Coverage Report

 /*
  * 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.giraph.block_app.library;
 
 import java.util.Iterator;
 
 import org.apache.giraph.block_app.framework.api.BlockMasterApi;
 import org.apache.giraph.block_app.framework.block.Block;
 import org.apache.giraph.block_app.framework.block.SequenceBlock;
 import org.apache.giraph.combiner.MessageCombiner;
 import org.apache.giraph.function.Consumer;
 import org.apache.giraph.function.Function;
 import org.apache.giraph.function.ObjectTransfer;
 import org.apache.giraph.function.PairConsumer;
 import org.apache.giraph.function.vertex.ConsumerWithVertex;
 import org.apache.giraph.function.vertex.FunctionWithVertex;
 import org.apache.giraph.function.vertex.SupplierFromVertex;
 import org.apache.giraph.graph.Vertex;
 import org.apache.giraph.reducers.ReduceOperation;
 import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.io.WritableComparable;
 
 /**
  * Utility class for creating sequences of sending replies to received
  * messages. Current instance of this object represents partial chain,
  * where we have specified which messages will be send at the lastly defined
  * link in the chain thus far, but we haven't specified yet what to do when
  * vertices receive them.
  *
  * Contains set of:
  * - static startX methods, used to create the chain
  * - thenX methods, used to add one more Piece to the chain, can be
  *   "chained" arbitrary number of times.
  * - endX methods, used to finish the chain, returning
  *   the Block representing the whole chain
  *
  * If messageSupplier or targetsSupplier returns null, current vertex
  * is not going to send any messages.
  *
  * @param <I> Vertex id type
  * @param <V> Vertex value type
  * @param <E> Edge value type
  * @param <P> Previous value
  */
 public class SendMessageChain<I extends WritableComparable, V extends Writable,
     E extends Writable, P> {
   /**
    * Represent current partial chain. Given a way to consume messages
    * received in lastly defined link in this chain, it will produce block
    * representing a chain created thus far.
    */
   private final Function<ConsumerWithVertex<I, V, E, P>, Block> blockCreator;
 
   private SendMessageChain(
       Function<ConsumerWithVertex<I, V, E, P>, Block> blockCreator) {
     this.blockCreator = blockCreator;
   }
 
   /**
    * Start chain with sending message provided by messageSupplier to all
    * targets provided by targetsSupplier.
    */
   public static <I extends WritableComparable, V extends Writable,
   E extends Writable, M extends Writable>
   SendMessageChain<I, V, E, Iterable<M>> startSend(
       final String name,
       final Class<M> messageClass,
       final SupplierFromVertex<I, V, E, M> messageSupplier,
       final SupplierFromVertex<I, V, E, Iterator<I>> targetsSupplier) {
     return new SendMessageChain<>(
         new Function<ConsumerWithVertex<I, V, E, Iterable<M>>, Block>() {
           @Override
           public Block apply(
               ConsumerWithVertex<I, V, E, Iterable<M>> messagesConsumer) {
             return Pieces.sendMessage(
                 name, messageClass, messageSupplier,
                 targetsSupplier, messagesConsumer);
           }
         });
   }
 
   /**
    * Start chain with sending message provided by messageSupplier to all
    * targets provided by targetsSupplier, and use given messageCombiner to
    * combine messages together.
    */
   public static <I extends WritableComparable, V extends Writable,
   E extends Writable, M extends Writable>
   SendMessageChain<I, V, E, M> startSend(
       final String name,
       final MessageCombiner<? super I, M> messageCombiner,
       final SupplierFromVertex<I, V, E, M> messageSupplier,
       final SupplierFromVertex<I, V, E, Iterator<I>> targetsSupplier) {
     return new SendMessageChain<>(
         new Function<ConsumerWithVertex<I, V, E, M>, Block>() {
           @Override
           public Block apply(ConsumerWithVertex<I, V, E, M> messagesConsumer) {
             return Pieces.sendMessage(
                 name, messageCombiner, messageSupplier,
                 targetsSupplier, messagesConsumer);
           }
         });
   }
 
   /**
    * Start chain with sending message provided by messageSupplier to all
    * neighbors of a current vertex.
    */
   public static <I extends WritableComparable, V extends Writable,
   E extends Writable, M extends Writable>
   SendMessageChain<I, V, E, Iterable<M>> startSendToNeighbors(
       final String name,
       final Class<M> messageClass,
       final SupplierFromVertex<I, V, E, M> messageSupplier) {
     return startSend(name, messageClass, messageSupplier,
         VertexSuppliers.<I, V, E>vertexNeighborsSupplier());
   }
 
   /**
    * Start chain with sending message provided by messageSupplier to all
    * neighbors of a current vertex, and use given messageCombiner to
    * combine messages together.
    */
   public static <I extends WritableComparable, V extends Writable,
   E extends Writable, M extends Writable>
   SendMessageChain<I, V, E, M> startSendToNeighbors(
       final String name,
       final MessageCombiner<? super I, M> messageCombiner,
       final SupplierFromVertex<I, V, E, M> messageSupplier) {
     return startSend(name, messageCombiner, messageSupplier,
         VertexSuppliers.<I, V, E>vertexNeighborsSupplier());
   }
 
   /**
    * Start chain by providing a function that will produce Block representing
    * beginning of the chain, given a consumer of messages send
    * by the last link in the created block.
    */
   public static <I extends WritableComparable, V extends Writable,
   E extends Writable, P extends Writable>
   SendMessageChain<I, V, E, P> startCustom(
       Function<ConsumerWithVertex<I, V, E, P>, Block> createStartingBlock) {
     return new SendMessageChain<>(createStartingBlock);
   }
 
   /**
    * Give previously received message(s) to messageSupplier, and send message
    * it returns to all targets provided by targetsSupplier.
    */
   public <M extends Writable>
   SendMessageChain<I, V, E, Iterable<M>> thenSend(
       final String name,
       final Class<M> messageClass,
       final FunctionWithVertex<I, V, E, P, M> messageSupplier,
       final SupplierFromVertex<I, V, E, Iterator<I>> targetsSupplier) {
     final ObjectTransfer<P> prevMessagesTransfer = new ObjectTransfer<>();
 
     return new SendMessageChain<>(
         new Function<ConsumerWithVertex<I, V, E, Iterable<M>>, Block>() {
           @Override
           public Block apply(
               ConsumerWithVertex<I, V, E, Iterable<M>> messagesConsumer) {
             return new SequenceBlock(
               blockCreator.apply(
                   prevMessagesTransfer.<I, V, E>castToConsumer()),
               Pieces.sendMessage(
                 name, messageClass,
                 new SupplierFromVertex<I, V, E, M>() {
                   @Override
                   public M get(Vertex<I, V, E> vertex) {
                     return messageSupplier.apply(
                         vertex, prevMessagesTransfer.get());
                   }
                 },
                 targetsSupplier, messagesConsumer));
           }
         });
   }
 
   /**
    * Give previously received message(s) to messageSupplier, and send message
    * it returns to all neighbors of current vertex.
    */
   public <M extends Writable>
   SendMessageChain<I, V, E, Iterable<M>> thenSendToNeighbors(
       final String name,
       final Class<M> messageClass,
       final FunctionWithVertex<I, V, E, P, M> messageSupplier) {
     return thenSend(name, messageClass, messageSupplier,
         VertexSuppliers.<I, V, E>vertexNeighborsSupplier());
   }
 
   /**
    * Give previously received message(s) to messageSupplier, and send message
    * it returns to all targets provided by targetsSupplier, and use given
    * messageCombiner to combine messages together.
    */
   public <M extends Writable>
   SendMessageChain<I, V, E, M> thenSend(
       final String name,
       final MessageCombiner<? super I, M> messageCombiner,
       final FunctionWithVertex<I, V, E, P, M> messageSupplier,
       final SupplierFromVertex<I, V, E, Iterator<I>> targetsSupplier) {
     final ObjectTransfer<P> prevMessagesTransfer = new ObjectTransfer<>();
 
     return new SendMessageChain<>(
         new Function<ConsumerWithVertex<I, V, E, M>, Block>() {
           @Override
           public Block apply(ConsumerWithVertex<I, V, E, M> messagesConsumer) {
             return new SequenceBlock(
               blockCreator.apply(
                   prevMessagesTransfer.<I, V, E>castToConsumer()),
               Pieces.sendMessage(
                 name, messageCombiner,
                 new SupplierFromVertex<I, V, E, M>() {
                   @Override
                   public M get(Vertex<I, V, E> vertex) {
                     return messageSupplier.apply(
                         vertex, prevMessagesTransfer.get());
                   }
                 },
                 targetsSupplier, messagesConsumer));
           }
         });
   }
 
   /**
    * Give previously received message(s) to messageSupplier, and send message
    * it returns to all neighbors of current vertex, and use given
    * messageCombiner to combine messages together.
    */
   public <M extends Writable>
   SendMessageChain<I, V, E, M> thenSendToNeighbors(
       final String name,
       final MessageCombiner<? super I, M> messageCombiner,
       final FunctionWithVertex<I, V, E, P, M> messageSupplier) {
     return thenSend(name, messageCombiner, messageSupplier,
         VertexSuppliers.<I, V, E>vertexNeighborsSupplier());
   }
 
   /**
    * End chain by giving received messages to valueSupplier,
    * to produce value that should be reduced, and consumed on master
    * by reducedValueConsumer.
    */
   public <S, R extends Writable>
   Block endReduce(final String name, final ReduceOperation<S, R> reduceOp,
       final FunctionWithVertex<I, V, E, P, S> valueSupplier,
       final Consumer<R> reducedValueConsumer) {
     return endCustom(new Function<SupplierFromVertex<I, V, E, P>, Block>() {
       @Override
       public Block apply(final SupplierFromVertex<I, V, E, P> prevMessages) {
         return Pieces.reduce(
             name,
             reduceOp,
             new SupplierFromVertex<I, V, E, S>() {
               @Override
               public S get(Vertex<I, V, E> vertex) {
                 return valueSupplier.apply(vertex, prevMessages.get(vertex));
               }
             },
             reducedValueConsumer);
       }
     });
   }
 
   /**
    * End chain by giving received messages to valueSupplier,
    * to produce value that should be reduced, and consumed on master
    * by reducedValueConsumer.
    */
   public <S, R extends Writable>
   Block endReduceWithMaster(
       final String name, final ReduceOperation<S, R> reduceOp,
       final FunctionWithVertex<I, V, E, P, S> valueSupplier,
       final PairConsumer<R, BlockMasterApi> reducedValueConsumer) {
     return endCustom(new Function<SupplierFromVertex<I, V, E, P>, Block>() {
       @Override
       public Block apply(final SupplierFromVertex<I, V, E, P> prevMessages) {
         return Pieces.reduceWithMaster(
             name,
             reduceOp,
             new SupplierFromVertex<I, V, E, S>() {
               @Override
               public S get(Vertex<I, V, E> vertex) {
                 return valueSupplier.apply(vertex, prevMessages.get(vertex));
               }
             },
             reducedValueConsumer);
       }
     });
   }
 
   /**
    * End chain by processing messages received within the last link
    * in the chain.
    */
   public Block endConsume(ConsumerWithVertex<I, V, E, P> messagesConsumer) {
     return blockCreator.apply(messagesConsumer);
   }
 
   /**
    * End chain by providing a function that will produce Block to be attached
    * to the end of current chain, given a supplier of messages received
    * within the last link in the chain.
    */
   public Block endCustom(
       Function<SupplierFromVertex<I, V, E, P>, Block> createBlockToAttach) {
     final ObjectTransfer<P> prevMessagesTransfer = new ObjectTransfer<>();
     return new SequenceBlock(
         blockCreator.apply(prevMessagesTransfer.<I, V, E>castToConsumer()),
         createBlockToAttach.apply(
             prevMessagesTransfer.<I, V, E>castToSupplier()));
   }
 }

1		/*
2		* Licensed to the Apache Software Foundation (ASF) under one
3		* or more contributor license agreements. See the NOTICE file
4		* distributed with this work for additional information
5		* regarding copyright ownership. The ASF licenses this file
6		* to you under the Apache License, Version 2.0 (the
7		* "License"); you may not use this file except in compliance
8		* with the License. You may obtain a copy of the License at
9		*
10		* http://www.apache.org/licenses/LICENSE-2.0
11		*
12		* Unless required by applicable law or agreed to in writing, software
13		* distributed under the License is distributed on an "AS IS" BASIS,
14		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15		* See the License for the specific language governing permissions and
16		* limitations under the License.
17		*/
18		package org.apache.giraph.block_app.library;
19
20		import java.util.Iterator;
21
22		import org.apache.giraph.block_app.framework.api.BlockMasterApi;
23		import org.apache.giraph.block_app.framework.block.Block;
24		import org.apache.giraph.block_app.framework.block.SequenceBlock;
25		import org.apache.giraph.combiner.MessageCombiner;
26		import org.apache.giraph.function.Consumer;
27		import org.apache.giraph.function.Function;
28		import org.apache.giraph.function.ObjectTransfer;
29		import org.apache.giraph.function.PairConsumer;
30		import org.apache.giraph.function.vertex.ConsumerWithVertex;
31		import org.apache.giraph.function.vertex.FunctionWithVertex;
32		import org.apache.giraph.function.vertex.SupplierFromVertex;
33		import org.apache.giraph.graph.Vertex;
34		import org.apache.giraph.reducers.ReduceOperation;
35		import org.apache.hadoop.io.Writable;
36		import org.apache.hadoop.io.WritableComparable;
37
38		/**
39		* Utility class for creating sequences of sending replies to received
40		* messages. Current instance of this object represents partial chain,
41		* where we have specified which messages will be send at the lastly defined
42		* link in the chain thus far, but we haven't specified yet what to do when
43		* vertices receive them.
44		*
45		* Contains set of:
46		* - static startX methods, used to create the chain
47		* - thenX methods, used to add one more Piece to the chain, can be
48		* "chained" arbitrary number of times.
49		* - endX methods, used to finish the chain, returning
50		* the Block representing the whole chain
51		*
52		* If messageSupplier or targetsSupplier returns null, current vertex
53		* is not going to send any messages.
54		*
55		* @param <I> Vertex id type
56		* @param <V> Vertex value type
57		* @param <E> Edge value type
58		* @param <P> Previous value
59		*/
60	0	public class SendMessageChain<I extends WritableComparable, V extends Writable,
61		E extends Writable, P> {
62		/**
63		* Represent current partial chain. Given a way to consume messages
64		* received in lastly defined link in this chain, it will produce block
65		* representing a chain created thus far.
66		*/
67		private final Function<ConsumerWithVertex<I, V, E, P>, Block> blockCreator;
68
69		private SendMessageChain(
70	0	Function<ConsumerWithVertex<I, V, E, P>, Block> blockCreator) {
71	0	this.blockCreator = blockCreator;
72	0	}
73
74		/**
75		* Start chain with sending message provided by messageSupplier to all
76		* targets provided by targetsSupplier.
77		*/
78		public static <I extends WritableComparable, V extends Writable,
79		E extends Writable, M extends Writable>
80		SendMessageChain<I, V, E, Iterable<M>> startSend(
81		final String name,
82		final Class<M> messageClass,
83		final SupplierFromVertex<I, V, E, M> messageSupplier,
84		final SupplierFromVertex<I, V, E, Iterator<I>> targetsSupplier) {
85	0	return new SendMessageChain<>(
86	0	new Function<ConsumerWithVertex<I, V, E, Iterable<M>>, Block>() {
87		@Override
88		public Block apply(
89		ConsumerWithVertex<I, V, E, Iterable<M>> messagesConsumer) {
90	0	return Pieces.sendMessage(
91		name, messageClass, messageSupplier,
92		targetsSupplier, messagesConsumer);
93		}
94		});
95		}
96
97		/**
98		* Start chain with sending message provided by messageSupplier to all
99		* targets provided by targetsSupplier, and use given messageCombiner to
100		* combine messages together.
101		*/
102		public static <I extends WritableComparable, V extends Writable,
103		E extends Writable, M extends Writable>
104		SendMessageChain<I, V, E, M> startSend(
105		final String name,
106		final MessageCombiner<? super I, M> messageCombiner,
107		final SupplierFromVertex<I, V, E, M> messageSupplier,
108		final SupplierFromVertex<I, V, E, Iterator<I>> targetsSupplier) {
109	0	return new SendMessageChain<>(
110	0	new Function<ConsumerWithVertex<I, V, E, M>, Block>() {
111		@Override
112		public Block apply(ConsumerWithVertex<I, V, E, M> messagesConsumer) {
113	0	return Pieces.sendMessage(
114		name, messageCombiner, messageSupplier,
115		targetsSupplier, messagesConsumer);
116		}
117		});
118		}
119
120		/**
121		* Start chain with sending message provided by messageSupplier to all
122		* neighbors of a current vertex.
123		*/
124		public static <I extends WritableComparable, V extends Writable,
125		E extends Writable, M extends Writable>
126		SendMessageChain<I, V, E, Iterable<M>> startSendToNeighbors(
127		final String name,
128		final Class<M> messageClass,
129		final SupplierFromVertex<I, V, E, M> messageSupplier) {
130	0	return startSend(name, messageClass, messageSupplier,
131	0	VertexSuppliers.<I, V, E>vertexNeighborsSupplier());
132		}
133
134		/**
135		* Start chain with sending message provided by messageSupplier to all
136		* neighbors of a current vertex, and use given messageCombiner to
137		* combine messages together.
138		*/
139		public static <I extends WritableComparable, V extends Writable,
140		E extends Writable, M extends Writable>
141		SendMessageChain<I, V, E, M> startSendToNeighbors(
142		final String name,
143		final MessageCombiner<? super I, M> messageCombiner,
144		final SupplierFromVertex<I, V, E, M> messageSupplier) {
145	0	return startSend(name, messageCombiner, messageSupplier,
146	0	VertexSuppliers.<I, V, E>vertexNeighborsSupplier());
147		}
148
149		/**
150		* Start chain by providing a function that will produce Block representing
151		* beginning of the chain, given a consumer of messages send
152		* by the last link in the created block.
153		*/
154		public static <I extends WritableComparable, V extends Writable,
155		E extends Writable, P extends Writable>
156		SendMessageChain<I, V, E, P> startCustom(
157		Function<ConsumerWithVertex<I, V, E, P>, Block> createStartingBlock) {
158	0	return new SendMessageChain<>(createStartingBlock);
159		}
160
161		/**
162		* Give previously received message(s) to messageSupplier, and send message
163		* it returns to all targets provided by targetsSupplier.
164		*/
165		public <M extends Writable>
166		SendMessageChain<I, V, E, Iterable<M>> thenSend(
167		final String name,
168		final Class<M> messageClass,
169		final FunctionWithVertex<I, V, E, P, M> messageSupplier,
170		final SupplierFromVertex<I, V, E, Iterator<I>> targetsSupplier) {
171	0	final ObjectTransfer<P> prevMessagesTransfer = new ObjectTransfer<>();
172
173	0	return new SendMessageChain<>(
174	0	new Function<ConsumerWithVertex<I, V, E, Iterable<M>>, Block>() {
175		@Override
176		public Block apply(
177		ConsumerWithVertex<I, V, E, Iterable<M>> messagesConsumer) {
178	0	return new SequenceBlock(
179	0	blockCreator.apply(
180	0	prevMessagesTransfer.<I, V, E>castToConsumer()),
181	0	Pieces.sendMessage(
182		name, messageClass,
183	0	new SupplierFromVertex<I, V, E, M>() {
184		@Override
185		public M get(Vertex<I, V, E> vertex) {
186	0	return messageSupplier.apply(
187	0	vertex, prevMessagesTransfer.get());
188		}
189		},
190		targetsSupplier, messagesConsumer));
191		}
192		});
193		}
194
195		/**
196		* Give previously received message(s) to messageSupplier, and send message
197		* it returns to all neighbors of current vertex.
198		*/
199		public <M extends Writable>
200		SendMessageChain<I, V, E, Iterable<M>> thenSendToNeighbors(
201		final String name,
202		final Class<M> messageClass,
203		final FunctionWithVertex<I, V, E, P, M> messageSupplier) {
204	0	return thenSend(name, messageClass, messageSupplier,
205	0	VertexSuppliers.<I, V, E>vertexNeighborsSupplier());
206		}
207
208		/**
209		* Give previously received message(s) to messageSupplier, and send message
210		* it returns to all targets provided by targetsSupplier, and use given
211		* messageCombiner to combine messages together.
212		*/
213		public <M extends Writable>
214		SendMessageChain<I, V, E, M> thenSend(
215		final String name,
216		final MessageCombiner<? super I, M> messageCombiner,
217		final FunctionWithVertex<I, V, E, P, M> messageSupplier,
218		final SupplierFromVertex<I, V, E, Iterator<I>> targetsSupplier) {
219	0	final ObjectTransfer<P> prevMessagesTransfer = new ObjectTransfer<>();
220
221	0	return new SendMessageChain<>(
222	0	new Function<ConsumerWithVertex<I, V, E, M>, Block>() {
223		@Override
224		public Block apply(ConsumerWithVertex<I, V, E, M> messagesConsumer) {
225	0	return new SequenceBlock(
226	0	blockCreator.apply(
227	0	prevMessagesTransfer.<I, V, E>castToConsumer()),
228	0	Pieces.sendMessage(
229		name, messageCombiner,
230	0	new SupplierFromVertex<I, V, E, M>() {
231		@Override
232		public M get(Vertex<I, V, E> vertex) {
233	0	return messageSupplier.apply(
234	0	vertex, prevMessagesTransfer.get());
235		}
236		},
237		targetsSupplier, messagesConsumer));
238		}
239		});
240		}
241
242		/**
243		* Give previously received message(s) to messageSupplier, and send message
244		* it returns to all neighbors of current vertex, and use given
245		* messageCombiner to combine messages together.
246		*/
247		public <M extends Writable>
248		SendMessageChain<I, V, E, M> thenSendToNeighbors(
249		final String name,
250		final MessageCombiner<? super I, M> messageCombiner,
251		final FunctionWithVertex<I, V, E, P, M> messageSupplier) {
252	0	return thenSend(name, messageCombiner, messageSupplier,
253	0	VertexSuppliers.<I, V, E>vertexNeighborsSupplier());
254		}
255
256		/**
257		* End chain by giving received messages to valueSupplier,
258		* to produce value that should be reduced, and consumed on master
259		* by reducedValueConsumer.
260		*/
261		public <S, R extends Writable>
262		Block endReduce(final String name, final ReduceOperation<S, R> reduceOp,
263		final FunctionWithVertex<I, V, E, P, S> valueSupplier,
264		final Consumer<R> reducedValueConsumer) {
265	0	return endCustom(new Function<SupplierFromVertex<I, V, E, P>, Block>() {
266		@Override
267		public Block apply(final SupplierFromVertex<I, V, E, P> prevMessages) {
268	0	return Pieces.reduce(
269		name,
270		reduceOp,
271	0	new SupplierFromVertex<I, V, E, S>() {
272		@Override
273		public S get(Vertex<I, V, E> vertex) {
274	0	return valueSupplier.apply(vertex, prevMessages.get(vertex));
275		}
276		},
277		reducedValueConsumer);
278		}
279		});
280		}
281
282		/**
283		* End chain by giving received messages to valueSupplier,
284		* to produce value that should be reduced, and consumed on master
285		* by reducedValueConsumer.
286		*/
287		public <S, R extends Writable>
288		Block endReduceWithMaster(
289		final String name, final ReduceOperation<S, R> reduceOp,
290		final FunctionWithVertex<I, V, E, P, S> valueSupplier,
291		final PairConsumer<R, BlockMasterApi> reducedValueConsumer) {
292	0	return endCustom(new Function<SupplierFromVertex<I, V, E, P>, Block>() {
293		@Override
294		public Block apply(final SupplierFromVertex<I, V, E, P> prevMessages) {
295	0	return Pieces.reduceWithMaster(
296		name,
297		reduceOp,
298	0	new SupplierFromVertex<I, V, E, S>() {
299		@Override
300		public S get(Vertex<I, V, E> vertex) {
301	0	return valueSupplier.apply(vertex, prevMessages.get(vertex));
302		}
303		},
304		reducedValueConsumer);
305		}
306		});
307		}
308
309		/**
310		* End chain by processing messages received within the last link
311		* in the chain.
312		*/
313		public Block endConsume(ConsumerWithVertex<I, V, E, P> messagesConsumer) {
314	0	return blockCreator.apply(messagesConsumer);
315		}
316
317		/**
318		* End chain by providing a function that will produce Block to be attached
319		* to the end of current chain, given a supplier of messages received
320		* within the last link in the chain.
321		*/
322		public Block endCustom(
323		Function<SupplierFromVertex<I, V, E, P>, Block> createBlockToAttach) {
324	0	final ObjectTransfer<P> prevMessagesTransfer = new ObjectTransfer<>();
325	0	return new SequenceBlock(
326	0	blockCreator.apply(prevMessagesTransfer.<I, V, E>castToConsumer()),
327	0	createBlockToAttach.apply(
328	0	prevMessagesTransfer.<I, V, E>castToSupplier()));
329		}
330		}