Package org.apache.jackrabbit.oak.segment

Class SegmentId

java.lang.Object

org.apache.jackrabbit.oak.segment.SegmentId

All Implemented Interfaces:

java.lang.Comparable<SegmentId>

public class SegmentId
extends java.lang.Object
implements java.lang.Comparable<SegmentId>

Segment identifier. There are two types of segments: data segments, and bulk segments. Data segments have a header and may reference other segments; bulk segments do not.

Field Summary

Fields

Modifier and Type	Field	Description
static SegmentId	NULL	A null segment id not representing any segment.

Constructor Summary

Constructors

Constructor	Description
SegmentId(@NotNull SegmentStore store, long msb, long lsb)	Create a new segment id without access tracking.
SegmentId(@NotNull SegmentStore store, long msb, long lsb, @NotNull java.lang.Runnable onAccess)	Create a new segment id with access tracking.

Method Summary

Modifier and Type	Method	Description
java.util.UUID	asUUID()
int	compareTo(@NotNull SegmentId that)
boolean	equals(java.lang.Object object)
int	estimateMemoryUsage()
long	getCreationTime()
@NotNull GCGeneration	getGcGeneration()	Get the underlying segment's gc generation.
long	getLeastSignificantBits()
long	getMostSignificantBits()
@NotNull Segment	getSegment()	Get the segment identified by this instance.
int	hashCode()
boolean	isBulkSegmentId()	Checks whether this is a bulk segment identifier.
boolean	isDataSegmentId()	Checks whether this is a data segment identifier.
static boolean	isDataSegmentId(long lsb)	Checks whether this is a data segment identifier.
void	reclaimed(@NotNull java.lang.String gcInfo)	Notify this id about the reclamation of its segment (e.g.
boolean	sameStore(@NotNull SegmentStore store)	Determine whether this instance belongs to the passed store
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NULL

public static final SegmentId NULL

A null segment id not representing any segment.

Constructor Detail

SegmentId

public SegmentId(@NotNull
                 @NotNull SegmentStore store,
                 long msb,
                 long lsb,
                 @NotNull
                 @NotNull java.lang.Runnable onAccess)

Create a new segment id with access tracking.

Parameters:

store - store this is belongs to

msb - most significant bits of this id

lsb - least significant bits of this id

onAccess - callback called whenever an underlying and locally memoised segment is accessed.

SegmentId

public SegmentId(@NotNull
                 @NotNull SegmentStore store,
                 long msb,
                 long lsb)

Create a new segment id without access tracking.

Parameters:

store - store this is belongs to

msb - most significant bits of this id

lsb - least significant bits of this id

Method Detail

isDataSegmentId

public static boolean isDataSegmentId(long lsb)

Checks whether this is a data segment identifier.

Returns:

true for a data segment, false otherwise

isDataSegmentId

public boolean isDataSegmentId()

Checks whether this is a data segment identifier.

Returns:

true for a data segment, false otherwise

isBulkSegmentId

public boolean isBulkSegmentId()

Checks whether this is a bulk segment identifier.

Returns:

true for a bulk segment, false otherwise

getMostSignificantBits

public long getMostSignificantBits()

getLeastSignificantBits

public long getLeastSignificantBits()

getSegment

@NotNull
public @NotNull Segment getSegment()

Get the segment identified by this instance. The segment is memoised in this instance's segment field.

Returns:

the segment identified by this instance.

See Also:

loaded(Segment), unloaded()

reclaimed

public void reclaimed(@NotNull
                      @NotNull java.lang.String gcInfo)

Notify this id about the reclamation of its segment (e.g. by the garbage collector).

Parameters:

gcInfo - details about the reclamation. This information is logged along with the SegmentNotFoundException when attempting to resolve the segment of this id.

sameStore

public boolean sameStore(@NotNull
                         @NotNull SegmentStore store)

Determine whether this instance belongs to the passed store

Parameters:

store -

Returns:

true iff this instance belongs to store

getCreationTime

public long getCreationTime()

asUUID

public java.util.UUID asUUID()

Returns:

this segment id as UUID

getGcGeneration

@NotNull
public @NotNull GCGeneration getGcGeneration()

Get the underlying segment's gc generation. Might cause the segment to get loaded if the generation info is missing

Returns:

the segment's gc generation

compareTo

public int compareTo(@NotNull
                     @NotNull SegmentId that)

Specified by:

compareTo in interface java.lang.Comparable<SegmentId>

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object object)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

estimateMemoryUsage

public int estimateMemoryUsage()