com.datastax.oss.driver.api.core.metadata.Metadata Maven / Gradle / Ivy
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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 com.datastax.oss.driver.api.core.metadata;
import com.datastax.oss.driver.api.core.CqlIdentifier;
import com.datastax.oss.driver.api.core.config.DefaultDriverOption;
import com.datastax.oss.driver.api.core.metadata.schema.KeyspaceMetadata;
import com.datastax.oss.driver.api.core.session.Session;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.net.InetSocketAddress;
import java.util.Map;
import java.util.Optional;
import java.util.UUID;
/**
* The metadata of the Cassandra cluster that this driver instance is connected to.
*
* Updates to this object are guaranteed to be atomic: the node list, schema, and token metadata
* are immutable, and will always be consistent for a given metadata instance. The node instances
* are the only mutable objects in the hierarchy, and some of their fields will be modified
* dynamically (in particular the node state).
*
* @see Session#getMetadata()
*/
public interface Metadata {
/**
* The nodes known to the driver, indexed by their unique identifier ({@code host_id} in {@code
* system.local}/{@code system.peers}). This might include nodes that are currently viewed as
* down, or ignored by the load balancing policy.
*/
@NonNull
Map getNodes();
/**
* Finds the node with the given {@linkplain Node#getEndPoint() connection information}, if it
* exists.
*
* Note that this method performs a linear search of {@link #getNodes()}.
*/
@NonNull
default Optional findNode(@NonNull EndPoint endPoint) {
for (Node node : getNodes().values()) {
if (node.getEndPoint().equals(endPoint)) {
return Optional.of(node);
}
}
return Optional.empty();
}
/**
* Finds the node with the given untranslated {@linkplain Node#getBroadcastRpcAddress()
* broadcast RPC address}, if it exists.
*
* Note that this method performs a linear search of {@link #getNodes()}.
*/
@NonNull
default Optional findNode(@NonNull InetSocketAddress broadcastRpcAddress) {
for (Node node : getNodes().values()) {
Optional o = node.getBroadcastRpcAddress();
if (o.isPresent() && o.get().equals(broadcastRpcAddress)) {
return Optional.of(node);
}
}
return Optional.empty();
}
/**
* The keyspaces defined in this cluster.
*
* Note that schema metadata can be disabled or restricted to a subset of keyspaces, therefore
* this map might be empty or incomplete.
*
* @see DefaultDriverOption#METADATA_SCHEMA_ENABLED
* @see Session#setSchemaMetadataEnabled(Boolean)
* @see DefaultDriverOption#METADATA_SCHEMA_REFRESHED_KEYSPACES
*/
@NonNull
Map getKeyspaces();
@NonNull
default Optional getKeyspace(@NonNull CqlIdentifier keyspaceId) {
return Optional.ofNullable(getKeyspaces().get(keyspaceId));
}
/**
* Shortcut for {@link #getKeyspace(CqlIdentifier)
* getKeyspace(CqlIdentifier.fromCql(keyspaceName))}.
*/
@NonNull
default Optional getKeyspace(@NonNull String keyspaceName) {
return getKeyspace(CqlIdentifier.fromCql(keyspaceName));
}
/**
* The token map for this cluster.
*
* Note that this property might be absent if token metadata was disabled, or if there was a
* runtime error while computing the map (this would generate a warning log).
*
* @see DefaultDriverOption#METADATA_TOKEN_MAP_ENABLED
*/
@NonNull
Optional getTokenMap();
/**
* The cluster name to which this session is connected. The Optional returned should contain the
* value from the server for system.local.cluster_name.
*
* Note that this method has a default implementation for backwards compatibility. It is
* expected that any implementing classes override this method.
*/
@NonNull
default Optional getClusterName() {
return Optional.empty();
}
}