com.hammurapi.store

Class AbstractStore<T,PK,S extends Store<T,PK,S>>

java.lang.Object

com.hammurapi.store.AbstractStore<T,PK,S>

Type Parameters:

T -

S - Self-type - sub-type of store. Generic parameter for predicates, extractors, update tasks and views. S should be an interface for master store, deputy store and views to implement.

All Implemented Interfaces:

Store<T,PK,S>, Iterable<T>, ReadWriteLock

Direct Known Subclasses:

DeputyStore, LocalStoreBase

public abstract class AbstractStore<T,PK,S extends Store<T,PK,S>>
extends Object
implements Store<T,PK,S>

Abstract base class for object stores.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	AbstractStore.ExtractorTask<V>
protected class	AbstractStore.IndexizationTask<V>
protected class	AbstractStore.QueryCallable<V>
protected class	AbstractStore.QueryItemCallable<V>
protected class	AbstractStore.QueryMultipleCallable<V>
protected class	AbstractStore.RemoveTask
protected class	AbstractStore.SelectorTask
protected class	AbstractStore.UpdateCallable
protected class	AbstractStore.ValueSelectorTask<V>

Nested classes/interfaces inherited from interface com.hammurapi.store.Store

Store.Handle<T,PK,S extends Store<T,PK,S>>, Store.QueryTask<T,PK,S extends Store<?,PK,S>>, Store.StoreIterator<T>, Store.UpdateTask<T,PK,S extends Store<T,PK,S>>, Store.ViewType

Constructor Summary

Constructors

Constructor and Description
AbstractStore()

Method Summary

Methods

Modifier and Type	Method and Description
<V,ST extends T> Index<T,ST,PK,V,S>	addIndex(Predicate<T,S> predicate, Extractor<ST,V,S> extractor, Index.Type type, boolean ordered, Comparator<V> comparator) Adds index to the store to speed-up extraction operations.
void	clear() Removes all entries from the store.
protected abstract Map<S,Map<Extractor<T,? super PK,S>,? super PK>>	createCache()
protected abstract S	createDeputy() Creates a store which encapsulates current call state (e.g.
protected abstract Store.Handle<T,PK,S>	createHandle(T obj, PK primaryKey, Map<S,Map<Extractor<T,? super PK,S>,? super PK>> cache, Predicate<T,S>[] validators) Creates handle.
protected Store.Handle<T,PK,S>	createHandle(T obj, Predicate<T,S>[] validators)
protected abstract <V,ST extends T> AbstractIndex<T,ST,PK,V,S>	createIndex(Predicate<T,S> predicate, Extractor<ST,V,S> extractor, Index.Type type, boolean ordered, Comparator<V> comparator)
protected abstract Collection<Store.Handle<T,PK,S>>	createIndexCollection(boolean unique, boolean ordered, Comparator<T> comparator) Creates collection for index entries
protected abstract S	createLiveView(Predicate<T,S> selector)
protected abstract ReadWriteLock	createMasterLock()
S	createView(Predicate<T,S> selector, Store.ViewType viewType) Creates a view - a store which sees only objects matching the given selector.
Iterable<T>	get(Predicate<T,S> selector) Retrieves objects matching the predicate.
<V> Iterable<V>	get(Predicate<T,S> selector, Extractor<T,V,S> extractor, boolean ordered, Comparator<V> comparator) Retrieves values from objects matching the predicate.
Iterable<T>	getAll() Retrieves all objects from the store.
T	getByPrimaryKey(PK primaryKey) Retrieves object with given primary key.
protected abstract ExecutorService	getExecutorService()
protected Iterable<Store.Handle<T,PK,S>>	getHandles(Predicate<T,S> selector)
protected abstract Collection<AbstractIndex<T,? extends T,PK,?,S>>	getIndices()
<V> Iterable<V>	getMultiple(Predicate<T,S> selector, Extractor<T,Iterable<V>,S> extractor, Predicate<V,S> valueSelector, boolean ordered, Comparator<V> comparator) Retrieves values from objects matching the predicate.
protected abstract Collection<Store.Handle<T,PK,S>>	getNoPkStore() Store for the mode without primary key or pkStore values collection.
protected abstract Map<PK,Store.Handle<T,PK,S>>	getPkStore()
Iterator<T>	iterator()
protected abstract void	onRemoved(int removed) Invoked when some handles have been removed.
Store.Handle<T,PK,S>	put(T obj, Predicate<T,S>... validators) Puts object to the store.
<V> int	query(Predicate<T,S> selector, Extractor<T,V,S> extractor, Store.QueryTask<V,PK,S> query) Processes values extracted from objects matching the predicate.
int	query(Predicate<T,S> selector, Store.QueryTask<T,PK,S> query) Processes objects matching the predicate.
int	queryAll(Store.QueryTask<T,PK,S> query) Processes all objects in the store.
<V> int	queryMultiple(Predicate<T,S> selector, Extractor<T,Iterable<V>,S> extractor, Predicate<V,S> valueSelector, Store.QueryTask<V,PK,S> query) Processes multiple values extracted from objects matching the predicate.
int	remove(Predicate<T,S> selector) Removes objects matching the predicate.
boolean	remove(T obj) Removes specified object from the store.
boolean	removeByPrimaryKey(PK primaryKey) Removes object by primary key.
int	update(Predicate<T,S> selector, Store.UpdateTask<T,PK,S> updater) Updates objects matching the predicate.
protected void	updateIndices(Store.Handle<T,PK,S> handle, boolean isNew) This method is invoked by handle implementations.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.hammurapi.store.Store

createUnmodifiableFacade, getPrimaryKeyExtractor

Methods inherited from interface java.util.concurrent.locks.ReadWriteLock

readLock, writeLock

Constructor Detail

AbstractStore

public AbstractStore()

Method Detail

getPkStore

protected abstract Map<PK,Store.Handle<T,PK,S>> getPkStore()

Returns:

Store for the mode with primary key.

getNoPkStore

protected abstract Collection<Store.Handle<T,PK,S>> getNoPkStore()

Store for the mode without primary key or pkStore values collection.

getExecutorService

protected abstract ExecutorService getExecutorService()

Returns:

Executor service to parallel processing.

createHandle

protected abstract Store.Handle<T,PK,S> createHandle(T obj,
                                PK primaryKey,
                                Map<S,Map<Extractor<T,? super PK,S>,? super PK>> cache,
                                Predicate<T,S>[] validators)

Creates handle.

createIndexCollection

protected abstract Collection<Store.Handle<T,PK,S>> createIndexCollection(boolean unique,
                                                     boolean ordered,
                                                     Comparator<T> comparator)

Creates collection for index entries

Parameters:

unique - Collection should be unique (set)

ordered - Collection should be ordered by the comparator or by natural order.

comparator -

Returns:

createHandle

protected Store.Handle<T,PK,S> createHandle(T obj,
                                Predicate<T,S>[] validators)

createCache

protected abstract Map<S,Map<Extractor<T,? super PK,S>,? super PK>> createCache()

Returns:

Cache for extractors.

createDeputy

protected abstract S createDeputy()

Creates a store which encapsulates current call state (e.g. locks currently held) and can be passed to executor for asynchronous execution. Delegates operate on behalf of the master store. They don't acquire locks if the master store already holds them. If the master store holds read lock then attempt of a deputy to acquire write lock will result in StoreException.

Returns:

createMasterLock

protected abstract ReadWriteLock createMasterLock()

onRemoved

protected abstract void onRemoved(int removed)

Invoked when some handles have been removed. This operation shall remove invalidated handles from store and index collections. This method is invoked outside of the write lock.

Parameters:

removed - Number of removed handles.

put

public Store.Handle<T,PK,S> put(T obj,
                       Predicate<T,S>... validators)

Description copied from interface: Store

Puts object to the store. If object is already present in the store, it gets updated in the store.

Specified by:

put in interface Store<T,PK,S extends Store<T,PK,S>>

Parameters:

obj - Object to put to the store.

validators - Predicate(s) which are checked when object is retrieved from the store. If there is more than one predicate, predicates are connected with AND. If validator(s) evaluate to false, the object handle is considered invalid, i.e. object is considered removed from the store. Once validator(s) evaluate to false, they shall always evaluate to false. One of use of validators can be to expire object in the store, i.e. after some time validator returns false and object is cleared from the database. If validators evaluate to false at put time, object is not put to the store and put() returns null. Validators evaluation result is not cached.

Returns:

Object handle or null if validator(s) evaluate to false.

getAll

public Iterable<T> getAll()

Description copied from interface: Store

Retrieves all objects from the store.

Specified by:

getAll in interface Store<T,PK,S extends Store<T,PK,S>>

Returns:

getByPrimaryKey

public T getByPrimaryKey(PK primaryKey)

Description copied from interface: Store

Retrieves object with given primary key.

Specified by:

getByPrimaryKey in interface Store<T,PK,S extends Store<T,PK,S>>

Returns:

get

public Iterable<T> get(Predicate<T,S> selector)

Description copied from interface: Store

Retrieves objects matching the predicate.

Specified by:

get in interface Store<T,PK,S extends Store<T,PK,S>>

Returns:

getHandles

protected Iterable<Store.Handle<T,PK,S>> getHandles(Predicate<T,S> selector)

Parameters:

selector -

Returns:

get

public <V> Iterable<V> get(Predicate<T,S> selector,
                  Extractor<T,V,S> extractor,
                  boolean ordered,
                  Comparator<V> comparator)

Description copied from interface: Store

Retrieves values from objects matching the predicate.

Specified by:

get in interface Store<T,PK,S extends Store<T,PK,S>>

Parameters:

selector - Object selector.

extractor - Value extractor. If null, then object itself is returned.

ordered - If true, then returned result is ordered by comparator or by natural order if comparator is null.

comparator - Comparator to use for ordering.

Returns:

getMultiple

public <V> Iterable<V> getMultiple(Predicate<T,S> selector,
                          Extractor<T,Iterable<V>,S> extractor,
                          Predicate<V,S> valueSelector,
                          boolean ordered,
                          Comparator<V> comparator)

Description copied from interface: Store

Retrieves values from objects matching the predicate. Multiple values are retrieved from each object.

Specified by:

getMultiple in interface Store<T,PK,S extends Store<T,PK,S>>

Parameters:

selector - Objects shall match this predicate. If null, all objects match.

extractor - Value extractor.

valueSelector - Values from matched objects shall match this predicate. If null, all values match. Value selectors are executed in separate tasks from extractor. Separation of value selection logic from value extraction logic makes sense if value selection logic is relatively heavy and parallelization of its execution will reduce overall query execution time.

ordered - If true, then returned result is ordered by comparator or by natural order if comparator is null.

comparator - Comparator to use for ordering.

Returns:

clear

public void clear()

Description copied from interface: Store

Removes all entries from the store.

Specified by:

clear in interface Store<T,PK,S extends Store<T,PK,S>>

remove

public boolean remove(T obj)

Description copied from interface: Store

Removes specified object from the store.

Specified by:

remove in interface Store<T,PK,S extends Store<T,PK,S>>

Parameters:

obj - Object to remove.

Returns:

true if object was removed.

removeByPrimaryKey

public boolean removeByPrimaryKey(PK primaryKey)

Description copied from interface: Store

Removes object by primary key.

Specified by:

removeByPrimaryKey in interface Store<T,PK,S extends Store<T,PK,S>>

Returns:

remove

public int remove(Predicate<T,S> selector)

Description copied from interface: Store

Removes objects matching the predicate.

Specified by:

remove in interface Store<T,PK,S extends Store<T,PK,S>>

Returns:

number of returned objects or -1 if number is unknown.

update

public int update(Predicate<T,S> selector,
         Store.UpdateTask<T,PK,S> updater)

Description copied from interface: Store

Updates objects matching the predicate.

Specified by:

update in interface Store<T,PK,S extends Store<T,PK,S>>

Returns:

getIndices

protected abstract Collection<AbstractIndex<T,? extends T,PK,?,S>> getIndices()

createIndex

protected abstract <V,ST extends T> AbstractIndex<T,ST,PK,V,S> createIndex(Predicate<T,S> predicate,
                                                      Extractor<ST,V,S> extractor,
                                                      Index.Type type,
                                                      boolean ordered,
                                                      Comparator<V> comparator)

addIndex

public <V,ST extends T> Index<T,ST,PK,V,S> addIndex(Predicate<T,S> predicate,
                                           Extractor<ST,V,S> extractor,
                                           Index.Type type,
                                           boolean ordered,
                                           Comparator<V> comparator)

Description copied from interface: Store

Adds index to the store to speed-up extraction operations.

Specified by:

addIndex in interface Store<T,PK,S extends Store<T,PK,S>>

Type Parameters:

V - Value type extracted by extractor for ordering.

ST - Type of index elements, which can be a sub-type of store element type. index creation parameters.

Parameters:

predicate - Only store items matching the predicate are indexed.

extractor - Extractor of the index key.

ordered - If true index is ordered.

comparator - Comparator to use for ordering. If null, then natural order is used.

Returns:

A "mix" of Index sub-interfaces corresponding to the

queryAll

public int queryAll(Store.QueryTask<T,PK,S> query)

Description copied from interface: Store

Processes all objects in the store.

Specified by:

queryAll in interface Store<T,PK,S extends Store<T,PK,S>>

Returns:

number of object queried.

query

public int query(Predicate<T,S> selector,
        Store.QueryTask<T,PK,S> query)

Description copied from interface: Store

Processes objects matching the predicate.

Specified by:

query in interface Store<T,PK,S extends Store<T,PK,S>>

Returns:

Number of objects queried.

query

public <V> int query(Predicate<T,S> selector,
            Extractor<T,V,S> extractor,
            Store.QueryTask<V,PK,S> query)

Description copied from interface: Store

Processes values extracted from objects matching the predicate.

Specified by:

query in interface Store<T,PK,S extends Store<T,PK,S>>

extractor - Extractor.

query - Processor of query results.

Returns:

Number of objects queried.

queryMultiple

public <V> int queryMultiple(Predicate<T,S> selector,
                    Extractor<T,Iterable<V>,S> extractor,
                    Predicate<V,S> valueSelector,
                    Store.QueryTask<V,PK,S> query)

Description copied from interface: Store

Processes multiple values extracted from objects matching the predicate.

Specified by:

queryMultiple in interface Store<T,PK,S extends Store<T,PK,S>>

Parameters:

selector - Objects shall match this predicate. If null, all objects match.

extractor - Extractor

valueSelector - Values from matched objects shall match this predicate. If null, all values match. Value selectors are executed in separate tasks from extractor. Separation of value selection logic from value extraction logic makes sense if value selection logic is relatively heavy and parallelization of its execution will reduce overall query execution time.

query - Processor of query results.

Returns:

Number of objects queried.

updateIndices

protected void updateIndices(Store.Handle<T,PK,S> handle,
                 boolean isNew)

This method is invoked by handle implementations. It shall not be invoked by client code.

Parameters:

handle -

isNew -

iterator

public Iterator<T> iterator()

Specified by:

iterator in interface Iterable<T>

createView

public S createView(Predicate<T,S> selector,
           Store.ViewType viewType)

Description copied from interface: Store

Creates a view - a store which sees only objects matching the given selector.

Specified by:

createView in interface Store<T,PK,S extends Store<T,PK,S>>

Parameters:

selector - View selector.

Returns:

Store which sees only objects matching give selector. The returned store is backed by the master store.

createLiveView

protected abstract S createLiveView(Predicate<T,S> selector)