org.github.jamm

Class Filters

java.lang.Object

org.github.jamm.Filters

public final class Filters
extends Object

Utility class providing the different filters used by MemoryMeter

Field Summary

Fields

Modifier and Type	Field and Description
static FieldFilter	IGNORE_CLEANER_FIELDS Filter excluding some of the fields from sun.misc.Cleaner as they should not be taken into account.
static FieldAndClassFilter	IGNORE_KNOWN_SINGLETONS Filter excluding class such as Enum, Class, ClassLoader and AccessControlContext
static FieldFilter	IGNORE_NON_STRONG_REFERENCES Filter excluding all the Reference's fields and the head field of ReferenceQueue.
static FieldFilter	IGNORE_OUTER_CLASS_REFERENCES Filter excluding the outer class reference from non-static inner classes.
static FieldFilter	IGNORE_STATIC_AND_PRIMITIVE_FIELDS Filter excluding static and primitive fields
static FieldFilter	IGNORE_THREAD_FIELDS Filter excluding the group field from thread classes as that field holds the references to all the other threads from the group to which the thread belongs.
static FieldAndClassFilter	IGNORE_UNMETERED_FIELDS_AND_CLASSES Filter excluding fields and class annotated with Unmetered

Method Summary

Modifier and Type	Method and Description
static FieldAndClassFilter	getClassFilters(boolean ignoreKnownSingletons)
static FieldFilter	getFieldFilters(boolean ignoreKnownSingletons, boolean ignoreOuterClassReference, boolean ignoreNonStrongReferences)

Methods inherited from class java.lang.Object

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

Field Detail

IGNORE_STATIC_AND_PRIMITIVE_FIELDS

public static final FieldFilter IGNORE_STATIC_AND_PRIMITIVE_FIELDS

Filter excluding static and primitive fields

IGNORE_KNOWN_SINGLETONS

public static final FieldAndClassFilter IGNORE_KNOWN_SINGLETONS

Filter excluding class such as Enum, Class, ClassLoader and AccessControlContext

IGNORE_NON_STRONG_REFERENCES

public static final FieldFilter IGNORE_NON_STRONG_REFERENCES

Filter excluding all the Reference's fields and the head field of ReferenceQueue. The Reference fields next and discovered are used by ReferenceQueue instances to create a linked list and are not part of what we want to measure. The queue field is either a singleton ReferenceQueue.NULL or a provided queue that user hold a reference to and therefore should be ignored too. To be consistent, the head field of ReferenceQueue is also ignored to fully decouple queue and references.

IGNORE_CLEANER_FIELDS

public static final FieldFilter IGNORE_CLEANER_FIELDS

Filter excluding some of the fields from sun.misc.Cleaner as they should not be taken into account. The fields being excluded are:

• queue: as it is a dummy queue referenced by all Cleaner instances.
• next and prev: as they are used to create a doubly-linked list of live cleaners and therefore refer to other Cleaners instances

IGNORE_THREAD_FIELDS

public static final FieldFilter IGNORE_THREAD_FIELDS

Filter excluding the group field from thread classes as that field holds the references to all the other threads from the group to which the thread belongs.

IGNORE_OUTER_CLASS_REFERENCES

public static final FieldFilter IGNORE_OUTER_CLASS_REFERENCES

Filter excluding the outer class reference from non-static inner classes. In practice that filter is only useful if the top class is an inner class, and we wish to ignore the outer class in the measurement.

IGNORE_UNMETERED_FIELDS_AND_CLASSES

public static final FieldAndClassFilter IGNORE_UNMETERED_FIELDS_AND_CLASSES

Filter excluding fields and class annotated with Unmetered

Method Detail

getClassFilters

public static FieldAndClassFilter getClassFilters(boolean ignoreKnownSingletons)

getFieldFilters

public static FieldFilter getFieldFilters(boolean ignoreKnownSingletons,
                                          boolean ignoreOuterClassReference,
                                          boolean ignoreNonStrongReferences)