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"""SCons.Sig.MD5
The MD5 signature package for the SCons software construction
utility.
"""
#
# __COPYRIGHT__
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
__revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__"
import imp
import string
# Force Python to load the builtin "md5" module. If we do this with a
# normal import statement, then case-insensitive systems (Win32) get
# confused and thinks there's a case mismatch with *this* MD5.py module.
file, name, desc = imp.find_module('md5')
try:
md5 = imp.load_module('md5', file, name, desc)
finally:
if file:
file.close()
def current(new, old):
"""Return whether a new signature is up-to-date with
respect to an old signature.
"""
return new == old
try:
md5.new('').hexdigest
except AttributeError:
# The md5 objects created by the module have no native hexdigest()
# method (*cough* 1.5.2 *cough*) so provide an equivalent.
class new_md5:
def __init__(self, s):
self.m = md5.new(str(s))
#def copy(self):
# return self.m.copy()
def digest(self):
return self.m.digest()
def hexdigest(self):
h = string.hexdigits
r = ''
for c in self.m.digest():
i = ord(c)
r = r + h[(i >> 4) & 0xF] + h[i & 0xF]
return r
def update(self, s):
return self.m.update(s)
else:
new_md5 = lambda s: md5.new(str(s))
def collect(signatures):
"""
Collect a list of signatures into an aggregate signature.
signatures - a list of signatures
returns - the aggregate signature
"""
if len(signatures) == 1:
return signatures[0]
else:
return new_md5(string.join(signatures, ', ')).hexdigest()
def signature(obj):
"""Generate a signature for an object
"""
try:
gc = obj.get_contents
except AttributeError:
raise AttributeError, "unable to fetch contents of '%s'" % str(obj)
return new_md5(gc()).hexdigest()
def to_string(signature):
"""Convert a signature to a string"""
return signature
def from_string(string):
"""Convert a string to a signature"""
return string
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