org.apache.hadoop.hbase.regionserver.compactions

Class CompactionContext

java.lang.Object

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

@InterfaceAudience.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 and Description
protected CompactionRequest	request

Constructor Summary

Constructors

Constructor and Description
CompactionContext()

Method Summary

Methods

Modifier and Type	Method and Description
abstract List<org.apache.hadoop.fs.Path>	compact() Runs the compaction based on current selection.
void	forceSelect(CompactionRequest request) Forces external selection to be applied for this compaction.
CompactionRequest	getRequest()
boolean	hasSelection()
abstract List<StoreFile>	preSelect(List<StoreFile> filesCompacting) Called before coprocessor preCompactSelection and should filter the candidates for coprocessor; i.e.
abstract boolean	select(List<StoreFile> 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 Detail

request

protected CompactionRequest request

Constructor Detail

CompactionContext

public CompactionContext()

Method Detail

preSelect

public abstract List<StoreFile> preSelect(List<StoreFile> 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<StoreFile> 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(CompactionRequest 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()
                                                 throws IOException

Runs the compaction based on current selection. select/forceSelect must have been called.

Returns:

The new file paths resulting from compaction.

Throws:

IOException

getRequest

public CompactionRequest getRequest()

hasSelection

public boolean hasSelection()