from twisted.internet.utils import getProcessOutputAndValue
import os


class CommandError(Exception):
"""Raised when an external command returns a non-zero status."""


class MemoryStats(object):

def __init__(self, filename="/proc/meminfo"):
data = {}
for line in open(filename):
if ":" in line:
key, value = line.split(":", 1)
if key in ["MemTotal", "SwapFree", "SwapTotal", "MemFree",
"Buffers", "Cached"]:
data[key] = int(value.split()[0])

self.total_memory = data["MemTotal"] // 1024
self.free_memory = (data["MemFree"] + data["Buffers"] +
data["Cached"]) // 1024
self.total_swap = data["SwapTotal"] // 1024
self.free_swap = data["SwapFree"] // 1024

@property
def used_memory(self):
return self.total_memory - self.free_memory

@property
def used_swap(self):
return self.total_swap - self.free_swap

@property
def free_memory_percentage(self):
return (self.free_memory / float(self.total_memory)) * 100

@property
def free_swap_percentage(self):
if self.total_swap == 0:
return 0.0
else:
return (self.free_swap / float(self.total_swap)) * 100

@property
def used_memory_percentage(self):
return 100 - self.free_memory_percentage

@property
def used_swap_percentage(self):
if self.total_swap == 0:
return 0.0
else:
return 100 - self.free_swap_percentage


def get_logged_in_users():
result = getProcessOutputAndValue("who", ["-q"], env=os.environ)

def parse_output((stdout_data, stderr_data, status)):
if status != 0:
raise CommandError(stderr_data)
first_line = stdout_data.split("\n", 1)[0]
return sorted(set(first_line.split()))
return result.addCallback(parse_output)


def get_thermal_zones(thermal_zone_path=None):
if thermal_zone_path is None:
thermal_zone_path = "/proc/acpi/thermal_zone"
if os.path.isdir(thermal_zone_path):
for zone_name in sorted(os.listdir(thermal_zone_path)):
yield ThermalZone(thermal_zone_path, zone_name)


class ThermalZone(object):

temperature = None
temperature_value = None
temperature_unit = None

def __init__(self, base_path, name):
self.name = name
self.path = os.path.join(base_path, name)
temperature_path = os.path.join(self.path, "temperature")
if os.path.isfile(temperature_path):
for line in open(temperature_path):
if line.startswith("temperature:"):
self.temperature = line[12:].strip()
try:
value, unit = self.temperature.split()
self.temperature_value = int(value)
self.temperature_unit = unit
except ValueError:
pass