    001/*
    002 * Copyright (c) 2007-2016 Concurrent, Inc. All Rights Reserved.
    003 *
    004 * Project and contact information: http://www.cascading.org/
    005 *
    006 * This file is part of the Cascading project.
    007 *
    008 * Licensed under the Apache License, Version 2.0 (the "License");
    009 * you may not use this file except in compliance with the License.
    010 * You may obtain a copy of the License at
    011 *
    012 *     http://www.apache.org/licenses/LICENSE-2.0
    013 *
    014 * Unless required by applicable law or agreed to in writing, software
    015 * distributed under the License is distributed on an "AS IS" BASIS,
    016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    017 * See the License for the specific language governing permissions and
    018 * limitations under the License.
    019 */
    020
    021package cascading.flow.stream.element;
    022
    023import cascading.flow.FlowElement;
    024import cascading.flow.FlowProcess;
    025import cascading.flow.planner.Scope;
    026import cascading.flow.stream.duct.Duct;
    027import cascading.operation.ConcreteCall;
    028import cascading.pipe.Operator;
    029import cascading.tuple.Fields;
    030import cascading.tuple.Tuple;
    031import cascading.tuple.TupleEntry;
    032import cascading.tuple.TupleEntryCollector;
    033import cascading.tuple.util.TupleBuilder;
    034import cascading.tuple.util.TupleViews;
    035
    036import static cascading.tuple.util.TupleViews.*;
    037
    038/**
    039 *
    040 */
    041public abstract class OperatorStage<Incoming> extends ElementStage<Incoming, TupleEntry>
    042  {
    043  /**
    044   * In 2.2 the collector is now nulled before the
    045   * {@link cascading.operation.Operation#cleanup(cascading.flow.FlowProcess, cascading.operation.OperationCall)}
    046   * is called. This property retains the collector to remain compatible with 2.1.
    047   */
    048  public static final String RETAIN_COLLECTOR = "cascading.compatibility.retain.collector";
    049
    050  protected ConcreteCall operationCall;
    051  protected TupleEntry incomingEntry;
    052  protected Fields argumentsSelector;
    053  protected TupleEntry argumentsEntry;
    054  protected Fields remainderFields;
    055  protected Fields outgoingSelector;
    056  protected TupleEntry outgoingEntry;
    057
    058  protected TupleBuilder argumentsBuilder;
    059  protected TupleBuilder outgoingBuilder;
    060
    061  private final boolean retainCollector;
    062
    063  protected TupleEntryCollector outputCollector;
    064
    065  public OperatorStage( FlowProcess flowProcess, FlowElement flowElement )
    066    {
    067    super( flowProcess, flowElement );
    068
    069    this.retainCollector = Boolean.parseBoolean( flowProcess.getStringProperty( RETAIN_COLLECTOR ) );
    070    }
    071
    072  public abstract Operator getOperator();
    073
    074  protected abstract Fields getOutgoingSelector();
    075
    076  protected Fields getOperationDeclaredFields()
    077    {
    078    return outgoingScopes.get( 0 ).getOperationDeclaredFields();
    079    }
    080
    081  protected abstract Fields getIncomingPassThroughFields();
    082
    083  protected abstract Fields getIncomingArgumentsFields();
    084
    085  protected TupleBuilder createArgumentsBuilder( final Fields incomingFields, final Fields argumentsSelector )
    086    {
    087    if( incomingFields.isUnknown() )
    088      return new TupleBuilder()
    089      {
    090      @Override
    091      public Tuple makeResult( Tuple input, Tuple output )
    092        {
    093        return input.get( incomingFields, argumentsSelector );
    094        }
    095      };
    096
    097    if( argumentsSelector.isAll() )
    098      return new TupleBuilder()
    099      {
    100      @Override
    101      public Tuple makeResult( Tuple input, Tuple output )
    102        {
    103        return input;
    104        }
    105      };
    106
    107    if( argumentsSelector.isNone() )
    108      return new TupleBuilder()
    109      {
    110      @Override
    111      public Tuple makeResult( Tuple input, Tuple output )
    112        {
    113        return Tuple.NULL;
    114        }
    115      };
    116
    117    final Fields inputDeclarationFields = Fields.asDeclaration( incomingFields );
    118
    119    return new TupleBuilder()
    120    {
    121    Tuple result = createNarrow( inputDeclarationFields.getPos( argumentsSelector ) );
    122
    123    @Override
    124    public Tuple makeResult( Tuple input, Tuple output )
    125      {
    126      return TupleViews.reset( result, input );
    127      }
    128    };
    129    }
    130
    131  protected TupleBuilder createOutgoingBuilder( final Operator operator, final Fields incomingFields, final Fields argumentSelector, final Fields remainderFields, final Fields declaredFields, final Fields outgoingSelector )
    132    {
    133    final Fields inputDeclarationFields = Fields.asDeclaration( incomingFields );
    134
    135    if( operator.getOutputSelector().isResults() )
    136      return new TupleBuilder()
    137      {
    138      @Override
    139      public Tuple makeResult( Tuple input, Tuple output )
    140        {
    141        return output;
    142        }
    143      };
    144
    145    if( operator.getOutputSelector().isAll() && !( incomingFields.isUnknown() || declaredFields.isUnknown() ) )
    146      return new TupleBuilder()
    147      {
    148      Tuple result = createComposite( inputDeclarationFields, declaredFields );
    149
    150      @Override
    151      public Tuple makeResult( Tuple input, Tuple output )
    152        {
    153        return TupleViews.reset( result, input, output );
    154        }
    155      };
    156
    157    if( operator.getOutputSelector().isReplace() )
    158      {
    159      if( incomingFields.isUnknown() )
    160        return new TupleBuilder()
    161        {
    162        Fields resultFields = operator.getFieldDeclaration().isArguments() ? argumentSelector : declaredFields;
    163
    164        @Override
    165        public Tuple makeResult( Tuple input, Tuple output )
    166          {
    167          Tuple result = new Tuple( input );
    168
    169          result.set( Fields.UNKNOWN, resultFields, output );
    170
    171          return result;
    172          }
    173        };
    174
    175      return new TupleBuilder()
    176      {
    177      Fields resultFields = operator.getFieldDeclaration().isArguments() ? argumentSelector : declaredFields;
    178      Tuple result = createOverride( inputDeclarationFields, resultFields );
    179
    180      @Override
    181      public Tuple makeResult( Tuple input, Tuple output )
    182        {
    183        return TupleViews.reset( result, input, output );
    184        }
    185      };
    186      }
    187
    188    if( operator.getOutputSelector().isSwap() )
    189      {
    190      if( remainderFields.size() == 0 ) // the same as Fields.RESULTS
    191        return new TupleBuilder()
    192        {
    193        @Override
    194        public Tuple makeResult( Tuple input, Tuple output )
    195          {
    196          return output;
    197          }
    198        };
    199      else if( declaredFields.isUnknown() )
    200        return new TupleBuilder()
    201        {
    202        @Override
    203        public Tuple makeResult( Tuple input, Tuple output )
    204          {
    205          return input.get( incomingFields, remainderFields ).append( output );
    206          }
    207        };
    208      else
    209        return new TupleBuilder()
    210        {
    211        Tuple view = createNarrow( inputDeclarationFields.getPos( remainderFields ) );
    212        Tuple result = createComposite( Fields.asDeclaration( remainderFields ), declaredFields );
    213
    214        @Override
    215        public Tuple makeResult( Tuple input, Tuple output )
    216          {
    217          TupleViews.reset( view, input );
    218
    219          return TupleViews.reset( result, view, output );
    220          }
    221        };
    222      }
    223
    224    if( incomingFields.isUnknown() || declaredFields.isUnknown() )
    225      return new TupleBuilder()
    226      {
    227      Fields selector = outgoingSelector.isUnknown() ? Fields.ALL : outgoingSelector;
    228      TupleEntry incoming = new TupleEntry( incomingFields, true );
    229      TupleEntry declared = new TupleEntry( declaredFields, true );
    230
    231      @Override
    232      public Tuple makeResult( Tuple input, Tuple output )
    233        {
    234        incoming.setTuple( input );
    235        declared.setTuple( output );
    236
    237        return TupleEntry.select( selector, incoming, declared );
    238        }
    239      };
    240
    241    return new TupleBuilder()
    242    {
    243    Fields inputFields = operator.getFieldDeclaration().isArguments() ? Fields.mask( inputDeclarationFields, declaredFields ) : inputDeclarationFields;
    244    Tuple appended = createComposite( inputFields, declaredFields );
    245    Fields allFields = Fields.resolve( Fields.ALL, inputFields, declaredFields );
    246    Tuple result = createNarrow( allFields.getPos( outgoingSelector ), appended );
    247
    248    @Override
    249    public Tuple makeResult( Tuple input, Tuple output )
    250      {
    251      TupleViews.reset( appended, input, output );
    252
    253      return result;
    254      }
    255    };
    256    }
    257
    258  @Override
    259  public void initialize()
    260    {
    261    Scope outgoingScope = outgoingScopes.get( 0 );
    262
    263    operationCall = new ConcreteCall( outgoingScope.getArgumentsDeclarator(), outgoingScope.getOperationDeclaredFields() );
    264
    265    argumentsSelector = outgoingScope.getArgumentsSelector();
    266    remainderFields = outgoingScope.getRemainderPassThroughFields();
    267    outgoingSelector = getOutgoingSelector();
    268
    269    argumentsEntry = new TupleEntry( outgoingScope.getArgumentsDeclarator(), true );
    270
    271    outgoingEntry = new TupleEntry( getOutgoingFields(), true );
    272
    273    operationCall.setArguments( argumentsEntry );
    274
    275    argumentsBuilder = createArgumentsBuilder( getIncomingArgumentsFields(), argumentsSelector );
    276    outgoingBuilder = createOutgoingBuilder( getOperator(), getIncomingPassThroughFields(), argumentsSelector, remainderFields, getOperationDeclaredFields(), outgoingSelector );
    277    }
    278
    279  @Override
    280  public void prepare()
    281    {
    282    super.prepare(); // if fails, skip the this prepare
    283
    284    ( (Operator) getFlowElement() ).getOperation().prepare( flowProcess, operationCall );
    285    }
    286
    287  @Override
    288  public void complete( Duct previous )
    289    {
    290    try
    291      {
    292      ( (Operator) getFlowElement() ).getOperation().flush( flowProcess, operationCall );
    293      }
    294    finally
    295      {
    296      super.complete( previous );
    297      }
    298    }
    299
    300  @Override
    301  public void cleanup()
    302    {
    303    if( !retainCollector ) // see comments for RETAIN_COLLECTOR
    304      operationCall.setOutputCollector( null );
    305
    306    try
    307      {
    308      ( (Operator) getFlowElement() ).getOperation().cleanup( flowProcess, operationCall );
    309      }
    310    finally
    311      {
    312      super.cleanup(); // guarantee this happens
    313      }
    314    }
    315  }