Add Aggregation to the metrics SDK

Fixes open-telemetry#2229

opentelemetry-sdk/src/opentelemetry/sdk/metrics/aggregation.py

@@ -0,0 +1,117 @@
+# Copyright The OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from abc import ABC, abstractmethod
+from collections import OrderedDict
+from math import inf
+
+from opentelemetry.proto.metrics.v1.metrics_pb2 import (
+    AGGREGATION_TEMPORALITY_CUMULATIVE,
+    AGGREGATION_TEMPORALITY_DELTA
+)
+
+
+class Aggregation(ABC):
+
+    def __init__(self):
+        self._value = 0
+
+    @property
+    def value(self):
+        return self._value
+
+    @abstractmethod
+    def aggregate(self, value):
+        pass
+
+    @abstractmethod
+    def collect(self):
+        pass
+
+
+class NoneAggregation(Aggregation):
+    """
+    This aggregation drops all instrument measurements.
+    """
+
+    def aggregate(self, value):
+        pass
+
+    def collect(self):
+        return self._value
+
+
+class SumAggregation(Aggregation):
+    """
+    This aggregation collects data for the SDK sum metric point.
+    """
+
+    def __init__(self, temporality=AGGREGATION_TEMPORALITY_CUMULATIVE):
+        super().__init__()
+        self._temporality = temporality
+
+    def aggregate(self, value):
+        self._value = self._value + value
+
+    def collect(self):
+        value = self._value
+        if self._temporality == AGGREGATION_TEMPORALITY_DELTA:
+            self._value = 0
+
+        return value
+
+
+class LastValueAggregation(Aggregation):
+
+    """
+    This aggregation collects data for the SDK sum metric point.
+    """
+
+    def aggregate(self, value):
+        self._value = value
+
+    def collect(self):
+        return self._value
+
+
+class ExplicitBucketHistogramAggregation(Aggregation):
+
+    """
+    This aggregation collects data for the SDK sum metric point.
+    """
+
+    def __init__(
+        self,
+        temporality=AGGREGATION_TEMPORALITY_CUMULATIVE,
+        boundaries=(0, 5, 10, 25, 50, 75, 100, 250, 500, 1000, inf)
+    ):
+        super().__init__()
+        self._temporality = temporality
+        self._boundaries = boundaries
+        self._value = OrderedDict([(key, 0) for key in boundaries])
+
+    def aggregate(self, value):
+        for key in self._value.keys():
+
+            if value < key:
+                self._value[key] = self._value[key] + value
+
+                break
+
+    def collect(self):
+        value = self._value
+        if self._temporality == AGGREGATION_TEMPORALITY_DELTA:
+            self._value = OrderedDict([(key, 0) for key in self._boundaries])
+
+        return value

opentelemetry-sdk/src/opentelemetry/sdk/metrics/instrument.py

@@ -0,0 +1,103 @@
+# Copyright The OpenTelemetry Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from opentelemetry.metrics.instrument import (
+    Counter,
+    ObservableCounter,
+    UpDownCounter,
+    ObservableUpDownCounter,
+    Histogram,
+    ObservableGauge
+)
+
+from opentelemetry.sdk.metrics.aggregation import (
+    SumAggregation,
+    LastValueAggregation,
+    ExplicitBucketHistogramAggregation,
+)
+
+
+class Counter(Counter):
+
+    def __init__(
+        self,
+        aggregation=SumAggregation,
+        aggregation_config={}
+    ):
+        self._aggregation = aggregation(**aggregation_config)
+        super().__init__()
+
+    def add(self, amount, attributes=None):
+        pass
+
+
+class UpDownCounter(UpDownCounter):
+
+    def __init__(
+        self,
+        aggregation=SumAggregation,
+        aggregation_config={}
+    ):
+        self._aggregation = aggregation(**aggregation_config)
+        super().__init__()
+
+    def add(self, amount, attributes=None):
+        pass
+
+
+class ObservableCounter(ObservableCounter):
+
+    def __init__(
+        self,
+        aggregation=SumAggregation,
+        aggregation_config={}
+    ):
+        self._aggregation = aggregation(**aggregation_config)
+        super().__init__()
+
+
+class ObservableUpDownCounter(ObservableUpDownCounter):
+
+    def __init__(
+        self,
+        aggregation=SumAggregation,
+        aggregation_config={}
+    ):
+        self._aggregation = aggregation(**aggregation_config)
+        super().__init__()
+
+
+class Histogram(Histogram):
+
+    def __init__(
+        self,
+        aggregation=ExplicitBucketHistogramAggregation,
+        aggregation_config={}
+    ):
+        self._aggregation = aggregation(**aggregation_config)
+        super().__init__()
+
+    def add(self, amount, attributes=None):
+        pass
+
+
+class ObservableGauge(ObservableGauge):
+
+    def __init__(
+        self,
+        aggregation=LastValueAggregation,
+        aggregation_config={}
+    ):
+        self._aggregation = aggregation(**aggregation_config)
+        super().__init__()