MapStorage.java
/*
* Copyright 2020 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.keycloak.models.map.storage;
import org.keycloak.models.map.common.AbstractEntity;
import java.util.stream.Stream;
/**
* A storage for entities that is based on a map and operates in the context of transaction
* managed by current {@code KeycloakSession}. Implementations of its methods should respect
* transactional boundaries of that transaction.
*/
public interface MapStorage<V extends AbstractEntity, M> {
/**
* Instructs this storage to add a new value into the underlying store on commit in the context of the current transaction.
* <p>
* Updates to the returned instances of {@code V} would be visible in the current transaction
* and will propagate into the underlying store upon commit.
*
* The ID of the entity passed in the parameter might change to a different value in the returned value
* if the underlying storage decided this was necessary.
* If the ID of the entity was null before, it will be set on the returned value.
*
* @param value the value
* @return Entity representing the {@code value} in the store. It may or may not be the same instance as {@code value}.
*/
V create(V value);
/**
* Provides possibility to lookup for values by a {@code key} in the underlying store with respect to changes done
* in current transaction. Updates to the returned instance would be visible in the current transaction
* and will propagate into the underlying store upon commit.
*
* If {@code V} implements {@link org.keycloak.models.map.common.ExpirableEntity} this method should not return
* entities that are expired. See {@link org.keycloak.models.map.common.ExpirableEntity} JavaDoc for more details.
*
* @param key identifier of a value
* @return a value associated with the given {@code key}
*/
V read(String key);
/**
* Returns a stream of values from underlying storage that are updated based on the current transaction changes;
* i.e. the result contains updates and excludes of records that have been created, updated or deleted in this
* transaction by respective methods of this interface.
* <p>
* Updates to the returned instances of {@code V} would be visible in the current transaction
* and will propagate into the underlying store upon commit.
*
* If {@code V} implements {@link org.keycloak.models.map.common.ExpirableEntity} this method should not return
* entities that are expired. See {@link org.keycloak.models.map.common.ExpirableEntity} JavaDoc for more details.
*
* @param queryParameters parameters for the query like firstResult, maxResult, requested ordering, etc.
* @return values that fulfill the given criteria, that are updated based on changes in the current transaction
*/
Stream<V> read(QueryParameters<M> queryParameters);
/**
* Returns a number of values present in the underlying storage that fulfill the given criteria with respect to
* changes done in the current transaction.
*
* @param queryParameters parameters for the query like firstResult, maxResult, requested ordering, etc.
* @return number of values present in the storage that fulfill the given criteria
*/
long getCount(QueryParameters<M> queryParameters);
/**
* Instructs this storage to delete a value associated with the identifier {@code key} from the underlying store
* upon commit.
*
* @return Returns {@code true} if the object has been deleted or result cannot be determined, {@code false} otherwise.
* @param key identifier of a value
*/
boolean delete(String key);
/**
* Instructs this transaction to remove values (identified by {@code mcb} filter) from the underlying store upon commit.
*
* @param queryParameters parameters for the query like firstResult, maxResult, requested ordering, etc.
* @return number of removed objects (might return {@code -1} if not supported)
*/
long delete(QueryParameters<M> queryParameters);
/**
* Returns {@code true} if the object with the given {@code key} exists in the underlying storage with respect to changes done
* in the current transaction. {@code false} otherwise.
*
* @param key Key of the object. Must not be {@code null}.
* @return See description
* @throws NullPointerException if the {@code key} is {@code null}
*/
default boolean exists(String key) {
return read(key) != null;
}
/**
* Returns {@code true} if at least one object is satisfying given {@code criteria} from the underlying storage with respect to changes done
* in the current transaction. {@code false} otherwise.
* The criteria are specified in the given criteria builder based on model properties.
*
* @param queryParameters parameters for the query
* @return See description
*/
default boolean exists(QueryParameters<M> queryParameters) {
return getCount(queryParameters) > 0;
}
}