fix: update step duration display and logic (#4506)

* feat: Add durationStore for managing chat durations and intervals and update duration display logic to use store

* [autofix.ci] apply automated fixes

* Expand `recursive_serialize_or_str` to support `BaseModelV1` subclasses

* fix: Update duration calculation for event handlers

Improve accuracy of duration measurement in event handlers by centralizing the calculation method. This ensures consistent timing across different events and enhances the reliability of event processing.

* refactor: improve duration calculation logic

Enhance the duration calculation by clearly handling both integer and float timestamps. This ensures accurate duration tracking and simplifies the code structure, improving maintainability and readability.

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>
Co-authored-by: Cristhian Zanforlin Lousa <cristhian.lousa@gmail.com>

src/backend/base/langflow/base/agents/events.py

@@ -39,11 +39,17 @@ def _build_agent_input_text_content(agent_input_dict: InputDict) -> str:
 
 def _calculate_duration(start_time: float) -> int:
     """Calculate duration in milliseconds from start time to now."""
+    # Handle the calculation
+    current_time = perf_counter()
     if isinstance(start_time, int):
-        # means it was transformed into ms so we need to reverse it
-        # to whatever perf_counter returns
-        return int((perf_counter() - start_time / 1000) * 1000)
-    return int((perf_counter() - start_time) * 1000)
+        # If we got an integer, treat it as milliseconds
+        duration = current_time - (start_time / 1000)
+        result = int(duration * 1000)
+    else:
+        # If we got a float, treat it as perf_counter time
+        result = int((current_time - start_time) * 1000)
+
+    return result
 
 
 def handle_on_chain_start(
@@ -111,6 +117,9 @@ def handle_on_tool_start(
     if not agent_message.content_blocks:
         agent_message.content_blocks = [ContentBlock(title="Agent Steps", contents=[])]
 
+    duration = _calculate_duration(start_time)
+    new_start_time = perf_counter()  # Get new start time for next operation
+
     # Create new tool content with the input exactly as received
     tool_content = ToolContent(
         type="tool_use",
@@ -119,7 +128,7 @@ def handle_on_tool_start(
         output=None,
         error=None,
         header={"title": f"Accessing **{tool_name}**", "icon": "Hammer"},
-        duration=int(start_time * 1000),
+        duration=duration,  # Store the actual duration
     )
 
     # Store in map and append to message
@@ -128,7 +137,7 @@ def handle_on_tool_start(
 
     agent_message = send_message_method(message=agent_message)
     tool_blocks_map[tool_key] = agent_message.content_blocks[0].contents[-1]
-    return agent_message, start_time
+    return agent_message, new_start_time
 
 
 def handle_on_tool_end(
@@ -145,12 +154,13 @@ def handle_on_tool_end(
 
     if tool_content and isinstance(tool_content, ToolContent):
         tool_content.output = event["data"].get("output")
-        # Calculate duration only when tool ends
+        duration = _calculate_duration(start_time)
+        tool_content.duration = duration
         tool_content.header = {"title": f"Executed **{tool_content.name}**", "icon": "Hammer"}
-        if isinstance(tool_content.duration, int):
-            tool_content.duration = _calculate_duration(tool_content.duration)
+
         agent_message = send_message_method(message=agent_message)
-        start_time = perf_counter()
+        new_start_time = perf_counter()  # Get new start time for next operation
+        return agent_message, new_start_time
     return agent_message, start_time
 
 
@@ -250,12 +260,11 @@ async def process_agent_events(
                 agent_message, start_time = tool_handler(
                     event, agent_message, tool_blocks_map, send_message_method, start_time
                 )
-                start_time = start_time or perf_counter()
             elif event["event"] in CHAIN_EVENT_HANDLERS:
                 chain_handler = CHAIN_EVENT_HANDLERS[event["event"]]
                 agent_message, start_time = chain_handler(event, agent_message, send_message_method, start_time)
-                start_time = start_time or perf_counter()
         agent_message.properties.state = "complete"
     except Exception as e:
         raise ExceptionWithMessageError(agent_message) from e
+
     return Message(**agent_message.model_dump())

src/backend/base/langflow/schema/serialize.py

@@ -8,7 +8,7 @@ from pydantic.v1 import BaseModel as BaseModelV1
 
 def recursive_serialize_or_str(obj):
     try:
-        if isinstance(obj, type) and issubclass(obj, BaseModel):
+        if isinstance(obj, type) and issubclass(obj, BaseModel | BaseModelV1):
             # This a type BaseModel and not an instance of it
             return repr(obj)
         if isinstance(obj, str):