Class Cacher

java.lang.Object

services.moleculer.service.MoleculerComponent

services.moleculer.service.Middleware

services.moleculer.cacher.Cacher

All Implemented Interfaces:

MetricConstants, MoleculerLifecycle

Direct Known Subclasses:

DistributedCacher, MemoryCacher

public abstract class Cacher
extends Middleware
implements MetricConstants

Base superclass of all Cacher implementations.

See Also:

• MemoryCacher
• RedisCacher

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	debug
protected Metrics	metrics

Fields inherited from class MoleculerComponent

broker, logger, name

Fields inherited from interface MetricConstants

MOLECULER_CACHER_CLEAN_TIME, MOLECULER_CACHER_CLEAN_TIME_DESC, MOLECULER_CACHER_CLEAN_TOTAL, MOLECULER_CACHER_CLEAN_TOTAL_DESC, MOLECULER_CACHER_DEL_TIME, MOLECULER_CACHER_DEL_TIME_DESC, MOLECULER_CACHER_DEL_TOTAL, MOLECULER_CACHER_DEL_TOTAL_DESC, MOLECULER_CACHER_EXPIRED_TOTAL, MOLECULER_CACHER_EXPIRED_TOTAL_DESC, MOLECULER_CACHER_FOUND_TOTAL, MOLECULER_CACHER_FOUND_TOTAL_DESC, MOLECULER_CACHER_GET_TIME, MOLECULER_CACHER_GET_TIME_DESC, MOLECULER_CACHER_GET_TOTAL, MOLECULER_CACHER_GET_TOTAL_DESC, MOLECULER_CACHER_SET_TIME, MOLECULER_CACHER_SET_TIME_DESC, MOLECULER_CACHER_SET_TOTAL, MOLECULER_CACHER_SET_TOTAL_DESC, MOLECULER_CIRCUIT_BREAKER_HALF_OPENED_ACTIVE, MOLECULER_CIRCUIT_BREAKER_HALF_OPENED_ACTIVE_DESC, MOLECULER_CIRCUIT_BREAKER_OPENED_ACTIVE, MOLECULER_CIRCUIT_BREAKER_OPENED_ACTIVE_DESC, MOLECULER_CIRCUIT_BREAKER_OPENED_TOTAL, MOLECULER_CIRCUIT_BREAKER_OPENED_TOTAL_DESC, MOLECULER_EVENT_BROADCAST_TOTAL, MOLECULER_EVENT_BROADCAST_TOTAL_DESC, MOLECULER_EVENT_BROADCASTLOCAL_TOTAL, MOLECULER_EVENT_BROADCASTLOCAL_TOTAL_DESC, MOLECULER_EVENT_EMIT_TOTAL, MOLECULER_EVENT_EMIT_TOTAL_DESC, MOLECULER_EVENT_RECEIVED_ACTIVE, MOLECULER_EVENT_RECEIVED_ACTIVE_DESC, MOLECULER_EVENT_RECEIVED_ERROR_TOTAL, MOLECULER_EVENT_RECEIVED_ERROR_TOTAL_DESC, MOLECULER_EVENT_RECEIVED_TIME, MOLECULER_EVENT_RECEIVED_TIME_DESC, MOLECULER_EVENT_RECEIVED_TOTAL, MOLECULER_EVENT_RECEIVED_TOTAL_DESC, MOLECULER_EXECUTOR, MOLECULER_REQUEST_ACTIVE, MOLECULER_REQUEST_ACTIVE_DESC, MOLECULER_REQUEST_ERROR_TOTAL, MOLECULER_REQUEST_ERROR_TOTAL_DESC, MOLECULER_REQUEST_LEVELS, MOLECULER_REQUEST_LEVELS_DESC, MOLECULER_REQUEST_RETRY_ATTEMPTS_TOTAL, MOLECULER_REQUEST_RETRY_ATTEMPTS_TOTAL_DESC, MOLECULER_REQUEST_TIME, MOLECULER_REQUEST_TIME_DESC, MOLECULER_REQUEST_TIMEOUT_TOTAL, MOLECULER_REQUEST_TIMEOUT_TOTAL_DESC, MOLECULER_REQUEST_TOTAL, MOLECULER_REQUEST_TOTAL_DESC, MOLECULER_SCHEDULER, MOLECULER_TRANSIT_CONNECTED, MOLECULER_TRANSIT_CONNECTED_DESC, MOLECULER_TRANSIT_ORPHAN_RESPONSE_TOTAL, MOLECULER_TRANSIT_ORPHAN_RESPONSE_TOTAL_DESC, MOLECULER_TRANSIT_REQUESTS_ACTIVE, MOLECULER_TRANSIT_REQUESTS_ACTIVE_DESC, MOLECULER_TRANSIT_STREAMS_RECEIVE_ACTIVE, MOLECULER_TRANSIT_STREAMS_RECEIVE_ACTIVE_DESC, MOLECULER_TRANSPORTER_PACKETS_RECEIVED_BYTES, MOLECULER_TRANSPORTER_PACKETS_RECEIVED_BYTES_DESC, MOLECULER_TRANSPORTER_PACKETS_RECEIVED_TOTAL, MOLECULER_TRANSPORTER_PACKETS_RECEIVED_TOTAL_DESC, MOLECULER_TRANSPORTER_PACKETS_SENT_BYTES, MOLECULER_TRANSPORTER_PACKETS_SENT_BYTES_DESC, MOLECULER_TRANSPORTER_PACKETS_SENT_TOTAL, MOLECULER_TRANSPORTER_PACKETS_SENT_TOTAL_DESC

Constructor Summary

Constructors

Constructor	Description
Cacher()

Method Summary

Modifier and Type	Method	Description
protected void	appendToKey(StringBuilder key, io.datatree.Tree tree)
protected void	appendTree(StringBuilder key, Object source)
abstract io.datatree.Promise	clean(String match)	Cleans this cache.
abstract io.datatree.Promise	del(String key)	Deletes a content from this cache.
abstract io.datatree.Promise	get(String key)	Gets a cached content by a key.
String	getCacheKey(String name, io.datatree.Tree params, String... keys)	Creates a cacher-specific key by name and params.
abstract io.datatree.Promise	getCacheKeys()	Lists all keys of cached entries.
Action	install(Action action, io.datatree.Tree config)
protected boolean	isCachingDisabledByTheContext(Context ctx)	Is the request disables caching?
boolean	isDebug()	Is debug enabled?
protected void	logClean(String cacheName, String match, long count)
protected void	serializeKey(StringBuilder key, io.datatree.Tree params, String... keys)
abstract io.datatree.Promise	set(String key, io.datatree.Tree value, int ttl)	Sets a content by key into the cache.
void	setDebug(boolean debug)	Enable debug messages.
void	started(ServiceBroker broker)

Methods inherited from class MoleculerComponent

getBroker, getLogger, getName, stopped

Methods inherited from class Object

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

Field Details

metrics

protected Metrics metrics

debug

protected boolean debug

Constructor Details

Cacher

public Cacher()

Method Details

started

public void started(ServiceBroker broker)
             throws Exception

Specified by:

started in interface MoleculerLifecycle

Overrides:

started in class MoleculerComponent

Throws:

Exception

install

public Action install(Action action,
 io.datatree.Tree config)

Specified by:

install in class Middleware

getCacheKey

public String getCacheKey(String name,
 io.datatree.Tree params,
 String... keys)

Creates a cacher-specific key by name and params. Concatenates the name and params.

Parameters:

name - qualified name of the action

params - input (key) structure (~JSON)

keys - optional array of keys (eg. "id")

Returns:

generated cache key

serializeKey

protected void serializeKey(StringBuilder key,
 io.datatree.Tree params,
 String... keys)

appendToKey

protected void appendToKey(StringBuilder key,
 io.datatree.Tree tree)

appendTree

protected void appendTree(StringBuilder key,
 Object source)

isCachingDisabledByTheContext

protected boolean isCachingDisabledByTheContext(Context ctx)

Is the request disables caching?

Parameters:

ctx - Input Context

Returns:

true, if the caching is disabled at the request level

logClean

protected void logClean(String cacheName,
 String match,
 long count)

get

public abstract io.datatree.Promise get(String key)

Gets a cached content by a key.

Parameters:

key - cache key

Returns:

Promise with cached value (or null, the returned Promise also can be null)

set

public abstract io.datatree.Promise set(String key,
 io.datatree.Tree value,
 int ttl)

Sets a content by key into the cache.

Parameters:

key - cache key

value - new value

ttl - optional TTL of entry (0 == use default TTL)

Returns:

Promise with empty value

del

public abstract io.datatree.Promise del(String key)

Deletes a content from this cache.

Parameters:

key - cache key

Returns:

Promise with empty value

clean

public abstract io.datatree.Promise clean(String match)

Cleans this cache. Removes every key by a match string. The default match string is "**".

Parameters:

match - regex

Returns:

Promise with empty value

getCacheKeys

public abstract io.datatree.Promise getCacheKeys()

Lists all keys of cached entries.

Returns:

a Tree object with a "keys" array.

isDebug

public boolean isDebug()

Is debug enabled?

Returns:

debug flag

setDebug

public void setDebug(boolean debug)

Enable debug messages.

Parameters:

debug - debug mode