Jenkins哈希的Python實現？

Question

是否存在Jenkins hash算法的本地Python實現？

我需要一個採用任意字符串並將其轉換爲32位整數的散列算法。對於給定的字符串，它必須保證跨平臺返回相同的整數。

我看過ELF哈希算法，其中我找到了一個Python實現。鑑於上述標準，這可能是一個合適的替代品嗎？ （http://www.partow.net/programming/hashfunctions/#ELFHashFunction）

Answer 1

PyPi上已經有"jenkins" package。但它不是「土」爲核心的實現是C.

Answer 2

你可以只使用了截至實現它在我自己的的md5sum

>>> from hashlib import md5 
>>> from struct import unpack 
>>> unpack("<IIII",md5("thestring").digest())[0] 
1515985217 

Answer 3

的前32位。根據原始版權聲明發布（見下文）。使用您自己的風險，並有樂趣:-)

'''Implements a straight Jenkins lookup hash - http://burtleburtle.net/bob/hash/doobs.html 

Usage: 
    from jhash import jhash 
    print jhash('My hovercraft is full of eels') 

Returns: unsigned 32 bit integer value 

Prereqs: None 

Tested with Python 2.6. 
Version 1.00 - der@dod.no - 23.08.2010 

Partly based on the Perl module Digest::JHash 
http://search.cpan.org/~shlomif/Digest-JHash-0.06/lib/Digest/JHash.pm 

Original copyright notice: 
    By Bob Jenkins, 1996. bob_jenkins@burtleburtle.net. You may use this 
    code any way you wish, private, educational, or commercial. It's free. 

    See http://burtleburtle.net/bob/hash/evahash.html 
    Use for hash table lookup, or anything where one collision in 2^^32 is 
    acceptable. Do NOT use for cryptographic purposes. 
''' 

def mix(a, b, c): 
    '''mix() -- mix 3 32-bit values reversibly. 
For every delta with one or two bits set, and the deltas of all three 
    high bits or all three low bits, whether the original value of a,b,c 
    is almost all zero or is uniformly distributed, 
* If mix() is run forward or backward, at least 32 bits in a,b,c 
    have at least 1/4 probability of changing. 
* If mix() is run forward, every bit of c will change between 1/3 and 
    2/3 of the time. (Well, 22/100 and 78/100 for some 2-bit deltas.)''' 
    # Need to constrain U32 to only 32 bits using the & 0xffffffff 
    # since Python has no native notion of integers limited to 32 bit 
    # http://docs.python.org/library/stdtypes.html#numeric-types-int-float-long-complex 
    a &= 0xffffffff; b &= 0xffffffff; c &= 0xffffffff 
    a -= b; a -= c; a ^= (c>>13); a &= 0xffffffff 
    b -= c; b -= a; b ^= (a<<8); b &= 0xffffffff 
    c -= a; c -= b; c ^= (b>>13); c &= 0xffffffff 
    a -= b; a -= c; a ^= (c>>12); a &= 0xffffffff 
    b -= c; b -= a; b ^= (a<<16); b &= 0xffffffff 
    c -= a; c -= b; c ^= (b>>5); c &= 0xffffffff 
    a -= b; a -= c; a ^= (c>>3); a &= 0xffffffff 
    b -= c; b -= a; b ^= (a<<10); b &= 0xffffffff 
    c -= a; c -= b; c ^= (b>>15); c &= 0xffffffff 
    return a, b, c 

def jhash(data, initval = 0): 
    '''hash() -- hash a variable-length key into a 32-bit value 
    data : the key (the unaligned variable-length array of bytes) 
    initval : can be any 4-byte value, defaults to 0 
Returns a 32-bit value. Every bit of the key affects every bit of 
the return value. Every 1-bit and 2-bit delta achieves avalanche.''' 
    length = lenpos = len(data) 

    # empty string returns 0 
    if length == 0: 
     return 0 

    # Set up the internal state 
    a = b = 0x9e3779b9 # the golden ratio; an arbitrary value 
    c = initval  # the previous hash value 
    p = 0    # string offset 

    # ------------------------- handle most of the key in 12 byte chunks 
    while lenpos >= 12: 
     a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)) 
     b += (ord(data[p+4]) + (ord(data[p+5])<<8) + (ord(data[p+6])<<16) + (ord(data[p+7])<<24)) 
     c += (ord(data[p+8]) + (ord(data[p+9])<<8) + (ord(data[p+10])<<16) + (ord(data[p+11])<<24)) 
     a, b, c = mix(a, b, c) 
     p += 12 
     lenpos -= 12 

    # ------------------------- handle the last 11 bytes 
    c += length 
    if lenpos >= 11: c += ord(data[p+10])<<24 
    if lenpos >= 10: c += ord(data[p+9])<<16 
    if lenpos >= 9: c += ord(data[p+8])<<8 
    # the first byte of c is reserved for the length 
    if lenpos >= 8: b += ord(data[p+7])<<24 
    if lenpos >= 7: b += ord(data[p+6])<<16 
    if lenpos >= 6: b += ord(data[p+5])<<8 
    if lenpos >= 5: b += ord(data[p+4]) 
    if lenpos >= 4: a += ord(data[p+3])<<24 
    if lenpos >= 3: a += ord(data[p+2])<<16 
    if lenpos >= 2: a += ord(data[p+1])<<8 
    if lenpos >= 1: a += ord(data[p+0]) 
    a, b, c = mix(a, b, c) 

    # ------------------------- report the result 
    return c 

if __name__ == "__main__": 
    hashstr = 'My hovercraft is full of eels' 
    myhash = jhash(hashstr) 
    print 'jhash("%s"): %d' % (hashstr, myhash) 

Answer 4

這種原生的Python代碼應該給你相同的哈希與原始lookup3.c

# Need to constrain U32 to only 32 bits using the & 0xffffffff 
# since Python has no native notion of integers limited to 32 bit 
# http://docs.python.org/library/stdtypes.html#numeric-types-int-float-long-complex 

'''Original copyright notice: 
    By Bob Jenkins, 1996. bob_jenkins@burtleburtle.net. You may use this 
    code any way you wish, private, educational, or commercial. Its free. 
''' 

def rot(x,k): 
    return (((x)<<(k)) | ((x)>>(32-(k)))) 

def mix(a, b, c): 
    a &= 0xffffffff; b &= 0xffffffff; c &= 0xffffffff 
    a -= c; a &= 0xffffffff; a ^= rot(c,4); a &= 0xffffffff; c += b; c &= 0xffffffff 
    b -= a; b &= 0xffffffff; b ^= rot(a,6); b &= 0xffffffff; a += c; a &= 0xffffffff 
    c -= b; c &= 0xffffffff; c ^= rot(b,8); c &= 0xffffffff; b += a; b &= 0xffffffff 
    a -= c; a &= 0xffffffff; a ^= rot(c,16); a &= 0xffffffff; c += b; c &= 0xffffffff 
    b -= a; b &= 0xffffffff; b ^= rot(a,19); b &= 0xffffffff; a += c; a &= 0xffffffff 
    c -= b; c &= 0xffffffff; c ^= rot(b,4); c &= 0xffffffff; b += a; b &= 0xffffffff 
    return a, b, c 

def final(a, b, c): 
    a &= 0xffffffff; b &= 0xffffffff; c &= 0xffffffff 
    c ^= b; c &= 0xffffffff; c -= rot(b,14); c &= 0xffffffff 
    a ^= c; a &= 0xffffffff; a -= rot(c,11); a &= 0xffffffff 
    b ^= a; b &= 0xffffffff; b -= rot(a,25); b &= 0xffffffff 
    c ^= b; c &= 0xffffffff; c -= rot(b,16); c &= 0xffffffff 
    a ^= c; a &= 0xffffffff; a -= rot(c,4); a &= 0xffffffff 
    b ^= a; b &= 0xffffffff; b -= rot(a,14); b &= 0xffffffff 
    c ^= b; c &= 0xffffffff; c -= rot(b,24); c &= 0xffffffff 
    return a, b, c 

def hashlittle2(data, initval = 0, initval2 = 0): 
    length = lenpos = len(data) 

    a = b = c = (0xdeadbeef + (length) + initval) 

    c += initval2; c &= 0xffffffff 

    p = 0 # string offset 
    while lenpos > 12: 
     a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)); a &= 0xffffffff 
     b += (ord(data[p+4]) + (ord(data[p+5])<<8) + (ord(data[p+6])<<16) + (ord(data[p+7])<<24)); b &= 0xffffffff 
     c += (ord(data[p+8]) + (ord(data[p+9])<<8) + (ord(data[p+10])<<16) + (ord(data[p+11])<<24)); c &= 0xffffffff 
     a, b, c = mix(a, b, c) 
     p += 12 
     lenpos -= 12 

    if lenpos == 12: c += (ord(data[p+8]) + (ord(data[p+9])<<8) + (ord(data[p+10])<<16) + (ord(data[p+11])<<24)); b += (ord(data[p+4]) + (ord(data[p+5])<<8) + (ord(data[p+6])<<16) + (ord(data[p+7])<<24)); a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)); 
    if lenpos == 11: c += (ord(data[p+8]) + (ord(data[p+9])<<8) + (ord(data[p+10])<<16)); b += (ord(data[p+4]) + (ord(data[p+5])<<8) + (ord(data[p+6])<<16) + (ord(data[p+7])<<24)); a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)); 
    if lenpos == 10: c += (ord(data[p+8]) + (ord(data[p+9])<<8)); b += (ord(data[p+4]) + (ord(data[p+5])<<8) + (ord(data[p+6])<<16) + (ord(data[p+7])<<24)); a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)); 
    if lenpos == 9: c += (ord(data[p+8])); b += (ord(data[p+4]) + (ord(data[p+5])<<8) + (ord(data[p+6])<<16) + (ord(data[p+7])<<24)); a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)); 
    if lenpos == 8: b += (ord(data[p+4]) + (ord(data[p+5])<<8) + (ord(data[p+6])<<16) + (ord(data[p+7])<<24)); a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)); 
    if lenpos == 7: b += (ord(data[p+4]) + (ord(data[p+5])<<8) + (ord(data[p+6])<<16)); a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)); 
    if lenpos == 6: b += ((ord(data[p+5])<<8) + ord(data[p+4])); a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)) 
    if lenpos == 5: b += (ord(data[p+4])); a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)); 
    if lenpos == 4: a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16) + (ord(data[p+3])<<24)) 
    if lenpos == 3: a += (ord(data[p+0]) + (ord(data[p+1])<<8) + (ord(data[p+2])<<16)) 
    if lenpos == 2: a += (ord(data[p+0]) + (ord(data[p+1])<<8)) 
    if lenpos == 1: a += ord(data[p+0]) 
    a &= 0xffffffff; b &= 0xffffffff; c &= 0xffffffff 
    if lenpos == 0: return c, b 

    a, b, c = final(a, b, c) 

    return c, b 

def hashlittle(data, initval=0): 
    c, b = hashlittle2(data, initval, 0) 
    return c 

if __name__ == "__main__": 
    import sys 
    hashstr = 'Four score and seven years ago' 
    hash, hash2 = hashlittle2(hashstr, 0xdeadbeef, 0xdeadbeef) 
    print '"%s": %x %x' % (hashstr, hash, hash2) 

    hash = hashlittle(hashstr, 0) 
    print '"%s": %x' % (hashstr, hash)