Commit e973d519 authored by Kirill Smelkov's avatar Kirill Smelkov

util += hashRegistry, null, adler32, crc32 hashers

hashRegistry will be needed for zodbdump reader to create a hasher by
its name. Since std hashlib does not have adler32/crc32 nor null - let's
add our own implementation for those hashers too.

The code is based on

	kirr/neo@a60c472c, and
	kirr/neo@3f578560
parent 624aeb09
# zodbtools - various utility routines
# Copyright (C) 2016-2017 Nexedi SA and Contributors.
# Copyright (C) 2016-2018 Nexedi SA and Contributors.
# Kirill Smelkov <kirr@nexedi.com>
#
# This program is free software: you can Use, Study, Modify and Redistribute
......@@ -18,9 +18,10 @@
# See COPYING file for full licensing terms.
# See https://www.nexedi.com/licensing for rationale and options.
import hashlib
import hashlib, struct
import zodburi
from six.moves.urllib_parse import urlsplit, urlunsplit
from zlib import crc32, adler32
def ashex(s):
return s.encode('hex')
......@@ -101,3 +102,63 @@ def storageFromURL(url, read_only=None):
stor = stor_factory()
return stor
# ---- hashing ----
# hasher that discards data
class NullHasher:
name = "null"
digest_size = 1
def update(self, data):
pass
def digest(self):
return b'\0'
def hexdigest(self):
return "00"
# adler32 in hashlib interface
class Adler32Hasher:
name = "adler32"
digest_size = 4
def __init__(self):
self._h = adler32('')
def update(self, data):
self._h = adler32(data, self._h)
def digest(self):
return struct.pack('>I', self._h & 0xffffffff)
def hexdigest(self):
return '%08x' % (self._h & 0xffffffff)
# crc32 in hashlib interface
class CRC32Hasher:
name = "crc32"
digest_size = 4
def __init__(self):
self._h = crc32('')
def update(self, data):
self._h = crc32(data, self._h)
def digest(self):
return struct.pack('>I', self._h & 0xffffffff)
def hexdigest(self):
return '%08x' % (self._h & 0xffffffff)
# {} name -> hasher
hashRegistry = {
"null": NullHasher,
"adler32": Adler32Hasher,
"crc32": CRC32Hasher,
"sha1": hashlib.sha1,
"sha256": hashlib.sha256,
"sha512": hashlib.sha512,
}
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