001 /* 002 * Copyright (c) 2007-2014 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 */ 020 021 package cascading.tap; 022 023 import java.beans.ConstructorProperties; 024 import java.io.IOException; 025 import java.util.ArrayList; 026 import java.util.Arrays; 027 import java.util.HashSet; 028 import java.util.Iterator; 029 import java.util.List; 030 import java.util.Map; 031 import java.util.Set; 032 033 import cascading.flow.FlowProcess; 034 import cascading.scheme.NullScheme; 035 import cascading.scheme.Scheme; 036 import cascading.tuple.Fields; 037 import cascading.tuple.TupleEntry; 038 import cascading.tuple.TupleEntryCollector; 039 import cascading.util.Util; 040 import org.slf4j.Logger; 041 import org.slf4j.LoggerFactory; 042 043 /** 044 * Class MultiSinkTap is both a {@link cascading.tap.CompositeTap} and {@link cascading.tap.SinkTap} that can write to 045 * multiple child {@link cascading.tap.Tap} instances simultaneously. 046 * <p/> 047 * It is the counterpart to {@link cascading.tap.MultiSourceTap}. 048 * <p/> 049 * Note all child Tap instances may or may not have the same declared Fields. In the case they do not, all 050 * sink fields will be merged into a single Fields instance via {@link Fields#merge(cascading.tuple.Fields...)}. 051 */ 052 public class MultiSinkTap<Child extends Tap, Config, Output> extends SinkTap<Config, Output> implements CompositeTap<Child> 053 { 054 /** Field LOG */ 055 private static final Logger LOG = LoggerFactory.getLogger( MultiSinkTap.class ); 056 057 /** Field taps */ 058 private final Child[] taps; 059 /** Field tempPath */ 060 private final String tempPath = "__multisink_placeholder_" + Util.createUniqueID(); 061 /** Field childConfigs */ 062 private List<Map<String, String>> childConfigs; 063 064 private class MultiSinkCollector extends TupleEntryCollector 065 { 066 TupleEntryCollector[] collectors; 067 068 public MultiSinkCollector( FlowProcess<Config> flowProcess, Tap... taps ) throws IOException 069 { 070 super( Fields.asDeclaration( getSinkFields() ) ); 071 072 collectors = new TupleEntryCollector[ taps.length ]; 073 074 Config conf = flowProcess.getConfigCopy(); 075 076 for( int i = 0; i < taps.length; i++ ) 077 { 078 Config mergedConf = childConfigs == null ? conf : flowProcess.mergeMapIntoConfig( conf, childConfigs.get( i ) ); 079 Tap tap = taps[ i ]; 080 LOG.info( "opening for write: {}", tap.toString() ); 081 082 collectors[ i ] = tap.openForWrite( flowProcess.copyWith( mergedConf ), null ); 083 } 084 } 085 086 protected void collect( TupleEntry tupleEntry ) throws IOException 087 { 088 for( int i = 0; i < taps.length; i++ ) 089 collectors[ i ].add( tupleEntry ); 090 } 091 092 @Override 093 public void close() 094 { 095 super.close(); 096 097 try 098 { 099 for( TupleEntryCollector collector : collectors ) 100 { 101 try 102 { 103 collector.close(); 104 } 105 catch( Exception exception ) 106 { 107 LOG.warn( "exception closing TupleEntryCollector", exception ); 108 } 109 } 110 } 111 finally 112 { 113 collectors = null; 114 } 115 } 116 } 117 118 /** 119 * Constructor MultiSinkTap creates a new MultiSinkTap instance. 120 * 121 * @param taps of type Tap... 122 */ 123 @ConstructorProperties({"taps"}) 124 public MultiSinkTap( Child... taps ) 125 { 126 this.taps = taps; 127 } 128 129 protected Child[] getTaps() 130 { 131 return taps; 132 } 133 134 @Override 135 public Iterator<Child> getChildTaps() 136 { 137 return Arrays.asList( getTaps() ).iterator(); 138 } 139 140 @Override 141 public long getNumChildTaps() 142 { 143 return getTaps().length; 144 } 145 146 @Override 147 public String getIdentifier() 148 { 149 return tempPath; 150 } 151 152 @Override 153 public void presentSinkFields( FlowProcess<Config> flowProcess, Fields fields ) 154 { 155 for( Tap child : getTaps() ) 156 child.presentSinkFields( flowProcess, fields ); 157 } 158 159 @Override 160 public TupleEntryCollector openForWrite( FlowProcess<Config> flowProcess, Output output ) throws IOException 161 { 162 return new MultiSinkCollector( flowProcess, getTaps() ); 163 } 164 165 @Override 166 public void sinkConfInit( FlowProcess<Config> process, Config conf ) 167 { 168 childConfigs = new ArrayList<Map<String, String>>(); 169 170 for( int i = 0; i < getTaps().length; i++ ) 171 { 172 Tap tap = getTaps()[ i ]; 173 Config jobConf = process.copyConfig( conf ); 174 175 tap.sinkConfInit( process, jobConf ); 176 177 childConfigs.add( process.diffConfigIntoMap( conf, jobConf ) ); 178 } 179 } 180 181 @Override 182 public boolean createResource( Config conf ) throws IOException 183 { 184 for( Tap tap : getTaps() ) 185 { 186 if( !tap.createResource( conf ) ) 187 return false; 188 } 189 190 return true; 191 } 192 193 @Override 194 public boolean deleteResource( Config conf ) throws IOException 195 { 196 for( Tap tap : getTaps() ) 197 { 198 if( !tap.deleteResource( conf ) ) 199 return false; 200 } 201 202 return true; 203 } 204 205 @Override 206 public boolean commitResource( Config conf ) throws IOException 207 { 208 for( Tap tap : getTaps() ) 209 { 210 if( !tap.commitResource( conf ) ) 211 return false; 212 } 213 214 return true; 215 } 216 217 @Override 218 public boolean rollbackResource( Config conf ) throws IOException 219 { 220 for( Tap tap : getTaps() ) 221 { 222 if( !tap.rollbackResource( conf ) ) 223 return false; 224 } 225 226 return true; 227 } 228 229 @Override 230 public boolean resourceExists( Config conf ) throws IOException 231 { 232 for( Tap tap : getTaps() ) 233 { 234 if( !tap.resourceExists( conf ) ) 235 return false; 236 } 237 238 return true; 239 } 240 241 @Override 242 public long getModifiedTime( Config conf ) throws IOException 243 { 244 long modified = getTaps()[ 0 ].getModifiedTime( conf ); 245 246 for( int i = 1; i < getTaps().length; i++ ) 247 modified = Math.max( getTaps()[ i ].getModifiedTime( conf ), modified ); 248 249 return modified; 250 } 251 252 @Override 253 public Scheme getScheme() 254 { 255 if( super.getScheme() != null ) 256 return super.getScheme(); 257 258 Set<Fields> fields = new HashSet<Fields>(); 259 260 for( Tap child : getTaps() ) 261 fields.add( child.getSinkFields() ); 262 263 // if all schemes have the same sink fields, the just use the scheme 264 if( fields.size() == 1 ) 265 { 266 setScheme( getTaps()[ 0 ].getScheme() ); 267 return super.getScheme(); 268 } 269 270 Fields allFields = Fields.merge( fields.toArray( new Fields[ fields.size() ] ) ); 271 272 setScheme( new NullScheme( allFields, allFields ) ); 273 274 return super.getScheme(); 275 } 276 277 @Override 278 public String toString() 279 { 280 return "MultiSinkTap[" + ( taps == null ? "none" : Arrays.asList( taps ) ) + ']'; 281 } 282 283 @Override 284 public boolean equals( Object o ) 285 { 286 if( this == o ) 287 return true; 288 if( !( o instanceof MultiSinkTap ) ) 289 return false; 290 if( !super.equals( o ) ) 291 return false; 292 293 MultiSinkTap that = (MultiSinkTap) o; 294 295 if( !Arrays.equals( taps, that.taps ) ) 296 return false; 297 298 return true; 299 } 300 301 @Override 302 public int hashCode() 303 { 304 int result = super.hashCode(); 305 result = 31 * result + ( taps != null ? Arrays.hashCode( taps ) : 0 ); 306 return result; 307 } 308 }