Created
December 31, 2014 20:32
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Key distribution
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#!/usr/bin/env python | |
# | |
import hashlib | |
def hasher(s): | |
m=hashlib.sha1() | |
m.update(s) | |
return m.hexdigest() | |
def stringify_keyspace(a): | |
s='' | |
for i in a: s+=chr(i) | |
return s[::-1] | |
def deserialize_hash(h): | |
a=[] | |
for i in h: a.append(i) | |
return a | |
def stringify_block(h,b): | |
s='' | |
for i in range(0,b): s+=h[i] | |
return s | |
""" | |
Analyze frequency of starting blocks (of size b) in | |
The hash (h) to determine optimal block size for | |
subtree roots. | |
""" | |
def analyze_distribution(h,b,a,grouping=0,blockcount=0): | |
try: | |
a[grouping][stringify_block(h,b)]+=1 | |
except: | |
a[grouping][stringify_block(h,b)]=1 | |
return a | |
""" | |
create the analysis table (empty) | |
""" | |
def init_analysis(groupingStart=0,groupingFinish=100): | |
a=[] | |
for i in range(groupingStart,groupingFinish): | |
a.append({}) | |
return a | |
def increment_array(a,i,zeroState=0,highState=255): | |
if a[i] == highState: | |
try: | |
increment_array(a,i+1) | |
except: | |
a.append(zeroState) | |
a[i]=zeroState | |
else: | |
a[i]+=1 | |
blocksize=4 | |
keyspace=[0] | |
counter=0 | |
groupingStart=0 | |
groupingEnd=1 | |
analysis=init_analysis(groupingStart,groupingEnd) | |
while len(keyspace) <=2: | |
increment_array(keyspace,0) | |
hash_string=hasher(stringify_keyspace(keyspace)) | |
hash_array=deserialize_hash(hash_string) | |
#Todo: determine grouping (e.g. tenths or 2TB blocks) | |
grouping=0 | |
analysis=analyze_distribution(hash_array,blocksize,analysis,grouping) | |
counter+=1 | |
print("{}: {}".format(hash_string,keyspace)) | |
block_count=0 | |
for group in analysis: | |
for i in group: | |
block_count+=1 | |
print "="*60 | |
print "Analysis:" | |
print "="*60 | |
print "block count:{}".format(block_count) |
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