org.elasticsearch.cluster.metadata.ClusterNameExpressionResolver Maven / Gradle / Ivy
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Elasticsearch subproject :server
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.cluster.metadata;
import org.elasticsearch.common.regex.Regex;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
/**
* Resolves cluster names from an expression. The expression must be the exact match of a cluster
* name or must be a wildcard expression.
*/
public final class ClusterNameExpressionResolver {
private final WildcardExpressionResolver wildcardResolver = new WildcardExpressionResolver();
/**
* Resolves the provided cluster expression to matching cluster names. This method only
* supports exact or wildcard matches.
*
* @param remoteClusters the aliases for remote clusters
* @param clusterExpression the expressions that can be resolved to cluster names.
* @return the resolved cluster aliases.
*/
public List resolveClusterNames(Set remoteClusters, String clusterExpression) {
if (remoteClusters.contains(clusterExpression)) {
return Collections.singletonList(clusterExpression);
} else if (Regex.isSimpleMatchPattern(clusterExpression)) {
return wildcardResolver.resolve(remoteClusters, clusterExpression);
} else {
return Collections.emptyList();
}
}
private static class WildcardExpressionResolver {
private List resolve(Set remoteClusters, String clusterExpression) {
if (isTrivialWildcard(clusterExpression)) {
return resolveTrivialWildcard(remoteClusters);
}
Set matches = matches(remoteClusters, clusterExpression);
if (matches.isEmpty()) {
return Collections.emptyList();
} else {
return new ArrayList<>(matches);
}
}
private boolean isTrivialWildcard(String clusterExpression) {
return Regex.isMatchAllPattern(clusterExpression);
}
private List resolveTrivialWildcard(Set remoteClusters) {
return new ArrayList<>(remoteClusters);
}
private static Set matches(Set remoteClusters, String expression) {
return otherWildcard(remoteClusters, expression);
}
private static Set otherWildcard(Set remoteClusters, String expression) {
final String pattern = expression;
return remoteClusters.stream()
.filter(n -> Regex.simpleMatch(pattern, n))
.collect(Collectors.toSet());
}
}
}