com.jparams.store.Store Maven / Gradle / Ivy
package com.jparams.store;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Optional;
import java.util.UUID;
import com.jparams.store.index.Index;
import com.jparams.store.index.IndexDefinition;
import com.jparams.store.index.IndexException;
import com.jparams.store.index.KeyMapper;
import com.jparams.store.index.reducer.Reducer;
import com.jparams.store.query.Query;
/**
* Store of data
*
* @param value type
*/
public interface Store extends Collection
{
/**
* Create an index using the index build provided
*
* @param indexName name of the index
* @param indexDefinition build of the index
* @param indexed key type
* @return index
* @throws IndexException thrown if the creation of the new index fails with exceptions.
*/
Index index(String indexName, IndexDefinition indexDefinition) throws IndexException;
/**
* Create an index using the index build provided
*
* @param indexDefinition build of the index
* @param indexed key type
* @return index
* @throws IndexException thrown if the creation of the new index fails with exceptions.
*/
default Index index(final IndexDefinition indexDefinition) throws IndexException
{
return index(UUID.randomUUID().toString(), indexDefinition);
}
/**
* Register a new index with this store, mapping a single value to a collection of indexed keys.
* This is a convenient of creating an index, for more options see {@link #index(IndexDefinition)}
*
* @param indexName name of the index
* @param keyMapper function to provide a value to one or more keys
* @param key type
* @return index
* @throws IndexException thrown if the new index failed with exceptions.
*/
default Index index(final String indexName, final KeyMapper keyMapper) throws IndexException
{
return index(indexName, IndexDefinition.withKeyMapping(keyMapper));
}
/**
* Register a new index with this store, mapping a single value to a collection of indexed keys.
* This is a convenient of creating an index, for more options see {@link #index(IndexDefinition)}
*
* @param indexName name of the index
* @param keyMapper function to provide a value to one or more keys
* @param reducer function to reduce indexed values
* @param key type
* @return index
* @throws IndexException thrown if the new index failed with exceptions.
*/
default Index index(final String indexName, final KeyMapper keyMapper, final Reducer reducer) throws IndexException
{
return index(indexName, IndexDefinition.withKeyMapping(keyMapper).withReducer(reducer));
}
/**
* Register a new index with this store, mapping a single value to a collection of indexed keys.
* This is a convenient of creating an index, for more options see {@link #index(IndexDefinition)}
*
* @param keyMapper function to provide a value to one or more keys
* @param reducer function to reduce indexed values
* @param key type
* @return index
* @throws IndexException thrown if the new index failed with exceptions.
*/
default Index index(final KeyMapper keyMapper, final Reducer reducer) throws IndexException
{
return index(IndexDefinition.withKeyMapping(keyMapper).withReducer(reducer));
}
/**
* Register a new index with this store, mapping a single value to a collection of indexed keys.
* This is a convenient of creating an index, for more options see {@link #index(IndexDefinition)}
*
* @param keyMapper function to provide a value to one or more keys
* @param key type
* @return index
* @throws IndexException thrown if the new index failed with exceptions.
*/
default Index index(final KeyMapper keyMapper) throws IndexException
{
return index(IndexDefinition.withKeyMapping(keyMapper));
}
/**
* Query an index by name and lookup the given key. This method is the equivalent of calling {@link #getIndex(String)}
* and then {@link Index#get(Object)}
*
* @param indexName name of the index to query
* @param key key to lookup
* @param limit limit results to the first x number of items
* @return values associated with this key or an empty list
*/
default List get(final String indexName, final Object key, final Integer limit)
{
return get(Query.where(indexName, key), limit);
}
/**
* Query an index by name and lookup the given key. This method is the equivalent of calling {@link #getIndex(String)}
* and then {@link Index#get(Object)}
*
* @param indexName name of the index to query
* @param key key to lookup
* @return values associated with this key or an empty list
*/
default List get(final String indexName, final Object key)
{
return get(Query.where(indexName, key), null);
}
/**
* Query an index by name and lookup the given key. This method is the equivalent of calling {@link #getIndex(String)}
* and then {@link Index#getFirst(Object)}
*
* @param indexName name of the index to query
* @param key key to lookup
* @return first value associated with this key or null
*/
default V getFirst(final String indexName, final Object key)
{
return getFirst(Query.where(indexName, key));
}
/**
* Query an index by name and lookup the given key. This method is the equivalent of calling {@link #getIndex(String)}
* and then {@link Index#findFirst(Object)}
*
* @param indexName name of the index to query
* @param key key to lookup
* @return first value associated with this key or an empty optional
*/
default Optional findFirst(final String indexName, final Object key)
{
return Optional.ofNullable(getFirst(indexName, key));
}
/**
* Query indexes and look up all matching value.
*
* @param query query to execute
* @param limit limit results to the first x number of items
* @return values associated with this key or an empty list
*/
List get(final Query query, Integer limit);
/**
* Query indexes and look up all matching value.
*
* @param query query to execute
* @return values associated with this key or an empty list
*/
default List get(final Query query)
{
return get(query, null);
}
/**
* Query indexes and look up the first matching value.
*
* @param query query to execute
* @return first value matching the query
*/
default V getFirst(final Query query)
{
final List results = get(query, 1);
return results.isEmpty() ? null : results.get(0);
}
/**
* Query indexes and look up the first matching value.
*
* @param query query to execute
* @return first value matching the query
*/
default Optional findFirst(final Query query)
{
return Optional.ofNullable(getFirst(query));
}
/**
* Find index with name. This is the same as {@link Store#findIndex(String)}, but returns a null instead of an optional if an index cannot be found.
*
* @param indexName name of index to lookup
* @return index
*/
Index getIndex(String indexName);
/**
* Get all indexes
*
* @return indexes
*/
Collection> getIndexes();
/**
* Remove all indexes associated with this store
*/
default void removeAllIndexes()
{
new ArrayList<>(getIndexes()).forEach(this::removeIndex);
}
/**
* Find index with name. This is the same as {@link Store#getIndex(String)}, but returns an optional instead of a null if an index cannot be found.
*
* @param indexName name of index to lookup
* @return index optional
*/
default Optional> findIndex(final String indexName)
{
return Optional.ofNullable(getIndex(indexName));
}
/**
* Remove an index from store
*
* @param indexName index to remove
* @return true if removed successfully
*/
boolean removeIndex(String indexName);
/**
* Remove an index from store
*
* @param index index to remove
* @return true if removed successfully
*/
boolean removeIndex(Index index);
/**
* Clear the existing indexes and reindex the entire store. This can be a slow operation
* depending on the number of items in the store and total number of indexes.
*
* @throws IndexException thrown if one or more indexes failed with exceptions.
*/
void reindex() throws IndexException;
/**
* Reindex a collection of items. This method will need to be called anytime a change
* is made to items stored within the store that causes its indexes to become out
* of date.
*
* @param items items to reindex
* @throws IndexException thrown if one or more indexes failed with exceptions.
*/
void reindex(Collection items) throws IndexException;
/**
* Reindex a particular item. This method will need to be called anytime a change
* is made to an item stored within the store that causes its indexes to become out
* of date.
*
* @param item item to reindex
* @throws IndexException thrown if one or more indexes failed with exceptions.
*/
void reindex(final V item) throws IndexException;
/**
* Adds an item to the store and indexes it. If the item already exists in the store,
* it will be reindexed.
*
* @param item item to on
* @return true if item did not previously exist in the store.
* @throws IndexException thrown if one or more indexes failed with exceptions.
*/
@Override
boolean add(V item) throws IndexException;
/**
* Adds all item to the store and indexes them. If an item already exists in the store,
* it will be reindexed.
*
* @param items items to on
* @return true if one or more items did not previously exist in the store.
* @throws IndexException thrown if one or more indexes failed with exceptions.
*/
@Override
boolean addAll(Collection items) throws IndexException;
/**
* Adds all item to the store and indexes them. If an item already exists in the store,
* it will be re-indexed.
*
* @param items items to on
* @return true if one or more items did not previously exist in the store.
* @throws IndexException thrown if one or more indexes failed with exceptions.
*/
default boolean addAll(final V[] items) throws IndexException
{
return addAll(Arrays.asList(items));
}
/**
* Create a copy of this store. This can be an expensive operation depending
* on the number of items and indexes present. The copied store will be fully
* independent from this store. Any changes made to the copy will not reflect back
* onto this store.
*
* @return copy
*/
Store copy();
/**
* Returns an unmodifiable view of this store. This method allows
* modules to provide users with "read-only" access to internal
* collections. Query operations on the returned store "read through"
* the backed store, and attempts to modify the returned
* store, whether direct or via its iterator, result in an
* UnsupportedOperationException.
*
* @return an unmodifiable view of this store.
*/
default Store unmodifiableStore()
{
return new UnmodifiableStore<>(this);
}
/**
* Returns a synchronized (thread-safe) map Store backed by this store.
* In order to guarantee serial access, it is critical that
* all access to the backing store is accomplished
* through the returned store. Any references held to {@link Index}es
* should be discarded. Call {@link Store#getIndex(String)} on the synchronized
* store to obtain synchronized indexes.
*
* It is imperative that the user manually synchronize on the returned
* Store when iterating over it:
*
* Store store = oldStore.synchronizedStore();
* ...
* synchronized (store) {
* Iterator i = store.iterator(); // Must be in synchronized block
* while (i.hasNext())
* foo(i.next());
* }
*
* Failure to follow this advice may result in non-deterministic behavior.
*
* @return synchronized store
*/
default Store synchronizedStore()
{
return new SynchronizedStore<>(this);
}
}
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