com.datastax.oss.driver.internal.core.metadata.schema.queries.KeyspaceFilter Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.datastax.oss.driver.internal.core.metadata.schema.queries;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.List;
/**
* Filters keyspaces during schema metadata queries.
*
* Depending on the circumstances, we do it either on the server side with a WHERE IN clause that
* will be appended to every query, or on the client side with a predicate that will be applied to
* every fetched row.
*/
public interface KeyspaceFilter {
static KeyspaceFilter newInstance(@NonNull String logPrefix, @NonNull List specs) {
if (specs.isEmpty()) {
return INCLUDE_ALL;
} else {
return new RuleBasedKeyspaceFilter(logPrefix, specs);
}
}
/** The WHERE IN clause, or an empty string if there is no server-side filtering. */
@NonNull
String getWhereClause();
/** The predicate that will be invoked for client-side filtering. */
boolean includes(@NonNull String keyspace);
KeyspaceFilter INCLUDE_ALL =
new KeyspaceFilter() {
@NonNull
@Override
public String getWhereClause() {
return "";
}
@Override
public boolean includes(@NonNull String keyspace) {
return true;
}
};
}