#!/usr/bin/env python
#
# Copyright 2007 Google Inc.
#
# 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.
#





"""Access to quota usage for this application."""








import os
import warnings

try:
  from google.appengine.runtime import apiproxy
except ImportError:
  apiproxy = None


def __get_request_cpu_usage():
  """Get the amount of CPU used so far for the current request.

  Returns the number of megacycles used so far for the current
  request. Does not include CPU used by API calls.

  Does nothing when used in the dev_appserver.
  """
  warnings.warn('get_request_cpu_usage may not always return correct values',
                DeprecationWarning,
                stacklevel=2)

  if apiproxy:
    return apiproxy.GetRequestCpuUsage()

  return 0


if os.environ.get('APPENGINE_RUNTIME') != 'python27':
  get_request_cpu_usage = __get_request_cpu_usage


def get_request_api_cpu_usage():
  """Get the amount of CPU used so far by API calls during the current request.

  Returns the number of megacycles used so far by API calls for the current
  request. Does not include CPU used by code in the request itself.

  Does nothing when used in the dev_appserver.
  """

  if apiproxy:
    return apiproxy.GetRequestApiCpuUsage()

  return 0

MCYCLES_PER_SECOND = 1200.0
"""Megacycles to CPU seconds.  Convert by using a 1.2 GHz 64-bit x86 CPU."""

def megacycles_to_cpu_seconds(mcycles):
  """Convert an input value in megacycles to CPU-seconds.

  Returns a double representing the CPU-seconds the input megacycle value
  converts to.
  """
  return mcycles / MCYCLES_PER_SECOND

def cpu_seconds_to_megacycles(cpu_secs):
  """Convert an input value in CPU-seconds to megacycles.

  Returns an integer representing the megacycles the input CPU-seconds value
  converts to.
  """
  return int(cpu_secs * MCYCLES_PER_SECOND)
