dify/api/core/workflow/workflow_entry.py

import logging
import time
import uuid
from collections.abc import Generator, Mapping, Sequence
from typing import Any, Optional, cast

from configs import dify_config
from core.app.apps.exc import GenerateTaskStoppedError
from core.app.entities.app_invoke_entities import InvokeFrom
from core.file.models import File
from core.workflow.callbacks import WorkflowCallback
from core.workflow.constants import ENVIRONMENT_VARIABLE_NODE_ID
from core.workflow.entities.variable_pool import VariablePool
from core.workflow.errors import WorkflowNodeRunFailedError
from core.workflow.graph_engine.entities.event import GraphEngineEvent, GraphRunFailedEvent, InNodeEvent
from core.workflow.graph_engine.entities.graph import Graph
from core.workflow.graph_engine.entities.graph_init_params import GraphInitParams
from core.workflow.graph_engine.entities.graph_runtime_state import GraphRuntimeState
from core.workflow.graph_engine.graph_engine import GraphEngine
from core.workflow.nodes import NodeType
from core.workflow.nodes.base import BaseNode
from core.workflow.nodes.event import NodeEvent
from core.workflow.nodes.node_mapping import NODE_TYPE_CLASSES_MAPPING
from core.workflow.system_variable import SystemVariable
from core.workflow.variable_loader import DUMMY_VARIABLE_LOADER, VariableLoader, load_into_variable_pool
from factories import file_factory
from models.enums import UserFrom
from models.workflow import (
    Workflow,
    WorkflowType,
)

logger = logging.getLogger(__name__)


class WorkflowEntry:
    def __init__(
        self,
        tenant_id: str,
        app_id: str,
        workflow_id: str,
        workflow_type: WorkflowType,
        graph_config: Mapping[str, Any],
        graph: Graph,
        user_id: str,
        user_from: UserFrom,
        invoke_from: InvokeFrom,
        call_depth: int,
        variable_pool: VariablePool,
        thread_pool_id: Optional[str] = None,
    ) -> None:
        """
        Init workflow entry
        :param tenant_id: tenant id
        :param app_id: app id
        :param workflow_id: workflow id
        :param workflow_type: workflow type
        :param graph_config: workflow graph config
        :param graph: workflow graph
        :param user_id: user id
        :param user_from: user from
        :param invoke_from: invoke from
        :param call_depth: call depth
        :param variable_pool: variable pool
        :param thread_pool_id: thread pool id
        """
        # check call depth
        workflow_call_max_depth = dify_config.WORKFLOW_CALL_MAX_DEPTH
        if call_depth > workflow_call_max_depth:
            raise ValueError(f"Max workflow call depth {workflow_call_max_depth} reached.")

        # init workflow run state
        graph_runtime_state = GraphRuntimeState(variable_pool=variable_pool, start_at=time.perf_counter())
        self.graph_engine = GraphEngine(
            tenant_id=tenant_id,
            app_id=app_id,
            workflow_type=workflow_type,
            workflow_id=workflow_id,
            user_id=user_id,
            user_from=user_from,
            invoke_from=invoke_from,
            call_depth=call_depth,
            graph=graph,
            graph_config=graph_config,
            graph_runtime_state=graph_runtime_state,
            max_execution_steps=dify_config.WORKFLOW_MAX_EXECUTION_STEPS,
            max_execution_time=dify_config.WORKFLOW_MAX_EXECUTION_TIME,
            thread_pool_id=thread_pool_id,
        )

    def run(
        self,
        *,
        callbacks: Sequence[WorkflowCallback],
    ) -> Generator[GraphEngineEvent, None, None]:
        """
        :param callbacks: workflow callbacks
        """
        graph_engine = self.graph_engine

        try:
            # run workflow
            generator = graph_engine.run()
            for event in generator:
                if callbacks:
                    for callback in callbacks:
                        callback.on_event(event=event)
                yield event
        except GenerateTaskStoppedError:
            pass
        except Exception as e:
            logger.exception("Unknown Error when workflow entry running")
            if callbacks:
                for callback in callbacks:
                    callback.on_event(event=GraphRunFailedEvent(error=str(e)))
            return

    @classmethod
    def single_step_run(
        cls,
        *,
        workflow: Workflow,
        node_id: str,
        user_id: str,
        user_inputs: Mapping[str, Any],
        variable_pool: VariablePool,
        variable_loader: VariableLoader = DUMMY_VARIABLE_LOADER,
    ) -> tuple[BaseNode, Generator[NodeEvent | InNodeEvent, None, None]]:
        """
        Single step run workflow node
        :param workflow: Workflow instance
        :param node_id: node id
        :param user_id: user id
        :param user_inputs: user inputs
        :return:
        """
        node_config = workflow.get_node_config_by_id(node_id)
        node_config_data = node_config.get("data", {})

        # Get node class
        node_type = NodeType(node_config_data.get("type"))
        node_version = node_config_data.get("version", "1")
        node_cls = NODE_TYPE_CLASSES_MAPPING[node_type][node_version]

        # init graph
        graph = Graph.init(graph_config=workflow.graph_dict)

        # init workflow run state
        node = node_cls(
            id=str(uuid.uuid4()),
            config=node_config,
            graph_init_params=GraphInitParams(
                tenant_id=workflow.tenant_id,
                app_id=workflow.app_id,
                workflow_type=WorkflowType.value_of(workflow.type),
                workflow_id=workflow.id,
                graph_config=workflow.graph_dict,
                user_id=user_id,
                user_from=UserFrom.ACCOUNT,
                invoke_from=InvokeFrom.DEBUGGER,
                call_depth=0,
            ),
            graph=graph,
            graph_runtime_state=GraphRuntimeState(variable_pool=variable_pool, start_at=time.perf_counter()),
        )
        node.init_node_data(node_config_data)

        try:
            # variable selector to variable mapping
            variable_mapping = node_cls.extract_variable_selector_to_variable_mapping(
                graph_config=workflow.graph_dict, config=node_config
            )
        except NotImplementedError:
            variable_mapping = {}

        # Loading missing variable from draft var here, and set it into
        # variable_pool.
        load_into_variable_pool(
            variable_loader=variable_loader,
            variable_pool=variable_pool,
            variable_mapping=variable_mapping,
            user_inputs=user_inputs,
        )

        cls.mapping_user_inputs_to_variable_pool(
            variable_mapping=variable_mapping,
            user_inputs=user_inputs,
            variable_pool=variable_pool,
            tenant_id=workflow.tenant_id,
        )

        try:
            # run node
            generator = node.run()
        except Exception as e:
            logger.exception(
                "error while running node, workflow_id=%s, node_id=%s, node_type=%s, node_version=%s",
                workflow.id,
                node.id,
                node.type_,
                node.version(),
            )
            raise WorkflowNodeRunFailedError(node=node, err_msg=str(e))
        return node, generator

    @classmethod
    def run_free_node(
        cls, node_data: dict, node_id: str, tenant_id: str, user_id: str, user_inputs: dict[str, Any]
    ) -> tuple[BaseNode, Generator[NodeEvent | InNodeEvent, None, None]]:
        """
        Run free node

        NOTE: only parameter_extractor/question_classifier are supported

        :param node_data: node data
        :param node_id: node id
        :param tenant_id: tenant id
        :param user_id: user id
        :param user_inputs: user inputs
        :return:
        """
        # generate a fake graph
        node_config = {"id": node_id, "width": 114, "height": 514, "type": "custom", "data": node_data}
        start_node_config = {
            "id": "start",
            "width": 114,
            "height": 514,
            "type": "custom",
            "data": {
                "type": NodeType.START.value,
                "title": "Start",
                "desc": "Start",
            },
        }
        graph_dict = {
            "nodes": [start_node_config, node_config],
            "edges": [
                {
                    "source": "start",
                    "target": node_id,
                    "sourceHandle": "source",
                    "targetHandle": "target",
                }
            ],
        }

        node_type = NodeType(node_data.get("type", ""))
        if node_type not in {NodeType.PARAMETER_EXTRACTOR, NodeType.QUESTION_CLASSIFIER}:
            raise ValueError(f"Node type {node_type} not supported")

        node_cls = NODE_TYPE_CLASSES_MAPPING[node_type]["1"]
        if not node_cls:
            raise ValueError(f"Node class not found for node type {node_type}")

        graph = Graph.init(graph_config=graph_dict)

        # init variable pool
        variable_pool = VariablePool(
            system_variables=SystemVariable.empty(),
            user_inputs={},
            environment_variables=[],
        )

        node_cls = cast(type[BaseNode], node_cls)
        # init workflow run state
        node: BaseNode = node_cls(
            id=str(uuid.uuid4()),
            config=node_config,
            graph_init_params=GraphInitParams(
                tenant_id=tenant_id,
                app_id="",
                workflow_type=WorkflowType.WORKFLOW,
                workflow_id="",
                graph_config=graph_dict,
                user_id=user_id,
                user_from=UserFrom.ACCOUNT,
                invoke_from=InvokeFrom.DEBUGGER,
                call_depth=0,
            ),
            graph=graph,
            graph_runtime_state=GraphRuntimeState(variable_pool=variable_pool, start_at=time.perf_counter()),
        )
        node.init_node_data(node_data)

        try:
            # variable selector to variable mapping
            try:
                variable_mapping = node_cls.extract_variable_selector_to_variable_mapping(
                    graph_config=graph_dict, config=node_config
                )
            except NotImplementedError:
                variable_mapping = {}

            cls.mapping_user_inputs_to_variable_pool(
                variable_mapping=variable_mapping,
                user_inputs=user_inputs,
                variable_pool=variable_pool,
                tenant_id=tenant_id,
            )

            # run node
            generator = node.run()

            return node, generator
        except Exception as e:
            logger.exception(
                "error while running node, node_id=%s, node_type=%s, node_version=%s",
                node.id,
                node.type_,
                node.version(),
            )
            raise WorkflowNodeRunFailedError(node=node, err_msg=str(e))

    @staticmethod
    def handle_special_values(value: Optional[Mapping[str, Any]]) -> Mapping[str, Any] | None:
        # NOTE(QuantumGhost): Avoid using this function in new code.
        # Keep values structured as long as possible and only convert to dict
        # immediately before serialization (e.g., JSON serialization) to maintain
        # data integrity and type information.
        result = WorkflowEntry._handle_special_values(value)
        return result if isinstance(result, Mapping) or result is None else dict(result)

    @staticmethod
    def _handle_special_values(value: Any) -> Any:
        if value is None:
            return value
        if isinstance(value, dict):
            res = {}
            for k, v in value.items():
                res[k] = WorkflowEntry._handle_special_values(v)
            return res
        if isinstance(value, list):
            res_list = []
            for item in value:
                res_list.append(WorkflowEntry._handle_special_values(item))
            return res_list
        if isinstance(value, File):
            return value.to_dict()
        return value

    @classmethod
    def mapping_user_inputs_to_variable_pool(
        cls,
        *,
        variable_mapping: Mapping[str, Sequence[str]],
        user_inputs: Mapping[str, Any],
        variable_pool: VariablePool,
        tenant_id: str,
    ) -> None:
        # NOTE(QuantumGhost): This logic should remain synchronized with
        # the implementation of `load_into_variable_pool`, specifically the logic about
        # variable existence checking.

        # WARNING(QuantumGhost): The semantics of this method are not clearly defined,
        # and multiple parts of the codebase depend on its current behavior.
        # Modify with caution.
        for node_variable, variable_selector in variable_mapping.items():
            # fetch node id and variable key from node_variable
            node_variable_list = node_variable.split(".")
            if len(node_variable_list) < 1:
                raise ValueError(f"Invalid node variable {node_variable}")

            node_variable_key = ".".join(node_variable_list[1:])

            if (node_variable_key not in user_inputs and node_variable not in user_inputs) and not variable_pool.get(
                variable_selector
            ):
                raise ValueError(f"Variable key {node_variable} not found in user inputs.")

            # environment variable already exist in variable pool, not from user inputs
            if variable_pool.get(variable_selector):
                continue

            # fetch variable node id from variable selector
            variable_node_id = variable_selector[0]
            variable_key_list = variable_selector[1:]
            variable_key_list = list(variable_key_list)

            # get input value
            input_value = user_inputs.get(node_variable)
            if not input_value:
                input_value = user_inputs.get(node_variable_key)

            if isinstance(input_value, dict) and "type" in input_value and "transfer_method" in input_value:
                input_value = file_factory.build_from_mapping(mapping=input_value, tenant_id=tenant_id)
            if (
                isinstance(input_value, list)
                and all(isinstance(item, dict) for item in input_value)
                and all("type" in item and "transfer_method" in item for item in input_value)
            ):
                input_value = file_factory.build_from_mappings(mappings=input_value, tenant_id=tenant_id)

            # append variable and value to variable pool
            if variable_node_id != ENVIRONMENT_VARIABLE_NODE_ID:
                variable_pool.add([variable_node_id] + variable_key_list, input_value)