Package org.springframework.ai.tool.toolsearch.eviction

Class NeverEvictStrategy

java.lang.Object

org.springframework.ai.tool.toolsearch.eviction.NeverEvictStrategy

All Implemented Interfaces:

ToolIndexEvictionStrategy

public final class NeverEvictStrategy
extends Object
implements ToolIndexEvictionStrategy

A ToolIndexEvictionStrategy that never evicts sessions automatically.

Tool indexes persist across requests for the lifetime of the ToolSearchToolCallingAdvisor bean, or until explicitly released via ToolSearchToolCallingAdvisor#evictSession(String).

Memory warning: this strategy accumulates one index entry per distinct session ID and never frees them. In a service that handles many short-lived conversations (e.g. HTTP sessions, anonymous users) the index map will grow without bound, eventually exhausting heap (Lucene ByteBuffersDirectory instances) or remote vector-store quota. For production deployments use LruEvictionStrategy to cap the number of concurrently retained indexes, TtlEvictionStrategy to expire idle sessions, or a CompositeEvictionStrategy combining both.

This strategy is appropriate only when the set of active sessions is small and stable (e.g. a single-user tool or a bounded pool of long-running agents), or when the application manages session lifecycle explicitly via ToolSearchToolCallingAdvisor#evictSession(String).

Since:

2.0.0

Author:

Christian Tzolov

Field Summary

Fields

Modifier and Type	Field	Description
static final NeverEvictStrategy	INSTANCE	Shared singleton instance.

Method Summary

Modifier and Type	Method	Description
Set<String>	onAccess(String sessionId)	Called each time a session is accessed at the start of request processing.
void	onRemoved(String sessionId)	Called after a session's tool index has been cleared — either because this strategy returned it from ToolIndexEvictionStrategy.onAccess(java.lang.String), or because of an explicit eviction request.

Methods inherited from class java.lang.Object

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

Field Details

INSTANCE

public static final NeverEvictStrategy INSTANCE

Shared singleton instance.

Method Details

onAccess

public Set<String> onAccess(String sessionId)

Description copied from interface: ToolIndexEvictionStrategy

Called each time a session is accessed at the start of request processing.

Implementations should update their internal tracking state for sessionId and return the set of session IDs whose tool indexes must now be cleared. The returned set must never include the currently-accessed sessionId.

Specified by:

onAccess in interface ToolIndexEvictionStrategy

Parameters:

sessionId - the session being accessed

Returns:

session IDs to evict; never null, may be empty

onRemoved

public void onRemoved(String sessionId)

Description copied from interface: ToolIndexEvictionStrategy

Called after a session's tool index has been cleared — either because this strategy returned it from ToolIndexEvictionStrategy.onAccess(java.lang.String), or because of an explicit eviction request.

Implementations should remove any internal tracking state for the evicted session.

Specified by:

onRemoved in interface ToolIndexEvictionStrategy

Parameters:

sessionId - the session that was evicted