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.base.AMutableInt32;
  import org.apache.asterix.om.exceptions.ExceptionUtil;
  import org.apache.asterix.om.types.ATypeTag;
  import org.apache.asterix.runtime.evaluators.common.ArgumentUtils;
  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;
  
  public abstract class AbstractStringStringStringIntEval implements IScalarEvaluator {
  
      private final IEvaluatorContext ctx;
      // Argument evaluators.
      private final IScalarEvaluator eval0;
      private final IScalarEvaluator eval1;
      private final IScalarEvaluator eval2;
      private final IScalarEvaluator eval3;
  
      // Argument pointables.
      final IPointable argPtrFirst = new VoidPointable();
      final IPointable argPtrSecond = new VoidPointable();
      final IPointable argPtrThird = new VoidPointable();
      final IPointable argPtrFourth = new VoidPointable();
      private final UTF8StringPointable strPtr1st = new UTF8StringPointable();
      private final UTF8StringPointable strPtr2nd = new UTF8StringPointable();
      private final UTF8StringPointable strPtr3rd = new UTF8StringPointable();
      private final AMutableInt32 mutableInt = new AMutableInt32(0);
  
      // For outputting results.
      ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
      DataOutput dout = resultStorage.getDataOutput();
  
      // Function ID, for error reporting.
      protected final FunctionIdentifier funcID;
      protected final SourceLocation sourceLoc;
  
      AbstractStringStringStringIntEval(IEvaluatorContext context, IScalarEvaluatorFactory eval0,
              IScalarEvaluatorFactory eval1, IScalarEvaluatorFactory eval2, IScalarEvaluatorFactory eval3,
              FunctionIdentifier funcID, SourceLocation sourceLoc) throws HyracksDataException {
          this.ctx = context;
          this.sourceLoc = sourceLoc;
          this.eval0 = eval0.createScalarEvaluator(context);
          this.eval1 = eval1.createScalarEvaluator(context);
          this.eval2 = eval2.createScalarEvaluator(context);
          this.eval3 = eval3.createScalarEvaluator(context);
          this.funcID = funcID;
      }
  
      @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);
          eval3.evaluate(tuple, argPtrFourth);
  
          if (PointableHelper.checkAndSetMissingOrNull(result, argPtrFirst, argPtrSecond, argPtrThird, argPtrFourth)) {
              return;
          }
  
          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();
  
          byte[] bytes3 = argPtrFourth.getByteArray();
          int start3 = argPtrFourth.getStartOffset();
  
          // Type check.
          if (!checkStringsAndWarn(bytes0[start0], bytes1[start1], bytes2[start2])) {
              PointableHelper.setNull(result);
              return;
          }
          // check that the int argument is numeric without fractions (in case arg is double or float)
          if (!ArgumentUtils.setInteger(ctx, sourceLoc, funcID, 3, bytes3, start3, mutableInt)) {
              PointableHelper.setNull(result);
              return;
          }
          int int4th = mutableInt.getIntegerValue();
          // 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, int4th, result);
      }
  
      /**
       * The actual processing of a string function.
       *
       * @param first
       *            , the first argument.
       * @param second
       *            , the second argument.
       * @param third
       *            , the third argument.
       * @param fourth
       *            , the fourth argument.
       * @param resultPointable
       *            , the result.
       * @throws HyracksDataException
       */
      protected abstract void process(UTF8StringPointable first, UTF8StringPointable second, UTF8StringPointable third,
              int fourth, IPointable resultPointable) throws HyracksDataException;
  
      /** Checks the arguments expected to be strings returning {@code false} if they are not and issuing a warning */
      private boolean checkStringsAndWarn(byte actualType0, byte actualType1, byte actualType2) {
          return checkAndWarn(0, actualType0) && checkAndWarn(1, actualType1) && checkAndWarn(2, actualType2);
      }
  
      private boolean checkAndWarn(int argIdx, byte actualType) {
          if (actualType != ATypeTag.SERIALIZED_STRING_TYPE_TAG) {
              ExceptionUtil.warnTypeMismatch(ctx, sourceLoc, funcID, actualType, argIdx, ATypeTag.STRING);
              return false;
          }
          return true;
      }
  }
  