org.apache.jackrabbit.oak.segment

Class WriterCacheManager

java.lang.Object

org.apache.jackrabbit.oak.segment.WriterCacheManager

Direct Known Subclasses:

WriterCacheManager.Default, WriterCacheManager.Empty

public abstract class WriterCacheManager
extends java.lang.Object

Instances of this class manage the deduplication caches used by the SegmentWriter to avoid writing multiple copies of the same record. The caches are striped into generations with one generation per gc cycle. This avoids records old generations being reused.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	WriterCacheManager.Default This implementation of WriterCacheManager returns RecordCache instances for the string and template cache and Cache instance for the node cache.
static class	WriterCacheManager.Empty This implementation of WriterCacheManager returns empty caches of size 0.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_NODE_CACHE_SIZE Default size of the node deduplication cache.
static int	DEFAULT_STRING_CACHE_SIZE Default size of the string cache.
static int	DEFAULT_TEMPLATE_CACHE_SIZE Default size of the template cache.

Constructor Summary

Constructors

Constructor and Description
WriterCacheManager()

Method Summary

Modifier and Type	Method and Description
abstract @NotNull Cache<java.lang.String,RecordId>	getNodeCache(int generation)
@Nullable java.lang.String	getNodeCacheOccupancyInfo() Get occupancy information for the node deduplication cache indicating occupancy and evictions per priority.
@Nullable CacheStatsMBean	getNodeCacheStats()
abstract @NotNull Cache<java.lang.String,RecordId>	getStringCache(int generation)
@Nullable CacheStatsMBean	getStringCacheStats()
abstract @NotNull Cache<Template,RecordId>	getTemplateCache(int generation)
@Nullable CacheStatsMBean	getTemplateCacheStats()
@NotNull WriterCacheManager	withAccessTracking(@NotNull java.lang.String name, @NotNull StatisticsProvider statisticsProvider) Enable access statistics for this cache.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_STRING_CACHE_SIZE

public static final int DEFAULT_STRING_CACHE_SIZE

Default size of the string cache.

See Also:

getStringCache(int)

DEFAULT_TEMPLATE_CACHE_SIZE

public static final int DEFAULT_TEMPLATE_CACHE_SIZE

Default size of the template cache.

See Also:

getTemplateCache(int)

DEFAULT_NODE_CACHE_SIZE

public static final int DEFAULT_NODE_CACHE_SIZE

Default size of the node deduplication cache.

See Also:

getNodeCache(int)

Constructor Detail

WriterCacheManager

public WriterCacheManager()

Method Detail

getStringCache

@NotNull
public abstract @NotNull Cache<java.lang.String,RecordId> getStringCache(int generation)

Returns:

cache for string records of the given generation and operation.

getTemplateCache

@NotNull
public abstract @NotNull Cache<Template,RecordId> getTemplateCache(int generation)

Parameters:

generation -

Returns:

cache for template records of the given generation and operation.

getNodeCache

@NotNull
public abstract @NotNull Cache<java.lang.String,RecordId> getNodeCache(int generation)

Returns:

cache for node records of the given generation and operation.

withAccessTracking

@NotNull
public @NotNull WriterCacheManager withAccessTracking(@NotNull
                                                               @NotNull java.lang.String name,
                                                               @NotNull
                                                               @NotNull StatisticsProvider statisticsProvider)

Enable access statistics for this cache. The instance returned by from this method delegates back to this instance and adds access statistics via the passed statisticsProvider.

Parameters:

name -

statisticsProvider -

Returns:

an instance of this cache with access statistics enabled.

getStringCacheStats

@Nullable
public @Nullable CacheStatsMBean getStringCacheStats()

Returns:

statistics for the string cache or null if not available.

getTemplateCacheStats

@Nullable
public @Nullable CacheStatsMBean getTemplateCacheStats()

Returns:

statistics for the template cache or null if not available.

getNodeCacheStats

@Nullable
public @Nullable CacheStatsMBean getNodeCacheStats()

Returns:

statistics for the node cache or null if not available.

getNodeCacheOccupancyInfo

@Nullable
public @Nullable java.lang.String getNodeCacheOccupancyInfo()

Get occupancy information for the node deduplication cache indicating occupancy and evictions per priority.

Returns:

occupancy information for the node deduplication cache.