/*
* 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.provenance;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Provides a mechanism for obtaining the identifiers of components, queues, etc.
*/
public interface IdentifierLookup {
/**
* @return the identifiers of components that may generate Provenance Events
*/
List<String> getComponentIdentifiers();
/**
* @return a list of component types that may generate Provenance Events
*/
List<String> getComponentTypes();
/**
*
* @return the identifiers of FlowFile Queues that are in the flow
*/
List<String> getQueueIdentifiers();
default Map<String, Integer> invertQueueIdentifiers() {
return invertList(getQueueIdentifiers());
}
default Map<String, Integer> invertComponentTypes() {
return invertList(getComponentTypes());
}
default Map<String, Integer> invertComponentIdentifiers() {
return invertList(getComponentIdentifiers());
}
default Map<String, Integer> invertList(final List<String> values) {
final Map<String, Integer> inverted = new HashMap<>(values.size());
for (int i = 0; i < values.size(); i++) {
inverted.put(values.get(i), i);
}
return inverted;
}
public static final IdentifierLookup EMPTY = new IdentifierLookup() {
@Override
public List<String> getComponentIdentifiers() {
return Collections.emptyList();
}
@Override
public List<String> getComponentTypes() {
return Collections.emptyList();
}
@Override
public List<String> getQueueIdentifiers() {
return Collections.emptyList();
}
@Override
public Map<String, Integer> invertList(List<String> values) {
return Collections.emptyMap();
}
};
}