chore: import upstream snapshot with attribution

tools/render_backend.py

@@ -0,0 +1,62 @@
+"""RenderBackend: config-driven factory for image and video generators.
+
+Reads the ``image_generator`` and ``video_generator`` sections from a
+ViMax YAML config, instantiates the concrete classes via *class_path*,
+and wires up rate limiters.
+
+Usage::
+
+    backend = RenderBackend.from_config(config)
+    image = await backend.image_generator.generate_single_image(...)
+    video = await backend.video_generator.generate_single_video(...)
+"""
+
+import importlib
+import logging
+from dataclasses import dataclass
+from typing import Any, Dict
+
+from utils.rate_limiter import RateLimiter
+
+
+@dataclass
+class RenderBackend:
+    """Bundles an image generator and a video generator."""
+
+    image_generator: Any
+    video_generator: Any
+
+    @classmethod
+    def from_config(cls, config: Dict[str, Any]) -> "RenderBackend":
+        """Build a RenderBackend from a parsed YAML config dict.
+
+        Rate limiters are created from ``max_requests_per_minute`` /
+        ``max_requests_per_day`` if present in each generator section.
+        """
+        img_cfg = config["image_generator"]
+        vid_cfg = config["video_generator"]
+
+        image_gen = _instantiate(img_cfg, _build_rate_limiter(img_cfg))
+        video_gen = _instantiate(vid_cfg, _build_rate_limiter(vid_cfg))
+
+        logging.info("RenderBackend: image=%s, video=%s",
+                     img_cfg["class_path"], vid_cfg["class_path"])
+
+        return cls(image_generator=image_gen, video_generator=video_gen)
+
+
+def _build_rate_limiter(section: Dict[str, Any]) -> RateLimiter | None:
+    rpm = section.get("max_requests_per_minute")
+    rpd = section.get("max_requests_per_day")
+    if rpm or rpd:
+        return RateLimiter(max_requests_per_minute=rpm, max_requests_per_day=rpd)
+    return None
+
+
+def _instantiate(section: Dict[str, Any], rate_limiter: RateLimiter | None) -> Any:
+    module_path, cls_name = section["class_path"].rsplit(".", 1)
+    cls = getattr(importlib.import_module(module_path), cls_name)
+    init_args = dict(section.get("init_args", {}))
+    if rate_limiter is not None:
+        init_args["rate_limiter"] = rate_limiter
+    return cls(**init_args)