nifi-extension-bundles/nifi-hazelcast-bundle/nifi-hazelcast-services/src/main/java/org/apache/nifi/hazelcast/services/cachemanager/ExternalHazelcastCacheManager.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.nifi.hazelcast.services.cachemanager;

import com.hazelcast.core.HazelcastInstance;
import org.apache.nifi.annotation.documentation.CapabilityDescription;
import org.apache.nifi.annotation.documentation.Tags;
import org.apache.nifi.components.PropertyDescriptor;
import org.apache.nifi.components.ValidationContext;
import org.apache.nifi.components.ValidationResult;
import org.apache.nifi.controller.ConfigurationContext;
import org.apache.nifi.expression.ExpressionLanguageScope;
import org.apache.nifi.processor.util.StandardValidators;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.TimeUnit;

@Tags({"hazelcast", "cache"})
@CapabilityDescription("A service that provides cache instances backed by Hazelcast running outside of NiFi.")
public class ExternalHazelcastCacheManager extends IMapBasedHazelcastCacheManager {

    public static final PropertyDescriptor HAZELCAST_SERVER_ADDRESS = new PropertyDescriptor.Builder()
            .name("hazelcast-server-address")
            .displayName("Hazelcast Server Address")
            .description("Addresses of one or more the Hazelcast instances, using {host:port} format, separated by comma.")
            .required(true)
            .addValidator(StandardValidators.HOSTNAME_PORT_LIST_VALIDATOR)
            .expressionLanguageSupported(ExpressionLanguageScope.ENVIRONMENT)
            .build();

    public static final PropertyDescriptor HAZELCAST_RETRY_BACKOFF_INITIAL = new PropertyDescriptor.Builder()
            .name("hazelcast-retry-backoff-initial")
            .displayName("Hazelcast Initial Backoff")
            .description("The amount of time the client waits before it tries to reestablish connection for the first time.")
            .addValidator(StandardValidators.TIME_PERIOD_VALIDATOR)
            .required(true)
            .defaultValue(DEFAULT_CLIENT_BACKOFF_INITIAL_IN_SEC + " secs")
            .build();

    public static final PropertyDescriptor HAZELCAST_RETRY_BACKOFF_MAXIMUM = new PropertyDescriptor.Builder()
            .name("hazelcast-retry-backoff-maximum")
            .displayName("Hazelcast Maximum Backoff")
            .description("The maximum amount of time the client waits before it tries to reestablish connection.")
            .addValidator(StandardValidators.TIME_PERIOD_VALIDATOR)
            .required(true)
            .defaultValue(DEFAULT_CLIENT_BACKOFF_MAXIMUM_IN_SEC + " secs")
            .build();

    public static final PropertyDescriptor HAZELCAST_RETRY_BACKOFF_MULTIPLIER = new PropertyDescriptor.Builder()
            .name("hazelcast-retry-backoff-multiplier")
            .displayName("Hazelcast Backoff Multiplier")
            .description("A multiplier by which the wait time is increased before each attempt to reestablish connection.")
            .addValidator(StandardValidators.NUMBER_VALIDATOR)
            .required(true)
            .defaultValue(String.valueOf(DEFAULT_CLIENT_BACKOFF_MULTIPLIER))
            .build();

    public static final PropertyDescriptor HAZELCAST_CONNECTION_TIMEOUT = new PropertyDescriptor.Builder()
            .name("hazelcast-connection-timeout")
            .displayName("Hazelcast Connection Timeout")
            .description("The maximum amount of time the client tries to connect or reconnect before giving up.")
            .addValidator(StandardValidators.TIME_PERIOD_VALIDATOR)
            .required(true)
            .defaultValue(DEFAULT_CLIENT_TIMEOUT_MAXIMUM_IN_SEC + " secs")
            .build();

    private static final List<PropertyDescriptor> PROPERTY_DESCRIPTORS;

    static {
        final List<PropertyDescriptor> properties = new ArrayList<>();
        properties.add(HAZELCAST_CLUSTER_NAME);
        properties.add(HAZELCAST_SERVER_ADDRESS);
        properties.add(HAZELCAST_RETRY_BACKOFF_INITIAL);
        properties.add(HAZELCAST_RETRY_BACKOFF_MAXIMUM);
        properties.add(HAZELCAST_RETRY_BACKOFF_MULTIPLIER);
        properties.add(HAZELCAST_CONNECTION_TIMEOUT);
        PROPERTY_DESCRIPTORS = Collections.unmodifiableList(properties);
    }

    @Override
    protected HazelcastInstance getInstance(final ConfigurationContext context) {
        return getClientInstance(
                context.getProperty(HAZELCAST_CLUSTER_NAME).evaluateAttributeExpressions().getValue(),
                Arrays.asList(context.getProperty(HAZELCAST_SERVER_ADDRESS).evaluateAttributeExpressions().getValue().split(ADDRESS_SEPARATOR)),
                context.getProperty(HAZELCAST_CONNECTION_TIMEOUT).asTimePeriod(TimeUnit.MILLISECONDS).longValue(),
                context.getProperty(HAZELCAST_RETRY_BACKOFF_INITIAL).asTimePeriod(TimeUnit.MILLISECONDS).intValue(),
                context.getProperty(HAZELCAST_RETRY_BACKOFF_MAXIMUM).asTimePeriod(TimeUnit.MILLISECONDS).intValue(),
                context.getProperty(HAZELCAST_RETRY_BACKOFF_MULTIPLIER).asDouble());
    }

    @Override
    protected List<PropertyDescriptor> getSupportedPropertyDescriptors() {
        return PROPERTY_DESCRIPTORS;
    }

    @Override
    protected Collection<ValidationResult> customValidate(final ValidationContext context) {
        final Set<ValidationResult> results = new HashSet<>();

        if (context.getProperty(HAZELCAST_RETRY_BACKOFF_INITIAL).asTimePeriod(TimeUnit.MILLISECONDS).compareTo((long) Integer.MAX_VALUE) > 0) {
            results.add(new ValidationResult.Builder()
                    .subject(HAZELCAST_RETRY_BACKOFF_INITIAL.getDisplayName())
                    .valid(false)
                    .explanation("millisecond representation of initial backoff time must not be above " + Integer.MAX_VALUE + "!")
                    .build());
        }

        if (context.getProperty(HAZELCAST_RETRY_BACKOFF_MAXIMUM).asTimePeriod(TimeUnit.MILLISECONDS).compareTo((long) Integer.MAX_VALUE) > 0) {
            results.add(new ValidationResult.Builder()
                    .subject(HAZELCAST_RETRY_BACKOFF_MAXIMUM.getDisplayName())
                    .valid(false)
                    .explanation("millisecond representation of maximum backoff time must not be above " + Integer.MAX_VALUE + "!")
                    .build());
        }

        return results;
    }
}