org.apache.giraph.comm.messages

Interface MessageStore<I extends org.apache.hadoop.io.WritableComparable,M extends org.apache.hadoop.io.Writable>

Type Parameters:

I - Vertex id

M - Message data

All Known Implementing Classes:

AbstractListPerVertexStore, AsyncMessageStoreWrapper, ByteArrayMessagesPerVertexStore, DiskBackedMessageStore, IdByteArrayMessageStore, IdOneMessagePerVertexStore, IntFloatMessageStore, LongAbstractListStore, LongAbstractStore, LongDoubleMessageStore, LongPointerListPerVertexStore, OneMessagePerVertexStore, PointerListPerVertexStore, SimpleMessageStore

public interface MessageStore<I extends org.apache.hadoop.io.WritableComparable,M extends org.apache.hadoop.io.Writable>

Message store

Method Summary

Modifier and Type	Method and Description
void	addMessage(I vertexId, M message) Adds a message for a particular vertex The method is used by InternalMessageStore to send local messages; for the general case, use a more efficient addPartitionMessages
void	addPartitionMessages(int partitionId, VertexIdMessages<I,M> messages) Adds messages for partition
void	clearAll() Clears all resources used by this store.
void	clearPartition(int partitionId) Clears messages for a partition.
void	clearVertexMessages(I vertexId) Clears messages for a vertex.
void	finalizeStore() Called before start of computation in bspworker Since it is run from a single thread while the store is not being accessed by any other thread - this is ensured to be thread-safe
Iterable<I>	getPartitionDestinationVertices(int partitionId) Gets vertex ids from selected partition which we have messages for
Iterable<M>	getVertexMessages(I vertexId) Gets messages for a vertex.
boolean	hasMessagesForPartition(int partitionId) Check if we have messages for some partition
boolean	hasMessagesForVertex(I vertexId) Check if we have messages for some vertex
boolean	isPointerListEncoding() True if this message-store encodes messages as a list of long pointers to compact serialized messages
void	readFieldsForPartition(DataInput in, int partitionId) Deserialize messages for one partition
void	writePartition(DataOutput out, int partitionId) Serialize messages for one partition.

Method Detail

isPointerListEncoding

boolean isPointerListEncoding()

True if this message-store encodes messages as a list of long pointers to compact serialized messages

Returns:

true if we encode messages as a list of pointers

getVertexMessages

Iterable<M> getVertexMessages(I vertexId)

Gets messages for a vertex. The lifetime of every message is only guaranteed until the iterator's next() method is called. Do not hold references to objects returned by this iterator.

Parameters:

vertexId - Vertex id for which we want to get messages

Returns:

Iterable of messages for a vertex id

clearVertexMessages

void clearVertexMessages(I vertexId)

Clears messages for a vertex.

Parameters:

vertexId - Vertex id for which we want to clear messages

clearAll

void clearAll()

Clears all resources used by this store.

hasMessagesForVertex

boolean hasMessagesForVertex(I vertexId)

Check if we have messages for some vertex

Parameters:

vertexId - Id of vertex which we want to check

Returns:

True iff we have messages for vertex with required id

hasMessagesForPartition

boolean hasMessagesForPartition(int partitionId)

Check if we have messages for some partition

Parameters:

partitionId - Id of partition which we want to check

Returns:

True iff we have messages for the given partition

addPartitionMessages

void addPartitionMessages(int partitionId,
                          VertexIdMessages<I,M> messages)

Adds messages for partition

Parameters:

partitionId - Id of partition

messages - Collection of vertex ids and messages we want to add

addMessage

void addMessage(I vertexId,
                M message)
         throws IOException

Adds a message for a particular vertex The method is used by InternalMessageStore to send local messages; for the general case, use a more efficient addPartitionMessages

Parameters:

vertexId - Id of target vertex

message - A message to send

Throws:

IOException

finalizeStore

void finalizeStore()

Called before start of computation in bspworker Since it is run from a single thread while the store is not being accessed by any other thread - this is ensured to be thread-safe

getPartitionDestinationVertices

Iterable<I> getPartitionDestinationVertices(int partitionId)

Gets vertex ids from selected partition which we have messages for

Parameters:

partitionId - Id of partition

Returns:

Iterable over vertex ids which we have messages for

clearPartition

void clearPartition(int partitionId)

Clears messages for a partition.

Parameters:

partitionId - Partition id for which we want to clear messages

writePartition

void writePartition(DataOutput out,
                    int partitionId)
             throws IOException

Serialize messages for one partition.

Parameters:

out - DataOutput to serialize this object into

partitionId - Id of partition

Throws:

IOException

readFieldsForPartition

void readFieldsForPartition(DataInput in,
                            int partitionId)
                     throws IOException

Deserialize messages for one partition

Parameters:

in - DataInput to deserialize this object from.

partitionId - Id of partition

Throws:

IOException