Package com.yahoo.config.subscription.impl

Class ConfigSubscription<T extends com.yahoo.config.ConfigInstance>

java.lang.Object

com.yahoo.config.subscription.impl.ConfigSubscription<T>

Direct Known Subclasses:

ConfigSetSubscription, FileConfigSubscription, JarConfigSubscription, JRTConfigSubscription, RawConfigSubscription

public abstract class ConfigSubscription<T extends com.yahoo.config.ConfigInstance>
extends java.lang.Object

Represents one active subscription to one config

Author:

Vegard Havdal

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ConfigSubscription.ConfigState<T extends com.yahoo.config.ConfigInstance>

Field Summary

Fields

Modifier and Type	Field	Description
protected java.lang.Class<T>	configClass
protected ConfigKey<T>	key
protected static java.util.logging.Logger	log
protected ConfigSubscriber	subscriber

Method Summary

Modifier and Type	Method	Description
protected boolean	checkReloaded()	True if someone has set the reloadedGeneration number by calling reload(long) and hence wants to force a given generation programmatically.
void	close()
boolean	equals(java.lang.Object o)
static <T extends com.yahoo.config.ConfigInstance> ConfigSubscription<T>	get(ConfigKey<T> key, ConfigSubscriber subscriber, ConfigSource source, TimingValues timingValues)	Correct type of ConfigSubscription instance based on type of source or form of config id
java.lang.Class<T>	getConfigClass()	The class of the subscription's desired ConfigInstance
ConfigSubscription.ConfigState<T>	getConfigState()	The config state object of this subscription
DefContent	getDefContent()	The config definition schema
java.lang.RuntimeException	getException()	Gets an exception set by for example a network thread.
ConfigKey<T>	getKey()	The config key which this subscription uses to identify its config
boolean	isConfigChangedAndReset(java.lang.Long requiredGen)	Called from ConfigSubscriber when the changed status of this config is propagated to the clients
abstract boolean	nextConfig(long timeout)	Polls this subscription for a change.
void	reload(long generation)	Force this into the given generation, used in testing
protected void	setConfigIfChanged(T config)
protected void	setConfigIncGen(T config)	Used by FileConfigSubscription and ConfigSetSubscription
void	setException(java.lang.RuntimeException e)	Called by for example network threads to signal that the user thread should throw this exception immediately
abstract boolean	subscribe(long timeout)	Will block until the next nextConfig(long) is guaranteed to return an answer (or throw) immediately (i.e.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static java.util.logging.Logger log

subscriber

protected final ConfigSubscriber subscriber

key

protected final ConfigKey<T extends com.yahoo.config.ConfigInstance> key

configClass

protected final java.lang.Class<T extends com.yahoo.config.ConfigInstance> configClass

Method Detail

get

public static <T extends com.yahoo.config.ConfigInstance> ConfigSubscription<T> get(ConfigKey<T> key,
                                                                                    ConfigSubscriber subscriber,
                                                                                    ConfigSource source,
                                                                                    TimingValues timingValues)

Correct type of ConfigSubscription instance based on type of source or form of config id

Parameters:

key - a ConfigKey

subscriber - the subscriber for this subscription

Returns:

a subclass of a ConfigsSubscription

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

isConfigChangedAndReset

public boolean isConfigChangedAndReset(java.lang.Long requiredGen)

Called from ConfigSubscriber when the changed status of this config is propagated to the clients

setConfigIncGen

protected void setConfigIncGen(T config)

Used by FileConfigSubscription and ConfigSetSubscription

setConfigIfChanged

protected void setConfigIfChanged(T config)

getConfigState

public ConfigSubscription.ConfigState<T> getConfigState()

The config state object of this subscription

Returns:

the ConfigInstance (the config) of this subscription

getConfigClass

public java.lang.Class<T> getConfigClass()

The class of the subscription's desired ConfigInstance

Returns:

the config class

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getKey

public ConfigKey<T> getKey()

The config key which this subscription uses to identify its config

Returns:

the ConfigKey for this subscription

nextConfig

public abstract boolean nextConfig(long timeout)

Polls this subscription for a change. The method is guaranteed to use all of the given timeout before returning false. It will also take into account a user-set generation, that can be set by ConfigSubscriber.reload(long).

Parameters:

timeout - in milliseconds

Returns:

false if timed out, true if generation or config or exception changed. If true, the config field will be set also. has changed

subscribe

public abstract boolean subscribe(long timeout)

Will block until the next nextConfig(long) is guaranteed to return an answer (or throw) immediately (i.e. not block)

Parameters:

timeout - in milliseconds

Returns:

false if timed out

setException

public void setException(java.lang.RuntimeException e)

Called by for example network threads to signal that the user thread should throw this exception immediately

Parameters:

e - a RuntimeException

getException

public java.lang.RuntimeException getException()

Gets an exception set by for example a network thread. If not null, it indicates that it should be thrown in the user's thread immediately.

Returns:

a RuntimeException if there exists one

close

public void close()

reload

public void reload(long generation)

Force this into the given generation, used in testing

Parameters:

generation - a config generation

checkReloaded

protected boolean checkReloaded()

True if someone has set the reloadedGeneration number by calling reload(long) and hence wants to force a given generation programmatically. If that is the case, sets the generation and flags it as changed accordingly.

Returns:

true if reload(long) has been called, false otherwise

getDefContent

public DefContent getDefContent()

The config definition schema

Returns:

the config definition for this subscription