terracotta/neat/common.py
Anton Beloglazov 49448a81fe Merge branch 'master' of ssh://github.com/beloglazov/openstack-neat
Conflicts:
	neat/common.py
	tests/test_common.py
2012-09-14 10:08:15 +10:00

131 lines
3.3 KiB
Python

# Copyright 2012 Anton Beloglazov
#
# 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.
""" The functions from this module are shared by other components.
"""
from contracts import contract
from neat.contracts_extra import *
import time
from neat.config import *
from neat.db_utils import *
@contract
def start(init_state, execute, config, time_interval, iterations):
""" Start the processing loop.
:param init_state: A function accepting a config and returning a state dictionary.
:type init_state: function
:param execute: A function performing the processing at each iteration.
:type execute: function
:param config: A config dictionary.
:type config: dict(str: *)
:param time_interval: The time interval to wait between iterations.
:type time_interval: int
:param iterations: The number of iterations to perform, -1 for infinite.
:type iterations: int
:return: The final state.
:rtype: dict(str: *)
"""
state = init_state(config)
if iterations == -1:
while True:
state = execute(config, state)
time.sleep(time_interval)
else:
for _ in xrange(iterations):
state = execute(config, state)
time.sleep(time_interval)
return state
@contract
def build_local_vm_path(local_data_directory):
""" Build the path to the local VM data directory.
:param local_data_directory: The base local data path.
:type local_data_directory: str
:return: The path to the local VM data directory.
:rtype: str
"""
return os.path.join(local_data_directory, 'vms')
@contract
def physical_cpu_count(vir_connection):
""" Get the number of physical CPUs using libvirt.
:param vir_connection: A libvirt connection object.
:type vir_connection: virConnect
:return: The number of physical CPUs.
:rtype: int
"""
return vir_connection.getInfo()[2]
@contract
def physical_cpu_mhz(vir_connection):
""" Get the CPU frequency in MHz using libvirt.
:param vir_connection: A libvirt connection object.
:type vir_connection: virConnect
:return: The CPU frequency in MHz.
:rtype: int
"""
return vir_connection.getInfo()[1]
@contract
def physical_cpu_mhz_total(vir_connection):
""" Get the sum of the core CPU frequencies in MHz using libvirt.
:param vir_connection: A libvirt connection object.
:type vir_connection: virConnect
:return: The total CPU frequency in MHz.
:rtype: int
"""
return physical_cpu_count(vir_connection) * physical_cpu_mhz(vir_connection)
@contract
def frange(start, end, step):
""" A range generator for floats.
:param start: The starting value.
:type start: number
:param end: The end value.
:type end: number
:param step: The step.
:type step: number
"""
while start <= end:
yield start
start += step