utils.py

import config

import errno
import itertools as it
import logging.handlers
import os
import sys
import hashlib

def e(s):
    if type(s) == bytes:
        return s
    return s.encode('utf-8')

def d(s):
    if type(s) == str:
        return s
    return str(s, 'utf-8')

def mkid(s):
    return hashlib.sha1(e(s)).hexdigest()[:2*4]

def running_in_tools_labs():
    return (os.path.exists('/etc/wmflabs-project') or
        os.path.exists('/etc/wmcs-project'))

# Thanks, StackOverflow! https://stackoverflow.com/questions/600268
def mkdir_p(path):
    try:
        os.makedirs(path)
    except OSError as exc:  # Python >2.5
        if exc.errno == errno.EEXIST and os.path.isdir(path):
            pass
        else:
            raise

def pair_with_next(iterator):
    """
    Given an iterator (..., x, y, z, w, ...), returns another iterator of
    tuples that pair each element to its successor, that is
    (..., (x, y), (y, z), (z, w), ...).

    The iterator "wraps around" at the end, that is, the last element is
    paired with the first.
    """

    i1, i2 = it.tee(iterator)
    return zip(i1, it.chain(i2, [next(i2)]))

def ichunk(iterable, chunk_size):
    it0 = iter(iterable)
    while True:
        it1, it2 = it.tee(it.islice(it0, chunk_size))
        try:
            next(it2)  # raises StopIteration if it0 is exhausted
        except StopIteration:
            return
        yield it1

def _setup_log_handler(logger, handler):
    handler.setFormatter(logging.Formatter(
        '%(asctime)s %(levelname)s: %(message)s [%(pathname)s:%(lineno)d]'))
    handler.setLevel(logging.INFO)
    logger.addHandler(handler)
    logger.setLevel(logging.INFO)

def setup_logger_to_logfile(logger, log_file):
    log_dir = config.get_global_config().log_dir
    mkdir_p(log_dir)
    log_path = os.path.join(log_dir, log_file)
    handler = logging.handlers.RotatingFileHandler(
        log_path, maxBytes = 1024 * 1024, encoding = 'utf-8')
    _setup_log_handler(logger, handler)

def setup_logger_to_stderr(logger):
    _setup_log_handler(logger, logging.StreamHandler())