content: /*
   * 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.cassandra.cql3.functions;
  
  import java.nio.ByteBuffer;
  import java.util.Arrays;
  import java.util.List;
  
  import org.apache.cassandra.cql3.AssignmentTestable;
  import org.apache.cassandra.schema.ColumnMetadata;
  import org.apache.cassandra.schema.Schema;
  import org.apache.cassandra.schema.TableMetadata;
  import org.apache.cassandra.db.CBuilder;
  import org.apache.cassandra.db.marshal.AbstractType;
  import org.apache.cassandra.exceptions.InvalidRequestException;
  import org.apache.cassandra.transport.ProtocolVersion;
  
  public class TokenFct extends NativeScalarFunction
  {
      private final TableMetadata metadata;
  
      public TokenFct(TableMetadata metadata)
      {
          super("token", metadata.partitioner.getTokenValidator(), getKeyTypes(metadata));
          this.metadata = metadata;
      }
  
      @Override
      public Arguments newArguments(ProtocolVersion version)
      {
          ArgumentDeserializer[] deserializers = new ArgumentDeserializer[argTypes.size()];
          Arrays.fill(deserializers, ArgumentDeserializer.NOOP_DESERIALIZER);
          return new FunctionArguments(version, deserializers);
      }
  
      private static AbstractType<?>[] getKeyTypes(TableMetadata metadata)
      {
          AbstractType<?>[] types = new AbstractType[metadata.partitionKeyColumns().size()];
          int i = 0;
          for (ColumnMetadata def : metadata.partitionKeyColumns())
              types[i++] = def.type;
          return types;
      }
  
      public ByteBuffer execute(Arguments arguments) throws InvalidRequestException
      {
          CBuilder builder = CBuilder.create(metadata.partitionKeyAsClusteringComparator());
          for (int i = 0; i < arguments.size(); i++)
          {
              ByteBuffer bb = arguments.get(i);
              if (bb == null)
                  return null;
              builder.add(bb);
          }
          return metadata.partitioner.getTokenFactory().toByteArray(metadata.partitioner.getToken(builder.build().serializeAsPartitionKey()));
      }
  
      public static void addFunctionsTo(NativeFunctions functions)
      {
          functions.add(new FunctionFactory("token")
          {
              @Override
              public NativeFunction getOrCreateFunction(List<? extends AssignmentTestable> args,
                                                        AbstractType<?> receiverType,
                                                        String receiverKeyspace,
                                                        String receiverTable)
              {
                  if (receiverKeyspace == null)
                      throw new InvalidRequestException("No receiver keyspace has been specified for function " + name);
  
                  if (receiverTable == null)
                      throw new InvalidRequestException("No receiver table has been specified for function " + name);
  
                  TableMetadata metadata = Schema.instance.getTableMetadata(receiverKeyspace, receiverTable);
                  if (metadata == null)
                      throw new InvalidRequestException(String.format("The receiver table %s.%s specified by call to " +
                                                                      "function %s hasn't been found",
                                                                      receiverKeyspace, receiverTable, name));
  
                  return new TokenFct(metadata);
              }
  
              @Override
              protected NativeFunction doGetOrCreateFunction(List<AbstractType<?>> argTypes, AbstractType<?> receiverType)
              {
                  throw new AssertionError("Should be unreachable");
              }
          });
      }
  }
  