#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You 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.
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"""
The classes in this file are interfaces for metrics. They are not intended
to be subclassed or created directly by users. To work with and access metrics,
users should use the classes and methods exposed in metric.py.
Available classes:
- Metric - Base interface of a metrics object.
- Counter - Counter metric interface. Allows a count to be incremented or
decremented during pipeline execution.
- Distribution - Distribution Metric interface. Allows statistics about the
distribution of a variable to be collected during pipeline execution.
- Gauge - Gauge Metric interface. Allows to track the latest value of a
variable during pipeline execution.
- MetricName - Namespace and name used to refer to a Metric.
"""
# pytype: skip-file
from __future__ import absolute_import
from builtins import object
from apache_beam.portability.api import beam_fn_api_pb2
__all__ = ['Metric', 'Counter', 'Distribution', 'Gauge', 'MetricName']
[docs]class MetricName(object):
"""The name of a metric.
The name of a metric consists of a namespace and a name. The namespace
allows grouping related metrics together and also prevents collisions
between multiple metrics of the same name.
"""
def __init__(self, namespace, name):
"""Initializes ``MetricName``.
Args:
namespace: A string with the namespace of a metric.
name: A string with the name of a metric.
"""
if not namespace:
raise ValueError('Metric namespace must be non-empty')
if not name:
raise ValueError('Metric name must be non-empty')
self.namespace = namespace
self.name = name
def __eq__(self, other):
return self.namespace == other.namespace and self.name == other.name
def __ne__(self, other):
# TODO(BEAM-5949): Needed for Python 2 compatibility.
return not self == other
def __str__(self):
return 'MetricName(namespace={}, name={})'.format(self.namespace, self.name)
def __hash__(self):
return hash((self.namespace, self.name))
# TODO: this proto structure is deprecated
[docs] def to_runner_api(self):
return beam_fn_api_pb2.Metrics.User.MetricName(
namespace=self.namespace, name=self.name)
[docs] @staticmethod
def from_runner_api(proto):
return MetricName(proto.namespace, proto.name)
[docs]class Metric(object):
"""Base interface of a metric object."""
pass
[docs]class Counter(Metric):
"""Counter metric interface. Allows a count to be incremented/decremented
during pipeline execution."""
[docs] def inc(self, n=1):
raise NotImplementedError
[docs] def dec(self, n=1):
self.inc(-n)
[docs]class Distribution(Metric):
"""Distribution Metric interface.
Allows statistics about the distribution of a variable to be collected during
pipeline execution."""
[docs] def update(self, value):
raise NotImplementedError
[docs]class Gauge(Metric):
"""Gauge Metric interface.
Allows tracking of the latest value of a variable during pipeline
execution."""
[docs] def set(self, value):
raise NotImplementedError