purushah commented on code in PR #852: URL: https://github.com/apache/flink-agents/pull/852#discussion_r3494566456
########## api/src/main/java/org/apache/flink/agents/api/chat/model/routing/CachingStrategy.java: ########## @@ -0,0 +1,102 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.flink.agents.api.chat.model.routing; + +import java.util.Collections; +import java.util.LinkedHashMap; +import java.util.Map; + +/** + * A {@link RoutingStrategy} decorator that memoizes the wrapped strategy's decision per + * conversation (keyed on {@link RoutingContext#firstUserMessage()}), so an expensive selection — + * e.g. an LLM judge — runs once per conversation rather than on every tool-call round. + * + * <p>The cache is a <b>bounded LRU</b> with real eviction (oldest entries are dropped past the + * capacity), so it never grows without bound and never silently stops caching. Empty keys (requests + * with no user message) are not cached, to avoid coupling unrelated empty-prompt conversations. A + * {@code null} decision (the strategy abstaining — e.g. a transient LLM-judge failure) is likewise + * not cached, so the strategy is re-consulted on the next round rather than pinned to a fallback. + * Thread-safe for the async execution pool. + */ +public final class CachingStrategy implements RoutingStrategy { + + /** Default cache capacity if none is specified. */ + public static final int DEFAULT_MAX_ENTRIES = 1024; + + private final RoutingStrategy delegate; + private final Map<String, String> cache; + + public CachingStrategy(RoutingStrategy delegate) { + this(delegate, DEFAULT_MAX_ENTRIES); + } + + public CachingStrategy(RoutingStrategy delegate, int maxEntries) { + if (delegate == null) { + throw new IllegalArgumentException("delegate strategy must not be null"); + } + if (maxEntries <= 0) { + throw new IllegalArgumentException("maxEntries must be positive: " + maxEntries); + } + this.delegate = delegate; + this.cache = Collections.synchronizedMap(new LruMap(maxEntries)); + } + + @Override + public String route(RoutingContext context) throws Exception { + String key = context.firstUserMessage(); + if (key.isEmpty()) { + // Don't cache empty keys: every empty-prompt conversation would otherwise share one + // decision. Recompute each time instead. + return delegate.route(context); + } + String cached = cache.get(key); Review Comment: Updated here as well. `LlmRoutingStrategy` now says the judge “typically” runs once per conversation when wrapped in `CachingStrategy`, and points readers to `CachingStrategy` for the concurrent first-touch caveat. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
