| /* |
| * 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.vxquery.runtime.functions.strings; |
| |
| import java.io.DataOutput; |
| import java.io.IOException; |
| |
| import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator; |
| import org.apache.hyracks.data.std.api.IPointable; |
| 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.vxquery.datamodel.accessors.TaggedValuePointable; |
| import org.apache.vxquery.datamodel.values.ValueTag; |
| import org.apache.vxquery.exceptions.ErrorCode; |
| import org.apache.vxquery.exceptions.SystemException; |
| import org.apache.vxquery.runtime.functions.base.AbstractTaggedValueArgumentScalarEvaluator; |
| import org.apache.vxquery.runtime.functions.util.FunctionHelper; |
| |
| public abstract class AbstractCharacterIteratorCopyingEvaluator extends AbstractTaggedValueArgumentScalarEvaluator { |
| private static final int STRING_EXPECTED_LENGTH = 300; |
| private final GrowableArray ga = new GrowableArray(); |
| private final UTF8StringBuilder sb = new UTF8StringBuilder(); |
| private final ICharacterIterator charIterator; |
| private final ArrayBackedValueStorage abvs; |
| |
| public AbstractCharacterIteratorCopyingEvaluator(IScalarEvaluator[] args, ICharacterIterator charIterator) { |
| super(args); |
| this.charIterator = charIterator; |
| abvs = new ArrayBackedValueStorage(); |
| } |
| |
| @Override |
| public final void evaluate(TaggedValuePointable[] args, IPointable result) throws SystemException { |
| preEvaluate(args); |
| abvs.reset(); |
| charIterator.reset(); |
| try { |
| // Byte Format: Type (1 byte) + String Length (X bytes) + String. |
| DataOutput out = abvs.getDataOutput(); |
| out.write(ValueTag.XS_STRING_TAG); |
| |
| ga.reset(); |
| sb.reset(ga, STRING_EXPECTED_LENGTH); |
| |
| int c; |
| while (ICharacterIterator.EOS_CHAR != (c = charIterator.next())) { |
| FunctionHelper.writeChar((char) c, sb); |
| } |
| |
| sb.finish(); |
| out.write(ga.getByteArray(), 0, ga.getLength()); |
| |
| result.set(abvs.getByteArray(), abvs.getStartOffset(), abvs.getLength()); |
| } catch (IOException e) { |
| throw new SystemException(ErrorCode.SYSE0001, e); |
| } |
| } |
| |
| protected abstract void preEvaluate(TaggedValuePointable[] args) throws SystemException; |
| |
| } |