pegasus.mapreduce.triangle

Class PTE.TriangleCountingMapper

java.lang.Object

org.apache.hadoop.mapreduce.Mapper<java.lang.Object,org.apache.hadoop.io.Text,org.apache.hadoop.io.Text,org.apache.hadoop.io.NullWritable>

pegasus.mapreduce.triangle.PTE.TriangleCountingMapper

Direct Known Subclasses:

PTE.TriangleListingMapper

Enclosing class:

PTE

public static class PTE.TriangleCountingMapper
extends org.apache.hadoop.mapreduce.Mapper<java.lang.Object,org.apache.hadoop.io.Text,org.apache.hadoop.io.Text,org.apache.hadoop.io.NullWritable>

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.Mapper

org.apache.hadoop.mapreduce.Mapper.Context

Constructor Summary

Constructors

Constructor and Description
TriangleCountingMapper()

Method Summary

Modifier and Type	Method and Description
static long	availableMemoryBytes(boolean gc) calculate available memory
protected long	enumTri(int[][] ij, int[][] ik, int[][] jk, int i, int j, int k) Counting triangles.
protected void	map(java.lang.Object key, org.apache.hadoop.io.Text value, org.apache.hadoop.mapreduce.Mapper.Context context) the map function of triangle enumeration step of PTE
protected void	setup(org.apache.hadoop.mapreduce.Mapper.Context context) setup before execution

Methods inherited from class org.apache.hadoop.mapreduce.Mapper

cleanup, run

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TriangleCountingMapper

public TriangleCountingMapper()

Method Detail

setup

protected void setup(org.apache.hadoop.mapreduce.Mapper.Context context)
              throws java.io.IOException,
                     java.lang.InterruptedException

setup before execution

Overrides:

setup in class org.apache.hadoop.mapreduce.Mapper<java.lang.Object,org.apache.hadoop.io.Text,org.apache.hadoop.io.Text,org.apache.hadoop.io.NullWritable>

Parameters:

context - of hadoop

Throws:

java.io.IOException - by hadoop

java.lang.InterruptedException - by hadoop

map

protected void map(java.lang.Object key,
                   org.apache.hadoop.io.Text value,
                   org.apache.hadoop.mapreduce.Mapper.Context context)
            throws java.io.IOException,
                   java.lang.InterruptedException

the map function of triangle enumeration step of PTE

Overrides:

map in class org.apache.hadoop.mapreduce.Mapper<java.lang.Object,org.apache.hadoop.io.Text,org.apache.hadoop.io.Text,org.apache.hadoop.io.NullWritable>

Parameters:

key - value meaning less

value - problem

context - of hadoop

Throws:

java.io.IOException - by hadoop

java.lang.InterruptedException - by hadoop

enumTri

protected long enumTri(int[][] ij,
                       int[][] ik,
                       int[][] jk,
                       int i,
                       int j,
                       int k)
                throws java.io.IOException,
                       java.lang.InterruptedException

Counting triangles. It counts the number of all triangles (u, v, w) that the colors of the vertices u, v, and w are i, j, and k, respectively.

Parameters:

ij - adjacency list of an edge set

ik - adjacency list of an edge set

jk - adjacency list of an edge set

i - the first node color

j - the second node color

k - the last node color

Returns:

the number of triangles of colors i, j, and k.

Throws:

java.io.IOException - by hadoop

java.lang.InterruptedException - by hadoop

availableMemoryBytes

public static long availableMemoryBytes(boolean gc)

calculate available memory

Parameters:

gc - do garbage collect if true

Returns:

the size of available memory