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

Class AlwaysEvictStrategy

java.lang.Object

org.springframework.ai.tool.toolsearch.eviction.AlwaysEvictStrategy

All Implemented Interfaces:

ToolIndexEvictionStrategy

public final class AlwaysEvictStrategy
extends Object
implements ToolIndexEvictionStrategy

A ToolIndexEvictionStrategy that clears a session's tool index before every request, ensuring tools are always re-indexed on each conversation turn.

Use this strategy when the tool set may change between turns (e.g. dynamically generated tool descriptions) and you want to guarantee freshness at the cost of re-indexing on every request. For stable tool sets, NeverEvictStrategy is more efficient.

Contract note: onAccess(java.lang.String) intentionally returns the currently-accessed session ID, which diverges from the general recommendation in ToolIndexEvictionStrategy.onAccess(java.lang.String). This is safe because the advisor's doEvict + fingerprint-recheck sequence is idempotent: evicting the current session removes its cached fingerprint, so the subsequent fingerprint comparison always sees null and triggers a full re-index. When combined with other strategies in a CompositeEvictionStrategy, the always-evict behaviour is preserved (the more aggressive strategy wins).

Since:

2.0.0

Author:

Christian Tzolov

See Also:

• NeverEvictStrategy
• LruEvictionStrategy
• TtlEvictionStrategy

Field Summary

Fields

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

Method Summary

Modifier and Type	Method	Description
Set<String>	onAccess(String sessionId)	Returns a set containing sessionId, causing the advisor to clear the session's index and remove its cached fingerprint before the fingerprint-comparison step.
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 AlwaysEvictStrategy INSTANCE

Shared singleton instance.

Method Details

onAccess

public Set<String> onAccess(String sessionId)

Returns a set containing sessionId, causing the advisor to clear the session's index and remove its cached fingerprint before the fingerprint-comparison step. The comparison then always sees a missing fingerprint and re-indexes the full tool set.

Specified by:

onAccess in interface ToolIndexEvictionStrategy

Parameters:

sessionId - the session being accessed

Returns:

a singleton set containing sessionId

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