Package org.aksw.commons.index.core

Interface StorageNode<D,C,V>

Type Parameters:

D -

C -

V -

All Known Subinterfaces:

StorageNodeMutable<D,C,V>

All Known Implementing Classes:

StorageNodeAlt2, StorageNodeAlt3, StorageNodeAltBase, StorageNodeAltN, StorageNodeBase, StorageNodeCompoundBase, StorageNodeDictionary, StorageNodeDomainWrapping, StorageNodeForwarding, StorageNodeInnerMap, StorageNodeLeafComponentSet, StorageNodeLeafDomainList, StorageNodeLeafDomainSet, StorageNodeLeafMap, StorageNodeMutableForwarding, StorageNodeMutableForwardingBase, StorageNodeWrapperCodec

public interface StorageNode<D,C,V>

A StorageNode can express nested storage such as nested maps, lists and sets for tuples. A Storage may have alternative child structures to choose from. All alternatives are assumed to be in sync and contain the same instance data - but the nesting may differ. This class only provides methods for reading data. The base interface that allows for addition and removal of data is StorageNodeMutable

Author:

Claus Stadler 11/09/2020

Method Summary

Modifier and Type	Method	Description
Object	chooseSubStore(V store, int subStoreIdx)
default Object	chooseSubStoreRaw(Object store, int subStoreIdx)
List<? extends StorageNode<D,C,?>>	getChildren()	Each node in the storage expression may have 0 or more children
C	getKeyComponentRaw(Object key, int idx)	Obtain components from the internal representation of key that was used for indexing w.r.t.
int[]	getKeyTupleIdxs()	The component indexes by which this node indexes May be empty but never null
default StorageNode<D,C,V>	getPublicDelegate()
default List<?>	getStoreAsList(Object store)
default Map<?,?>	getStoreAsMap(Object store)
default Set<?>	getStoreAsSet(Object store)
org.aksw.commons.tuple.TupleAccessor<D,C>	getTupleAccessor()	Future: Allow the storageNode to answer how efficiently it can answer the constraints in a given constraint list E.g.
default boolean	holdsDomainTuples()	Flag that when true indicates that this storage node's values are tuples of type D - i.e.
default boolean	isAltNode()	Whether this storage node stores are a sequences of alternatives Experimental method; may be replaced by a generic getStoreType() method that returns e.g Alt.class, Set.class, etc.
default boolean	isDelegate()	Attempt to access a store as a map.
default boolean	isListNode()	Whether this storage node stores are lists Experimental method; may be replaced by a generic getStoreType() method that returns e.g Alt.class, Set.class, etc.
default boolean	isMapNode()	Whether this storage node stores are a maps Experimental method; may be replaced by a generic getStoreType() method that returns e.g Alt.class, Set.class, etc.
default boolean	isSetNode()	Whether this storage node stores are sets Experimental method; may be replaced by a generic getStoreType() method that returns e.g Alt.class, Set.class, etc.
default java.util.stream.Stream<?>	streamEntries(V store)
<T> java.util.stream.Stream<?>	streamEntries(V store, T tupleLike, org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> tupleAccessor)	Stream all entries under equality constraints obtained from a tuple-like pattern
default java.util.stream.Stream<?>	streamEntriesRaw(Object store)	Generic method to stream the content - mainly for debugging
default <T> java.util.stream.Stream<?>	streamEntriesRaw(Object store, T tupleLike, org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> tupleAccessor)
<T> Streamer<V,? extends Map.Entry<?,?>>	streamerForKeyAndSubStoreAlts(T pattern, org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)	The streamer returns entry that hold a tuple-like key and conceptually alternatives of sub-stores The tuple components of the key can be accessed using getKeyComponentRaw(Object, int) There are as many components as the length of getKeyTupleIdxs() If there is 0 components then any invocation of getKeyComponentRaw(Object, int) will fail with a UnsupportedOperationException.
<T> Streamer<V,?>	streamerForKeys(T pattern, org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)
<T> Streamer<V,C>	streamerForKeysAsComponent(T pattern, org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)	Compiles from a given pattern a function that can stream the matching keys from the appropriate store.
<T> Streamer<V,List<C>>	streamerForKeysAsTuples(T pattern, org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)	Compiles from a given pattern a function that can stream the matching keys from the appropriate store.
<T> Streamer<V,?>	streamerForValues(T pattern, org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)	Returns an object that can extract the stream of values at an index node under constraints map: { entry.value | entry in map and entry.key matches condition} leafSet: set.entries.stream() A leaf set does not have any keys that could affect the result stream

Method Detail

getChildren

List<? extends StorageNode<D,C,?>> getChildren()

Each node in the storage expression may have 0 or more children

Returns:

isDelegate

default boolean isDelegate()

Attempt to access a store as a map. The StorageNode and the store must be of the appropriate types in order for this operation to succeed.

Parameters:

store -

Returns:

getPublicDelegate

default StorageNode<D,C,V> getPublicDelegate()

isAltNode

default boolean isAltNode()

Whether this storage node stores are a sequences of alternatives Experimental method; may be replaced by a generic getStoreType() method that returns e.g Alt.class, Set.class, etc.

Returns:

isSetNode

default boolean isSetNode()

Whether this storage node stores are sets Experimental method; may be replaced by a generic getStoreType() method that returns e.g Alt.class, Set.class, etc.

Returns:

isListNode

default boolean isListNode()

Whether this storage node stores are lists Experimental method; may be replaced by a generic getStoreType() method that returns e.g Alt.class, Set.class, etc.

Returns:

isMapNode

default boolean isMapNode()

Whether this storage node stores are a maps Experimental method; may be replaced by a generic getStoreType() method that returns e.g Alt.class, Set.class, etc.

Returns:

holdsDomainTuples

default boolean holdsDomainTuples()

Flag that when true indicates that this storage node's values are tuples of type D - i.e. "domain tuples".

Returns:

getStoreAsMap

default Map<?,?> getStoreAsMap(Object store)

getStoreAsList

default List<?> getStoreAsList(Object store)

getStoreAsSet

default Set<?> getStoreAsSet(Object store)

getKeyTupleIdxs

int[] getKeyTupleIdxs()

The component indexes by which this node indexes May be empty but never null

Returns:

getTupleAccessor

org.aksw.commons.tuple.TupleAccessor<D,C> getTupleAccessor()

Future: Allow the storageNode to answer how efficiently it can answer the constraints in a given constraint list E.g. O(1) or O(log(n)) or O(n)

Returns:

streamerForKeysAsComponent

<T> Streamer<V,C> streamerForKeysAsComponent(T pattern,
                                                   org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)

Compiles from a given pattern a function that can stream the matching keys from the appropriate store. The keys must be instances of the component type otherwise an exception is raised

Returns:

streamerForKeysAsTuples

<T> Streamer<V,List<C>> streamerForKeysAsTuples(T pattern,
                                                      org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)

Compiles from a given pattern a function that can stream the matching keys from the appropriate store. The keys must be instances of the component type otherwise an exception is raised if getKeyTupleIdxs().length == 0 then returns a single tuple that projects no components

Parameters:

store -

Returns:

streamerForKeys

<T> Streamer<V,?> streamerForKeys(T pattern,
                                        org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)

getKeyComponentRaw

C getKeyComponentRaw(Object key,
                     int idx)

Obtain components from the internal representation of key that was used for indexing w.r.t. getKeyTupleIdxs().

Parameters:

key -

idx - In the range 0 to {@link getKeyTupleIdxs().length} (exclusive) If a key has no components calling this method will always raise IndexOutOfBoundsException

Returns:

chooseSubStore

Object chooseSubStore(V store,
                      int subStoreIdx)

chooseSubStoreRaw

default Object chooseSubStoreRaw(Object store,
                                 int subStoreIdx)

streamerForValues

<T> Streamer<V,?> streamerForValues(T pattern,
                                          org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)

Returns an object that can extract the stream of values at an index node under constraints map: { entry.value | entry in map and entry.key matches condition} leafSet: set.entries.stream() A leaf set does not have any keys that could affect the result stream

Type Parameters:

T -

Parameters:

pattern -

accessor -

Returns:

streamerForKeyAndSubStoreAlts

<T> Streamer<V,? extends Map.Entry<?,?>> streamerForKeyAndSubStoreAlts(T pattern,
                                                                                   org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> accessor)

The streamer returns entry that hold a tuple-like key and conceptually alternatives of sub-stores The tuple components of the key can be accessed using getKeyComponentRaw(Object, int) There are as many components as the length of getKeyTupleIdxs() If there is 0 components then any invocation of getKeyComponentRaw(Object, int) will fail with a UnsupportedOperationException. To extract a specific alternative from the substore use chooseSubStore(Object, int). If getChildren() is not empty then there are as many substore indices as there are children If there are no children then there is an implicit single sub store with index 0

Type Parameters:

T -

Parameters:

pattern -

accessor -

Returns:

streamEntries

<T> java.util.stream.Stream<?> streamEntries(V store,
                                             T tupleLike,
                                             org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> tupleAccessor)

Stream all entries under equality constraints obtained from a tuple-like pattern

Type Parameters:

T -

Parameters:

store -

tupleLike -

tupleAccessor -

Returns:

streamEntriesRaw

default <T> java.util.stream.Stream<?> streamEntriesRaw(Object store,
                                                        T tupleLike,
                                                        org.aksw.commons.tuple.TupleAccessorCore<? super T,? extends C> tupleAccessor)

streamEntriesRaw

default java.util.stream.Stream<?> streamEntriesRaw(Object store)

Generic method to stream the content - mainly for debugging

Returns:

streamEntries

default java.util.stream.Stream<?> streamEntries(V store)