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Diffstat (limited to 'fstringhash.py')
| -rw-r--r-- | fstringhash.py | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/fstringhash.py b/fstringhash.py new file mode 100644 index 0000000..dbde39c --- /dev/null +++ b/fstringhash.py @@ -0,0 +1,156 @@ +#/*************************************************************************** +# fstringhash.h +# ----------- +# begin : sam nov 2 2002 +# copyright : (C) 1992-2004 by Fabian Padilla +# email : fp@bridgethink.com +# ***************************************************************************/ + +# /*************************************************************************** +# * * +# * This program is free software; you can redistribute it and/or modify * +# * it under the terms of the Foundation Public License as published by * +# * bridgethink sarl; either version 2 of the License, or * +# * (at your option) any later version. * +# * * +# ***************************************************************************/ + +# +# from C++ to python by Jeremy Zurcher <jeremy@asynk.ch> +# + +# TODO method equals should be __eq__ for the beauty ... +# TODO do we really need this, as python allready provides it's hash value technology in PyObject [ obj.__hash__() ] +# +# ob_sval == char* +# ob_size == strlen() +# +# int +# _PyString_Eq(PyObject *o1, PyObject *o2) +# { +# PyStringObject *a, *b; +# a = (PyStringObject*)o1; +# b = (PyStringObject*)o2; +# return a->ob_size == b->ob_size +# && *a->ob_sval == *b->ob_sval +# && memcmp(a->ob_sval, b->ob_sval, a->ob_size) == 0; +# } +# +# static long +# string_hash(PyStringObject *a) +# { +# register int len; +# register unsigned char *p; +# register long x; +# +# if (a->ob_shash != -1) +# return a->ob_shash; +# len = a->ob_size; +# p = (unsigned char *) a->ob_sval; +# x = *p << 7; +# while (--len >= 0) +# x = (1000003*x) ^ *p++; +# x ^= a->ob_size; +# if (x == -1) +# x = -2; +# a->ob_shash = x; +# return x; +# } + + + + +"""/** To speed up the process of comparaison between values, we use a hash technology. + function : hash a string and show hashvalue and string. + + description : the method "setString" is used to set the the value of the stringhash. + Then the hash value is available. + This will speedup the comparaison between the different "string" in evenja rooms. + ( it is faster to compare two int than complete string). + + *@author Fabian Padilla + */""" + +__all__ =["FstringHash"] + +try: + import hashlib +except: + print "no MD5 capabilities ... aborting" + import sys + sys.exit(1) + + +class FstringHash: + """This class is wrapper around the python builtin string providing an extra (virtual) hash function""" + def __init__(self): + self.string = None + self.hashValue = None + + def __str__(self): + return "FstringHash : "+str(self.string)+"\n" + + def __hash(self): + """ default hash function, may be overriden """ + return hashlib.md5(self.string).hexdigest() + + def setString(self,string): + self.string = string + if string is None: + self.hashValue = None + else: + self.hashValue = self.__hash() + + def getString(self): + return self.string + + def getHashValue(self): + return self.hashValue + + def copyFrom(self,other): + """copy my attributes from other""" + self.string = other.string + self.hashValue = other.hashValue + + #def __eq__(self,other): + def equals(self,other): + return self.string == other.string and self.hashValue == other.hashValue + + +if __name__ == '__main__': + + import unittest + + str1 = FstringHash() + str2 = FstringHash() + + class FstringHashTestCase(unittest.TestCase): + + def test1Equal(self): + str1.setString("WWW.TEST.ORG") + str2.setString("WWW.TEST.ORG") + self.assertEquals(str1.equals(str2),1) + + def test2NotEqual(self): + str1.setString("WWW.TEST.ORG") + str2.setString("WWW.NOTEST.ORG") + self.assertEquals(str1.equals(str2),0) + + def test3Copy(self): + str1.setString("WWW.TEST.ORG") + str2.copyFrom(str1) + self.assertEquals(str1.equals(str2),1) + + def test4Hash(self): + str1.setString("WWW.TEST.ORG") + self.assertEquals(hashlib.md5("WWW.TEST.ORG").hexdigest(),str1.getHashValue()) + + def test5None(self): + str1.setString("WWW.TEST.ORG") + str1.setString(None) + self.assertEquals(str1.getHashValue(),None) + self.assertEquals(str1.getString(),None) + + + + unittest.main() |