#!/usr/bin/env vpython3

# Copyright 2024 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""A metric implementation to calculate the time consumption.

Example:
  with TimeConsumption('foo'):
    do_something()
"""

import time

from contextlib import AbstractContextManager

from measure import Measure
from test_script_metrics_pb2 import TestScriptMetric


class TimeConsumption(AbstractContextManager, Measure):
    def __init__(self, name: str) -> None:
        self._name = name + ' (seconds)'
        self._start = 0
        self._end = 0

    def __enter__(self) -> None:
        self._start = time.time()

    def __exit__(self, exc_type, exc_value, traceback) -> bool:
        self._end = time.time()
        # Do not suppress exceptions.
        return False

    def dump(self) -> TestScriptMetric:
        result = TestScriptMetric()
        result.name = self._name
        result.value = self._end - self._start
        return result