org.apache.whirr.RolePredicates.java Source code

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Here is the source code for org.apache.whirr.RolePredicates.java

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/**
 * 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.whirr;

import java.util.Collections;
import java.util.Set;

import org.apache.whirr.Cluster.Instance;
import org.jclouds.javax.annotation.Nullable;

import com.google.common.base.Predicate;
import com.google.common.collect.Sets;

/**
 * {@link Predicate}s for matching {@link Instance}s with certain cluster roles.
 */
public class RolePredicates {

    /**
     * @param role
     * @return A {@link Predicate} that matches {@link Instance}s whose roles
     * include <code>role</code>.
     */
    public static Predicate<Instance> role(final String role) {
        return allRolesIn(Collections.singleton(role));
    }

    /**
     * @param roles
     * @return A {@link Predicate} that matches {@link Instance}s whose roles
     * are exactly the same as those in <code>roles</code>.
     */
    public static Predicate<Instance> onlyRolesIn(final Set<String> roles) {
        return new Predicate<Instance>() {
            @Override
            public boolean apply(Instance instance) {
                return instance.getRoles().equals(roles);
            }
        };
    }

    /**
     * @param roles
     * @return A {@link Predicate} that matches {@link Instance}s whose roles
     * contain all of <code>roles</code>.
     */
    public static Predicate<Instance> allRolesIn(final Set<String> roles) {
        return new Predicate<Instance>() {
            @Override
            public boolean apply(Instance instance) {
                return instance.getRoles().containsAll(roles);
            }
        };
    }

    /**
     * @param roles
     * @return A {@link Predicate} that matches {@link Instance}s whose roles
     * contain at least one of <code>roles</code>.
     */
    public static Predicate<Instance> anyRoleIn(final Set<String> roles) {
        return new Predicate<Instance>() {
            @Override
            public boolean apply(Instance instance) {
                Set<String> copy = Sets.newLinkedHashSet(instance.getRoles());
                copy.retainAll(roles);
                return !copy.isEmpty();
            }
        };
    }

    /**
     *
     * @param ids list of instance ids
     * @return  A {@link Predicate} that matches {@link Instance} whose id is
     * found in the IDs list
     */
    public static Predicate<Instance> withIds(String... ids) {
        return withIds(Sets.<String>newHashSet(ids));
    }

    /**
     *
     * @param ids list of instance ids
     * @return  A {@link Predicate} that matches {@link Instance} whose id is
     * found in the IDs list
     */
    public static Predicate<Instance> withIds(final Set<String> ids) {
        return new Predicate<Instance>() {
            @Override
            public boolean apply(@Nullable Instance input) {
                return (input != null) ? ids.contains(input.getId()) : false;
            }
        };
    }

}