Lazy loading to avoid importing all files (#29716)

Signed-off-by: Luke <yq0536@gmail.com>

vllm/transformers_utils/configs/__init__.py

@@ -10,46 +10,47 @@ Model configs may be defined in this directory for the following reasons:
   deepseek-ai/DeepSeek-V3.2-Exp.
 """
 
-from transformers import DeepseekV3Config
+from __future__ import annotations
 
-from vllm.transformers_utils.configs.afmoe import AfmoeConfig
-from vllm.transformers_utils.configs.chatglm import ChatGLMConfig
-from vllm.transformers_utils.configs.deepseek_vl2 import DeepseekVLV2Config
-from vllm.transformers_utils.configs.dotsocr import DotsOCRConfig
-from vllm.transformers_utils.configs.eagle import EAGLEConfig
+import importlib
 
-# RWConfig is for the original tiiuae/falcon-40b(-instruct) and
-# tiiuae/falcon-7b(-instruct) models. Newer Falcon models will use the
-# `FalconConfig` class from the official HuggingFace transformers library.
-from vllm.transformers_utils.configs.falcon import RWConfig
-from vllm.transformers_utils.configs.flex_olmo import FlexOlmoConfig
-from vllm.transformers_utils.configs.hunyuan_vl import (
-    HunYuanVLConfig,
-    HunYuanVLTextConfig,
-    HunYuanVLVisionConfig,
-)
-from vllm.transformers_utils.configs.jais import JAISConfig
-from vllm.transformers_utils.configs.kimi_linear import KimiLinearConfig
-from vllm.transformers_utils.configs.kimi_vl import KimiVLConfig
-from vllm.transformers_utils.configs.lfm2_moe import Lfm2MoeConfig
-from vllm.transformers_utils.configs.medusa import MedusaConfig
-from vllm.transformers_utils.configs.midashenglm import MiDashengLMConfig
-from vllm.transformers_utils.configs.mlp_speculator import MLPSpeculatorConfig
-from vllm.transformers_utils.configs.moonvit import MoonViTConfig
-from vllm.transformers_utils.configs.nemotron import NemotronConfig
-from vllm.transformers_utils.configs.nemotron_h import NemotronHConfig
-from vllm.transformers_utils.configs.olmo3 import Olmo3Config
-from vllm.transformers_utils.configs.ovis import OvisConfig
-from vllm.transformers_utils.configs.qwen3_next import Qwen3NextConfig
-from vllm.transformers_utils.configs.radio import RadioConfig
-from vllm.transformers_utils.configs.speculators.base import SpeculatorsConfig
-from vllm.transformers_utils.configs.step3_vl import (
-    Step3TextConfig,
-    Step3VisionEncoderConfig,
-    Step3VLConfig,
-)
-from vllm.transformers_utils.configs.tarsier2 import Tarsier2Config
-from vllm.transformers_utils.configs.ultravox import UltravoxConfig
+_CLASS_TO_MODULE: dict[str, str] = {
+    "AfmoeConfig": "vllm.transformers_utils.configs.afmoe",
+    "ChatGLMConfig": "vllm.transformers_utils.configs.chatglm",
+    "DeepseekVLV2Config": "vllm.transformers_utils.configs.deepseek_vl2",
+    "DotsOCRConfig": "vllm.transformers_utils.configs.dotsocr",
+    "EAGLEConfig": "vllm.transformers_utils.configs.eagle",
+    "FlexOlmoConfig": "vllm.transformers_utils.configs.flex_olmo",
+    "HunYuanVLConfig": "vllm.transformers_utils.configs.hunyuan_vl",
+    "HunYuanVLTextConfig": "vllm.transformers_utils.configs.hunyuan_vl",
+    "HunYuanVLVisionConfig": "vllm.transformers_utils.configs.hunyuan_vl",
+    # RWConfig is for the original tiiuae/falcon-40b(-instruct) and
+    # tiiuae/falcon-7b(-instruct) models. Newer Falcon models will use the
+    # `FalconConfig` class from the official HuggingFace transformers library.
+    "RWConfig": "vllm.transformers_utils.configs.falcon",
+    "JAISConfig": "vllm.transformers_utils.configs.jais",
+    "Lfm2MoeConfig": "vllm.transformers_utils.configs.lfm2_moe",
+    "MedusaConfig": "vllm.transformers_utils.configs.medusa",
+    "MiDashengLMConfig": "vllm.transformers_utils.configs.midashenglm",
+    "MLPSpeculatorConfig": "vllm.transformers_utils.configs.mlp_speculator",
+    "MoonViTConfig": "vllm.transformers_utils.configs.moonvit",
+    "KimiLinearConfig": "vllm.transformers_utils.configs.kimi_linear",
+    "KimiVLConfig": "vllm.transformers_utils.configs.kimi_vl",
+    "NemotronConfig": "vllm.transformers_utils.configs.nemotron",
+    "NemotronHConfig": "vllm.transformers_utils.configs.nemotron_h",
+    "Olmo3Config": "vllm.transformers_utils.configs.olmo3",
+    "OvisConfig": "vllm.transformers_utils.configs.ovis",
+    "RadioConfig": "vllm.transformers_utils.configs.radio",
+    "SpeculatorsConfig": "vllm.transformers_utils.configs.speculators.base",
+    "UltravoxConfig": "vllm.transformers_utils.configs.ultravox",
+    "Step3VLConfig": "vllm.transformers_utils.configs.step3_vl",
+    "Step3VisionEncoderConfig": "vllm.transformers_utils.configs.step3_vl",
+    "Step3TextConfig": "vllm.transformers_utils.configs.step3_vl",
+    "Qwen3NextConfig": "vllm.transformers_utils.configs.qwen3_next",
+    "Tarsier2Config": "vllm.transformers_utils.configs.tarsier2",
+    # Special case: DeepseekV3Config is from HuggingFace Transformers
+    "DeepseekV3Config": "transformers",
+}
 
 __all__ = [
     "AfmoeConfig",
@@ -84,3 +85,16 @@ __all__ = [
     "Qwen3NextConfig",
     "Tarsier2Config",
 ]
+
+
+def __getattr__(name: str):
+    if name in _CLASS_TO_MODULE:
+        module_name = _CLASS_TO_MODULE[name]
+        module = importlib.import_module(module_name)
+        return getattr(module, name)
+
+    raise AttributeError(f"module 'configs' has no attribute '{name}'")
+
+
+def __dir__():
+    return sorted(list(__all__))