fix(replay): short-circuit .npz planner imports (#8050)

Signed-off-by: PeaBrane <yanrpei@gmail.com>

components/src/dynamo/mocker/args.py

@@ -55,15 +55,15 @@ def resolve_planner_profile_data(
     Raises:
         FileNotFoundError: If path doesn't contain valid profile data in any supported format.
     """
+    if planner_profile_data is None:
+        return ProfileDataResult(npz_path=None, tmpdir=None)
+
     from .utils.planner_profiler_perf_data_converter import (
         convert_profile_results_to_npz,
         is_mocker_format_npz,
         is_profile_results_dir,
     )
 
-    if planner_profile_data is None:
-        return ProfileDataResult(npz_path=None, tmpdir=None)
-
     # Case 1: Already a mocker-format NPZ file
     if is_mocker_format_npz(planner_profile_data):
         logger.info(f"Using mocker-format NPZ file: {planner_profile_data}")

components/src/dynamo/mocker/utils/planner_profiler_perf_data_converter.py

@@ -32,12 +32,6 @@ from typing import Any
 
 import numpy as np
 
-from dynamo.planner.core.perf_model import DecodeRegressionModel, PrefillRegressionModel
-from dynamo.planner.monitoring.perf_metrics import (
-    _convert_decode_profiling,
-    _convert_prefill_profiling,
-)
-
 logger = logging.getLogger(__name__)
 
 
@@ -61,6 +55,15 @@ def convert_profile_results_to_npz(
     Returns:
         Path to the generated NPZ file.
     """
+    from dynamo.planner.core.perf_model import (
+        DecodeRegressionModel,
+        PrefillRegressionModel,
+    )
+    from dynamo.planner.monitoring.perf_metrics import (
+        _convert_decode_profiling,
+        _convert_prefill_profiling,
+    )
+
     profile_results_dir = str(Path(profile_results_dir).resolve())
     output_path = Path(output_path)
 

lib/bindings/python/src/dynamo/replay/main.py

@@ -27,15 +27,17 @@ class PlannerProfileDataResult(Protocol):
 def resolve_planner_profile_data(
     planner_profile_data: Path | None,
 ) -> PlannerProfileDataResult:
+    if planner_profile_data is None:
+        return SimpleNamespace(npz_path=None)
+
+    if planner_profile_data.suffix == ".npz":
+        return SimpleNamespace(npz_path=planner_profile_data)
+
     try:
         module = importlib.import_module("dynamo.mocker.args")
     except ImportError:
-        if planner_profile_data is None:
-            return SimpleNamespace(npz_path=None)
         return SimpleNamespace(
-            npz_path=planner_profile_data
-            if planner_profile_data.suffix == ".npz"
-            else None
+            npz_path=None,
         )
     return module.resolve_planner_profile_data(planner_profile_data)
 
@@ -62,13 +64,16 @@ def _load_engine_args(raw_args: str | None):
                 "worker_type must be one of 'aggregated', 'prefill', or 'decode'"
             )
     if "planner_profile_data" in raw:
-        profile_data_result = resolve_planner_profile_data(
-            Path(raw["planner_profile_data"])
-        )
-        if profile_data_result.npz_path is not None:
-            raw["planner_profile_data"] = str(profile_data_result.npz_path)
-        else:
+        if raw["planner_profile_data"] is None:
             del raw["planner_profile_data"]
+        else:
+            profile_data_result = resolve_planner_profile_data(
+                Path(raw["planner_profile_data"])
+            )
+            if profile_data_result.npz_path is not None:
+                raw["planner_profile_data"] = str(profile_data_result.npz_path)
+            else:
+                del raw["planner_profile_data"]
     return MockEngineArgs.from_json(json.dumps(raw))