Package org.apache.hadoop.hbase.regionserver.compactions

Class CompactionContext

java.lang.Object

org.apache.hadoop.hbase.regionserver.compactions.CompactionContext

Direct Known Subclasses:

DateTieredStoreEngine.DateTieredCompactionContext, DefaultStoreEngine.DefaultCompactionContext, StripeStoreEngine.StripeCompaction

@Private
public abstract class CompactionContext
extends Object

This class holds all "physical" details necessary to run a compaction, and abstracts away the details specific to a particular compaction. It also has compaction request with all the logical details. Hence, this class is basically the compaction.

Field Summary

Fields

Modifier and Type	Field	Description
protected CompactionRequestImpl	request

Constructor Summary

Constructors

Constructor	Description
CompactionContext()

Method Summary

Modifier and Type	Method	Description
abstract List<org.apache.hadoop.fs.Path>	compact(ThroughputController throughputController, User user)
void	forceSelect(CompactionRequestImpl request)	Forces external selection to be applied for this compaction.
CompactionRequestImpl	getRequest()
boolean	hasSelection()
abstract List<HStoreFile>	preSelect(List<HStoreFile> filesCompacting)	Called before coprocessor preCompactSelection and should filter the candidates for coprocessor; i.e.
abstract boolean	select(List<HStoreFile> filesCompacting, boolean isUserCompaction, boolean mayUseOffPeak, boolean forceMajor)	Called to select files for compaction.

Methods inherited from class java.lang.Object

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

Field Details

request

protected CompactionRequestImpl request

Constructor Details

CompactionContext

public CompactionContext()

Method Details

preSelect

public abstract List<HStoreFile> preSelect(List<HStoreFile> filesCompacting)

Called before coprocessor preCompactSelection and should filter the candidates for coprocessor; i.e. exclude the files that definitely cannot be compacted at this time.

Parameters:

filesCompacting - files currently compacting

Returns:

the list of files that can theoretically be compacted.

select

public abstract boolean select(List<HStoreFile> filesCompacting,
 boolean isUserCompaction,
 boolean mayUseOffPeak,
 boolean forceMajor)
                        throws IOException

Called to select files for compaction. Must fill in the request field if successful.

Parameters:

filesCompacting - Files currently being compacted by other compactions.

isUserCompaction - Whether this is a user compaction.

mayUseOffPeak - Whether the underlying policy may assume it's off-peak hours.

forceMajor - Whether to force major compaction.

Returns:

Whether the selection succeeded. Selection may be empty and lead to no compaction.

Throws:

IOException

forceSelect

public void forceSelect(CompactionRequestImpl request)

Forces external selection to be applied for this compaction.

Parameters:

request - The pre-cooked request with selection and other settings.

compact

public abstract List<org.apache.hadoop.fs.Path> compact(ThroughputController throughputController,
 User user)
                                                 throws IOException

Throws:

IOException

getRequest

public CompactionRequestImpl getRequest()

hasSelection

public boolean hasSelection()