Package org.eclipse.tracecompass.tmf.core.trace.indexer.checkpoint

Class TmfCheckpointIndexer

java.lang.Object

org.eclipse.tracecompass.tmf.core.trace.indexer.checkpoint.TmfCheckpointIndexer

All Implemented Interfaces:

ITmfTraceIndexer

Direct Known Subclasses:

TmfBTreeTraceIndexer, TmfFlatArrayTraceIndexer

public class TmfCheckpointIndexer
extends Object
implements ITmfTraceIndexer

A simple indexer that manages the trace index as an array of trace checkpoints. Checkpoints are stored in memory at fixed intervals (event rank) in ascending timestamp order.

The goal being to access a random trace event reasonably fast from the user's standpoint, picking the right interval value becomes a trade-off between speed and memory usage (a shorter inter-event interval is faster but requires more checkpoints).

Locating a specific checkpoint is trivial for both rank (rank % interval) and timestamp (bsearch in the array). *

Author:

Francois Chouinard

See Also:

• ITmfTrace
• ITmfEvent

Constructor Summary

Constructors

Constructor	Description
TmfCheckpointIndexer(ITmfTrace trace)	Basic constructor that uses the default trace block size as checkpoints intervals
TmfCheckpointIndexer(ITmfTrace trace, int interval)	Full trace indexer

Method Summary

Modifier and Type	Method	Description
void	buildIndex(long offset, TmfTimeRange range, boolean waitForCompletion)	Start an asynchronous index building job and waits for the job completion if required.
void	dispose()	Perform cleanup when the indexer is no longer required.
boolean	isIndexing()	Indicates that the indexer is busy indexing the trace.
ITmfContext	seekIndex(long rank)	Returns the context of the checkpoint immediately preceding the requested rank (or at rank if it coincides with a checkpoint).
ITmfContext	seekIndex(ITmfTimestamp timestamp)	Returns the context of the checkpoint immediately preceding the requested timestamp (or at the timestamp if it coincides with a checkpoint).
void	updateIndex(ITmfContext context, ITmfTimestamp timestamp)	Adds an entry to the trace index.

Methods inherited from class java.lang.Object

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

Constructor Details

TmfCheckpointIndexer

public TmfCheckpointIndexer(ITmfTrace trace)

Basic constructor that uses the default trace block size as checkpoints intervals

Parameters:

trace - the trace to index

TmfCheckpointIndexer

public TmfCheckpointIndexer(ITmfTrace trace,
 int interval)

Full trace indexer

Parameters:

trace - the trace to index

interval - the checkpoints interval

Method Details

dispose

public void dispose()

Description copied from interface: ITmfTraceIndexer

Perform cleanup when the indexer is no longer required.

Specified by:

dispose in interface ITmfTraceIndexer

isIndexing

public boolean isIndexing()

Description copied from interface: ITmfTraceIndexer

Indicates that the indexer is busy indexing the trace. Will always return false if the indexing is done synchronously.

Specified by:

isIndexing in interface ITmfTraceIndexer

Returns:

the state of the indexer (indexing or not)

buildIndex

public void buildIndex(long offset,
 TmfTimeRange range,
 boolean waitForCompletion)

Description copied from interface: ITmfTraceIndexer

Start an asynchronous index building job and waits for the job completion if required. Typically, the indexing job sends notifications at regular intervals to indicate its progress.

Example 1: Index a whole trace asynchronously

 trace.getIndexer().buildIndex(0, TmfTimeRange.ETERNITY, false);
 

Example 2: Index a whole trace synchronously

 trace.getIndexer().buildIndex(0, TmfTimeRange.ETERNITY, true);
 

Example 3: Index a trace asynchronously, starting at rank 100

 trace.getIndexer().buildIndex(100, TmfTimeRange.ETERNITY, false);
 

Example 4: Index a trace asynchronously, starting at rank 100 for events between T1 and T2 (inclusive). This is used for incremental indexing.

 TmfTimeRange range = new TmfTimeRange(T1, T2);
 trace.getIndexer().buildIndex(100, range, false);
 

Specified by:

buildIndex in interface ITmfTraceIndexer

Parameters:

offset - The offset of the first event to consider

range - The time range to consider

waitForCompletion - Should we block the calling thread until the build is complete?

updateIndex

public void updateIndex(ITmfContext context,
 ITmfTimestamp timestamp)

Description copied from interface: ITmfTraceIndexer

Adds an entry to the trace index.

Specified by:

updateIndex in interface ITmfTraceIndexer

Parameters:

context - The trace context to save

timestamp - The timestamp matching this context

seekIndex

public ITmfContext seekIndex(ITmfTimestamp timestamp)

Description copied from interface: ITmfTraceIndexer

Returns the context of the checkpoint immediately preceding the requested timestamp (or at the timestamp if it coincides with a checkpoint).

Specified by:

seekIndex in interface ITmfTraceIndexer

Parameters:

timestamp - the requested timestamp

Returns:

the checkpoint context

seekIndex

public ITmfContext seekIndex(long rank)

Description copied from interface: ITmfTraceIndexer

Returns the context of the checkpoint immediately preceding the requested rank (or at rank if it coincides with a checkpoint).

Specified by:

seekIndex in interface ITmfTraceIndexer

Parameters:

rank - the requested event rank

Returns:

the checkpoint context