org.infinispan.commands.write

Enum ValueMatcher

java.lang.Object

java.lang.Enum<ValueMatcher>

org.infinispan.commands.write.ValueMatcher

All Implemented Interfaces:

Serializable, Comparable<ValueMatcher>

public enum ValueMatcher
extends Enum<ValueMatcher>

A policy for determining if a write command should be executed based on the current value in the cache. When retrying conditional write commands in non-transactional caches, it is also used to determine the appropriate return value. E.g. if a putIfAbsent(k, v) already succeeded on a backup owner which became the primary owner, when retrying the command will find v in the cache but should return null. For non-conditional commands it's impossible to know what the previous value was, so the command is allowed to return v.

Since:

6.0

Author:

Dan Berindei

Enum Constant Summary

Enum Constants

Enum Constant and Description
MATCH_ALWAYS Always match.
MATCH_EXPECTED Match when the existing value is equal to the expected value.
MATCH_EXPECTED_OR_NEW Match when the existing value is equal to the expected value or to the new value.
MATCH_NEVER Never match.
MATCH_NON_NULL Match any non-null value.

Method Summary

Methods

Modifier and Type	Method and Description
protected boolean	equal(Object a, Object b, Equivalence valueEquivalence)
protected Object	extractValue(MVCCEntry mvccEntry)
abstract ValueMatcher	matcherForRetry()
abstract boolean	matches(MVCCEntry existingEntry, Object expectedValue, Object newValue, Equivalence valueEquivalence)
abstract boolean	nonExistentEntryCanMatch()
static ValueMatcher	valueOf(String name) Returns the enum constant of this type with the specified name.
static ValueMatcher[]	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, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

MATCH_ALWAYS

public static final ValueMatcher MATCH_ALWAYS

Always match. Used when the command is not conditional or when the value was already checked (on the primary owner, in non-tx caches, or on the originator, in tx caches). Also used when retrying BasicCache.remove(Object) operations.

MATCH_EXPECTED

public static final ValueMatcher MATCH_EXPECTED

Match when the existing value is equal to the expected value. Used for ConcurrentMap.putIfAbsent(Object, Object), ConcurrentMap.replace(Object, Object, Object), and ConcurrentMap.remove(Object, Object).

MATCH_EXPECTED_OR_NEW

public static final ValueMatcher MATCH_EXPECTED_OR_NEW

Match when the existing value is equal to the expected value or to the new value. Used only in non-tx caches, when retrying a conditional command on the primary owner.

MATCH_NON_NULL

public static final ValueMatcher MATCH_NON_NULL

Match any non-null value. Used for ConcurrentMap.replace(Object, Object) and BasicCache.remove(Object).

MATCH_NEVER

public static final ValueMatcher MATCH_NEVER

Never match. Only used in transactional mode, as unsuccessful commands are still sent remotely, even though they should not be performed.

Method Detail

values

public static ValueMatcher[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ValueMatcher c : ValueMatcher.values())
    System.out.println(c);

Returns:

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

valueOf

public static ValueMatcher 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

matches

public abstract boolean matches(MVCCEntry existingEntry,
              Object expectedValue,
              Object newValue,
              Equivalence valueEquivalence)

nonExistentEntryCanMatch

public abstract boolean nonExistentEntryCanMatch()

matcherForRetry

public abstract ValueMatcher matcherForRetry()

extractValue

protected Object extractValue(MVCCEntry mvccEntry)

equal

protected boolean equal(Object a,
            Object b,
            Equivalence valueEquivalence)