tahoe-lafs/src/allmydata/test/test_spans.py

618 lines
22 KiB
Python

"""
Tests for allmydata.util.spans.
"""
from __future__ import print_function
from __future__ import absolute_import
from __future__ import division
from __future__ import unicode_literals
from future.utils import PY2
if PY2:
from builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min # noqa: F401
from past.builtins import long
import binascii
import hashlib
from twisted.trial import unittest
from allmydata.util.spans import Spans, overlap, DataSpans
def sha256(data):
"""
:param bytes data: data to hash
:returns: a hex-encoded SHA256 hash of the data
"""
return binascii.hexlify(hashlib.sha256(data).digest())
class SimpleSpans(object):
# this is a simple+inefficient form of util.spans.Spans . We compare the
# behavior of this reference model against the real (efficient) form.
def __init__(self, _span_or_start=None, length=None):
self._have = set()
if length is not None:
for i in range(_span_or_start, _span_or_start+length):
self._have.add(i)
elif _span_or_start:
for (start,length) in _span_or_start:
self.add(start, length)
def add(self, start, length):
for i in range(start, start+length):
self._have.add(i)
return self
def remove(self, start, length):
for i in range(start, start+length):
self._have.discard(i)
return self
def each(self):
return sorted(self._have)
def __iter__(self):
items = sorted(self._have)
prevstart = None
prevend = None
for i in items:
if prevstart is None:
prevstart = prevend = i
continue
if i == prevend+1:
prevend = i
continue
yield (prevstart, prevend-prevstart+1)
prevstart = prevend = i
if prevstart is not None:
yield (prevstart, prevend-prevstart+1)
def __bool__(self): # this gets us bool()
return bool(self.len())
def len(self):
return len(self._have)
def __add__(self, other):
s = self.__class__(self)
for (start, length) in other:
s.add(start, length)
return s
def __sub__(self, other):
s = self.__class__(self)
for (start, length) in other:
s.remove(start, length)
return s
def __iadd__(self, other):
for (start, length) in other:
self.add(start, length)
return self
def __isub__(self, other):
for (start, length) in other:
self.remove(start, length)
return self
def __and__(self, other):
s = self.__class__()
for i in other.each():
if i in self._have:
s.add(i, 1)
return s
def __contains__(self, start_and_length):
(start, length) = start_and_length
for i in range(start, start+length):
if i not in self._have:
return False
return True
class ByteSpans(unittest.TestCase):
def test_basic(self):
s = Spans()
self.failUnlessEqual(list(s), [])
self.failIf(s)
self.failIf((0,1) in s)
self.failUnlessEqual(s.len(), 0)
s1 = Spans(3, 4) # 3,4,5,6
self._check1(s1)
s1 = Spans(long(3), long(4)) # 3,4,5,6
self._check1(s1)
s2 = Spans(s1)
self._check1(s2)
s2.add(10,2) # 10,11
self._check1(s1)
self.failUnless((10,1) in s2)
self.failIf((10,1) in s1)
self.failUnlessEqual(list(s2.each()), [3,4,5,6,10,11])
self.failUnlessEqual(s2.len(), 6)
s2.add(15,2).add(20,2)
self.failUnlessEqual(list(s2.each()), [3,4,5,6,10,11,15,16,20,21])
self.failUnlessEqual(s2.len(), 10)
s2.remove(4,3).remove(15,1)
self.failUnlessEqual(list(s2.each()), [3,10,11,16,20,21])
self.failUnlessEqual(s2.len(), 6)
s1 = SimpleSpans(3, 4) # 3 4 5 6
s2 = SimpleSpans(5, 4) # 5 6 7 8
i = s1 & s2
self.failUnlessEqual(list(i.each()), [5, 6])
def _check1(self, s):
self.failUnlessEqual(list(s), [(3,4)])
self.failUnless(s)
self.failUnlessEqual(s.len(), 4)
self.failIf((0,1) in s)
self.failUnless((3,4) in s)
self.failUnless((3,1) in s)
self.failUnless((5,2) in s)
self.failUnless((6,1) in s)
self.failIf((6,2) in s)
self.failIf((7,1) in s)
self.failUnlessEqual(list(s.each()), [3,4,5,6])
def test_large(self):
s = Spans(4, 2**65) # don't do this with a SimpleSpans
self.failUnlessEqual(list(s), [(4, 2**65)])
self.failUnless(s)
self.failUnlessEqual(s.len(), 2**65)
self.failIf((0,1) in s)
self.failUnless((4,2) in s)
self.failUnless((2**65,2) in s)
def test_math(self):
s1 = Spans(0, 10) # 0,1,2,3,4,5,6,7,8,9
s2 = Spans(5, 3) # 5,6,7
s3 = Spans(8, 4) # 8,9,10,11
s = s1 - s2
self.failUnlessEqual(list(s.each()), [0,1,2,3,4,8,9])
s = s1 - s3
self.failUnlessEqual(list(s.each()), [0,1,2,3,4,5,6,7])
s = s2 - s3
self.failUnlessEqual(list(s.each()), [5,6,7])
s = s1 & s2
self.failUnlessEqual(list(s.each()), [5,6,7])
s = s2 & s1
self.failUnlessEqual(list(s.each()), [5,6,7])
s = s1 & s3
self.failUnlessEqual(list(s.each()), [8,9])
s = s3 & s1
self.failUnlessEqual(list(s.each()), [8,9])
s = s2 & s3
self.failUnlessEqual(list(s.each()), [])
s = s3 & s2
self.failUnlessEqual(list(s.each()), [])
s = Spans() & s3
self.failUnlessEqual(list(s.each()), [])
s = s3 & Spans()
self.failUnlessEqual(list(s.each()), [])
s = s1 + s2
self.failUnlessEqual(list(s.each()), [0,1,2,3,4,5,6,7,8,9])
s = s1 + s3
self.failUnlessEqual(list(s.each()), [0,1,2,3,4,5,6,7,8,9,10,11])
s = s2 + s3
self.failUnlessEqual(list(s.each()), [5,6,7,8,9,10,11])
s = Spans(s1)
s -= s2
self.failUnlessEqual(list(s.each()), [0,1,2,3,4,8,9])
s = Spans(s1)
s -= s3
self.failUnlessEqual(list(s.each()), [0,1,2,3,4,5,6,7])
s = Spans(s2)
s -= s3
self.failUnlessEqual(list(s.each()), [5,6,7])
s = Spans(s1)
s += s2
self.failUnlessEqual(list(s.each()), [0,1,2,3,4,5,6,7,8,9])
s = Spans(s1)
s += s3
self.failUnlessEqual(list(s.each()), [0,1,2,3,4,5,6,7,8,9,10,11])
s = Spans(s2)
s += s3
self.failUnlessEqual(list(s.each()), [5,6,7,8,9,10,11])
def test_random(self):
# attempt to increase coverage of corner cases by comparing behavior
# of a simple-but-slow model implementation against the
# complex-but-fast actual implementation, in a large number of random
# operations
S1 = SimpleSpans
S2 = Spans
s1 = S1(); s2 = S2()
seed = b""
def _create(subseed):
ns1 = S1(); ns2 = S2()
for i in range(10):
what = sha256(subseed+bytes(i))
start = int(what[2:4], 16)
length = max(1,int(what[5:6], 16))
ns1.add(start, length); ns2.add(start, length)
return ns1, ns2
#print()
for i in range(1000):
what = sha256(seed+bytes(i))
op = what[0:1]
subop = what[1:2]
start = int(what[2:4], 16)
length = max(1,int(what[5:6], 16))
#print(what)
if op in b"0":
if subop in b"01234":
s1 = S1(); s2 = S2()
elif subop in b"5678":
s1 = S1(start, length); s2 = S2(start, length)
else:
s1 = S1(s1); s2 = S2(s2)
#print("s2 = %s" % s2.dump())
elif op in b"123":
#print("s2.add(%d,%d)" % (start, length))
s1.add(start, length); s2.add(start, length)
elif op in b"456":
#print("s2.remove(%d,%d)" % (start, length))
s1.remove(start, length); s2.remove(start, length)
elif op in b"78":
ns1, ns2 = _create(what[7:11])
#print("s2 + %s" % ns2.dump())
s1 = s1 + ns1; s2 = s2 + ns2
elif op in b"9a":
ns1, ns2 = _create(what[7:11])
#print("%s - %s" % (s2.dump(), ns2.dump()))
s1 = s1 - ns1; s2 = s2 - ns2
elif op in b"bc":
ns1, ns2 = _create(what[7:11])
#print("s2 += %s" % ns2.dump())
s1 += ns1; s2 += ns2
elif op in b"de":
ns1, ns2 = _create(what[7:11])
#print("%s -= %s" % (s2.dump(), ns2.dump()))
s1 -= ns1; s2 -= ns2
else:
ns1, ns2 = _create(what[7:11])
#print("%s &= %s" % (s2.dump(), ns2.dump()))
s1 = s1 & ns1; s2 = s2 & ns2
#print("s2 now %s" % s2.dump())
self.failUnlessEqual(list(s1.each()), list(s2.each()))
self.failUnlessEqual(s1.len(), s2.len())
self.failUnlessEqual(bool(s1), bool(s2))
self.failUnlessEqual(list(s1), list(s2))
for j in range(10):
what = sha256(what[12:14]+bytes(j))
start = int(what[2:4], 16)
length = max(1, int(what[5:6], 16))
span = (start, length)
self.failUnlessEqual(bool(span in s1), bool(span in s2))
# s()
# s(start,length)
# s(s0)
# s.add(start,length) : returns s
# s.remove(start,length)
# s.each() -> list of byte offsets, mostly for testing
# list(s) -> list of (start,length) tuples, one per span
# (start,length) in s -> True if (start..start+length-1) are all members
# NOT equivalent to x in list(s)
# s.len() -> number of bytes, for testing, bool(), and accounting/limiting
# bool(s) (__nonzeron__)
# s = s1+s2, s1-s2, +=s1, -=s1
def test_overlap(self):
for a in range(20):
for b in range(10):
for c in range(20):
for d in range(10):
self._test_overlap(a,b,c,d)
def _test_overlap(self, a, b, c, d):
s1 = set(range(a,a+b))
s2 = set(range(c,c+d))
#print("---")
#self._show_overlap(s1, "1")
#self._show_overlap(s2, "2")
o = overlap(a,b,c,d)
expected = s1.intersection(s2)
if not expected:
self.failUnlessEqual(o, None)
else:
start,length = o
so = set(range(start,start+length))
#self._show(so, "o")
self.failUnlessEqual(so, expected)
def _show_overlap(self, s, c):
import sys
out = sys.stdout
if s:
for i in range(max(s)):
if i in s:
out.write(c)
else:
out.write(" ")
out.write("\n")
def extend(s, start, length, fill):
if len(s) >= start+length:
return s
assert len(fill) == 1
return s + fill*(start+length-len(s))
def replace(s, start, data):
assert len(s) >= start+len(data)
return s[:start] + data + s[start+len(data):]
class SimpleDataSpans(object):
def __init__(self, other=None):
self.missing = "" # "1" where missing, "0" where found
self.data = b""
if other:
for (start, data) in other.get_chunks():
self.add(start, data)
def __bool__(self): # this gets us bool()
return bool(self.len())
def len(self):
return len(self.missing.replace("1", ""))
def _dump(self):
return [i for (i,c) in enumerate(self.missing) if c == "0"]
def _have(self, start, length):
m = self.missing[start:start+length]
if not m or len(m)<length or int(m):
return False
return True
def get_chunks(self):
for i in self._dump():
yield (i, self.data[i:i+1])
def get_spans(self):
return SimpleSpans([(start,len(data))
for (start,data) in self.get_chunks()])
def get(self, start, length):
if self._have(start, length):
return self.data[start:start+length]
return None
def pop(self, start, length):
data = self.get(start, length)
if data:
self.remove(start, length)
return data
def remove(self, start, length):
self.missing = replace(extend(self.missing, start, length, "1"),
start, "1"*length)
def add(self, start, data):
self.missing = replace(extend(self.missing, start, len(data), "1"),
start, "0"*len(data))
self.data = replace(extend(self.data, start, len(data), b" "),
start, data)
class StringSpans(unittest.TestCase):
def do_basic(self, klass):
ds = klass()
self.failUnlessEqual(ds.len(), 0)
self.failUnlessEqual(list(ds._dump()), [])
self.failUnlessEqual(sum([len(d) for (s,d) in ds.get_chunks()]), 0)
s1 = ds.get_spans()
self.failUnlessEqual(ds.get(0, 4), None)
self.failUnlessEqual(ds.pop(0, 4), None)
ds.remove(0, 4)
ds.add(2, b"four")
self.failUnlessEqual(ds.len(), 4)
self.failUnlessEqual(list(ds._dump()), [2,3,4,5])
self.failUnlessEqual(sum([len(d) for (s,d) in ds.get_chunks()]), 4)
s1 = ds.get_spans()
self.failUnless((2,2) in s1)
self.failUnlessEqual(ds.get(0, 4), None)
self.failUnlessEqual(ds.pop(0, 4), None)
self.failUnlessEqual(ds.get(4, 4), None)
ds2 = klass(ds)
self.failUnlessEqual(ds2.len(), 4)
self.failUnlessEqual(list(ds2._dump()), [2,3,4,5])
self.failUnlessEqual(sum([len(d) for (s,d) in ds2.get_chunks()]), 4)
self.failUnlessEqual(ds2.get(0, 4), None)
self.failUnlessEqual(ds2.pop(0, 4), None)
self.failUnlessEqual(ds2.pop(2, 3), b"fou")
self.failUnlessEqual(sum([len(d) for (s,d) in ds2.get_chunks()]), 1)
self.failUnlessEqual(ds2.get(2, 3), None)
self.failUnlessEqual(ds2.get(5, 1), b"r")
self.failUnlessEqual(ds.get(2, 3), b"fou")
self.failUnlessEqual(sum([len(d) for (s,d) in ds.get_chunks()]), 4)
ds.add(0, b"23")
self.failUnlessEqual(ds.len(), 6)
self.failUnlessEqual(list(ds._dump()), [0,1,2,3,4,5])
self.failUnlessEqual(sum([len(d) for (s,d) in ds.get_chunks()]), 6)
self.failUnlessEqual(ds.get(0, 4), b"23fo")
self.failUnlessEqual(ds.pop(0, 4), b"23fo")
self.failUnlessEqual(sum([len(d) for (s,d) in ds.get_chunks()]), 2)
self.failUnlessEqual(ds.get(0, 4), None)
self.failUnlessEqual(ds.pop(0, 4), None)
ds = klass()
ds.add(2, b"four")
ds.add(3, b"ea")
self.failUnlessEqual(ds.get(2, 4), b"fear")
ds = klass()
ds.add(long(2), b"four")
ds.add(long(3), b"ea")
self.failUnlessEqual(ds.get(long(2), long(4)), b"fear")
def do_scan(self, klass):
# do a test with gaps and spans of size 1 and 2
# left=(1,11) * right=(1,11) * gapsize=(1,2)
# 111, 112, 121, 122, 211, 212, 221, 222
# 211
# 121
# 112
# 212
# 222
# 221
# 111
# 122
# 11 1 1 11 11 11 1 1 111
# 0123456789012345678901234567
# abcdefghijklmnopqrstuvwxyz-=
pieces = [(1, b"bc"),
(4, b"e"),
(7, b"h"),
(9, b"jk"),
(12, b"mn"),
(16, b"qr"),
(20, b"u"),
(22, b"w"),
(25, b"z-="),
]
p_elements = set([1,2,4,7,9,10,12,13,16,17,20,22,25,26,27])
S = b"abcdefghijklmnopqrstuvwxyz-="
# TODO: when adding data, add capital letters, to make sure we aren't
# just leaving the old data in place
l = len(S)
def base():
ds = klass()
for start, data in pieces:
ds.add(start, data)
return ds
def dump(s):
p = set(s._dump())
d = b"".join([((i not in p) and b" " or S[i]) for i in range(l)])
assert len(d) == l
return d
DEBUG = False
for start in range(0, l):
for end in range(start+1, l):
# add [start-end) to the baseline
which = "%d-%d" % (start, end-1)
p_added = set(range(start, end))
b = base()
if DEBUG:
print()
print(dump(b), which)
add = klass(); add.add(start, S[start:end])
print(dump(add))
b.add(start, S[start:end])
if DEBUG:
print(dump(b))
# check that the new span is there
d = b.get(start, end-start)
self.failUnlessEqual(d, S[start:end], which)
# check that all the original pieces are still there
for t_start, t_data in pieces:
t_len = len(t_data)
self.failUnlessEqual(b.get(t_start, t_len),
S[t_start:t_start+t_len],
"%s %d+%d" % (which, t_start, t_len))
# check that a lot of subspans are mostly correct
for t_start in range(l):
for t_len in range(1,4):
d = b.get(t_start, t_len)
if d is not None:
which2 = "%s+(%d-%d)" % (which, t_start,
t_start+t_len-1)
self.failUnlessEqual(d, S[t_start:t_start+t_len],
which2)
# check that removing a subspan gives the right value
b2 = klass(b)
b2.remove(t_start, t_len)
removed = set(range(t_start, t_start+t_len))
for i in range(l):
exp = (((i in p_elements) or (i in p_added))
and (i not in removed))
which2 = "%s-(%d-%d)" % (which, t_start,
t_start+t_len-1)
self.failUnlessEqual(bool(b2.get(i, 1)), exp,
which2+" %d" % i)
def test_test(self):
self.do_basic(SimpleDataSpans)
self.do_scan(SimpleDataSpans)
def test_basic(self):
self.do_basic(DataSpans)
self.do_scan(DataSpans)
def test_random(self):
# attempt to increase coverage of corner cases by comparing behavior
# of a simple-but-slow model implementation against the
# complex-but-fast actual implementation, in a large number of random
# operations
S1 = SimpleDataSpans
S2 = DataSpans
s1 = S1(); s2 = S2()
seed = b""
def _randstr(length, seed):
created = 0
pieces = []
while created < length:
piece = sha256(seed + bytes(created))
pieces.append(piece)
created += len(piece)
return b"".join(pieces)[:length]
def _create(subseed):
ns1 = S1(); ns2 = S2()
for i in range(10):
what = sha256(subseed+bytes(i))
start = int(what[2:4], 16)
length = max(1,int(what[5:6], 16))
ns1.add(start, _randstr(length, what[7:9]));
ns2.add(start, _randstr(length, what[7:9]))
return ns1, ns2
#print()
for i in range(1000):
what = sha256(seed+bytes(i))
op = what[0:1]
subop = what[1:2]
start = int(what[2:4], 16)
length = max(1,int(what[5:6], 16))
#print(what)
if op in b"0":
if subop in b"0123456":
s1 = S1(); s2 = S2()
else:
s1, s2 = _create(what[7:11])
#print("s2 = %s" % list(s2._dump()))
elif op in b"123456":
#print("s2.add(%d,%d)" % (start, length))
s1.add(start, _randstr(length, what[7:9]));
s2.add(start, _randstr(length, what[7:9]))
elif op in b"789abc":
#print("s2.remove(%d,%d)" % (start, length))
s1.remove(start, length); s2.remove(start, length)
else:
#print("s2.pop(%d,%d)" % (start, length))
d1 = s1.pop(start, length); d2 = s2.pop(start, length)
self.failUnlessEqual(d1, d2)
#print("s1 now %s" % list(s1._dump()))
#print("s2 now %s" % list(s2._dump()))
self.failUnlessEqual(s1.len(), s2.len())
self.failUnlessEqual(list(s1._dump()), list(s2._dump()))
for j in range(100):
what = sha256(what[12:14]+bytes(j))
start = int(what[2:4], 16)
length = max(1, int(what[5:6], 16))
d1 = s1.get(start, length); d2 = s2.get(start, length)
self.failUnlessEqual(d1, d2, "%d+%d" % (start, length))