refactor: inject memory interface into LLMNode (#32754)

Signed-off-by: -LAN- <laipz8200@outlook.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

api/core/app/workflow/node_factory.py

@@ -12,6 +12,7 @@ from core.helper.ssrf_proxy import ssrf_proxy
 from core.model_manager import ModelInstance
 from core.model_runtime.entities.model_entities import ModelType
 from core.model_runtime.model_providers.__base.large_language_model import LargeLanguageModel
+from core.prompt.entities.advanced_prompt_entities import MemoryConfig
 from core.rag.retrieval.dataset_retrieval import DatasetRetrieval
 from core.tools.tool_file_manager import ToolFileManager
 from core.workflow.entities.graph_config import NodeConfigDict
@@ -26,9 +27,11 @@ from core.workflow.nodes.datasource import DatasourceNode
 from core.workflow.nodes.document_extractor import DocumentExtractorNode, UnstructuredApiConfig
 from core.workflow.nodes.http_request import HttpRequestNode, build_http_request_config
 from core.workflow.nodes.knowledge_retrieval.knowledge_retrieval_node import KnowledgeRetrievalNode
+from core.workflow.nodes.llm import llm_utils
 from core.workflow.nodes.llm.entities import ModelConfig
 from core.workflow.nodes.llm.exc import LLMModeRequiredError, ModelNotExistError
 from core.workflow.nodes.llm.node import LLMNode
+from core.workflow.nodes.llm.protocols import PromptMessageMemory
 from core.workflow.nodes.node_mapping import LATEST_VERSION, NODE_TYPE_CLASSES_MAPPING
 from core.workflow.nodes.parameter_extractor.parameter_extractor_node import ParameterExtractorNode
 from core.workflow.nodes.question_classifier.question_classifier_node import QuestionClassifierNode
@@ -177,6 +180,7 @@ class DifyNodeFactory(NodeFactory):
 
         if node_type == NodeType.LLM:
             model_instance = self._build_model_instance_for_llm_node(node_data)
+            memory = self._build_memory_for_llm_node(node_data=node_data, model_instance=model_instance)
             return LLMNode(
                 id=node_id,
                 config=node_config,
@@ -185,6 +189,7 @@ class DifyNodeFactory(NodeFactory):
                 credentials_provider=self._llm_credentials_provider,
                 model_factory=self._llm_model_factory,
                 model_instance=model_instance,
+                memory=memory,
             )
 
         if node_type == NodeType.DATASOURCE:
@@ -278,3 +283,21 @@ class DifyNodeFactory(NodeFactory):
         model_instance.stop = tuple(stop)
         model_instance.model_type_instance = cast(LargeLanguageModel, model_instance.model_type_instance)
         return model_instance
+
+    def _build_memory_for_llm_node(
+        self,
+        *,
+        node_data: Mapping[str, Any],
+        model_instance: ModelInstance,
+    ) -> PromptMessageMemory | None:
+        raw_memory_config = node_data.get("memory")
+        if raw_memory_config is None:
+            return None
+
+        node_memory = MemoryConfig.model_validate(raw_memory_config)
+        return llm_utils.fetch_memory(
+            variable_pool=self.graph_runtime_state.variable_pool,
+            app_id=self.graph_init_params.app_id,
+            node_data_memory=node_memory,
+            model_instance=model_instance,
+        )