Class ClientRequestDeduplicator

java.lang.Object

com.loomcache.client.ClientRequestDeduplicator

All Implemented Interfaces:

AutoCloseable

public class ClientRequestDeduplicator
extends Object
implements AutoCloseable

Client-side request deduplicator that prevents duplicate sends and coalesces identical in-flight requests.

Features: - Assigns unique request IDs (UUID-based) to outgoing requests - Tracks in-flight requests to prevent duplicate sends - Coalesces identical requests: if same operation is already in-flight, returns the same CompletableFuture instead of sending another request

Request coalescing key = operation type + map name + key. This prevents duplicate network traffic for concurrent identical operations.

Thread-safe: uses ReentrantLock for coordinated operations and ConcurrentHashMap for the underlying tracking.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	ClientRequestDeduplicator.CoalescingKey	Record representing a request coalescing key.
static final record	ClientRequestDeduplicator.CoalescingStats	Statistics for request deduplication.
static final record	ClientRequestDeduplicator.InFlightRequest	Record representing an in-flight request.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_MAX_IN_FLIGHT_REQUESTS

Constructor Summary

Constructors

Constructor	Description
ClientRequestDeduplicator()	Creates a new ClientRequestDeduplicator.
ClientRequestDeduplicator(Duration requestTimeout)	Creates a new ClientRequestDeduplicator with a stale-request timeout derived from the request timeout.
ClientRequestDeduplicator(Duration requestTimeout, int maxInFlightRequests)	Creates a new ClientRequestDeduplicator with a stale-request timeout derived from the request timeout and an explicit in-flight request limit.
ClientRequestDeduplicator(Duration staleRequestTimeout, Duration cleanupInterval)	Creates a new ClientRequestDeduplicator with explicit stale-request sweep configuration.
ClientRequestDeduplicator(Duration staleRequestTimeout, Duration cleanupInterval, int maxInFlightRequests)	Creates a new ClientRequestDeduplicator with explicit stale-request sweep and capacity configuration.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears all tracked requests (useful for testing/cleanup).
void	close()
String	generateRequestId()	Generates a unique request ID.
int	getInFlightCount()	Returns the number of currently in-flight requests.
ClientRequestDeduplicator.CoalescingStats	getStats()	Returns current statistics about request deduplication.
@Nullable CompletableFuture<?>	trackRequest(String requestId, String operation, String mapName, String key, CompletableFuture<?> future)	Registers an in-flight request for tracking and coalescing.
void	untrackRequest(String requestId)	Unregisters a completed request from tracking.

Methods inherited from class Object

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

Field Details

DEFAULT_MAX_IN_FLIGHT_REQUESTS

public static final int DEFAULT_MAX_IN_FLIGHT_REQUESTS

See Also:

• Constant Field Values

Constructor Details

ClientRequestDeduplicator

public ClientRequestDeduplicator()

Creates a new ClientRequestDeduplicator.

ClientRequestDeduplicator

public ClientRequestDeduplicator(Duration requestTimeout)

Creates a new ClientRequestDeduplicator with a stale-request timeout derived from the request timeout.

Parameters:

requestTimeout - request timeout used to derive stale request eviction (2x request timeout)

ClientRequestDeduplicator

public ClientRequestDeduplicator(Duration requestTimeout,
 int maxInFlightRequests)

Creates a new ClientRequestDeduplicator with a stale-request timeout derived from the request timeout and an explicit in-flight request limit.

Parameters:

requestTimeout - request timeout used to derive stale request eviction (2x request timeout)

maxInFlightRequests - maximum unique in-flight reads tracked for coalescing

ClientRequestDeduplicator

public ClientRequestDeduplicator(Duration staleRequestTimeout,
 Duration cleanupInterval)

Creates a new ClientRequestDeduplicator with explicit stale-request sweep configuration.

Parameters:

staleRequestTimeout - maximum age for tracked requests before forced cleanup

cleanupInterval - how often the stale-request sweep runs

ClientRequestDeduplicator

public ClientRequestDeduplicator(Duration staleRequestTimeout,
 Duration cleanupInterval,
 int maxInFlightRequests)

Creates a new ClientRequestDeduplicator with explicit stale-request sweep and capacity configuration.

Parameters:

staleRequestTimeout - maximum age for tracked requests before forced cleanup

cleanupInterval - how often the stale-request sweep runs

maxInFlightRequests - maximum unique in-flight reads tracked for coalescing

Method Details

generateRequestId

public String generateRequestId()

Generates a unique request ID.

Returns:

a new UUID-based request ID

trackRequest

public @Nullable CompletableFuture<?> trackRequest(String requestId,
 String operation,
 String mapName,
 String key,
 CompletableFuture<?> future)

Registers an in-flight request for tracking and coalescing. If an identical request is already in-flight, returns the existing future. Otherwise, returns null and the request should be sent.

Parameters:

requestId - the unique request ID

operation - the operation type (e.g., "MAP_GET", "MAP_PUT")

mapName - the map/structure name

key - the key being accessed

future - the CompletableFuture for this request

Returns:

the existing future if a duplicate is in-flight, null if this is a new request

untrackRequest

public void untrackRequest(String requestId)

Unregisters a completed request from tracking.

Parameters:

requestId - the request ID to unregister

getStats

public ClientRequestDeduplicator.CoalescingStats getStats()

Returns current statistics about request deduplication.

clear

public void clear()

Clears all tracked requests (useful for testing/cleanup).

getInFlightCount

public int getInFlightCount()

Returns the number of currently in-flight requests.

close

public void close()

Specified by:

close in interface AutoCloseable