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 java.io.IOException;
  
  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;
  
  public abstract class AbstractBinaryStringEval implements IScalarEvaluator {
  
      private final IEvaluatorContext ctx;
      // Argument evaluators.
      private final IScalarEvaluator evalLeft;
      private final IScalarEvaluator evalRight;
  
      // Argument pointables.
      private final IPointable argPtrLeft = new VoidPointable();
      private final IPointable argPtrSecond = new VoidPointable();
      private final UTF8StringPointable leftStringPointable = new UTF8StringPointable();
      private final UTF8StringPointable rightStringPointable = new UTF8StringPointable();
  
      // For results.
      protected final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
      protected final DataOutput dataOutput = resultStorage.getDataOutput();
  
      // Function ID, for error reporting.
      private final FunctionIdentifier funcID;
      protected final SourceLocation sourceLoc;
  
      public AbstractBinaryStringEval(IEvaluatorContext context, IScalarEvaluatorFactory evalLeftFactory,
              IScalarEvaluatorFactory evalRightFactory, FunctionIdentifier funcID, SourceLocation sourceLoc)
              throws HyracksDataException {
          this.sourceLoc = sourceLoc;
          this.evalLeft = evalLeftFactory.createScalarEvaluator(context);
          this.evalRight = evalRightFactory.createScalarEvaluator(context);
          this.funcID = funcID;
          this.ctx = context;
      }
  
      @SuppressWarnings("unchecked")
      @Override
      public void evaluate(IFrameTupleReference tuple, IPointable resultPointable) throws HyracksDataException {
          resultStorage.reset();
  
          // Gets the arguments
          evalLeft.evaluate(tuple, argPtrLeft);
          evalRight.evaluate(tuple, argPtrSecond);
  
          if (PointableHelper.checkAndSetMissingOrNull(resultPointable, argPtrLeft, argPtrSecond)) {
              return;
          }
  
          byte[] bytes0 = argPtrLeft.getByteArray();
          int offset0 = argPtrLeft.getStartOffset();
          int len0 = argPtrLeft.getLength();
          byte[] bytes1 = argPtrSecond.getByteArray();
          int offset1 = argPtrSecond.getStartOffset();
          int len1 = argPtrSecond.getLength();
  
          // Type check.
          if (bytes0[offset0] != ATypeTag.SERIALIZED_STRING_TYPE_TAG) {
              PointableHelper.setNull(resultPointable);
              ExceptionUtil.warnTypeMismatch(ctx, sourceLoc, funcID, bytes0[offset0], 0, ATypeTag.STRING);
              return;
          }
          if (bytes1[offset1] != ATypeTag.SERIALIZED_STRING_TYPE_TAG) {
              PointableHelper.setNull(resultPointable);
              ExceptionUtil.warnTypeMismatch(ctx, sourceLoc, funcID, bytes1[offset1], 1, ATypeTag.STRING);
              return;
          }
  
          // Sets StringUTF8Pointables.
          leftStringPointable.set(bytes0, offset0 + 1, len0 - 1);
          rightStringPointable.set(bytes1, offset1 + 1, len1 - 1);
  
          // The actual processing.
          try {
              process(leftStringPointable, rightStringPointable, resultPointable);
          } catch (HyracksDataException ex) {
              if (ExceptionUtil.isStringUnicodeError(ex)) {
                  PointableHelper.setNull(resultPointable);
                  ExceptionUtil.warnFunctionEvalFailed(ctx, sourceLoc, funcID, ex.getMessageNoCode());
                  return;
              }
              throw ex;
          } catch (IOException e) {
              throw HyracksDataException.create(e);
          }
      }
  
      /**
       * The actual processing of a string function.
       *
       * @param left
       *            , the first argument.
       * @param right
       *            , the second argument.
       * @param resultPointable
       *            , the result.
       * @throws IOException
       */
      protected abstract void process(UTF8StringPointable left, UTF8StringPointable right, IPointable resultPointable)
              throws IOException;
  
  }
  