Avoid using cache and tools in the same @RegisterAiService

Author: andreadimaio

core/deployment/src/main/java/io/quarkiverse/langchain4j/deployment/AiServicesProcessor.java

@@ -447,6 +447,13 @@ public void handleDeclarativeServices(AiServicesRecorder recorder,
             String aiCacheEmbeddingModelName = aiCacheBuildItem.getEmbeddingModelName();
             boolean enableCache = aiCacheBuildItem.isEnable();
 
+            // It is not possible to use the cache in combination with the tools.
+            if (!toolClassNames.isEmpty() && enableCache
+                    && declarativeAiServiceClassInfo.hasAnnotation(LangChain4jDotNames.CACHE_RESULT)) {
+                throw new RuntimeException("The cache cannot be used in combination with the tools. Affected class: %s"
+                        .formatted(serviceClassName));
+            }
+
             SyntheticBeanBuildItem.ExtendedBeanConfigurator configurator = SyntheticBeanBuildItem
                     .configure(QuarkusAiServiceContext.class)
                     .forceApplicationClass()

core/runtime/src/main/java/io/quarkiverse/langchain4j/runtime/aiservice/AiServiceMethodImplementationSupport.java

@@ -16,7 +16,6 @@
 import java.util.Map;
 import java.util.Optional;
 import java.util.concurrent.Callable;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Future;
 import java.util.function.Consumer;
@@ -62,7 +61,6 @@ public class AiServiceMethodImplementationSupport {
     private static final Logger log = Logger.getLogger(AiServiceMethodImplementationSupport.class);
     private static final int MAX_SEQUENTIAL_TOOL_EXECUTIONS = 10;
     private static final List<DefaultMemoryIdProvider> DEFAULT_MEMORY_ID_PROVIDERS;
-    private static final Map<UserMessage, Embedding> CACHE = new ConcurrentHashMap<>();
 
     static {
         var defaultMemoryIdProviders = ServiceHelper.loadFactories(

model-providers/bam/deployment/src/test/java/io/quarkiverse/langchain4j/bam/deployment/CacheWithToolTest.java

@@ -0,0 +1,38 @@
+package io.quarkiverse.langchain4j.bam.deployment;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import org.jboss.shrinkwrap.api.ShrinkWrap;
+import org.jboss.shrinkwrap.api.spec.JavaArchive;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import dev.langchain4j.service.UserMessage;
+import io.quarkiverse.langchain4j.CacheResult;
+import io.quarkiverse.langchain4j.RegisterAiService;
+import io.quarkus.test.QuarkusUnitTest;
+
+public class CacheWithToolTest {
+
+    @RegisterExtension
+    static final QuarkusUnitTest unitTest = new QuarkusUnitTest()
+            .setArchiveProducer(() -> ShrinkWrap.create(JavaArchive.class))
+            .assertException(t -> {
+                assertThat(t).isInstanceOf(RuntimeException.class);
+                assertEquals("The cache cannot be used in combination with the tools. Affected class: %s"
+                        .formatted(AiService.class.getName()), t.getMessage());
+            });
+
+    @RegisterAiService(tools = Object.class)
+    public interface AiService {
+        @CacheResult
+        public String poem(@UserMessage("{text}") String text);
+    }
+
+    @Test
+    void test() {
+        fail("Should not be called");
+    }
+}