com.orientechnologies.orient.core.index

Class OIndexAbstractDelegate<T>

java.lang.Object

com.orientechnologies.orient.core.index.OIndexAbstractDelegate<T>

All Implemented Interfaces:

OIndex<T>, Comparable<OIndex<T>>

Direct Known Subclasses:

OIndexTxAware

public class OIndexAbstractDelegate<T>
extends Object
implements OIndex<T>

Generic abstract wrapper for indexes. It delegates all the operations to the wrapped OIndex instance.

Author:

Luca Garulli (l.garulli--(at)--orientdb.com)

Field Summary

Fields

Modifier and Type	Field and Description
protected OIndex<T>	delegate

Fields inherited from interface com.orientechnologies.orient.core.index.OIndex

MERGE_KEYS

Constructor Summary

Constructors

Constructor and Description
OIndexAbstractDelegate(OIndex<T> iDelegate)

Method Summary

Modifier and Type	Method and Description
protected void	checkForKeyType(Object iKey)
OIndex<T>	clear() Clears the index removing all the entries in one shot.
int	compareTo(OIndex<T> o)
boolean	contains(Object iKey) Tells if a key is contained in the index.
long	count(Object iKey) Counts the entries for the key.
OIndex<T>	create(String name, OIndexDefinition indexDefinition, String clusterIndexName, Set<String> clustersToIndex, boolean rebuild, OProgressListener progressListener) Creates the index.
OIndexCursor	cursor()
OIndex<T>	delete() Delete the index.
OIndexCursor	descCursor()
boolean	equals(Object o)
void	flush() Flushes in-memory changes to disk.
T	get(Object iKey) Gets the set of records associated with the passed key.
String	getAlgorithm() Returns the engine of the index as string.
Set<String>	getClusters() Returns Names of clusters that will be indexed.
ODocument	getConfiguration() Returns the index configuration.
String	getDatabaseName()
OIndexDefinition	getDefinition()
Object	getFirstKey()
int	getIndexId()
OIndexInternal<T>	getInternal() Returns the internal index used.
long	getKeySize()
OType[]	getKeyTypes() Types of the keys that index can accept, if index contains composite key, list of types of elements from which this index consist will be returned, otherwise single element (key type obviously) will be returned.
Object	getLastKey()
ODocument	getMetadata()
String	getName() Returns the index name.
long	getRebuildVersion() Returns amount of times when index was rebuilt since storage was opened.
long	getSize()
String	getType() Returns the type of the index as string.
int	getVersion() Returns binary format version for this index.
int	hashCode()
boolean	isAutomatic() Tells if the index is automatic.
boolean	isRebuilding()
boolean	isUnique()
OIndexCursor	iterateEntries(Collection<?> keys, boolean ascSortOrder) Returns cursor which presents data associated with passed in keys.
OIndexCursor	iterateEntriesBetween(Object fromKey, boolean fromInclusive, Object toKey, boolean toInclusive, boolean ascOrder) Returns cursor which presents subset of index data between passed in keys.
OIndexCursor	iterateEntriesMajor(Object fromKey, boolean fromInclusive, boolean ascOrder) Returns cursor which presents subset of data which associated with key which is greater than passed in key.
OIndexCursor	iterateEntriesMinor(Object toKey, boolean toInclusive, boolean ascOrder) Returns cursor which presents subset of data which associated with key which is less than passed in key.
OIndexKeyCursor	keyCursor()
OIndex<T>	put(Object iKey, OIdentifiable iValue) Inserts a new entry in the index.
long	rebuild() Rebuilds an automatic index.
long	rebuild(OProgressListener iProgressListener) Populate the index with all the existent records.
boolean	remove(Object key) Removes an entry by its key.
boolean	remove(Object iKey, OIdentifiable iRID) Removes an entry by its key and value.
boolean	supportsOrderedIterations()
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

delegate

protected OIndex<T> delegate

Constructor Detail

OIndexAbstractDelegate

public OIndexAbstractDelegate(OIndex<T> iDelegate)

Method Detail

getInternal

public OIndexInternal<T> getInternal()

Description copied from interface: OIndex

Returns the internal index used.

Specified by:

getInternal in interface OIndex<T>

create

public OIndex<T> create(String name,
                        OIndexDefinition indexDefinition,
                        String clusterIndexName,
                        Set<String> clustersToIndex,
                        boolean rebuild,
                        OProgressListener progressListener)

Description copied from interface: OIndex

Creates the index.

Specified by:

create in interface OIndex<T>

clusterIndexName - Cluster name where to place the TreeMap

get

public T get(Object iKey)

Description copied from interface: OIndex

Gets the set of records associated with the passed key.

Specified by:

get in interface OIndex<T>

Parameters:

iKey - The key to search

Returns:

The Record set if found, otherwise an empty Set

contains

public boolean contains(Object iKey)

Description copied from interface: OIndex

Tells if a key is contained in the index.

Specified by:

contains in interface OIndex<T>

Parameters:

iKey - The key to search

Returns:

True if the key is contained, otherwise false

put

public OIndex<T> put(Object iKey,
                     OIdentifiable iValue)

Description copied from interface: OIndex

Inserts a new entry in the index. The behaviour depends by the index implementation.

Specified by:

put in interface OIndex<T>

Parameters:

iKey - Entry's key

iValue - Entry's value as OIdentifiable instance

Returns:

The index instance itself to allow in chain calls

getRebuildVersion

public long getRebuildVersion()

Description copied from interface: OIndex

Returns amount of times when index was rebuilt since storage was opened.

It is used to support so called "live index rebuild" feature.

Value of this version is increased every time when index is going to be rebuild. So if two sequential calls of this method return different numbers it means that index at least started to rebuild itself.

If you use indexes to increase speed of fetching data from database you should follow following workflow:

1. Read index rebuild version.
2. Check index rebuild flag OIndex.isRebuilding(), if it is true, do not use index and fetch data directly from database clusters.
3. Fetch data from index.
4. Read index rebuild version again, if it is not equal to version which was read at first time, go to step 2. It is VERY important do not reorder steps 1 and 2. Such recording may lead to situation when index is rebuilding but we miss this state.

This approach works well ONLY if you do not use methods which return OIndexCursor instance. In case of you work with cursors index rebuild may cause data inconsistency issues in both:

1. Code which calls index methods to create cursor (can be avoided using steps are listed above)
2. During iteration over the cursor itself

To detect last data inconsistency issue please use cursor wrapper OIndexChangesWrapper which throws OIndexIsRebuildingException in case of index rebuild.

Both of these approaches are used in implementation of support of "live index rebuild" for SELECT SQL queries.

1. In case of index which we are going to use to speed up SELECT query is rebuilding we skip this index.
2. If index is rebuilding at the moment when we iterate over the cursor we catch OIndexIsRebuildingException exception and retry whole query again.

Specified by:

getRebuildVersion in interface OIndex<T>

Returns:

amount of times when index was rebuilt since the start of the storage.

See Also:

OAbstractPaginatedStorage.command(com.orientechnologies.orient.core.command.OCommandRequestText), OIndexChangesWrapper, OIndexIsRebuildingException, ORetryQueryException

getVersion

public int getVersion()

Description copied from interface: OIndex

Returns binary format version for this index. Index format changes during system development but old formats are supported for binary compatibility. This method may be used to detect version of binary format which is used by current index and upgrade index to new one.

Specified by:

getVersion in interface OIndex<T>

Returns:

Returns binary format version for this index if possible, otherwise -1.

remove

public boolean remove(Object key)

Description copied from interface: OIndex

Removes an entry by its key.

Specified by:

remove in interface OIndex<T>

Parameters:

key - The entry's key to remove

Returns:

True if the entry has been found and removed, otherwise false

remove

public boolean remove(Object iKey,
                      OIdentifiable iRID)

Description copied from interface: OIndex

Removes an entry by its key and value.

Specified by:

remove in interface OIndex<T>

Parameters:

iKey - The entry's key to remove

Returns:

True if the entry has been found and removed, otherwise false

clear

public OIndex<T> clear()

Description copied from interface: OIndex

Clears the index removing all the entries in one shot.

Specified by:

clear in interface OIndex<T>

Returns:

The index instance itself to allow in chain calls

checkForKeyType

protected void checkForKeyType(Object iKey)

iterateEntriesBetween

public OIndexCursor iterateEntriesBetween(Object fromKey,
                                          boolean fromInclusive,
                                          Object toKey,
                                          boolean toInclusive,
                                          boolean ascOrder)

Description copied from interface: OIndex

Returns cursor which presents subset of index data between passed in keys.

Specified by:

iterateEntriesBetween in interface OIndex<T>

Parameters:

fromKey - Lower border of index data.

fromInclusive - Indicates whether lower border should be inclusive or exclusive.

toKey - Upper border of index data.

toInclusive - Indicates whether upper border should be inclusive or exclusive.

ascOrder - Flag which determines whether data iterated by cursor should be in ascending or descending order.

Returns:

Cursor which presents subset of index data between passed in keys.

iterateEntriesMajor

public OIndexCursor iterateEntriesMajor(Object fromKey,
                                        boolean fromInclusive,
                                        boolean ascOrder)

Description copied from interface: OIndex

Returns cursor which presents subset of data which associated with key which is greater than passed in key.

Specified by:

iterateEntriesMajor in interface OIndex<T>

Parameters:

fromKey - Lower border of index data.

fromInclusive - Indicates whether lower border should be inclusive or exclusive.

ascOrder - Flag which determines whether data iterated by cursor should be in ascending or descending order.

Returns:

cursor which presents subset of data which associated with key which is greater than passed in key.

iterateEntriesMinor

public OIndexCursor iterateEntriesMinor(Object toKey,
                                        boolean toInclusive,
                                        boolean ascOrder)

Description copied from interface: OIndex

Returns cursor which presents subset of data which associated with key which is less than passed in key.

Specified by:

iterateEntriesMinor in interface OIndex<T>

Parameters:

toKey - Upper border of index data.

toInclusive - Indicates Indicates whether upper border should be inclusive or exclusive.

ascOrder - Flag which determines whether data iterated by cursor should be in ascending or descending order.

Returns:

cursor which presents subset of data which associated with key which is less than passed in key.

getSize

public long getSize()

Specified by:

getSize in interface OIndex<T>

Returns:

number of entries in the index.

count

public long count(Object iKey)

Description copied from interface: OIndex

Counts the entries for the key.

Specified by:

count in interface OIndex<T>

flush

public void flush()

Description copied from interface: OIndex

Flushes in-memory changes to disk.

Specified by:

flush in interface OIndex<T>

delete

public OIndex<T> delete()

Description copied from interface: OIndex

Delete the index.

Specified by:

delete in interface OIndex<T>

Returns:

The index instance itself to allow in chain calls

getName

public String getName()

Description copied from interface: OIndex

Returns the index name.

Specified by:

getName in interface OIndex<T>

Returns:

The name of the index

getType

public String getType()

Description copied from interface: OIndex

Returns the type of the index as string.

Specified by:

getType in interface OIndex<T>

getAlgorithm

public String getAlgorithm()

Description copied from interface: OIndex

Returns the engine of the index as string.

Specified by:

getAlgorithm in interface OIndex<T>

isAutomatic

public boolean isAutomatic()

Description copied from interface: OIndex

Tells if the index is automatic. Automatic means it's maintained automatically by OrientDB. This is the case of indexes created against schema properties. Automatic indexes can always been rebuilt.

Specified by:

isAutomatic in interface OIndex<T>

Returns:

True if the index is automatic, otherwise false

isUnique

public boolean isUnique()

Specified by:

isUnique in interface OIndex<T>

getConfiguration

public ODocument getConfiguration()

Description copied from interface: OIndex

Returns the index configuration.

Specified by:

getConfiguration in interface OIndex<T>

Returns:

An ODocument object containing all the index properties

getMetadata

public ODocument getMetadata()

Specified by:

getMetadata in interface OIndex<T>

rebuild

public long rebuild()

Description copied from interface: OIndex

Rebuilds an automatic index.

Specified by:

rebuild in interface OIndex<T>

Returns:

The number of entries rebuilt

See Also:

OIndex.getRebuildVersion()

rebuild

public long rebuild(OProgressListener iProgressListener)

Description copied from interface: OIndex

Populate the index with all the existent records.

Specified by:

rebuild in interface OIndex<T>

See Also:

OIndex.getRebuildVersion()

getKeyTypes

public OType[] getKeyTypes()

Description copied from interface: OIndex

Types of the keys that index can accept, if index contains composite key, list of types of elements from which this index consist will be returned, otherwise single element (key type obviously) will be returned.

Specified by:

getKeyTypes in interface OIndex<T>

getDefinition

public OIndexDefinition getDefinition()

Specified by:

getDefinition in interface OIndex<T>

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

iterateEntries

public OIndexCursor iterateEntries(Collection<?> keys,
                                   boolean ascSortOrder)

Description copied from interface: OIndex

Returns cursor which presents data associated with passed in keys.

Specified by:

iterateEntries in interface OIndex<T>

Parameters:

keys - Keys data of which should be returned.

ascSortOrder - Flag which determines whether data iterated by cursor should be in ascending or descending order.

Returns:

cursor which presents data associated with passed in keys.

getClusters

public Set<String> getClusters()

Description copied from interface: OIndex

Returns Names of clusters that will be indexed.

Specified by:

getClusters in interface OIndex<T>

Returns:

Names of clusters that will be indexed.

toString

public String toString()

Overrides:

toString in class Object

getKeySize

public long getKeySize()

Specified by:

getKeySize in interface OIndex<T>

Returns:

Number of keys in index

getDatabaseName

public String getDatabaseName()

Specified by:

getDatabaseName in interface OIndex<T>

supportsOrderedIterations

public boolean supportsOrderedIterations()

Specified by:

supportsOrderedIterations in interface OIndex<T>

isRebuilding

public boolean isRebuilding()

Specified by:

isRebuilding in interface OIndex<T>

Returns:

Indicates whether index is rebuilding at the moment.

See Also:

OIndex.getRebuildVersion()

getFirstKey

public Object getFirstKey()

Specified by:

getFirstKey in interface OIndex<T>

getLastKey

public Object getLastKey()

Specified by:

getLastKey in interface OIndex<T>

getIndexId

public int getIndexId()

Specified by:

getIndexId in interface OIndex<T>

cursor

public OIndexCursor cursor()

Specified by:

cursor in interface OIndex<T>

descCursor

public OIndexCursor descCursor()

Specified by:

descCursor in interface OIndex<T>

keyCursor

public OIndexKeyCursor keyCursor()

Specified by:

keyCursor in interface OIndex<T>

compareTo

public int compareTo(OIndex<T> o)

Specified by:

compareTo in interface Comparable<OIndex<T>>