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Diffstat (limited to 'src/sugar/util.py')
| -rw-r--r-- | src/sugar/util.py | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/src/sugar/util.py b/src/sugar/util.py new file mode 100644 index 0000000..d375b87 --- /dev/null +++ b/src/sugar/util.py @@ -0,0 +1,293 @@ +"""Various utility functions""" +# Copyright (C) 2006-2007 Red Hat, Inc. +# +# This library is free software; you can redistribute it and/or +# modify it under the terms of the GNU Lesser General Public +# License as published by the Free Software Foundation; either +# version 2 of the License, or (at your option) any later version. +# +# This library is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# Lesser General Public License for more details. +# +# You should have received a copy of the GNU Lesser General Public +# License along with this library; if not, write to the +# Free Software Foundation, Inc., 59 Temple Place - Suite 330, +# Boston, MA 02111-1307, USA. + +""" +UNSTABLE. We have been adding helpers randomly to this module. +""" + +import os +import time +import sha +import random +import binascii +import gettext +import tempfile +import logging + +_ = lambda msg: gettext.dgettext('sugar-toolkit', msg) + +def printable_hash(in_hash): + """Convert binary hash data into printable characters.""" + printable = "" + for char in in_hash: + printable = printable + binascii.b2a_hex(char) + return printable + +def sha_data(data): + """sha1 hash some bytes.""" + sha_hash = sha.new() + sha_hash.update(data) + return sha_hash.digest() + +def unique_id(data = ''): + """Generate a likely-unique ID for whatever purpose + + data -- suffix appended to working data before hashing + + Returns a 40-character string with hexidecimal digits + representing an SHA hash of the time, a random digit + within a constrained range and the data passed. + + Note: these are *not* crypotographically secure or + globally unique identifiers. While they are likely + to be unique-enough, no attempt is made to make + perfectly unique values. + """ + data_string = "%s%s%s" % (time.time(), random.randint(10000, 100000), data) + return printable_hash(sha_data(data_string)) + + +ACTIVITY_ID_LEN = 40 + +def is_hex(s): + try: + int(s, 16) + except ValueError: + return False + + return True + +def validate_activity_id(actid): + """Validate an activity ID.""" + if not isinstance(actid, (str, unicode)): + return False + if len(actid) != ACTIVITY_ID_LEN: + return False + if not is_hex(actid): + return False + return True + +def set_proc_title(title): + """Sets the process title so ps and top show more + descriptive names. This does not modify argv[0] + and only the first 15 characters will be shown. + + title -- the title you wish to change the process + title to + + Returns True on success. We don't raise exceptions + because if something goes wrong here it is not a big + deal as this is intended as a nice thing to have for + debugging + """ + try: + import ctypes + libc = ctypes.CDLL('libc.so.6') + libc.prctl(15, str(title), 0, 0, 0) + + return True + except Exception: + return False + +class Node(object): + __slots__ = ['prev', 'next', 'me'] + def __init__(self, prev, me): + self.prev = prev + self.me = me + self.next = None + +class LRU: + """ + Implementation of a length-limited O(1) LRU queue. + Built for and used by PyPE: + http://pype.sourceforge.net + Copyright 2003 Josiah Carlson. + """ + # pylint: disable-msg=W0102,W0612 + def __init__(self, count, pairs=[]): + self.count = max(count, 1) + self.d = {} + self.first = None + self.last = None + for key, value in pairs: + self[key] = value + def __contains__(self, obj): + return obj in self.d + def __getitem__(self, obj): + a = self.d[obj].me + self[a[0]] = a[1] + return a[1] + def __setitem__(self, obj, val): + if obj in self.d: + del self[obj] + nobj = Node(self.last, (obj, val)) + if self.first is None: + self.first = nobj + if self.last: + self.last.next = nobj + self.last = nobj + self.d[obj] = nobj + if len(self.d) > self.count: + if self.first == self.last: + self.first = None + self.last = None + return + a = self.first + a.next.prev = None + self.first = a.next + a.next = None + del self.d[a.me[0]] + del a + def __delitem__(self, obj): + nobj = self.d[obj] + if nobj.prev: + nobj.prev.next = nobj.next + else: + self.first = nobj.next + if nobj.next: + nobj.next.prev = nobj.prev + else: + self.last = nobj.prev + del self.d[obj] + def __iter__(self): + cur = self.first + while cur != None: + cur2 = cur.next + yield cur.me[1] + cur = cur2 + def iteritems(self): + cur = self.first + while cur != None: + cur2 = cur.next + yield cur.me + cur = cur2 + def iterkeys(self): + return iter(self.d) + def itervalues(self): + for i, j in self.iteritems(): + yield j + def keys(self): + return self.d.keys() + +units = [['%d year', '%d years', 356 * 24 * 60 * 60], + ['%d month', '%d months', 30 * 24 * 60 * 60], + ['%d week', '%d weeks', 7 * 24 * 60 * 60], + ['%d day', '%d days', 24 * 60 * 60], + ['%d hour', '%d hours', 60 * 60], + ['%d minute', '%d minutes', 60]] + +AND = _(' and ') +COMMA = _(', ') + +# TRANS: Indicating something that just happened, eg. "just now", "moments ago" +NOW = _('Seconds ago') + +# TRANS: Indicating time passed, eg. "[10 day, 5 hours] ago", +# "[2 minutes] in the past", or "[3 years, 1 month] earlier" +ELAPSED = _('%s ago') + +# Explanation of the following hack: +# The xgettext utility extracts plural forms by reading the strings included as +# parameters of ngettext(). As our plurals are not passed to ngettext() +# straight away because there needs to be a calculation before we know which +# strings need to be used, then we need to call ngettext() in a fake way so +# xgettext will pick them up as plurals. + +def ngettext(singular, plural, n): + pass + +# TRANS: Relative dates (eg. 1 month and 5 days). +ngettext('%d year', '%d years', 1) +ngettext('%d month', '%d months', 1) +ngettext('%d week', '%d weeks', 1) +ngettext('%d day', '%d days', 1) +ngettext('%d hour', '%d hours', 1) +ngettext('%d minute', '%d minutes', 1) + +del ngettext + +# End of plurals hack + +# gettext perfs hack (#7959) +_i18n_timestamps_cache = LRU(60) + +def timestamp_to_elapsed_string(timestamp, max_levels=2): + levels = 0 + time_period = '' + elapsed_seconds = int(time.time() - timestamp) + + for name_singular, name_plural, factor in units: + elapsed_units = elapsed_seconds / factor + if elapsed_units > 0: + + if levels > 0: + time_period += COMMA + + key = ''.join((os.environ['LANG'], name_singular, + str(elapsed_units))) + if key in _i18n_timestamps_cache: + time_period += _i18n_timestamps_cache[key] + else: + translation = gettext.dngettext('sugar-toolkit', + name_singular, + name_plural, + elapsed_units) % elapsed_units + _i18n_timestamps_cache[key] = translation + time_period += translation + + elapsed_seconds -= elapsed_units * factor + + if time_period != '': + levels += 1 + + if levels == max_levels: + break + + if levels == 0: + return NOW + + return ELAPSED % time_period + +_tracked_paths = {} + +class TempFilePath(str): + def __new__(cls, path=None): + if path is None: + fd, path = tempfile.mkstemp() + os.close(fd) + logging.debug('TempFilePath created %r' % path) + + if path in _tracked_paths: + _tracked_paths[path] += 1 + else: + _tracked_paths[path] = 1 + + return str.__new__(cls, path) + + def __del__(self): + if _tracked_paths[self] == 1: + del _tracked_paths[self] + + if os.path.exists(self): + os.unlink(self) + logging.debug('TempFilePath deleted %r' % self) + else: + logging.warning('TempFilePath already deleted %r' % self) + else: + _tracked_paths[self] -= 1 + |