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.asterix.runtime.functions;
  
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.asterix.common.exceptions.AsterixException;
  import org.apache.asterix.common.exceptions.ErrorCode;
  import org.apache.asterix.om.functions.BuiltinFunctions;
  import org.apache.asterix.om.functions.IFunctionDescriptor;
  import org.apache.asterix.om.functions.IFunctionDescriptorFactory;
  import org.apache.asterix.om.functions.IFunctionManager;
  import org.apache.asterix.om.functions.IFunctionTypeInferer;
  import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
  import org.apache.hyracks.algebricks.common.utils.Pair;
  import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
  import org.apache.hyracks.api.exceptions.SourceLocation;
  
  /**
   * Default implementation of {@link IFunctionManager}.
   */
  public final class FunctionManager implements IFunctionManager {
  
      private final Map<Pair<FunctionIdentifier, Integer>, IFunctionDescriptorFactory> functions;
  
      private final Map<FunctionIdentifier, IFunctionTypeInferer> typeInferers;
  
      public FunctionManager(FunctionCollection functionCollection) {
          Map<Pair<FunctionIdentifier, Integer>, IFunctionDescriptorFactory> functionsMap = new HashMap<>();
          Map<FunctionIdentifier, IFunctionTypeInferer> typeInferersMap = new HashMap<>();
  
          for (IFunctionDescriptorFactory descriptorFactory : functionCollection.getFunctionDescriptorFactories()) {
              FunctionIdentifier fid = descriptorFactory.createFunctionDescriptor().getIdentifier();
              functionsMap.put(new Pair<>(fid, fid.getArity()), descriptorFactory);
              IFunctionTypeInferer typeInferer = descriptorFactory.createFunctionTypeInferer();
              if (typeInferer != null) {
                  typeInferersMap.put(fid, typeInferer);
              }
          }
  
          this.functions = functionsMap;
          this.typeInferers = typeInferersMap;
      }
  
      @Override
      public IFunctionDescriptor lookupFunction(FunctionIdentifier fid, SourceLocation src) throws AlgebricksException {
          Pair<FunctionIdentifier, Integer> key = new Pair<>(fid, fid.getArity());
          IFunctionDescriptorFactory factory = functions.get(key);
          if (factory == null) {
              String msg;
              if (fid.equals(BuiltinFunctions.META)) {
                  msg = "No source collection found for META(): collection not supported or cannot reference collection";
              } else {
                  msg = "Could not resolve function '" + fid.getName() + "'";
              }
              throw AsterixException.create(ErrorCode.COMPILATION_ERROR, src, msg);
          }
          return factory.createFunctionDescriptor();
      }
  
      @Override
      public IFunctionTypeInferer lookupFunctionTypeInferer(FunctionIdentifier fid) {
          return typeInferers.get(fid);
      }
  }
  