org.sonar.duplications.index
Class PackedMemoryCloneIndex

java.lang.Object
  org.sonar.duplications.index.AbstractCloneIndex
      org.sonar.duplications.index.PackedMemoryCloneIndex

All Implemented Interfaces:

CloneIndex

public class PackedMemoryCloneIndex
extends AbstractCloneIndex

Provides an index optimized by memory.

Each object in Java has an overhead - see "HOWTO: Determine the size of a Java Object or Class". So to optimize memory consumption, we use flat arrays, however this increases time of queries. During usual detection of duplicates most time consuming method is a getByResourceId(String): around 50% of time spent in this class and number of invocations of this method is 1% of total invocations, however total time spent in this class less than 1 second for small projects and around 2 seconds for projects like JDK.

Note that this implementation currently does not support deletion, however it's possible to implement.

Constructor Summary

PackedMemoryCloneIndex()

PackedMemoryCloneIndex(int hashBytes, int initialCapacity)

Method Summary

Collection<Block>	getByResourceId(String resourceId) Performs search of blocks for specified resource.
Collection<Block>	getBySequenceHash(ByteArray sequenceHash) Performs search of blocks for specified hash value.
void	insert(Block block) Adds specified block into index.

Methods inherited from class java.lang.Object

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

Constructor Detail

PackedMemoryCloneIndex

public PackedMemoryCloneIndex()

PackedMemoryCloneIndex

public PackedMemoryCloneIndex(int hashBytes,
                              int initialCapacity)

Parameters:

hashBytes - size of hash in bytes

initialCapacity - the initial capacity

Method Detail

getByResourceId

public Collection<Block> getByResourceId(String resourceId)

Performs search of blocks for specified resource.

Note that this implementation does not guarantee that blocks would be sorted by index.

Returns:

collection of blocks from index for specified resource and empty collection if nothing found

getBySequenceHash

public Collection<Block> getBySequenceHash(ByteArray sequenceHash)

Performs search of blocks for specified hash value.

Returns:

collection of blocks from index with specified hash and empty collection if nothing found

insert

public void insert(Block block)

Adds specified block into index.

Note that this implementation allows insertion of two blocks with same index for one resource.