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oracle.hadoop.balancer.examples.invindx
Class InvertedIndex.InvertedIndexKey

java.lang.Object
oracle.hadoop.balancer.examples.invindx.InvertedIndex.InvertedIndexKey

All Implemented Interfaces:

org.apache.hadoop.io.Writable

Enclosing class:

InvertedIndex

public static class InvertedIndex.InvertedIndexKey

extends java.lang.Object

implements org.apache.hadoop.io.Writable

Key class for the inverted index application. Since we want Hadoop to do a secondary-sort (produce a sorted list of reduce-values per key), we have a composite key class that contains both key and value elements.

• Sorting comparator is via #compareTo(InvertedIndexKey)
• Grouping comparator is InvertedIndexKey.WordComparator
• Partitioner is InvertedIndex.InvertedIndexKey.WordPartitioner

Nested Class Summary

static class	InvertedIndex.InvertedIndexKey.GroupingComparator This comparator compares only the key element (the word) of this composite key class.
static class	InvertedIndex.InvertedIndexKey.SortingComparator This comparator extends the InvertedIndex.InvertedIndexKey.GroupingComparator and compares the value elements (location and offset) of this composite key.
static class	InvertedIndex.InvertedIndexKey.WordPartitioner<V> Partition on the word's hashcode.

Constructor Summary

InvertedIndex.InvertedIndexKey()

Method Summary

int	hashCode()
void	readFields(java.io.DataInput in)
java.lang.String	toString() TextOutputFormat calls this to print the key
void	write(java.io.DataOutput out)

Methods inherited from class java.lang.Object

equals, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

InvertedIndex.InvertedIndexKey

public InvertedIndex.InvertedIndexKey()

Method Detail

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

readFields

public void readFields(java.io.DataInput in)
                throws java.io.IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

toString

public java.lang.String toString()

TextOutputFormat calls this to print the key

Overrides:

toString in class java.lang.Object

Returns:

the word for this key

write

public void write(java.io.DataOutput out)
           throws java.io.IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

java.io.IOException

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