIndex

Find and return the partition spanning the given key.

Specified by:

find in interface IMetadataIndex

Parameters:

key - A key (optional). When null the locator for the last index partition will be returned.

Returns:

The partition spanning the given key or null if there are no partitions defined.

rangeCount

public long rangeCount()

Description copied from interface: IRangeQuery

Return the #of tuples in the index.

Note: If the index supports deletion markers then the range count will be an upper bound and may double count tuples which have been overwritten, including the special case where the overwrite is a delete.

Specified by:

rangeCount in interface IRangeQuery

Returns:

The #of tuples in the index.

See Also:

ISimpleIndexAccess.rangeCount()

rangeCount

public long rangeCount(byte[] fromKey,
              byte[] toKey)

Description copied from interface: IRangeQuery

Return the #of tuples in a half-open key range. The fromKey and toKey need not exist in the B+Tree.

Note: If the index supports deletion markers then the range count will be an upper bound and may double count tuples which have been overwritten, including the special case where the overwrite is a delete.

Specified by:

rangeCount in interface IRangeQuery

Parameters:

fromKey - The lowest key that will be counted (inclusive). When null there is no lower bound.

toKey - The first key that will not be counted (exclusive). When null there is no upper bound.

Returns:

The #of tuples in the half-open key range.

rangeCountExact

public long rangeCountExact(byte[] fromKey,
                   byte[] toKey)

Description copied from interface: IRangeQuery

Return the exact #of tuples in a half-open key range. The fromKey and toKey need not exist in the B+Tree.

Note: If the index supports deletion markers then this operation will require a key-range scan.

Specified by:

rangeCountExact in interface IRangeQuery

Parameters:

fromKey - The lowest key that will be counted (inclusive). When null there is no lower bound.

toKey - The first key that will not be counted (exclusive). When null there is no upper bound.

Returns:

The exact #of tuples in the half-open key range.

rangeCountExactWithDeleted

public long rangeCountExactWithDeleted(byte[] fromKey,
                              byte[] toKey)

Description copied from interface: IRangeQuery

Return the exact #of tuples in a half-open key range, including any deleted tuples. The fromKey and toKey need not exist in the B+Tree.

When the view is just an AbstractBTree the result is the same as for IRangeQuery.rangeCount(byte[], byte[]), which already reports all tuples regardless of whether or not they are deleted.

When the index is a view with multiple sources, this operation requires a key-range scan where both deleted and undeleted tuples are visited.

Specified by:

rangeCountExactWithDeleted in interface IRangeQuery

Parameters:

fromKey - The lowest key that will be counted (inclusive). When null there is no lower bound.

toKey - The first key that will not be counted (exclusive). When null there is no upper bound.

Returns:

The exact #of deleted and undeleted tuples in the half-open key range.

See Also:

IRangeQuery.rangeCountExact(byte[], byte[])

rangeIterator

public ITupleIterator rangeIterator()

Description copied from interface: IRangeQuery

Visits all tuples in key order. This is identical to

 rangeIterator(null, null)
 

Specified by:

rangeIterator in interface IRangeQuery

Returns:

An iterator that will visit all entries in key order.

rangeIterator

public ITupleIterator rangeIterator(byte[] fromKey,
                           byte[] toKey,
                           int capacity,
                           int flags,
                           IFilter filter)

Description copied from interface: IRangeQuery

Designated variant (the one that gets overridden) for an iterator that visits the entries in a half-open key range. When toKey EQ fromKey nothing will be visited. It is an error if toKey LT fromKey.

Specified by:

rangeIterator in interface IRangeQuery

Parameters:

fromKey - The first key that will be visited (inclusive lower bound). When null there is no lower bound.

toKey - The first key that will NOT be visited (exclusive upper bound). When null there is no upper bound.

capacity - The #of entries to buffer at a time. This is a hint and MAY be zero (0) to use an implementation specific default capacity. A non-zero value may be used if you know that you want at most N results or if you want to override the default #of results to be buffered before sending them across a network interface. (Note that you can control the default value using IBigdataClient.Options#DEFAULT_CLIENT_RANGE_QUERY_CAPACITY).

flags - A bitwise OR of IRangeQuery.KEYS, IRangeQuery.VALS, etc.

filter - An optional object used to construct a stacked iterator. When IRangeQuery.CURSOR is specified in flags, the base iterator will implement ITupleCursor and the first filter in the stack can safely cast the source iterator to an ITupleCursor. If the outermost filter in the stack does not implement ITupleIterator, then it will be wrapped an ITupleIterator.

See Also:

SuccessorUtil, which may be used to compute the successor of a value before encoding it as a component of a key., BytesUtil#successor(byte[]), which may be used to compute the successor of an encoded key., IFilterConstructor, which may be used to construct an iterator stack performing filtering or other operations.

rangeIterator

public ITupleIterator rangeIterator(byte[] fromKey,
                           byte[] toKey)

Description copied from interface: IRangeQuery

Return an iterator that visits the entries in a half-open key range. When toKey EQ fromKey nothing will be visited. It is an error if toKey LT fromKey.

Specified by:

rangeIterator in interface IRangeQuery

Parameters:

fromKey - The first key that will be visited (inclusive lower bound). When null there is no lower bound.

toKey - The first key that will NOT be visited (exclusive upper bound). When null there is no upper bound.

See Also:

SuccessorUtil, which may be used to compute the successor of a value before encoding it as a component of a key., BytesUtil#successor(byte[]), which may be used to compute the successor of an encoded key., EntryFilter, which may be used to filter the entries visited by the iterator.