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.data.std.util.GrowableArray;
  import org.apache.hyracks.data.std.util.UTF8StringBuilder;
  import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;
  
  abstract class AbstractUnaryStringStringEval implements IScalarEvaluator {
  
      private final IEvaluatorContext ctx;
      // For the argument.
      private final IScalarEvaluator argEval;
      private final VoidPointable argPtr = new VoidPointable();
      private final UTF8StringPointable stringPtr = new UTF8StringPointable();
  
      // For writing results.
      final GrowableArray resultArray = new GrowableArray();
      final UTF8StringBuilder resultBuilder = new UTF8StringBuilder();
      private final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
      private final DataOutput dataOutput = resultStorage.getDataOutput();
      private final FunctionIdentifier funcID;
      protected final SourceLocation sourceLoc;
  
      AbstractUnaryStringStringEval(IEvaluatorContext context, IScalarEvaluatorFactory argEvalFactory,
              FunctionIdentifier funcID, SourceLocation sourceLoc) throws HyracksDataException {
          this.argEval = argEvalFactory.createScalarEvaluator(context);
          this.funcID = funcID;
          this.sourceLoc = sourceLoc;
          this.ctx = context;
      }
  
      @Override
      public void evaluate(IFrameTupleReference tuple, IPointable resultPointable) throws HyracksDataException {
          resultStorage.reset();
          argEval.evaluate(tuple, argPtr);
  
          if (PointableHelper.checkAndSetMissingOrNull(resultPointable, argPtr)) {
              return;
          }
  
          byte[] argBytes = argPtr.getByteArray();
          int offset = argPtr.getStartOffset();
          byte inputTypeTag = argBytes[offset];
          if (inputTypeTag != ATypeTag.SERIALIZED_STRING_TYPE_TAG) {
              PointableHelper.setNull(resultPointable);
              ExceptionUtil.warnTypeMismatch(ctx, sourceLoc, funcID, argBytes[offset], 0, ATypeTag.STRING);
              return;
          }
          stringPtr.set(argBytes, offset + 1, argPtr.getLength() - 1);
          resultArray.reset();
          try {
              process(stringPtr, resultPointable);
              writeResult(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);
          }
      }
  
      /**
       * Processes an input UTF8 string.
       *
       * @param inputString
       *            , the input string.
       * @param resultPointable
       *            , a pointable that is supposed to point to the result.
       */
      abstract void process(UTF8StringPointable inputString, IPointable resultPointable) throws IOException;
  
      // Writes the result.
      void writeResult(IPointable resultPointable) throws IOException {
          dataOutput.writeByte(ATypeTag.SERIALIZED_STRING_TYPE_TAG);
          dataOutput.write(resultArray.getByteArray(), 0, resultArray.getLength());
          resultPointable.set(resultStorage);
      }
  }
  