zipkin2.storage.cassandra.v1.SelectAutocompleteValues Maven / Gradle / Ivy

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/*
 * Copyright 2015-2020 The OpenZipkin Authors
 *
 * Licensed 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 zipkin2.storage.cassandra.v1;

import com.datastax.oss.driver.api.core.CqlSession;
import com.datastax.oss.driver.api.core.cql.AsyncResultSet;
import com.datastax.oss.driver.api.core.cql.PreparedStatement;
import java.util.List;
import java.util.concurrent.CompletionStage;
import zipkin2.Call;
import zipkin2.storage.cassandra.internal.call.DistinctSortedStrings;
import zipkin2.storage.cassandra.internal.call.ResultSetFutureCall;

import static zipkin2.storage.cassandra.v1.Tables.AUTOCOMPLETE_TAGS;

final class SelectAutocompleteValues extends ResultSetFutureCall {
  static final class Factory {
    final CqlSession session;
    final PreparedStatement preparedStatement;

    Factory(CqlSession session) {
      this.session = session;
      this.preparedStatement = session.prepare("SELECT value"
        + " FROM " + AUTOCOMPLETE_TAGS
        + " WHERE key=?"
        + " LIMIT " + 10000);
    }

    Call> create(String key) {
      return new SelectAutocompleteValues(this, key).flatMap(DistinctSortedStrings.get());
    }
  }

  final SelectAutocompleteValues.Factory factory;
  final String key;

  SelectAutocompleteValues(SelectAutocompleteValues.Factory factory, String key) {
    this.factory = factory;
    this.key = key;
  }

  @Override protected CompletionStage newCompletionStage() {
    return factory.session.executeAsync(factory.preparedStatement.boundStatementBuilder()
      .setString(0, key).build());
  }

  @Override public AsyncResultSet map(AsyncResultSet input) {
    return input;
  }

  @Override public Call clone() {
    return new SelectAutocompleteValues(factory, key);
  }
}