com.hazelcast.spi.hotrestart.impl.gc.chunk

Class StableValChunk

java.lang.Object

com.hazelcast.spi.hotrestart.impl.gc.chunk.Chunk

com.hazelcast.spi.hotrestart.impl.gc.chunk.StableChunk

com.hazelcast.spi.hotrestart.impl.gc.chunk.StableValChunk

All Implemented Interfaces:

com.hazelcast.nio.Disposable

public final class StableValChunk
extends StableChunk

Represents a chunk whose on-disk contents are stable (immutable).

Field Summary

Fields

Modifier and Type	Field and Description
com.hazelcast.internal.util.collection.LongSet	clearedPrefixesFoundAtRestart A key prefix could exist in a chunk file, yet during Hot Restart no record with that key prefix might be added to a record map due to a prefix tombstone (Rebuilder.acceptCleared(RestartItem) doesn't add the record to the record map).

Fields inherited from class com.hazelcast.spi.hotrestart.impl.gc.chunk.StableChunk

BY_BENEFIT_COST_DESC

Fields inherited from class com.hazelcast.spi.hotrestart.impl.gc.chunk.Chunk

ACTIVE_FNAME_SUFFIX, FNAME_SUFFIX, garbage, liveRecordCount, records, seq, SURVIVOR_FNAME_SUFFIX, SYSPROP_TOMB_CHUNK_SIZE_LIMIT, SYSPROP_VAL_CHUNK_SIZE_LIMIT, TOMB_BASEDIR, TOMB_SIZE_LIMIT_DEFAULT, VAL_BASEDIR, VAL_SIZE_LIMIT_DEFAULT

Constructor Summary

Constructors

Constructor and Description
StableValChunk(ActiveValChunk from)
StableValChunk(long seq, RecordMap records, int liveRecordCount, long size, long garbage, boolean needsDismissing)
StableValChunk(long seq, RecordMap records, com.hazelcast.internal.util.collection.LongSet clearedPrefixesFoundAtRestart, int liveRecordCount, long size, long garbage, boolean needsDismissing)

Method Summary

Modifier and Type	Method and Description
long	cost()
double	updateBenefitToCost(long currChunkSeq) Updates the cached value of the benefit/cost factor.

Methods inherited from class com.hazelcast.spi.hotrestart.impl.gc.chunk.StableChunk

cachedBenefitToCost, size

Methods inherited from class com.hazelcast.spi.hotrestart.impl.gc.chunk.Chunk

base, dispose, fnameSuffix, needsDismissing, needsDismissing, retire, retire, tombChunkSizeLimit, toString, valChunkSizeLimit

Methods inherited from class java.lang.Object

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

Field Detail

clearedPrefixesFoundAtRestart

public final com.hazelcast.internal.util.collection.LongSet clearedPrefixesFoundAtRestart

A key prefix could exist in a chunk file, yet during Hot Restart no record with that key prefix might be added to a record map due to a prefix tombstone (Rebuilder.acceptCleared(RestartItem) doesn't add the record to the record map). Then the prefix tombstone might be incorrectly garbage-collected, leading to the resurrection of dead records. To prevent that, this set holds the key prefixes of all records in this chunk interred by a prefix tombstone and is consulted in PrefixTombstoneManager.Sweeper.markLiveTombstones(Chunk).

This set will be empty for all chunks except those that were constructed by Rebuilder during Hot Restart.

Constructor Detail

StableValChunk

public StableValChunk(ActiveValChunk from)

StableValChunk

public StableValChunk(long seq,
                      RecordMap records,
                      int liveRecordCount,
                      long size,
                      long garbage,
                      boolean needsDismissing)

StableValChunk

public StableValChunk(long seq,
                      RecordMap records,
                      com.hazelcast.internal.util.collection.LongSet clearedPrefixesFoundAtRestart,
                      int liveRecordCount,
                      long size,
                      long garbage,
                      boolean needsDismissing)

Method Detail

cost

public long cost()

Returns:

the GC cost of this chunk (amount of live data in it).

updateBenefitToCost

public double updateBenefitToCost(long currChunkSeq)

Updates the cached value of the benefit/cost factor.

Returns:

the updated value.