solr/core/src/java/org/apache/solr/cloud/api/collections/SetAliasPropCmd.java

/*
 * 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.solr.cloud.api.collections;

import java.lang.invoke.MethodHandles;
import java.util.LinkedHashMap;
import java.util.Locale;
import java.util.Map;

import org.apache.solr.common.SolrException;
import org.apache.solr.common.cloud.ClusterState;
import org.apache.solr.common.cloud.ZkNodeProps;
import org.apache.solr.common.cloud.ZkStateReader;
import org.apache.solr.common.util.NamedList;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static org.apache.solr.cloud.api.collections.OverseerCollectionMessageHandler.Cmd;
import static org.apache.solr.common.SolrException.ErrorCode.BAD_REQUEST;
import static org.apache.solr.common.params.CommonParams.NAME;

public class SetAliasPropCmd implements Cmd {

  public static final String PROPERTIES = "property";

  private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

  private final OverseerCollectionMessageHandler messageHandler;

  SetAliasPropCmd(OverseerCollectionMessageHandler messageHandler) {
    this.messageHandler = messageHandler;
  }

  @Override
  public void call(ClusterState state, ZkNodeProps message, @SuppressWarnings({"rawtypes"})NamedList results) throws Exception {
    String aliasName = message.getStr(NAME);

    final ZkStateReader.AliasesManager aliasesManager = messageHandler.zkStateReader.aliasesManager;

    // Ensure we see the alias.  This may be redundant but SetAliasPropCmd isn't expected to be called very frequently
    aliasesManager.update();

    if (aliasesManager.getAliases().getCollectionAliasMap().get(aliasName) == null) {
      // nicer than letting aliases object throw later on...
      throw new SolrException(BAD_REQUEST,
          String.format(Locale.ROOT,  "Can't modify non-existent alias %s", aliasName));
    }

    @SuppressWarnings("unchecked")
    Map<String, String> properties = new LinkedHashMap<>((Map<String, String>) message.get(PROPERTIES));

    // check & cleanup properties.  It's a mutable copy.
    for (Map.Entry<String, String> entry : properties.entrySet()) {
      String key = entry.getKey();
      if ("".equals(key.trim())) {
        throw new SolrException(BAD_REQUEST, "property keys must not be pure whitespace");
      }
      if (!key.equals(key.trim())) {
        throw new SolrException(BAD_REQUEST, "property keys should not begin or end with whitespace");
      }
      String value = entry.getValue();
      if ("".equals(value)) {
        entry.setValue(null);
      }
    }

    aliasesManager.applyModificationAndExportToZk(aliases1 -> aliases1.cloneWithCollectionAliasProperties(aliasName, properties));
  }
}