SimplePartitionStore (Apache Giraph Parent 1.4.0-SNAPSHOT API)

java.lang.Object
- org.apache.giraph.partition.SimplePartitionStore<I,V,E>

Type Parameters:: I - Vertex id; V - Vertex data; E - Edge data

All Implemented Interfaces:: PartitionStore<I,V,E>

public class SimplePartitionStore<I extends org.apache.hadoop.io.WritableComparable,V extends org.apache.hadoop.io.Writable,E extends org.apache.hadoop.io.Writable>
extends Object
implements PartitionStore<I,V,E>

A simple in-memory partition store.

Constructor Summary

Constructors
Constructor and Description
`SimplePartitionStore(ImmutableClassesGiraphConfiguration<I,V,E> conf, org.apache.hadoop.mapreduce.Mapper.Context context)` Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`addPartition(Partition<I,V,E> partition)` Add a new partition to the store.
`void`	`addPartitionVertices(Integer partitionId, ExtendedDataOutput extendedDataOutput)` Add vertices to a given partition from a given DataOutput instance.
`Partition<I,V,E>`	`getNextPartition()` Return the next partition in iteration for the current superstep.
`int`	`getNumPartitions()` Return the number of stored partitions.
`long`	`getPartitionEdgeCount(Integer partitionId)` Return the number of edges in a partition.
`Iterable<Integer>`	`getPartitionIds()` Return the ids of all the stored partitions as an Iterable.
`long`	`getPartitionVertexCount(Integer partitionId)` Return the number of vertices in a partition.
`boolean`	`hasPartition(Integer partitionId)` Whether a specific partition is present in the store.
`void`	`initialize()` Called at the beginning of the computation.
`boolean`	`isEmpty()` Whether the partition store is empty.
`void`	`putPartition(Partition<I,V,E> partition)` Put a partition back to the store.
`Partition<I,V,E>`	`removePartition(Integer partitionId)` Remove a partition and return it.
`void`	`shutdown()` Called at the end of the computation.
`void`	`startIteration()` Start the iteration cycle to iterate over partitions.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
 - SimplePartitionStore
```
public SimplePartitionStore(ImmutableClassesGiraphConfiguration<I,V,E> conf,
 org.apache.hadoop.mapreduce.Mapper.Context context)
```
 Constructor.
 
 Parameters:
 
 conf - Configuration
 
 context - Mapper context
- Method Detail
 - addPartition
```
public boolean addPartition(Partition<I,V,E> partition)
```
 Description copied from interface: PartitionStore
 
 Add a *new* partition to the store. If the partition is already existed, it does not add the partition and returns false. Note: this method is not thread-safe and should be called by a single thread.
 
 Specified by:
 
 addPartition in interface PartitionStore
 
 Parameters:
 
 partition - Partition to add
 
 Returns:
 
 Whether the addition made any change in the partition store
 - removePartition
```
public Partition<I,V,E> removePartition(Integer partitionId)
```
 Description copied from interface: PartitionStore
 
 Remove a partition and return it. Called from a single thread, *not* from within a scheduling cycle. This method should *not* be called in INPUT_SUPERSTEP.
 
 Specified by:
 
 removePartition in interface PartitionStore
 
 Parameters:
 
 partitionId - Partition id
 
 Returns:
 
 The removed partition
 - hasPartition
```
public boolean hasPartition(Integer partitionId)
```
 Description copied from interface: PartitionStore
 
 Whether a specific partition is present in the store.
 
 Specified by:
 
 hasPartition in interface PartitionStore
 
 Parameters:
 
 partitionId - Partition id
 
 Returns:
 
 True iff the partition is present
 - getPartitionIds
```
public Iterable<Integer> getPartitionIds()
```
 Description copied from interface: PartitionStore
 
 Return the ids of all the stored partitions as an Iterable.
 
 Specified by:
 
 getPartitionIds in interface PartitionStore
 
 Returns:
 
 The partition ids
 - getNumPartitions
```
public int getNumPartitions()
```
 Description copied from interface: PartitionStore
 
 Return the number of stored partitions.
 
 Specified by:
 
 getNumPartitions in interface PartitionStore
 
 Returns:
 
 The number of partitions
 - getPartitionVertexCount
```
public long getPartitionVertexCount(Integer partitionId)
```
 Description copied from interface: PartitionStore
 
 Return the number of vertices in a partition.
 
 Specified by:
 
 getPartitionVertexCount in interface PartitionStore
 
 Parameters:
 
 partitionId - Partition id
 
 Returns:
 
 The number of vertices in the specified partition
 - getPartitionEdgeCount
```
public long getPartitionEdgeCount(Integer partitionId)
```
 Description copied from interface: PartitionStore
 
 Return the number of edges in a partition.
 
 Specified by:
 
 getPartitionEdgeCount in interface PartitionStore
 
 Parameters:
 
 partitionId - Partition id
 
 Returns:
 
 The number of edges in the specified partition
 - isEmpty
```
public boolean isEmpty()
```
 Description copied from interface: PartitionStore
 
 Whether the partition store is empty.
 
 Specified by:
 
 isEmpty in interface PartitionStore
 
 Returns:
 
 True iff there are no partitions in the store
 - startIteration
```
public void startIteration()
```
 Description copied from interface: PartitionStore
 
 Start the iteration cycle to iterate over partitions. Note that each iteration cycle *must* iterate over *all* partitions. Usually an iteration cycle is necessary for 1) moving edges (from edge store) to vertices after edge input splits are loaded in INPUT_SUPERSTEP, 2) computing partitions in each superstep (called once per superstep), 3) saving vertices/edges in the output superstep. 4) any sort of populating a data-structure based on the partitions in this store. After an iteration is started, multiple threads can access the partition store using PartitionStore.getNextPartition() to iterate over the partitions. Each time PartitionStore.getNextPartition() is called an unprocessed partition in the current iteration is returned. After processing of the partition is done, partition should be put back in the store using PartitionStore.putPartition(Partition). Here is an example of the entire workflow: In the main thread: partitionStore.startIteration(); In multiple threads iterating over the partitions: Partition partition = partitionStore.getNextPartition(); ... do stuff with partition ... partitionStore.putPartition(partition); Called from a single thread.
 
 Specified by:
 
 startIteration in interface PartitionStore
 - getNextPartition
```
public Partition<I,V,E> getNextPartition()
```
 Description copied from interface: PartitionStore
 
 Return the next partition in iteration for the current superstep. Note: user has to put back the partition to the store through PartitionStore.putPartition(Partition) after use. Look at comments on PartitionStore.startIteration() for more detail.
 
 Specified by:
 
 getNextPartition in interface PartitionStore
 
 Returns:
 
 The next partition to process
 - putPartition
```
public void putPartition(Partition<I,V,E> partition)
```
 Description copied from interface: PartitionStore
 
 Put a partition back to the store. Use this method to put a partition back after it has been retrieved through PartitionStore.getNextPartition(). Look at comments on PartitionStore.startIteration() for more detail.
 
 Specified by:
 
 putPartition in interface PartitionStore
 
 Parameters:
 
 partition - Partition
 - addPartitionVertices
```
public void addPartitionVertices(Integer partitionId,
 ExtendedDataOutput extendedDataOutput)
```
 Description copied from interface: PartitionStore
 
 Add vertices to a given partition from a given DataOutput instance. This method is called right after receipt of vertex request in INPUT_SUPERSTEP.
 
 Specified by:
 
 addPartitionVertices in interface PartitionStore
 
 Parameters:
 
 partitionId - Partition id
 
 extendedDataOutput - Output containing serialized vertex data
 - shutdown
```
public void shutdown()
```
 Description copied from interface: PartitionStore
 
 Called at the end of the computation. Called from a single thread.
 
 Specified by:
 
 shutdown in interface PartitionStore
 - initialize
```
public void initialize()
```
 Description copied from interface: PartitionStore
 
 Called at the beginning of the computation. Called from a single thread.
 
 Specified by:
 
 initialize in interface PartitionStore

Class SimplePartitionStore<I extends org.apache.hadoop.io.WritableComparable,V extends org.apache.hadoop.io.Writable,E extends org.apache.hadoop.io.Writable>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

SimplePartitionStore

Method Detail

addPartition

removePartition

hasPartition

getPartitionIds

getNumPartitions

getPartitionVertexCount

getPartitionEdgeCount

isEmpty

startIteration

getNextPartition

putPartition

addPartitionVertices

shutdown

initialize