content: /*
  * 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.ambari.server.state;
  
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.ambari.server.AmbariException;
  
  /**
   * Single entity that tracks all clusters and hosts that are managed
   * by the Ambari server
   */
  public interface Clusters {
  
    /**
     * Add a new Cluster
     * @param clusterName
     *          the cluster name (not {@code null}).
     * @param stackId
     *          the stack for the cluster (not {@code null}).
     */
    void addCluster(String clusterName, StackId stackId)
        throws AmbariException;
  
    /**
     * Add a new cluster
     * @param clusterName
     *          the cluster name (not {@code null}).
     * @param stackId
     *          the stack for the cluster (not {@code null}).
     * @param securityType
     *          the cluster will be created with this security type.
     * @throws AmbariException
     */
    void addCluster(String clusterName, StackId stackId, SecurityType securityType)
      throws AmbariException;
  
    /**
     * Gets the Cluster given the cluster name
     * @param clusterName Name of the Cluster to retrieve
     * @return  <code>Cluster</code> identified by the given name
     */
    Cluster getCluster(String clusterName)
        throws AmbariException;
  
    /**
     * Gets the Cluster given the cluster id
     * @param clusterId Id of the Cluster to retrieve
     * @return  <code>Cluster</code> identified by the given id
     */
    Cluster getCluster(Long clusterId)
      throws AmbariException;
  
    /**
     * Get all clusters
     * @return <code>Map</code> of clusters with cluster name as key
     */
    Map<String, Cluster> getClusters();
  
    /**
     * Get all hosts being tracked by the Ambari server
     * @return <code>List</code> of <code>Host</code>
     */
    List<Host> getHosts();
  
    /**
     * Returns all the cluster names for this hostname
     * @param hostname
     * @return List of cluster names
     * @throws AmbariException
     */
    Set<Cluster> getClustersForHost(String hostname)
        throws AmbariException;
  
  
    /**
     * Get a Host object managed by this server
     * @param hostname Name of the host requested
     * @return Host object
     * @throws AmbariException
     */
    Host getHost(String hostname) throws AmbariException;
  
    /**
     * Check if host exists
     * @param hostname Name of the host requested
     * @return is host exists
     */
    boolean hostExists(String hostname);
  
    /**
     * Gets whether the specified cluster has a mapping for the specified host.
     *
     * @param clusterId the cluster ID
     * @param hostName
     *          the host (not {@code null}).
     * @return {@code true} if the host belongs to the cluster, {@code false}
     *         otherwise.
     */
    boolean isHostMappedToCluster(long clusterId, String hostName);
  
    /**
     * Get a Host object managed by this server
     * @param hostId Host Id from the {@link org.apache.ambari.server.orm.entities.HostEntity} objecty
     * @return Host object
     * @throws AmbariException
     */
    Host getHostById(Long hostId) throws AmbariException;
  
    /**
     * Updates the internal mappings of hosts using the specified host.
     *
     * @param host
     *          the host to update the internal mappings for.
     */
    void updateHostMappings(Host host);
  
    /**
     * Add a Host object to be managed by this server
     * @param hostname Host to be added
     * @throws AmbariException
     */
    void addHost(String hostname) throws AmbariException;
  
    /**
     * Map host to the given cluster.
     * A host can belong to multiple clusters
     * @param hostname
     * @param clusterName
     * @throws AmbariException
     */
    void mapHostToCluster(String hostname, String clusterName)
        throws AmbariException;
  
    /**
     * Maps a set of hosts to the given cluster
     * @param hostnames
     * @param clusterName
     * @throws AmbariException
     */
    void mapAndPublishHostsToCluster(Set<String> hostnames, String clusterName)
        throws AmbariException;
  
    /**
     * Updates the name of the cluster
     * @param oldName
     * @param newName
     * @throws AmbariException
     */
    void updateClusterName(String oldName, String newName);
  
    /**
     * Gets the cluster using the id.
     * @param id The identifier associated with the cluster
     * @return <code>Cluster</code> identified by the identifier
     * @throws AmbariException
     */
    Cluster getClusterById(long id) throws AmbariException;
  
    /**
     * Produces a debug dump into the supplied string buffer
     * @param sb The string buffer to add the debug dump to
     */
    void debugDump(StringBuilder sb);
  
    /**
     * Gets all the hosts associated with the cluster
     * @param clusterName The name of the cluster
     * @return <code>Map</code> containing host name and <code>Host</code>
     */
    Map<String, Host> getHostsForCluster(String clusterName);
  
    /**
     * Gets all the host Ids associated with the cluster
     * @param clusterName The name of the cluster
     * @return <code>Map</code> containing host id and <code>Host</code>
     * @throws AmbariException
     */
    Map<Long, Host> getHostIdsForCluster(String clusterName)
        throws AmbariException;
  
    /**
     * Deletes the cluster identified by the name
     * @param clusterName The name of the cluster
     * @throws AmbariException
     */
    void deleteCluster(String clusterName)
        throws AmbariException;
  
    /**
     * Update the host set for clusters and the host attributes associated with the hosts
     * @param hostsClusters
     * @param hostAttributes
     * @throws AmbariException
     */
    void updateHostWithClusterAndAttributes(
        Map<String, Set<String>> hostsClusters, Map<String, Map<String, String>> hostAttributes)
        throws AmbariException;
  
    /**
     * Removes a host from a cluster.  Inverts {@link #mapHostToCluster(String, String)
     * @param hostname
     * @param clusterName
     */
    void unmapHostFromCluster(String hostname, String clusterName)
        throws AmbariException;
  
    /**
     * Removes a host.  Inverts {@link #addHost(String)}
     * @param hostname
     */
    void deleteHost(String hostname) throws AmbariException;
  
    /**
     * Publish event set of hosts were removed
     */
    void publishHostsDeletion(Set<Long> hostIds, Set<String> hostNames)
        throws AmbariException;
  
    /**
     * Determine whether or not access to the cluster resource identified
     * by the given cluster name should be allowed based on the permissions
     * granted to the current user.
     *
     * @param clusterName  the cluster name
     * @param readOnly     indicate whether or not this check is for a read only operation
     *
     * @return true if access to the cluster is allowed
     */
    boolean checkPermission(String clusterName, boolean readOnly);
  
    /**
     * Add the given map of attributes to the session for the cluster identified by the given name.
     *
     * @param name        the cluster name
     * @param attributes  the session attributes
     */
    void addSessionAttributes(String name, Map<String, Object> attributes);
  
    /**
     * Get the map of session attributes for the cluster identified by the given name.
     *
     * @param name  the cluster name
     *
     * @return the map of session attributes for the cluster; never null
     */
    Map<String, Object> getSessionAttributes(String name);
  
    /**
     * Returns the number of hosts that form the cluster identified by the given name.
     * @param clusterName the name that identifies the cluster
     * @return  number of hosts that form the cluster
     */
    int getClusterSize(String clusterName);
  
    /**
     * Invalidates the specified cluster by retrieving it from the database and
     * refreshing all of the internal stateful collections.
     *
     * @param cluster
     *          the cluster to invalidate and refresh (not {@code null}).
     */
    void invalidate(Cluster cluster);
  
    /**
     * Invalidates all clusters by retrieving each from the database and refreshing all of its internal
     * stateful collections.
     */
    void invalidateAllClusters();
  }
  