org.eclipse.mat.snapshot

Class Histogram

java.lang.Object

org.eclipse.mat.snapshot.HistogramRecord

org.eclipse.mat.snapshot.Histogram

All Implemented Interfaces:

Serializable, IIconProvider, IResult, IResultTable, IStructuredResult

public class Histogram
extends HistogramRecord
implements IResultTable, IIconProvider

Class histogram - heap objects aggregated by their class. It holds the number and consumed memory of the objects aggregated per class and aggregated per class loader.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Histogram.ClassLoaderTree
static class	Histogram.PackageTree
static class	Histogram.SuperclassTree

Field Summary

Fields inherited from class org.eclipse.mat.snapshot.HistogramRecord

COMPARATOR_FOR_LABEL, COMPARATOR_FOR_NUMBEROFOBJECTS, COMPARATOR_FOR_RETAINEDHEAPSIZE, COMPARATOR_FOR_USEDHEAPSIZE

Fields inherited from interface org.eclipse.mat.query.IIconProvider

EMPTY

Constructor Summary

Constructors

Constructor and Description
Histogram(String label, ArrayList<ClassHistogramRecord> classHistogramRecords, ArrayList<ClassLoaderHistogramRecord> classLoaderHistogramRecords, long numberOfObjects, long usedHeapSize, long retainedHeapSize) Construct a histogram
Histogram(String label, ArrayList<ClassHistogramRecord> classHistogramRecords, ArrayList<ClassLoaderHistogramRecord> classLoaderHistogramRecords, long numberOfObjects, long usedHeapSize, long retainedHeapSize, boolean isDefaultHistogram) Construct a histogram

Method Summary

Modifier and Type	Method and Description
Histogram	diffWithBaseline(Histogram baseline) Compute a new histogram as difference of this histogram compared to (minus) the given baseline histogram.
static String	generateClassHistogramRecordCsvReport(Histogram histogram, Comparator<HistogramRecord> comparator) Generate machine/human readable comma separated report from an histogram.
static String	generateClassHistogramRecordTextReport(Histogram histogram, Comparator<HistogramRecord> comparator) Generate human readable text based report from a histogram.
static String	generateClassLoaderHistogramRecordCsvReport(Histogram histogram, Comparator<HistogramRecord> comparator) Generate machine/human readable comma separated report from an histogram.
Collection<ClassHistogramRecord>	getClassHistogramRecords() Get collection of all the classes for all the objects which were found in the set of objects on which the class histogram was computed.
Collection<ClassLoaderHistogramRecord>	getClassLoaderHistogramRecords() Get collection of all the class loaders for all the classes for all the objects which were found in the set of objects on which the class histogram was computed.
Column[]	getColumns() The columns of the tree or table.
Object	getColumnValue(Object row, int columnIndex) Returns the (unformatted) value of a table/tree cell.
IContextObject	getContext(Object row) The default context of the row which is used to display information in the object inspector.
URL	getIcon(Object row)
ResultMetaData	getResultMetaData() (Optionally) Return meta data of the result needed to fine-tune the display of the result.
Object	getRow(int rowId) Returns the object of the row with the given row number.
int	getRowCount() Returns the number of rows in the result table.
IResultTree	groupByClassLoader() implementation as result tree grouped by class loader
IResultTree	groupByPackage() implementation as result tree grouped by package
IResultTree	groupBySuperclass(ISnapshot snapshot) implementation as result tree grouped by superclass
Histogram	intersectWithAnother(Histogram another) Compute a new histogram as intersection of this histogram compared to (equals) the given another histogram.
boolean	isDefaultHistogram()
String	toString()

Methods inherited from class org.eclipse.mat.snapshot.HistogramRecord

getLabel, getNumberOfObjects, getRetainedHeapSize, getUsedHeapSize, incNumberOfObjects, incNumberOfObjects, incRetainedHeapSize, incUsedHeapSize, reverseComparator, setLabel, setNumberOfObjects, setRetainedHeapSize, setUsedHeapSize

Methods inherited from class java.lang.Object

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

Constructor Detail

Histogram

public Histogram(String label,
                 ArrayList<ClassHistogramRecord> classHistogramRecords,
                 ArrayList<ClassLoaderHistogramRecord> classLoaderHistogramRecords,
                 long numberOfObjects,
                 long usedHeapSize,
                 long retainedHeapSize)

Construct a histogram

Parameters:

label - the name of the whole histogram

classHistogramRecords - the classes

classLoaderHistogramRecords - the class loaders

numberOfObjects - the total number of objects

usedHeapSize - the shallow size of all the objects

retainedHeapSize - the retained size of all the objects, or 0 if unknown

Histogram

public Histogram(String label,
                 ArrayList<ClassHistogramRecord> classHistogramRecords,
                 ArrayList<ClassLoaderHistogramRecord> classLoaderHistogramRecords,
                 long numberOfObjects,
                 long usedHeapSize,
                 long retainedHeapSize,
                 boolean isDefaultHistogram)

Construct a histogram

Parameters:

label - the name of the whole histogram

classHistogramRecords - the classes

classLoaderHistogramRecords - the class loaders

numberOfObjects - the total number of objects

usedHeapSize - the shallow size of all the objects

retainedHeapSize - the retained size of all the objects, or 0 if unknown

isDefaultHistogram - a histogram of the whole snapshot

Method Detail

getClassHistogramRecords

public Collection<ClassHistogramRecord> getClassHistogramRecords()

Get collection of all the classes for all the objects which were found in the set of objects on which the class histogram was computed.

Returns:

collection of all the classes for all the objects which were found in the set of objects on which the class histogram was computed

getClassLoaderHistogramRecords

public Collection<ClassLoaderHistogramRecord> getClassLoaderHistogramRecords()

Get collection of all the class loaders for all the classes for all the objects which were found in the set of objects on which the class histogram was computed.

Returns:

collection of all the class loaders for all the classes for all the objects which were found in the set of objects on which the class histogram was computed

diffWithBaseline

public Histogram diffWithBaseline(Histogram baseline)

Compute a new histogram as difference of this histogram compared to (minus) the given baseline histogram.

This method can be used to check what has changed from one histogram to another, to compute a delta.

Parameters:

baseline - baseline histogram

Returns:

difference histogram between this histogram compared to (minus) the given baseline histogram

intersectWithAnother

public Histogram intersectWithAnother(Histogram another)

Compute a new histogram as intersection of this histogram compared to (equals) the given another histogram.

This method can be used to check what remains the same within two histograms, e.g. if you have two histograms it shows what hasn't changed, e.g. if you have two difference histograms it shows what remained the same change (increase or decrease; used in gradient memory leak analysis).

Note: Heap space is not taken into account in this analysis, only the number of objects, i.e. when the number of objects is the same, you will see this number of objects, otherwise or if there are no objects of a particular class you won't get a histogram record for it!

Parameters:

another - another histogram

Returns:

intersection histogram of this histogram compared to (equals) the given another histogram

isDefaultHistogram

public boolean isDefaultHistogram()

toString

public String toString()

Overrides:

toString in class Object

generateClassHistogramRecordTextReport

public static String generateClassHistogramRecordTextReport(Histogram histogram,
                                                            Comparator<HistogramRecord> comparator)

Generate human readable text based report from a histogram.

Parameters:

histogram - histogram you want a human reable text based report for

comparator - comparator to be used for sorting the histogram records ( HistogramRecord provides some default comparators)

Returns:

human redable text based report for the given histogram

generateClassHistogramRecordCsvReport

public static String generateClassHistogramRecordCsvReport(Histogram histogram,
                                                           Comparator<HistogramRecord> comparator)

Generate machine/human readable comma separated report from an histogram.

Parameters:

histogram - histogram you want a machine/human readable comma separated report for

comparator - comparator to be used for sorting the histogram records ( HistogramRecord provides some default comparators)

Returns:

machine/human readable comma separated report for the given histogram

generateClassLoaderHistogramRecordCsvReport

public static String generateClassLoaderHistogramRecordCsvReport(Histogram histogram,
                                                                 Comparator<HistogramRecord> comparator)

Generate machine/human readable comma separated report from an histogram.

Parameters:

histogram - histogram you want a machine/human readable comma separated report for

comparator - comparator to be used for sorting the histogram records ( HistogramRecord provides some default comparators)

Returns:

machine/human readable comma separated report for the given histogram

getResultMetaData

public ResultMetaData getResultMetaData()

Description copied from interface: IResult

(Optionally) Return meta data of the result needed to fine-tune the display of the result. This could include an additional context, an additional query to run on selected data from the result , additional calculated columns, or an indication that the results are already presorted.

Specified by:

getResultMetaData in interface IResult

Returns:

the metadata for the result, used to obtain extra data

getColumns

public Column[] getColumns()

Description copied from interface: IStructuredResult

The columns of the tree or table.

Specified by:

getColumns in interface IStructuredResult

Returns:

an array of all the columns

getRowCount

public int getRowCount()

Description copied from interface: IResultTable

Returns the number of rows in the result table.

Specified by:

getRowCount in interface IResultTable

Returns:

the number of rows

getRow

public Object getRow(int rowId)

Description copied from interface: IResultTable

Returns the object of the row with the given row number.

Specified by:

getRow in interface IResultTable

Parameters:

rowId - The row number.

Returns:

The row object, which can be passed to IStructuredResult.getContext(Object) or IStructuredResult.getColumnValue(Object, int).

getColumnValue

public Object getColumnValue(Object row,
                             int columnIndex)

Description copied from interface: IStructuredResult

Returns the (unformatted) value of a table/tree cell.

Specified by:

getColumnValue in interface IStructuredResult

Parameters:

row - The row object as returned by the IResultTable.getRow(int) or IResultTree.getElements() or IResultTree.getChildren(Object) methods

columnIndex - The index of the column.

Returns:

the cell value

getContext

public IContextObject getContext(Object row)

Description copied from interface: IStructuredResult

The default context of the row which is used to display information in the object inspector. Unless no context provider is given via the ResultMetaData, it is also used for the context menu on a row.

Specified by:

getContext in interface IStructuredResult

Parameters:

row - The row object as returned by the IResultTable.getRow(int) or IResultTree.getElements() or IResultTree.getChildren(Object) methods.

Returns:

a context object holding details about that row

getIcon

public URL getIcon(Object row)

Specified by:

getIcon in interface IIconProvider

groupByClassLoader

public IResultTree groupByClassLoader()

implementation as result tree grouped by class loader

groupByPackage

public IResultTree groupByPackage()

implementation as result tree grouped by package

groupBySuperclass

public IResultTree groupBySuperclass(ISnapshot snapshot)

implementation as result tree grouped by superclass

Since:

1.0