    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.tuple.hadoop;
    022
    023import java.io.DataInputStream;
    024import java.io.DataOutputStream;
    025import java.io.IOException;
    026import java.util.ArrayList;
    027import java.util.Collection;
    028import java.util.Collections;
    029import java.util.Comparator;
    030import java.util.HashMap;
    031import java.util.LinkedList;
    032import java.util.List;
    033import java.util.Map;
    034
    035import cascading.CascadingException;
    036import cascading.flow.FlowProcess;
    037import cascading.flow.FlowProps;
    038import cascading.flow.hadoop.util.HadoopUtil;
    039import cascading.tuple.Comparison;
    040import cascading.tuple.Fields;
    041import cascading.tuple.Tuple;
    042import cascading.tuple.TupleException;
    043import cascading.tuple.hadoop.io.HadoopTupleOutputStream;
    044import cascading.tuple.hadoop.io.IndexTupleDeserializer;
    045import cascading.tuple.hadoop.io.IndexTupleSerializer;
    046import cascading.tuple.hadoop.io.KeyIndexTupleDeserializer;
    047import cascading.tuple.hadoop.io.KeyIndexTupleSerializer;
    048import cascading.tuple.hadoop.io.KeyTupleDeserializer;
    049import cascading.tuple.hadoop.io.KeyTupleSerializer;
    050import cascading.tuple.hadoop.io.TupleDeserializer;
    051import cascading.tuple.hadoop.io.TuplePairDeserializer;
    052import cascading.tuple.hadoop.io.TuplePairSerializer;
    053import cascading.tuple.hadoop.io.TupleSerializer;
    054import cascading.tuple.hadoop.io.ValueIndexTupleDeserializer;
    055import cascading.tuple.hadoop.io.ValueIndexTupleSerializer;
    056import cascading.tuple.hadoop.io.ValueTupleDeserializer;
    057import cascading.tuple.hadoop.io.ValueTupleSerializer;
    058import cascading.tuple.io.IndexTuple;
    059import cascading.tuple.io.KeyIndexTuple;
    060import cascading.tuple.io.KeyTuple;
    061import cascading.tuple.io.TupleInputStream;
    062import cascading.tuple.io.TupleOutputStream;
    063import cascading.tuple.io.TuplePair;
    064import cascading.tuple.io.ValueIndexTuple;
    065import cascading.tuple.io.ValueTuple;
    066import cascading.util.Util;
    067import org.apache.hadoop.conf.Configuration;
    068import org.apache.hadoop.conf.Configured;
    069import org.apache.hadoop.io.WritableUtils;
    070import org.apache.hadoop.io.serializer.Deserializer;
    071import org.apache.hadoop.io.serializer.Serialization;
    072import org.apache.hadoop.io.serializer.SerializationFactory;
    073import org.apache.hadoop.io.serializer.Serializer;
    074import org.apache.hadoop.io.serializer.WritableSerialization;
    075import org.apache.hadoop.util.ReflectionUtils;
    076import org.slf4j.Logger;
    077import org.slf4j.LoggerFactory;
    078
    079import static cascading.tuple.hadoop.TupleSerializationProps.HADOOP_IO_SERIALIZATIONS;
    080
    081/**
    082 * Class TupleSerialization is an implementation of Hadoop's {@link Serialization} interface.
    083 * <p/>
    084 * Typically developers will not use this implementation directly as it is automatically added
    085 * to any relevant MapReduce jobs via the {@link org.apache.hadoop.conf.Configuration}.
    086 * <p/>
    087 * By default, all primitive types are natively handled, and {@link org.apache.hadoop.io.BytesWritable}
    088 * has a pre-configured serialization token since byte arrays are not handled natively by {@link Tuple}.
    089 * <p/>
    090 * To add or manipulate Hadoop serializations or Cascading serializations tokens, see
    091 * {@link TupleSerializationProps} for a fluent property builder class.
    092 * <p/>
    093 * By default this Serialization interface registers the class {@link org.apache.hadoop.io.ByteWritable} as
    094 * token 127.
    095 */
    096@SerializationToken(
    097  tokens = {127},
    098  classNames = {"org.apache.hadoop.io.BytesWritable"})
    099public class TupleSerialization extends Configured implements Serialization
    100  {
    101
    102  /** Field LOG */
    103  private static final Logger LOG = LoggerFactory.getLogger( TupleSerialization.class );
    104
    105  /** Field defaultComparator * */
    106  private Comparator defaultComparator;
    107  /** Field classCache */
    108  private final Map<String, Class> classCache = new HashMap<String, Class>();
    109  /** Field serializationFactory */
    110  private SerializationFactory serializationFactory;
    111
    112  /** Field tokenClassesMap */
    113  private HashMap<Integer, String> tokenClassesMap;
    114  /** Field classesTokensMap */
    115  private HashMap<String, Integer> classesTokensMap;
    116  /** Field tokenMapSize */
    117  private long tokensSize = 0;
    118
    119  List<Integer> ordinals;
    120
    121  Map<Integer, Fields> keyFieldsMap;
    122  Map<Integer, Fields> sortFieldsMap;
    123  Map<Integer, Fields> valueFieldsMap;
    124
    125  Fields keyFields;
    126  Fields sortFields;
    127  Fields valueFields;
    128
    129  Boolean typesRequired; // for testing purposes
    130  Boolean typesIgnored; // for testing purposes
    131
    132  static String getSerializationTokens( Configuration jobConf )
    133    {
    134    return jobConf.get( TupleSerializationProps.SERIALIZATION_TOKENS );
    135    }
    136
    137  /**
    138   * Adds this class as a Hadoop Serialization class. This method is safe to call redundantly.
    139   * <p/>
    140   * This method will guarantee {@link TupleSerialization} and {@link WritableSerialization} are
    141   * first in the list, as both are required.
    142   *
    143   * @param jobConf of type JobConf
    144   */
    145  public static void setSerializations( Configuration jobConf )
    146    {
    147    String serializations = getSerializations( jobConf );
    148
    149    LinkedList<String> list = new LinkedList<String>();
    150
    151    if( serializations != null && !serializations.isEmpty() )
    152      Collections.addAll( list, serializations.split( "," ) );
    153
    154    // required by MultiInputSplit
    155    String writable = WritableSerialization.class.getName();
    156    String tuple = TupleSerialization.class.getName();
    157
    158    list.remove( writable );
    159    list.remove( tuple );
    160
    161    list.addFirst( writable );
    162    list.addFirst( tuple );
    163
    164    // make writable last
    165    jobConf.set( HADOOP_IO_SERIALIZATIONS, Util.join( list, "," ) );
    166    }
    167
    168  static String getSerializations( Configuration jobConf )
    169    {
    170    return jobConf.get( HADOOP_IO_SERIALIZATIONS, null );
    171    }
    172
    173  public static Comparator getDefaultComparator( Comparator comparator, Configuration jobConf )
    174    {
    175    String typeName = jobConf.get( FlowProps.DEFAULT_ELEMENT_COMPARATOR );
    176
    177    if( Util.isEmpty( typeName ) )
    178      return null;
    179
    180    if( comparator == null )
    181      return createComparator( jobConf, typeName );
    182
    183    if( comparator.getClass().getName().equals( typeName ) && !( comparator instanceof Configured ) )
    184      return comparator;
    185
    186    return createComparator( jobConf, typeName );
    187    }
    188
    189  public static Comparator getDefaultComparator( Configuration jobConf )
    190    {
    191    String typeName = jobConf.get( FlowProps.DEFAULT_ELEMENT_COMPARATOR );
    192
    193    if( Util.isEmpty( typeName ) )
    194      return null;
    195
    196    return createComparator( jobConf, typeName );
    197    }
    198
    199  private static Comparator createComparator( Configuration jobConf, String typeName )
    200    {
    201    LOG.debug( "using default comparator: {}", typeName );
    202
    203    try
    204      {
    205      Class<Comparator> type = (Class<Comparator>) TupleSerialization.class.getClassLoader().loadClass( typeName );
    206
    207      return ReflectionUtils.newInstance( type, jobConf );
    208      }
    209    catch( ClassNotFoundException exception )
    210      {
    211      throw new CascadingException( "unable to load class: " + typeName, exception );
    212      }
    213    }
    214
    215  /** Constructor TupleSerialization creates a new TupleSerialization instance. */
    216  public TupleSerialization()
    217    {
    218    }
    219
    220  public TupleSerialization( final FlowProcess<? extends Configuration> flowProcess )
    221    {
    222    super( new Configuration()
    223    {
    224    @Override
    225    public String get( String name )
    226      {
    227      return get( name, null );
    228      }
    229
    230    @Override
    231    public String get( String name, String defaultValue )
    232      {
    233      Object value = flowProcess.getProperty( name );
    234      return value == null ? defaultValue : String.valueOf( value );
    235      }
    236    } );
    237    }
    238
    239  /**
    240   * Constructor TupleSerialization creates a new TupleSerialization instance.
    241   *
    242   * @param conf of type Configuration
    243   */
    244  public TupleSerialization( Configuration conf )
    245    {
    246    super( conf );
    247    }
    248
    249  @Override
    250  public void setConf( Configuration conf )
    251    {
    252    super.setConf( conf );
    253
    254    if( conf != null )
    255      defaultComparator = getDefaultComparator( conf );
    256    }
    257
    258  @Override
    259  public Configuration getConf()
    260    {
    261    if( super.getConf() == null )
    262      setConf( new Configuration() );
    263
    264    return super.getConf();
    265    }
    266
    267  public boolean areTypesIgnored()
    268    {
    269    if( typesIgnored == null )
    270      {
    271      typesIgnored = getConf().getBoolean( TupleSerializationProps.IGNORE_TYPES, false );
    272
    273      if( typesIgnored )
    274        LOG.info( "types are being ignored during serialization" );
    275      }
    276
    277    return typesIgnored;
    278    }
    279
    280  public boolean areTypesRequired()
    281    {
    282    if( typesRequired == null )
    283      {
    284      typesRequired = getConf().getBoolean( TupleSerializationProps.REQUIRE_TYPES, false );
    285
    286      if( typesRequired )
    287        LOG.info( "types are being enforced during serialization" );
    288      }
    289
    290    return typesRequired;
    291    }
    292
    293  SerializationFactory getSerializationFactory()
    294    {
    295    if( serializationFactory == null )
    296      serializationFactory = new SerializationFactory( getConf() );
    297
    298    return serializationFactory;
    299    }
    300
    301  public Fields getKeyFields()
    302    {
    303    if( keyFields == null && getFirstOrdinal() != null )
    304      keyFields = getKeyFieldsMap().get( getFirstOrdinal() );
    305
    306    return keyFields;
    307    }
    308
    309  public Class[] getKeyTypes()
    310    {
    311    Fields fields = getKeyFields();
    312
    313    return getTypesFor( fields );
    314    }
    315
    316  public Class[] getTypesFor( Fields fields )
    317    {
    318    if( areTypesIgnored() || fields == null )
    319      return null;
    320
    321    return fields.getTypesClasses();
    322    }
    323
    324  public Fields getSortFields()
    325    {
    326    if( sortFields == null && getFirstOrdinal() != null )
    327      sortFields = getSortFieldsMap().get( getFirstOrdinal() );
    328
    329    return sortFields;
    330    }
    331
    332  public Class[] getSortTypes()
    333    {
    334    return getTypesFor( getSortFields() );
    335    }
    336
    337  public Fields getValueFields()
    338    {
    339    if( valueFields == null && getFirstOrdinal() != null )
    340      valueFields = getValueFieldsMap().get( getFirstOrdinal() );
    341
    342    return valueFields;
    343    }
    344
    345  public Fields getMaskedValueFields()
    346    {
    347    return maskVoid( getValueFields(), getKeyFields() );
    348    }
    349
    350  public Class[] getValueTypes()
    351    {
    352    return getTypesFor( getValueFields() );
    353    }
    354
    355  public Map<Integer, Class[]> getKeyTypeMap()
    356    {
    357    if( areTypesIgnored() || getKeyFieldsMap() == null )
    358      return Collections.emptyMap();
    359
    360    Map<Integer, Class[]> map = new HashMap<>();
    361
    362    for( Map.Entry<Integer, Fields> entry : getKeyFieldsMap().entrySet() )
    363      map.put( entry.getKey(), entry.getValue().getTypesClasses() );
    364
    365    return map;
    366    }
    367
    368  public Map<Integer, Class[]> getValueTypeMap()
    369    {
    370    if( areTypesIgnored() || getValueFieldsMap() == null )
    371      return Collections.emptyMap();
    372
    373    Map<Integer, Class[]> map = new HashMap<>();
    374
    375    for( Map.Entry<Integer, Fields> entry : getValueFieldsMap().entrySet() )
    376      map.put( entry.getKey(), entry.getValue().getTypesClasses() );
    377
    378    return map;
    379    }
    380
    381  public Map<Integer, Class[]> getMaskedValueTypeMap()
    382    {
    383    if( areTypesIgnored() || getValueFieldsMap() == null )
    384      return Collections.emptyMap();
    385
    386    Map<Integer, Fields> keyFieldsMap = getKeyFieldsMap();
    387
    388    if( keyFieldsMap == null || keyFieldsMap.isEmpty() )
    389      return getValueTypeMap();
    390
    391    Map<Integer, Class[]> map = new HashMap<>();
    392
    393    for( Map.Entry<Integer, Fields> entry : getValueFieldsMap().entrySet() )
    394      {
    395      Integer ordinal = entry.getKey();
    396      Fields valueFields = entry.getValue();
    397      Fields keyFields = keyFieldsMap.get( ordinal );
    398
    399      map.put( ordinal, maskVoid( valueFields, keyFields ).getTypesClasses() );
    400      }
    401
    402    return map;
    403    }
    404
    405  public List<Integer> getOrdinals()
    406    {
    407    if( ordinals == null )
    408      ordinals = Util.split( Integer.class, ",", getConf().get( "cascading.node.ordinals" ) );
    409
    410    return ordinals;
    411    }
    412
    413  public Integer getFirstOrdinal()
    414    {
    415    if( getOrdinals().isEmpty() )
    416      return null;
    417
    418    return Util.getFirst( getOrdinals() );
    419    }
    420
    421  public Map<Integer, Fields> getKeyFieldsMap()
    422    {
    423    if( keyFieldsMap == null )
    424      keyFieldsMap = getFields( getConf(), "cascading.node.key.fields" );
    425
    426    return keyFieldsMap;
    427    }
    428
    429  public Map<Integer, Fields> getSortFieldsMap()
    430    {
    431    if( sortFields == null )
    432      sortFieldsMap = getFields( getConf(), "cascading.node.sort.fields" );
    433
    434    return sortFieldsMap;
    435    }
    436
    437  public Map<Integer, Fields> getValueFieldsMap()
    438    {
    439    if( valueFieldsMap == null )
    440      valueFieldsMap = getFields( getConf(), "cascading.node.value.fields" );
    441
    442    return valueFieldsMap;
    443    }
    444
    445  /** Must be called before {@link #getClassNameFor(int)} and {@link #getTokenFor(String)} methods. */
    446  void initTokenMaps()
    447    {
    448    if( tokenClassesMap != null )
    449      return;
    450
    451    tokenClassesMap = new HashMap<>();
    452    classesTokensMap = new HashMap<>();
    453
    454    String tokenProperty = getSerializationTokens( getConf() );
    455
    456    if( tokenProperty != null )
    457      {
    458      tokenProperty = tokenProperty.replaceAll( "\\s", "" ); // allow for whitespace in token set
    459
    460      for( String pair : tokenProperty.split( "," ) )
    461        {
    462        String[] elements = pair.split( "=" );
    463        addToken( null, Integer.parseInt( elements[ 0 ] ), elements[ 1 ] );
    464        }
    465      }
    466
    467    String serializationsString = getSerializations( getConf() );
    468
    469    LOG.debug( "using hadoop serializations from the job conf: {} ", serializationsString );
    470
    471    if( serializationsString == null )
    472      return;
    473
    474    String[] serializations = serializationsString.split( "," );
    475
    476    for( String serializationName : serializations )
    477      {
    478      try
    479        {
    480        Class type = getConf().getClassByName( serializationName );
    481
    482        SerializationToken tokenAnnotation = (SerializationToken) type.getAnnotation( SerializationToken.class );
    483
    484        if( tokenAnnotation == null )
    485          continue;
    486
    487        if( tokenAnnotation.tokens().length != tokenAnnotation.classNames().length )
    488          throw new CascadingException( "serialization annotation tokens and classNames must be the same length" );
    489
    490        int[] tokens = tokenAnnotation.tokens();
    491
    492        for( int i = 0; i < tokens.length; i++ )
    493          addToken( type, tokens[ i ], tokenAnnotation.classNames()[ i ] );
    494        }
    495      catch( ClassNotFoundException exception )
    496        {
    497        LOG.warn( "unable to load serialization class: {}", serializationName, exception );
    498        }
    499      }
    500
    501    tokensSize = tokenClassesMap.size();
    502    }
    503
    504  private void addToken( Class type, int token, String className )
    505    {
    506    if( type != null && !type.getName().startsWith( "cascading." ) && token < 128 )
    507      throw new CascadingException( "serialization annotation tokens may not be less than 128, was: " + token );
    508
    509    if( tokenClassesMap.containsKey( token ) )
    510      {
    511      if( type == null )
    512        throw new IllegalStateException( "duplicate serialization token: " + token + " for class: " + className + " found in properties" );
    513
    514      throw new IllegalStateException( "duplicate serialization token: " + token + " for class: " + className + " on serialization: " + type.getName() );
    515      }
    516
    517    if( classesTokensMap.containsKey( className ) )
    518      {
    519      if( type == null )
    520        throw new IllegalStateException( "duplicate serialization classname: " + className + " for token: " + token + " found in properties " );
    521
    522      throw new IllegalStateException( "duplicate serialization classname: " + className + " for token: " + token + " on serialization: " + type.getName() );
    523      }
    524
    525    LOG.debug( "adding serialization token: {}, for classname: {}", token, className );
    526
    527    tokenClassesMap.put( token, className );
    528    classesTokensMap.put( className, token );
    529    }
    530
    531  /**
    532   * Returns the className for the given token.
    533   *
    534   * @param token of type int
    535   * @return a String
    536   */
    537  final String getClassNameFor( int token )
    538    {
    539    initTokenMaps();
    540
    541    if( tokensSize == 0 )
    542      return null;
    543
    544    return tokenClassesMap.get( token );
    545    }
    546
    547  final long getTokensMapSize()
    548    {
    549    return tokensSize;
    550    }
    551
    552  /**
    553   * Returns the token for the given className.
    554   *
    555   * @param className of type String
    556   * @return an Integer
    557   */
    558  final Integer getTokenFor( String className )
    559    {
    560    initTokenMaps();
    561
    562    if( tokensSize == 0 )
    563      return null;
    564
    565    return classesTokensMap.get( className );
    566    }
    567
    568  public Comparator getDefaultComparator()
    569    {
    570    return defaultComparator;
    571    }
    572
    573  public Comparator getComparator( Class type )
    574    {
    575    Serialization serialization = getSerialization( type );
    576
    577    Comparator comparator = null;
    578
    579    if( serialization instanceof Comparison )
    580      comparator = ( (Comparison) serialization ).getComparator( type );
    581
    582    if( comparator != null )
    583      return comparator;
    584
    585    return defaultComparator;
    586    }
    587
    588  Serialization getSerialization( String className )
    589    {
    590    return getSerialization( getClass( className ) );
    591    }
    592
    593  Serialization getSerialization( Class type )
    594    {
    595    return getSerializationFactory().getSerialization( type );
    596    }
    597
    598  Serializer getNewSerializer( Class type )
    599    {
    600    try
    601      {
    602      Serializer serializer = getSerializationFactory().getSerializer( type );
    603
    604      if( serializer == null )
    605        throw new CascadingException( "unable to load serializer for: " + type.getName() + " from: " + getSerializationFactory().getClass().getName() );
    606
    607      return serializer;
    608      }
    609    catch( NullPointerException exception )
    610      {
    611      throw new CascadingException( "unable to load serializer for: " + type.getName() + " from: " + getSerializationFactory().getClass().getName() );
    612      }
    613    }
    614
    615  Deserializer getNewDeserializer( String className )
    616    {
    617    try
    618      {
    619      Deserializer deserializer = getSerializationFactory().getDeserializer( getClass( className ) );
    620
    621      if( deserializer == null )
    622        throw new CascadingException( "unable to load deserializer for: " + className + " from: " + getSerializationFactory().getClass().getName() );
    623
    624      return deserializer;
    625      }
    626    catch( NullPointerException exception )
    627      {
    628      throw new CascadingException( "unable to load deserializer for: " + className + " from: " + getSerializationFactory().getClass().getName() );
    629      }
    630    }
    631
    632  KeyTupleDeserializer getKeyTupleDeserializer()
    633    {
    634    return new KeyTupleDeserializer( getElementReader() );
    635    }
    636
    637  ValueTupleDeserializer getValueTupleDeserializer()
    638    {
    639    return new ValueTupleDeserializer( getElementReader() );
    640    }
    641
    642  TuplePairDeserializer getTuplePairDeserializer()
    643    {
    644    return new TuplePairDeserializer( getElementReader() );
    645    }
    646
    647  /**
    648   * Method getElementReader returns the elementReader of this TupleSerialization object.
    649   *
    650   * @return the elementReader (type SerializationElementReader) of this TupleSerialization object.
    651   */
    652  public SerializationElementReader getElementReader()
    653    {
    654    return new SerializationElementReader( this );
    655    }
    656
    657  TupleDeserializer getTupleDeserializer()
    658    {
    659    return new TupleDeserializer( getElementReader() );
    660    }
    661
    662  private KeyTupleSerializer getKeyTupleSerializer()
    663    {
    664    return new KeyTupleSerializer( getElementWriter() );
    665    }
    666
    667  private ValueTupleSerializer getValueTupleSerializer()
    668    {
    669    return new ValueTupleSerializer( getElementWriter() );
    670    }
    671
    672  private TuplePairSerializer getTuplePairSerializer()
    673    {
    674    return new TuplePairSerializer( getElementWriter() );
    675    }
    676
    677  KeyIndexTupleDeserializer getKeyIndexTupleDeserializer()
    678    {
    679    return new KeyIndexTupleDeserializer( getElementReader() );
    680    }
    681
    682  ValueIndexTupleDeserializer getValueIndexTupleDeserializer()
    683    {
    684    return new ValueIndexTupleDeserializer( getElementReader() );
    685    }
    686
    687  IndexTupleDeserializer getIndexTupleDeserializer()
    688    {
    689    return new IndexTupleDeserializer( getElementReader() );
    690    }
    691
    692  /**
    693   * Method getElementWriter returns the elementWriter of this TupleSerialization object.
    694   *
    695   * @return the elementWriter (type SerializationElementWriter) of this TupleSerialization object.
    696   */
    697  public SerializationElementWriter getElementWriter()
    698    {
    699    return new SerializationElementWriter( this );
    700    }
    701
    702  private TupleSerializer getTupleSerializer()
    703    {
    704    return new TupleSerializer( getElementWriter() );
    705    }
    706
    707  private KeyIndexTupleSerializer getKeyIndexTupleSerializer()
    708    {
    709    return new KeyIndexTupleSerializer( getElementWriter() );
    710    }
    711
    712  private ValueIndexTupleSerializer getValueIndexTupleSerializer()
    713    {
    714    return new ValueIndexTupleSerializer( getElementWriter() );
    715    }
    716
    717  private IndexTupleSerializer getIndexTupleSerializer()
    718    {
    719    return new IndexTupleSerializer( getElementWriter() );
    720    }
    721
    722  /**
    723   * Method accept implements {@link Serialization#accept(Class)}.
    724   *
    725   * @param c of type Class
    726   * @return boolean
    727   */
    728  public boolean accept( Class c )
    729    {
    730    return Tuple.class == c ||
    731      KeyTuple.class == c || ValueTuple.class == c ||
    732      KeyIndexTuple.class == c || ValueIndexTuple.class == c ||
    733      TuplePair.class == c || IndexTuple.class == c;
    734    }
    735
    736  /**
    737   * Method getDeserializer implements {@link Serialization#getDeserializer(Class)}.
    738   *
    739   * @param c of type Class
    740   * @return Deserializer
    741   */
    742  public Deserializer getDeserializer( Class c )
    743    {
    744    if( c == Tuple.class )
    745      return getTupleDeserializer();
    746    else if( c == KeyTuple.class )
    747      return getKeyTupleDeserializer();
    748    else if( c == ValueTuple.class )
    749      return getValueTupleDeserializer();
    750    else if( c == KeyIndexTuple.class )
    751      return getKeyIndexTupleDeserializer();
    752    else if( c == ValueIndexTuple.class )
    753      return getValueIndexTupleDeserializer();
    754    else if( c == TuplePair.class )
    755      return getTuplePairDeserializer();
    756    else if( c == IndexTuple.class )
    757      return getIndexTupleDeserializer();
    758
    759    throw new IllegalArgumentException( "unknown class, cannot deserialize: " + c.getName() );
    760    }
    761
    762  /**
    763   * Method getSerializer implements {@link Serialization#getSerializer(Class)}.
    764   *
    765   * @param c of type Class
    766   * @return Serializer
    767   */
    768  public Serializer getSerializer( Class c )
    769    {
    770    if( c == Tuple.class )
    771      return getTupleSerializer();
    772    else if( c == KeyTuple.class )
    773      return getKeyTupleSerializer();
    774    else if( c == ValueTuple.class )
    775      return getValueTupleSerializer();
    776    else if( c == KeyIndexTuple.class )
    777      return getKeyIndexTupleSerializer();
    778    else if( c == ValueIndexTuple.class )
    779      return getValueIndexTupleSerializer();
    780    else if( c == TuplePair.class )
    781      return getTuplePairSerializer();
    782    else if( c == IndexTuple.class )
    783      return getIndexTupleSerializer();
    784
    785    throw new IllegalArgumentException( "unknown class, cannot serialize: " + c.getName() );
    786    }
    787
    788  public Class getClass( String className )
    789    {
    790    Class type = classCache.get( className );
    791
    792    if( type != null )
    793      return type;
    794
    795    try
    796      {
    797      if( className.charAt( 0 ) == '[' )
    798        type = Class.forName( className, true, Thread.currentThread().getContextClassLoader() );
    799      else
    800        type = Thread.currentThread().getContextClassLoader().loadClass( className );
    801      }
    802    catch( ClassNotFoundException exception )
    803      {
    804      throw new TupleException( "unable to load class named: " + className, exception );
    805      }
    806
    807    classCache.put( className, type );
    808
    809    return type;
    810    }
    811
    812  public static Map<Integer, Fields> getFields( Configuration conf, String property )
    813    {
    814    try
    815      {
    816      return HadoopUtil.getFields( conf, property );
    817      }
    818    catch( IOException exception )
    819      {
    820      LOG.warn( "unable to get fields for: " + property );
    821
    822      return Collections.emptyMap();
    823      }
    824    }
    825
    826  private static Fields maskVoid( Fields fields, Fields mask )
    827    {
    828    if( fields == null )
    829      return null;
    830
    831    if( mask == null || !fields.hasTypes() || !mask.hasTypes() )
    832      return fields;
    833
    834    Fields voidedKey = mask.applyTypes( Fields.size( mask.size(), Void.class ) );
    835
    836    fields = fields.applyTypes( voidedKey );
    837
    838    return fields;
    839    }
    840
    841  public static class SerializationElementReader implements TupleInputStream.ElementReader
    842    {
    843    /** Field LOG */
    844    private static final Logger LOG = LoggerFactory.getLogger( SerializationElementReader.class );
    845
    846    /** Field tupleSerialization */
    847    private final TupleSerialization tupleSerialization;
    848
    849    /** Field deserializers */
    850    final Map<String, Deserializer> deserializers = new HashMap<String, Deserializer>();
    851
    852    /**
    853     * Constructor SerializationElementReader creates a new SerializationElementReader instance.
    854     *
    855     * @param tupleSerialization of type TupleSerialization
    856     */
    857    public SerializationElementReader( TupleSerialization tupleSerialization )
    858      {
    859      this.tupleSerialization = tupleSerialization;
    860      }
    861
    862    public TupleSerialization getTupleSerialization()
    863      {
    864      return tupleSerialization;
    865      }
    866
    867    public Object read( int token, DataInputStream inputStream ) throws IOException
    868      {
    869      String className = getClassNameFor( token, inputStream );
    870      Deserializer deserializer = getDeserializerFor( inputStream, className );
    871
    872      Object foundObject = null;
    873      Object object;
    874
    875      try
    876        {
    877        object = deserializer.deserialize( foundObject );
    878        }
    879      catch( IOException exception )
    880        {
    881        LOG.error( "failed deserializing token: " + token + " with classname: " + className, exception );
    882
    883        throw exception;
    884        }
    885
    886      return object;
    887      }
    888
    889    public Object read( Class type, DataInputStream inputStream ) throws IOException
    890      {
    891      String className = type.getName();
    892      Deserializer deserializer = getDeserializerFor( inputStream, className );
    893
    894      Object foundObject = null;
    895      Object object;
    896
    897      try
    898        {
    899        object = deserializer.deserialize( foundObject );
    900        }
    901      catch( IOException exception )
    902        {
    903        LOG.error( "failed deserializing: " + className, exception );
    904
    905        throw exception;
    906        }
    907
    908      return object;
    909      }
    910
    911    @Override
    912    public Comparator getComparatorFor( int token, DataInputStream inputStream ) throws IOException
    913      {
    914      Class type = tupleSerialization.getClass( getClassNameFor( token, inputStream ) );
    915
    916      return tupleSerialization.getComparator( type );
    917      }
    918
    919    private Deserializer getDeserializerFor( DataInputStream inputStream, String className ) throws IOException
    920      {
    921      Deserializer deserializer = deserializers.get( className );
    922
    923      if( deserializer == null )
    924        {
    925        deserializer = tupleSerialization.getNewDeserializer( className );
    926        deserializer.open( inputStream );
    927        deserializers.put( className, deserializer );
    928        }
    929
    930      return deserializer;
    931      }
    932
    933    public String getClassNameFor( int token, DataInputStream inputStream ) throws IOException
    934      {
    935      String className = tupleSerialization.getClassNameFor( token );
    936
    937      try
    938        {
    939        if( className == null )
    940          className = WritableUtils.readString( inputStream );
    941        }
    942      catch( IOException exception )
    943        {
    944        LOG.error( "unable to resolve token: {}, to a valid classname, with token map of size: {}, rethrowing IOException", token, tupleSerialization.getTokensMapSize() );
    945        throw exception;
    946        }
    947
    948      return className;
    949      }
    950
    951    public void close()
    952      {
    953      if( deserializers.size() == 0 )
    954        return;
    955
    956      Collection<Deserializer> clone = new ArrayList<Deserializer>( deserializers.values() );
    957
    958      deserializers.clear();
    959
    960      for( Deserializer deserializer : clone )
    961        {
    962        try
    963          {
    964          deserializer.close();
    965          }
    966        catch( IOException exception )
    967          {
    968          // do nothing
    969          }
    970        }
    971      }
    972    }
    973
    974  public static class SerializationElementWriter implements TupleOutputStream.ElementWriter
    975    {
    976    /** Field LOG */
    977    private static final Logger LOG = LoggerFactory.getLogger( SerializationElementWriter.class );
    978
    979    /** Field tupleSerialization */
    980    private final TupleSerialization tupleSerialization;
    981
    982    /** Field serializers */
    983    final Map<Class, Serializer> serializers = new HashMap<Class, Serializer>();
    984
    985    public SerializationElementWriter( TupleSerialization tupleSerialization )
    986      {
    987      this.tupleSerialization = tupleSerialization;
    988      }
    989
    990    public TupleSerialization getTupleSerialization()
    991      {
    992      return tupleSerialization;
    993      }
    994
    995    public void write( DataOutputStream outputStream, Object object ) throws IOException
    996      {
    997      Class<?> type = object.getClass();
    998      String className = type.getName();
    999      Integer token = tupleSerialization.getTokenFor( className );
    1000
    1001      if( token == null )
    1002        {
    1003        LOG.debug( "no serialization token found for classname: {}", className );
    1004
    1005        WritableUtils.writeVInt( outputStream, HadoopTupleOutputStream.WRITABLE_TOKEN ); // denotes to punt to hadoop serialization
    1006        WritableUtils.writeString( outputStream, className );
    1007        }
    1008      else
    1009        {
    1010        WritableUtils.writeVInt( outputStream, token );
    1011        }
    1012
    1013      Serializer serializer = getSerializer( outputStream, type );
    1014
    1015      try
    1016        {
    1017        serializer.serialize( object );
    1018        }
    1019      catch( IOException exception )
    1020        {
    1021        LOG.error( "failed serializing token: " + token + " with classname: " + className, exception );
    1022
    1023        throw exception;
    1024        }
    1025      }
    1026
    1027    private Serializer getSerializer( DataOutputStream outputStream, Class<?> type ) throws IOException
    1028      {
    1029      Serializer serializer = serializers.get( type );
    1030
    1031      if( serializer == null )
    1032        {
    1033        serializer = tupleSerialization.getNewSerializer( type );
    1034        serializer.open( outputStream );
    1035        serializers.put( type, serializer );
    1036        }
    1037
    1038      return serializer;
    1039      }
    1040
    1041    public void write( DataOutputStream outputStream, Class<?> type, Object object ) throws IOException
    1042      {
    1043      Serializer serializer = getSerializer( outputStream, type );
    1044
    1045      try
    1046        {
    1047        serializer.serialize( object );
    1048        }
    1049      catch( IOException exception )
    1050        {
    1051        LOG.error( "failed serializing type: " + type.getName(), exception );
    1052
    1053        throw exception;
    1054        }
    1055      }
    1056
    1057    public void close()
    1058      {
    1059      if( serializers.size() == 0 )
    1060        return;
    1061
    1062      Collection<Serializer> clone = new ArrayList<Serializer>( serializers.values() );
    1063
    1064      serializers.clear();
    1065
    1066      for( Serializer serializer : clone )
    1067        {
    1068        try
    1069          {
    1070          serializer.close();
    1071          }
    1072        catch( IOException exception )
    1073          {
    1074          // do nothing
    1075          }
    1076        }
    1077      }
    1078    }
    1079  }