[feat] add otel adapters

adapter/otel/metrics.py

@@ -0,0 +1,59 @@
+from threading import Lock
+
+from opentelemetry.metrics import Counter, Histogram, Meter
+
+from usecase.interface import Attrs
+
+
+class OtelMetrics:
+    def __init__(self, meter: Meter) -> None:
+        self._meter = meter
+        self._lock = Lock()
+        self._counters: dict[str, Counter] = {}
+        self._histograms: dict[str, Histogram] = {}
+
+    def increment(
+        self,
+        name: str,
+        value: int = 1,
+        attrs: Attrs | None = None,
+    ) -> None:
+        self._counter(name).add(
+            value,
+            attributes=None if attrs is None else dict(attrs),
+        )
+
+    def record(
+        self,
+        name: str,
+        value: float,
+        attrs: Attrs | None = None,
+    ) -> None:
+        self._histogram(name).record(
+            value,
+            attributes=None if attrs is None else dict(attrs),
+        )
+
+    def _counter(self, name: str) -> Counter:
+        counter = self._counters.get(name)
+        if counter is not None:
+            return counter
+
+        with self._lock:
+            counter = self._counters.get(name)
+            if counter is None:
+                counter = self._meter.create_counter(name)
+                self._counters[name] = counter
+        return counter
+
+    def _histogram(self, name: str) -> Histogram:
+        histogram = self._histograms.get(name)
+        if histogram is not None:
+            return histogram
+
+        with self._lock:
+            histogram = self._histograms.get(name)
+            if histogram is None:
+                histogram = self._meter.create_histogram(name)
+                self._histograms[name] = histogram
+        return histogram