com.bigdata.mdi

Interface IResourceMetadata

All Superinterfaces:

Cloneable, Serializable

All Known Implementing Classes:

AbstractResourceMetadata, JournalMetadata, SegmentMetadata, TransientResourceMetadata

public interface IResourceMetadata
extends Serializable, Cloneable

Interface for metadata about a Journal or IndexSegment.

Version:

$Id$

Author:

Bryan Thompson

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(IResourceMetadata o) Compares two resource metadata objects for consistent state.
long	getCommitTime() The commit time of the view from which the caller should read.
long	getCreateTime() The commit time associated with the creation of this resource.
String	getFile() The name of the file containing the resource (this is always relative to some local data directory).
UUID	getUUID() The unique identifier for the resource.
int	hashCode() The hash code of the resource UUID.
boolean	isIndexSegment() True iff this resource is an IndexSegment.
boolean	isJournal() True iff this resource is a Journal.

Method Detail

isIndexSegment

boolean isIndexSegment()

True iff this resource is an IndexSegment. Each IndexSegment contains historical read-only data for exactly one partition of a scale-out index.

isJournal

boolean isJournal()

True iff this resource is a Journal. When the resource is a Journal, there will be a named mutable btree on the journal that is absorbing writes for one or more index partition of a scale-out index.

getFile

String getFile()

The name of the file containing the resource (this is always relative to some local data directory).

Note: This property is primarily used for debugging. It is NOT used by the ResourceManager. Instead, the ResourceManager builds up the mapping from resource UUID to local filename during startup.

getUUID

UUID getUUID()

The unique identifier for the resource.

See Also:

IRootBlockView#getUUID(), the UUID for an {@link AbstractJournal}., IndexSegmentCheckpoint#segmentUUID, the UUID for an {@link IndexSegment}.

getCreateTime

long getCreateTime()

The commit time associated with the creation of this resource. When the index is an IndexSegment this is the commit time of the view from which that IndexSegment was generated. When the resource is a Journal, the create time is the commit time associated with the journal creation, which is generally an overflow operation. Regardless, the create time MUST be assigned by the same time source that is used to assign commit timestamps.

getCommitTime

long getCommitTime()

The commit time of the view from which the caller should read. For an IndexSegment, this is always the same as getCreateTime() . For a Journal, this may be a specific commit time for a source in an ILocalBTreeView. A value of 0L indicates that no specific commit time is indicated. For historical journals, this implies a read from the lastCommitTime on the journal in order to constitute the view. For the current journal, this implies a read at whatever timestamp the caller desires.

See Also:

IndexManager

hashCode

int hashCode()

The hash code of the resource UUID.

Overrides:

hashCode in class Object

equals

boolean equals(IResourceMetadata o)

Compares two resource metadata objects for consistent state.

Parameters:

o -

Returns: