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.evaluators.functions;
  
  import java.io.DataOutput;
  
  import org.apache.asterix.om.exceptions.ExceptionUtil;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator;
  import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory;
  import org.apache.hyracks.api.context.IEvaluatorContext;
  import org.apache.hyracks.api.exceptions.HyracksDataException;
  import org.apache.hyracks.api.exceptions.SourceLocation;
  import org.apache.hyracks.data.std.api.IPointable;
  import org.apache.hyracks.data.std.primitive.UTF8StringPointable;
  import org.apache.hyracks.data.std.primitive.VoidPointable;
  import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
  import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
  
  abstract class AbstractTripleStringEval implements IScalarEvaluator {
  
      private final IEvaluatorContext ctx;
      // Argument evaluators.
      private IScalarEvaluator eval0;
      private IScalarEvaluator eval1;
      private IScalarEvaluator eval2;
  
      // Argument pointables.
      final IPointable argPtrFirst = new VoidPointable();
      final IPointable argPtrSecond = new VoidPointable();
      final IPointable argPtrThird = new VoidPointable();
      private final UTF8StringPointable strPtr1st = new UTF8StringPointable();
      private final UTF8StringPointable strPtr2nd = new UTF8StringPointable();
      private final UTF8StringPointable strPtr3rd = new UTF8StringPointable();
  
      // For outputting results.
      ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
      DataOutput dout = resultStorage.getDataOutput();
  
      // Function ID, for error reporting.
      protected final FunctionIdentifier funcID;
      protected final SourceLocation sourceLoc;
  
      AbstractTripleStringEval(IEvaluatorContext context, IScalarEvaluatorFactory eval0, IScalarEvaluatorFactory eval1,
              IScalarEvaluatorFactory eval2, FunctionIdentifier funcID, SourceLocation sourceLoc)
              throws HyracksDataException {
          this.eval0 = eval0.createScalarEvaluator(context);
          this.eval1 = eval1.createScalarEvaluator(context);
          this.eval2 = eval2.createScalarEvaluator(context);
          this.funcID = funcID;
          this.sourceLoc = sourceLoc;
          this.ctx = context;
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public void evaluate(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
          // Gets the arguments
          eval0.evaluate(tuple, argPtrFirst);
          eval1.evaluate(tuple, argPtrSecond);
          eval2.evaluate(tuple, argPtrThird);
  
          if (PointableHelper.checkAndSetMissingOrNull(result, argPtrFirst, argPtrSecond, argPtrThird)) {
              return;
          }
  
          // Arguments
          byte[] bytes0 = argPtrFirst.getByteArray();
          int start0 = argPtrFirst.getStartOffset();
          int len0 = argPtrFirst.getLength();
          byte[] bytes1 = argPtrSecond.getByteArray();
          int start1 = argPtrSecond.getStartOffset();
          int len1 = argPtrSecond.getLength();
          byte[] bytes2 = argPtrThird.getByteArray();
          int start2 = argPtrThird.getStartOffset();
          int len2 = argPtrThird.getLength();
  
          // Type check.
          if (bytes0[start0] != ATypeTag.SERIALIZED_STRING_TYPE_TAG) {
              PointableHelper.setNull(result);
              ExceptionUtil.warnTypeMismatch(ctx, sourceLoc, funcID, bytes0[start0], 0, ATypeTag.STRING);
              return;
          }
          if (bytes1[start1] != ATypeTag.SERIALIZED_STRING_TYPE_TAG) {
              PointableHelper.setNull(result);
              ExceptionUtil.warnTypeMismatch(ctx, sourceLoc, funcID, bytes1[start1], 1, ATypeTag.STRING);
              return;
          }
          if (bytes2[start2] != ATypeTag.SERIALIZED_STRING_TYPE_TAG) {
              PointableHelper.setNull(result);
              ExceptionUtil.warnTypeMismatch(ctx, sourceLoc, funcID, bytes2[start2], 2, ATypeTag.STRING);
              return;
          }
  
          // Sets argument UTF8Pointables.
          strPtr1st.set(bytes0, start0 + 1, len0 - 1);
          strPtr2nd.set(bytes1, start1 + 1, len1 - 1);
          strPtr3rd.set(bytes2, start2 + 1, len2 - 1);
  
          // Resets the output storage.
          resultStorage.reset();
          // The actual processing.
          process(strPtr1st, strPtr2nd, strPtr3rd, result);
      }
  
      /**
       * The actual processing of a string function.
       *
       * @param first
       *            , the first argument.
       * @param second
       *            , the second argument.
       * @param third
       *            , the third argument.
       * @param resultPointable
       *            , the result.
       * @throws HyracksDataException
       */
      protected abstract void process(UTF8StringPointable first, UTF8StringPointable second, UTF8StringPointable third,
              IPointable resultPointable) throws HyracksDataException;
  }
  