Package org.apache.druid.metadata.segment.cache

Enum SegmentMetadataCache.UsageMode

java.lang.Object

java.lang.Enum<SegmentMetadataCache.UsageMode>

org.apache.druid.metadata.segment.cache.SegmentMetadataCache.UsageMode

All Implemented Interfaces:

Serializable, Comparable<SegmentMetadataCache.UsageMode>

Enclosing interface:

SegmentMetadataCache

public static enum SegmentMetadataCache.UsageMode
extends Enum<SegmentMetadataCache.UsageMode>

Cache usage modes.

Enum Constant Summary

Enum Constants

Enum Constant	Description
ALWAYS	Always read from the cache.
IF_SYNCED	Read from the cache only if it is already synced with the metadata store.
NEVER	Cache is disabled.

Method Summary

Modifier and Type	Method	Description
static SegmentMetadataCache.UsageMode	fromString(String value)
String	toString()
static SegmentMetadataCache.UsageMode	valueOf(String name)	Returns the enum constant of this type with the specified name.
static SegmentMetadataCache.UsageMode[]	values()	Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

ALWAYS

public static final SegmentMetadataCache.UsageMode ALWAYS

Always read from the cache. Service start-up may be blocked until cache has synced with the metadata store at least once. Transactions may block until cache has synced with the metadata store at least once after becoming leader.

NEVER

public static final SegmentMetadataCache.UsageMode NEVER

Cache is disabled.

IF_SYNCED

public static final SegmentMetadataCache.UsageMode IF_SYNCED

Read from the cache only if it is already synced with the metadata store. Does not block service start-up or transactions. Writes may still go to cache to reduce sync times.

Method Details

values

public static SegmentMetadataCache.UsageMode[] values()

Returns an array containing the constants of this enum type, in the order they are declared.

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static SegmentMetadataCache.UsageMode valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

fromString

public static SegmentMetadataCache.UsageMode fromString(String value)

toString

public String toString()

Overrides:

toString in class Enum<SegmentMetadataCache.UsageMode>