Package org.apache.jackrabbit.oak.segment

Class SegmentId

java.lang.Object
org.apache.jackrabbit.oak.segment.SegmentId
All Implemented Interfaces:
Comparable<SegmentId>
public class SegmentId extends Object implements 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 Details

    • NULL

      public static final SegmentId NULL
      A null segment id not representing any segment.

  • Constructor Details

    • SegmentId

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

    • 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 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 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 Comparable<SegmentId>

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • equals

      public boolean equals(Object object)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • estimateMemoryUsage

      public int estimateMemoryUsage()