sugar-toolkit-gtk3/sugar/util.py

223 lines
6.4 KiB
Python

"""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.
import time
import sha
import random
import binascii
import string
import os
import logging
from ConfigParser import ConfigParser
from ConfigParser import NoOptionError
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):
return s.strip(string.hexdigits) == ''
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
class _ServiceParser(ConfigParser):
def optionxform(self, option):
return option
def write_service(name, bin, path):
"""Write a D-BUS service definition file
These are written by the bundleregistry when
a new activity is registered. They bind a
D-BUS bus-name with an executable which is
to provide the named service.
name -- D-BUS service name, must be a valid
filename/D-BUS name
bin -- executable providing named service
path -- directory into which to write the
name.service file
The service files themselves are written using
the _ServiceParser class, which is a subclass
of the standard ConfigParser class.
"""
service_cp = _ServiceParser()
section = 'D-BUS Service'
service_cp.add_section(section)
service_cp.set(section, 'Name', name)
service_cp.set(section, 'Exec', bin)
dest_filename = os.path.join(path, name + '.service')
fileobject = open(dest_filename, 'w')
service_cp.write(fileobject)
fileobject.close()
def delete_service(name, path):
"""Delete a D-BUS service definition file
Deletes a D-BUS service file previously
created by write_service().
name -- D-BUS service name, must be a valid
filename/D-BUS name
path -- directory containing the name.service
file
"""
os.remove(os.path.join(path, name + '.service'))
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:
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.
"""
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()