# Copyright 2016 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.

# Utilities for the server and things that run on the server (like

# algorithms).

from utils import clock

# Helper function to determine if a resource is in learning mode.

def in_learning_mode(resource):

return resource.learning_mode_expiry_time >= clock.get_time()

# Helper function to determine if a lease is expired.

# Note: If there is no lease, it is not expired!

def lease_expired(thing):

return thing and thing.HasField('has') and thing.has.expiry_time <= clock.get_time()

# Calculates the sum of all wants by clients and servers that depend on this

# server.

def sum_wants(resource):

return n

# Calculates the sum of capacity that this server has outstanding

# leases for.

def sum_leases(resource):

if server.HasField('has')])

# Calculates the sum of capacity that this server has outstanding

# responsibilities for. These responsibilities include all the

# clients that have leases, and all the outstanding responsibilities

# of the server. In a time of shrinking allocations a server might

# have more outstanding responsibilities than it has capacity to

# give out. We call this phenomenon 'shortfall'.

def sum_outstanding(resource):

for server in resource.server])