core/homeassistant/util.py

231 lines
6.8 KiB
Python

"""
homeassistant.util
~~~~~~~~~~~~~~~~~~
Helper methods for various modules.
"""
import threading
import queue
import datetime
import re
import enum
RE_SANITIZE_FILENAME = re.compile(r'(~|\.\.|/|\\)')
RE_SLUGIFY = re.compile(r'[^A-Za-z0-9_]+')
DATE_STR_FORMAT = "%H:%M:%S %d-%m-%Y"
def sanitize_filename(filename):
""" Sanitizes a filename by removing .. / and \\. """
return RE_SANITIZE_FILENAME.sub("", filename)
def slugify(text):
""" Slugifies a given text. """
text = text.strip().replace(" ", "_")
return RE_SLUGIFY.sub("", text)
def datetime_to_str(dattim):
""" Converts datetime to a string format.
@rtype : str
"""
return dattim.strftime(DATE_STR_FORMAT)
def str_to_datetime(dt_str):
""" Converts a string to a datetime object.
@rtype: datetime
"""
try:
return datetime.datetime.strptime(dt_str, DATE_STR_FORMAT)
except ValueError: # If dt_str did not match our format
return None
def split_entity_id(entity_id):
""" Splits a state entity_id into domain, object_id. """
return entity_id.split(".", 1)
def repr_helper(inp):
""" Helps creating a more readable string representation of objects. """
if isinstance(inp, dict):
return ", ".join(
repr_helper(key)+"="+repr_helper(item) for key, item
in inp.items())
elif isinstance(inp, datetime.datetime):
return datetime_to_str(inp)
else:
return str(inp)
# Taken from: http://www.cse.unr.edu/~quiroz/inc/colortransforms.py
# License: Code is given as is. Use at your own risk and discretion.
# pylint: disable=invalid-name
def color_RGB_to_xy(R, G, B):
""" Convert from RGB color to XY color. """
var_R = (R / 255.)
var_G = (G / 255.)
var_B = (B / 255.)
if var_R > 0.04045:
var_R = ((var_R + 0.055) / 1.055) ** 2.4
else:
var_R /= 12.92
if var_G > 0.04045:
var_G = ((var_G + 0.055) / 1.055) ** 2.4
else:
var_G /= 12.92
if var_B > 0.04045:
var_B = ((var_B + 0.055) / 1.055) ** 2.4
else:
var_B /= 12.92
var_R *= 100
var_G *= 100
var_B *= 100
# Observer. = 2 deg, Illuminant = D65
X = var_R * 0.4124 + var_G * 0.3576 + var_B * 0.1805
Y = var_R * 0.2126 + var_G * 0.7152 + var_B * 0.0722
Z = var_R * 0.0193 + var_G * 0.1192 + var_B * 0.9505
# Convert XYZ to xy, see CIE 1931 color space on wikipedia
return X / (X + Y + Z), Y / (X + Y + Z)
def convert(value, to_type, default=None):
""" Converts value to to_type, returns default if fails. """
try:
return default if value is None else to_type(value)
except ValueError:
# If value could not be converted
return default
def ensure_unique_string(preferred_string, current_strings):
""" Returns a string that is not present in current_strings.
If preferred string exists will append _2, _3, .. """
string = preferred_string
tries = 1
while preferred_string in current_strings:
tries += 1
string = "{}_{}".format(preferred_string, tries)
return string
class OrderedEnum(enum.Enum):
""" Taken from Python 3.4.0 docs. """
# pylint: disable=no-init
def __ge__(self, other):
if self.__class__ is other.__class__:
return self.value >= other.value
return NotImplemented
def __gt__(self, other):
if self.__class__ is other.__class__:
return self.value > other.value
return NotImplemented
def __le__(self, other):
if self.__class__ is other.__class__:
return self.value <= other.value
return NotImplemented
def __lt__(self, other):
if self.__class__ is other.__class__:
return self.value < other.value
return NotImplemented
# Reason why I decided to roll my own ThreadPool instead of using
# multiprocessing.dummy.pool or even better, use multiprocessing.pool and
# not be hurt by the GIL in the cpython interpreter:
# 1. The built in threadpool does not allow me to create custom workers and so
# I would have to wrap every listener that I passed into it with code to log
# the exceptions. Saving a reference to the logger in the worker seemed
# like a more sane thing to do.
# 2. Most event listeners are simple checks if attributes match. If the method
# that they will call takes a long time to complete it might be better to
# put that request in a seperate thread. This is for every component to
# decide on its own instead of enforcing it for everyone.
class ThreadPool(object):
""" A simple queue-based thread pool.
Will initiate it's workers using worker(queue).start() """
# pylint: disable=too-few-public-methods
def __init__(self, worker_count, job_handler, busy_callback=None):
"""
worker_count: number of threads to run that handle jobs
job_handler: method to be called from worker thread to handle job
busy_callback: method to be called when queue gets too big.
Parameters: list_of_current_jobs, number_pending_jobs
"""
work_queue = self.work_queue = queue.PriorityQueue()
current_jobs = self.current_jobs = []
self.busy_callback = busy_callback
self.busy_warning_limit = worker_count**2
for _ in range(worker_count):
worker = threading.Thread(target=_threadpool_worker,
args=(work_queue, current_jobs,
job_handler))
worker.daemon = True
worker.start()
def add_job(self, priority, job):
""" Add a job to be sent to the workers. """
self.work_queue.put(PriorityQueueItem(priority, job))
# check if our queue is getting too big
if self.work_queue.qsize() > self.busy_warning_limit:
# Increase limit we will issue next warning
self.busy_warning_limit *= 2
self.busy_callback(self.current_jobs, self.work_queue.qsize())
class PriorityQueueItem(object):
""" Holds a priority and a value. Used within PriorityQueue. """
# pylint: disable=too-few-public-methods
def __init__(self, priority, item):
self.priority = priority
self.item = item
def __lt__(self, other):
return self.priority < other.priority
def _threadpool_worker(work_queue, current_jobs, job_handler):
""" Provides the base functionality of a worker for the thread pool. """
while True:
# Get new item from work_queue
job = work_queue.get().item
# Add to current running jobs
job_log = (datetime.datetime.now(), job)
current_jobs.append(job_log)
# Do the job
job_handler(job)
# Remove from current running job
current_jobs.remove(job_log)
# Tell work_queue a task is done
work_queue.task_done()