alessandrobenedetti commented on code in PR #4259: URL: https://github.com/apache/solr/pull/4259#discussion_r3101163502
########## solr/modules/language-models/src/java/org/apache/solr/languagemodels/documentenrichment/model/SolrChatModel.java: ########## @@ -0,0 +1,211 @@ +/* + * 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.solr.languagemodels.documentenrichment.model; + +import dev.langchain4j.data.message.UserMessage; +import dev.langchain4j.model.chat.ChatModel; +import dev.langchain4j.model.chat.request.ChatRequest; +import dev.langchain4j.model.chat.request.ResponseFormat; +import java.lang.invoke.MethodHandles; +import java.lang.reflect.Method; +import java.time.Duration; +import java.util.ArrayList; +import java.util.Map; +import java.util.Objects; +import org.apache.lucene.util.Accountable; +import org.apache.lucene.util.RamUsageEstimator; +import org.apache.solr.common.SolrException; +import org.apache.solr.common.util.Utils; +import org.apache.solr.core.SolrResourceLoader; +import org.apache.solr.languagemodels.documentenrichment.store.ChatModelException; +import org.apache.solr.languagemodels.documentenrichment.store.rest.ManagedChatModelStore; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * This object wraps a {@link dev.langchain4j.model.chat.ChatModel} to produce the content of a + * field based on the content of other fields specified as input. It's meant to be used as a managed + * resource with the {@link ManagedChatModelStore} + */ +public class SolrChatModel implements Accountable { + private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass()); + private static final long BASE_RAM_BYTES = + RamUsageEstimator.shallowSizeOfInstance(SolrChatModel.class); + private static final String TIMEOUT_PARAM = "timeout"; + private static final String MAX_RETRIES_PARAM = "maxRetries"; + private static final String THINKING_BUDGET_TOKENS = "thinkingBudgetTokens"; + private static final String RANDOM_SEED = "randomSeed"; + + private final String name; + private final Map<String, Object> params; + private final ChatModel chatModel; + private final int hashCode; + + public static SolrChatModel getInstance( + SolrResourceLoader solrResourceLoader, + String className, + String name, + Map<String, Object> params) + throws ChatModelException { + try { + /* + * The idea here is to build a {@link dev.langchain4j.model.chat.ChatModel} using inversion + * of control. + * Each model has its own list of parameters we don't know beforehand, but each {@link dev.langchain4j.model.chat.ChatModel} class + * has its own builder that uses setters with the same name of the parameter in input. + * */ + ChatModel chatModel; + Class<?> modelClass = solrResourceLoader.findClass(className, ChatModel.class); + var builder = modelClass.getMethod("builder").invoke(null); + if (params != null) { + /* + * This block of code has the responsibility of instantiate a {@link + * dev.langchain4j.model.chat.ChatModel} using the params provided. Classes have + * params of the specific implementation of {@link + * dev.langchain4j.model.chat.ChatModel}, which is not known beforehand. So we benefit of + * the design choice in langchain4j that each subclass implementing {@link + * dev.langchain4j.model.chat.ChatModel} uses setters with the same name of the + * param. + */ + for (String paramName : params.keySet()) { + /* + * When a param is not primitive, we need to instantiate the object explicitly and then call the + * setter method. + * N.B. when adding support to new models, pay attention to all the parameters they + * support, some of them may require to be handled in here as separate switch cases + */ + switch (paramName) { + case TIMEOUT_PARAM -> builder + .getClass() + .getMethod(paramName, Duration.class) + .invoke(builder, Duration.ofSeconds((Long) params.get(paramName))); + + case MAX_RETRIES_PARAM, THINKING_BUDGET_TOKENS, RANDOM_SEED -> builder + .getClass() + .getMethod(paramName, Integer.class) + .invoke(builder, ((Long) params.get(paramName)).intValue()); + + /* + * For primitive params if there's only one setter available, we call it. + * If there's choice we default to the string one + */ + default -> { + ArrayList<Method> paramNameMatches = new ArrayList<>(); + for (var method : builder.getClass().getMethods()) { + if (paramName.equals(method.getName()) && method.getParameterCount() == 1) { + paramNameMatches.add(method); + } + } + if (paramNameMatches.size() == 1) { + paramNameMatches.getFirst().invoke(builder, params.get(paramName)); + } else { + try { + builder + .getClass() + .getMethod(paramName, String.class) + .invoke(builder, params.get(paramName).toString()); + } catch (NoSuchMethodException e) { + log.error("Parameter {} not supported by model {}", paramName, className); + throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, e.getMessage(), e); + } + } + } + } + } + } + chatModel = (ChatModel) builder.getClass().getMethod("build").invoke(builder); + return new SolrChatModel(name, chatModel, params); + } catch (final Exception e) { + throw new ChatModelException("Model loading failed for " + className, e); + } + } + + public SolrChatModel(String name, ChatModel chatModel, Map<String, Object> params) { + this.name = name; + this.chatModel = chatModel; + this.params = params; + this.hashCode = calculateHashCode(); + } + + /** + * Sends a structured chat request and returns the parsed value from the {@code {"value": ...}} + * JSON object that the model is instructed to produce via {@code responseFormat}. + * + * @return the extracted value: a {@link String}, {@link Number}, {@link Integer}, {@link + * Boolean}, or {@link java.util.List} depending on the Solr output field type + */ + public Object chat(String prompt, ResponseFormat responseFormat) { + ChatRequest chatRequest = + ChatRequest.builder() + .responseFormat(responseFormat) + .messages(UserMessage.from(prompt)) + .build(); + String rawJson = chatModel.chat(chatRequest).aiMessage().text(); + Object parsed = Utils.fromJSONString(rawJson); Review Comment: Is parsing an 'Object' necessary? -- This is an automated message from the Apache Git Service. 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