Package org.eclipse.mat.internal.collectionextract

Class IdentityHashMapCollectionExtractor

java.lang.Object

org.eclipse.mat.internal.collectionextract.FieldArrayCollectionExtractor

org.eclipse.mat.internal.collectionextract.FieldSizeArrayCollectionExtractor

org.eclipse.mat.internal.collectionextract.IdentityHashMapCollectionExtractor

All Implemented Interfaces:

ICollectionExtractor, IMapExtractor

public class IdentityHashMapCollectionExtractor
extends FieldSizeArrayCollectionExtractor
implements IMapExtractor

Info for IdentityHashMaps These are stored as key/value pairs in an array

Nested Class Summary

Nested classes/interfaces inherited from interface org.eclipse.mat.inspections.collectionextract.IMapExtractor

IMapExtractor.EntryObject

Constructor Summary

Constructors

Constructor	Description
IdentityHashMapCollectionExtractor(String sizeField, String arrayField)

Method Summary

Modifier and Type	Method	Description
int[]	extractEntryIds(IObject idMap)	Returns the object ids (int) for all objects which are contained in the collection
Iterator<Map.Entry<IObject,IObject>>	extractMapEntries(IObject coll)	Extracts the contents of a map (i.e.
Integer	getCapacity(IObject collection)	Gets the capacity of the map.
Double	getCollisionRatio(IObject coll)	Complete guess as to collision ratio.
Double	getFillRatio(IObject coll)	Calculate the fill ratio of a collection
Integer	getNumberOfNotNullElements(IObject coll)	Returns the number of non-null elements in the collection.
Integer	getSize(IObject coll)	Extract the size of the collection.
boolean	hasCollisionRatio()	Can't calculate the collision ratio as we don't have the identityHashCode for the keys, even if we did know the hash algorithm.
boolean	hasExtractableArray()	Return true if the collection array based and the array can be extracted from the heap dump
boolean	hasExtractableContents()	Check if the collection has extractable contents

Methods inherited from class org.eclipse.mat.internal.collectionextract.FieldSizeArrayCollectionExtractor

hasSize

Methods inherited from class org.eclipse.mat.internal.collectionextract.FieldArrayCollectionExtractor

extractEntries, hasCapacity, hasFillRatio

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.mat.inspections.collectionextract.ICollectionExtractor

extractEntries, hasCapacity, hasFillRatio, hasSize

Constructor Details

IdentityHashMapCollectionExtractor

public IdentityHashMapCollectionExtractor(String sizeField,
 String arrayField)

Method Details

getCapacity

public Integer getCapacity(IObject collection)
                    throws SnapshotException

Gets the capacity of the map. Needs two array elements for each entry.

Specified by:

getCapacity in interface ICollectionExtractor

Overrides:

getCapacity in class FieldArrayCollectionExtractor

Parameters:

collection - - the collection to find the capacity of

Returns:

the capacity in bytes, or null if unavailable

Throws:

SnapshotException - if there is a problem retrieving data from the snapshot

See Also:

• ICollectionExtractor.hasCapacity()

hasExtractableArray

public boolean hasExtractableArray()

Description copied from interface: ICollectionExtractor

Return true if the collection array based and the array can be extracted from the heap dump

Specified by:

hasExtractableArray in interface ICollectionExtractor

Overrides:

hasExtractableArray in class FieldArrayCollectionExtractor

Returns:

true if ICollectionExtractor.extractEntries(IObject) could be called

See Also:

• ICollectionExtractor.extractEntries(IObject)

hasExtractableContents

public boolean hasExtractableContents()

Description copied from interface: ICollectionExtractor

Check if the collection has extractable contents

Specified by:

hasExtractableContents in interface ICollectionExtractor

Overrides:

hasExtractableContents in class FieldArrayCollectionExtractor

Returns:

true if ICollectionExtractor.extractEntryIds(IObject) could be called

See Also:

• ICollectionExtractor.extractEntryIds(IObject)

getSize

public Integer getSize(IObject coll)
                throws SnapshotException

Description copied from interface: ICollectionExtractor

Extract the size of the collection.

Specified by:

getSize in interface ICollectionExtractor

Overrides:

getSize in class FieldSizeArrayCollectionExtractor

Parameters:

coll - - the collection to find the size of

Returns:

the size, or null if not available

Throws:

SnapshotException - if there is a problem retrieving data from the snapshot

See Also:

• ICollectionExtractor.hasSize()

extractEntryIds

public int[] extractEntryIds(IObject idMap)
                      throws SnapshotException

Description copied from interface: ICollectionExtractor

Returns the object ids (int) for all objects which are contained in the collection

Specified by:

extractEntryIds in interface ICollectionExtractor

Overrides:

extractEntryIds in class FieldArrayCollectionExtractor

Parameters:

idMap - - the collection to find the objects it holds

Returns:

an array of ints which are the object ids.

Throws:

SnapshotException - if there is a problem retrieving data from the snapshot

See Also:

• ICollectionExtractor.hasExtractableContents()

hasCollisionRatio

public boolean hasCollisionRatio()

Can't calculate the collision ratio as we don't have the identityHashCode for the keys, even if we did know the hash algorithm.

Specified by:

hasCollisionRatio in interface IMapExtractor

Returns:

true if @IMapExtractor.getCollisionRatio(IObject) could be called

See Also:

• IMapExtractor.getCollisionRatio(IObject)

getCollisionRatio

public Double getCollisionRatio(IObject coll)
                         throws SnapshotException

Complete guess as to collision ratio. Look for consecutive entries - perhaps they were caused by a linear probe.

Specified by:

getCollisionRatio in interface IMapExtractor

Parameters:

coll - - the collection to calculate the collision ratio of

Returns:

Double number of elements with colliding keys / size

Throws:

SnapshotException

See Also:

• IMapExtractor.hasCollisionRatio()

getFillRatio

public Double getFillRatio(IObject coll)
                    throws SnapshotException

Description copied from interface: ICollectionExtractor

Calculate the fill ratio of a collection

Specified by:

getFillRatio in interface ICollectionExtractor

Overrides:

getFillRatio in class FieldArrayCollectionExtractor

Parameters:

coll - - the collection to find the fill ratio of

Returns:

the fill ratio, between 0.0 and 1.0, or null if unavailable

Throws:

SnapshotException - if there is a problem retrieving data from the snapshot

See Also:

• ICollectionExtractor.hasFillRatio()

getNumberOfNotNullElements

public Integer getNumberOfNotNullElements(IObject coll)
                                   throws SnapshotException

Description copied from interface: ICollectionExtractor

Returns the number of non-null elements in the collection. Requires hasExtractableContents or hasExtractableArray

Specified by:

getNumberOfNotNullElements in interface ICollectionExtractor

Overrides:

getNumberOfNotNullElements in class FieldArrayCollectionExtractor

Parameters:

coll - - the collection to find the number of non-null content objects

Returns:

the number of non-null elements, or null if not available

Throws:

SnapshotException

See Also:

• ICollectionExtractor.hasExtractableContents()
• ICollectionExtractor.hasExtractableArray()

extractMapEntries

public Iterator<Map.Entry<IObject,IObject>> extractMapEntries(IObject coll)
                                                       throws SnapshotException

Description copied from interface: IMapExtractor

Extracts the contents of a map (i.e. an IObject representing a Map) and provides an Iterator over them

Specified by:

extractMapEntries in interface IMapExtractor

Parameters:

coll - - the map to extract contents from

Returns:

an Iterator over the entries. If the original Map had an Entry object, the content of the iterator would usually be EntryObject

Throws:

SnapshotException