org.springframework.data.redis.connection.lettuce.LettuceConnectionProvider.java Source code

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Here is the source code for org.springframework.data.redis.connection.lettuce.LettuceConnectionProvider.java

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/*
 * Copyright 2017-2019 the original author or authors.
 *
 * 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
 *
 *      https://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.springframework.data.redis.connection.lettuce;

import io.lettuce.core.RedisURI;
import io.lettuce.core.api.StatefulConnection;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionStage;

/**
 * Defines a provider for Lettuce connections.
 * <p />
 * This interface is typically used to encapsulate a native factory which returns a {@link StatefulConnection
 * connection} of on each invocation.
 * <p/>
 * Connection providers may create a new connection on each invocation or return pooled instances. Each obtained
 * connection must be released through its connection provider to allow disposal or release back to the pool.
 * <p/>
 * Connection providers are usually associated with a {@link io.lettuce.core.codec.RedisCodec} to create connections
 * with an appropriate codec.
 *
 * @author Mark Paluch
 * @author Christoph Strobl
 * @since 2.0
 * @see StatefulConnection
 */
@FunctionalInterface
public interface LettuceConnectionProvider {

    /**
     * Request a connection given {@code connectionType}. Providing a connection type allows specialization to provide a
     * more specific connection type.
     *
     * @param connectionType must not be {@literal null}.
     * @return the requested connection. Must be {@link #release(StatefulConnection) released} if the connection is no
     *         longer in use.
     */
    default <T extends StatefulConnection<?, ?>> T getConnection(Class<T> connectionType) {
        return LettuceFutureUtils.join(getConnectionAsync(connectionType));
    }

    /**
     * Request asynchronously a connection given {@code connectionType}. Providing a connection type allows specialization
     * to provide a more specific connection type.
     *
     * @param connectionType must not be {@literal null}.
     * @return a {@link CompletionStage} that is notified with the connection progress. Must be
     *         {@link #releaseAsync(StatefulConnection) released} if the connection is no longer in use.
     * @since 2.2
     */
    <T extends StatefulConnection<?, ?>> CompletionStage<T> getConnectionAsync(Class<T> connectionType);

    /**
     * Release the {@link StatefulConnection connection}. Closes connection {@link StatefulConnection#close()} by default.
     * Implementations may choose whether they override this method and return the connection to a pool.
     *
     * @param connection must not be {@literal null}.
     */
    default void release(StatefulConnection<?, ?> connection) {
        LettuceFutureUtils.join(releaseAsync(connection));
    }

    /**
     * Release asynchronously the {@link StatefulConnection connection}. Closes connection
     * {@link StatefulConnection#closeAsync()} by default. Implementations may choose whether they override this method
     * and return the connection to a pool.
     *
     * @param connection must not be {@literal null}.
     * @return Close {@link CompletableFuture future} notified once the connection is released.
     * @since 2.2
     */
    default CompletableFuture<Void> releaseAsync(StatefulConnection<?, ?> connection) {
        return connection.closeAsync();
    }

    /**
     * Extension to {@link LettuceConnectionProvider} for providers that allow connection creation to specific nodes.
     */
    @FunctionalInterface
    interface TargetAware {

        /**
         * Request a connection given {@code connectionType} for a specific {@link RedisURI}. Providing a connection type
         * allows specialization to provide a more specific connection type.
         *
         * @param connectionType must not be {@literal null}.
         * @param redisURI must not be {@literal null}.
         * @return the requested connection.
         */
        default <T extends StatefulConnection<?, ?>> T getConnection(Class<T> connectionType, RedisURI redisURI) {
            return LettuceFutureUtils.join(getConnectionAsync(connectionType, redisURI));
        }

        /**
         * Request asynchronously a connection given {@code connectionType} for a specific {@link RedisURI}. Providing a
         * connection type allows specialization to provide a more specific connection type.
         *
         * @param connectionType must not be {@literal null}.
         * @param redisURI must not be {@literal null}.
         * @return a {@link CompletionStage} that is notified with the connection progress.
         * @since 2.2
         */
        <T extends StatefulConnection<?, ?>> CompletionStage<T> getConnectionAsync(Class<T> connectionType,
                RedisURI redisURI);
    }
}