Limit OCR runtime threads

wechat_local_ocr.py

@@ -67,6 +67,8 @@ DAMAGE_HEARTBEAT_SECONDS = 2.0
 CAPTURE_BUFFER_FRAMES = 12
 OCR_MESSAGE_CACHE_SIZE = 256
 OCR_CACHE_REFRESH_SCANS = 120
+DEFAULT_OCR_ONNX_INTRA_OP_THREADS = 1
+DEFAULT_OCR_ONNX_INTER_OP_THREADS = 1
 WINDOW_LAYOUT_SETTLE_SECONDS = 0.25
 FOLLOW_LATEST_SETTLE_SECONDS = 0.20
 FOLLOW_LATEST_MOUSE_X = 1432
@@ -224,6 +226,17 @@ def normalize_text(value: str) -> str:
     return re.sub(r"\s+", " ", value).strip()
 
 
+def env_int(name: str, default: int) -> int:
+    raw = os.environ.get(name, "").strip()
+    if not raw:
+        return default
+    try:
+        return int(raw)
+    except ValueError:
+        logging.warning("invalid integer environment value name=%s", name)
+        return default
+
+
 def bubble_sequence_signature(
     sender_crop: Image.Image,
     body_crop: Image.Image,
@@ -1099,7 +1112,18 @@ class OcrEngine:
         from rapidocr import RapidOCR
 
         self._numpy = np
-        self._engine = RapidOCR()
+        self._engine = RapidOCR(
+            params={
+                "EngineConfig.onnxruntime.intra_op_num_threads": env_int(
+                    "WECHAT_OCR_ONNX_INTRA_OP_THREADS",
+                    DEFAULT_OCR_ONNX_INTRA_OP_THREADS,
+                ),
+                "EngineConfig.onnxruntime.inter_op_num_threads": env_int(
+                    "WECHAT_OCR_ONNX_INTER_OP_THREADS",
+                    DEFAULT_OCR_ONNX_INTER_OP_THREADS,
+                ),
+            }
+        )
         self._message_cache: OrderedDict[
             str,
             tuple[str, str, float, float, float],