share a unit's temperature across repeated detector devices

Detector temperatures were matched to units by counting detectors of each type, so a device listed twice to run a second inference process (`hailo:PCIe` and `hailo:PCIe#2`) showed the next unit's temperature, or none at all. Distinct devices are numbered now and repeats share their unit's reading.

frigate/stats/util.py

@@ -111,15 +111,18 @@ def get_detector_stats(
 ) -> dict[str, dict[str, Any]]:
     """Get stats for all detectors, including temperatures based on detector type."""
     detector_stats: dict[str, dict[str, Any]] = {}
-    detector_type_indices: dict[str, int] = {}
+    # detector type -> device -> index into that type's temperatures
+    device_indices: dict[str, dict[str, int]] = {}
 
     for name, detector in stats_tracking["detectors"].items():
         pid = detector.detect_process.pid if detector.detect_process else None
         detector_type = detector.detector_config.type
 
-        # Keep track of the index for each detector type to match temperatures correctly
-        current_index = detector_type_indices.get(detector_type, 0)
-        detector_type_indices[detector_type] = current_index + 1
+        # temperatures are per physical unit, so a repeated device
+        # ("hailo:PCIe#2", see runner_names) shares its unit's reading
+        device = name.partition("#")[0]
+        type_devices = device_indices.setdefault(detector_type, {})
+        current_index = type_devices.setdefault(device, len(type_devices))
 
         detector_stat = {
             "inference_speed": round(detector.avg_inference_speed.value * 1000, 2),  # type: ignore[attr-defined]

frigate/test/test_detector_stats.py

@@ -0,0 +1,39 @@
+"""Tests for per-detector stats."""
+
+import unittest
+from unittest.mock import MagicMock, patch
+
+from frigate.stats.util import get_detector_stats
+
+
+def _detector(detector_type: str) -> MagicMock:
+    detector = MagicMock()
+    detector.detector_config.type = detector_type
+    detector.avg_inference_speed.value = 0.01
+    detector.detection_start.value = 0.0
+    detector.detect_process.pid = 1
+    return detector
+
+
+class TestDetectorTemperatures(unittest.TestCase):
+    def test_repeated_device_shares_its_unit_temperature(self):
+        stats_tracking = {
+            "detectors": {
+                "hailo:PCIe": _detector("hailo8l"),
+                "hailo:PCIe#2": _detector("hailo8l"),
+                "hailo:PCIe:1": _detector("hailo8l"),
+            }
+        }
+
+        with patch(
+            "frigate.stats.util.get_hardware_temperatures", return_value=[50.0, 60.0]
+        ):
+            stats = get_detector_stats(stats_tracking)
+
+        self.assertEqual(stats["hailo:PCIe"]["temperature"], 50.0)
+        self.assertEqual(stats["hailo:PCIe#2"]["temperature"], 50.0)
+        self.assertEqual(stats["hailo:PCIe:1"]["temperature"], 60.0)
+
+
+if __name__ == "__main__":
+    unittest.main()