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author | Tim Peters <tim.peters@gmail.com> | 2001-05-13 00:19:31 (GMT) |
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committer | Tim Peters <tim.peters@gmail.com> | 2001-05-13 00:19:31 (GMT) |
commit | 2f228e75e4d5ac8c3eb4a6334dbc43243bff1095 (patch) | |
tree | ce1923e23fad608ef3d5749ed5a0e59f08530182 /Lib/test/output | |
parent | 0194ad5c7d2a0ffe473b87933768cb509417ff59 (diff) | |
download | cpython-2f228e75e4d5ac8c3eb4a6334dbc43243bff1095.zip cpython-2f228e75e4d5ac8c3eb4a6334dbc43243bff1095.tar.gz cpython-2f228e75e4d5ac8c3eb4a6334dbc43243bff1095.tar.bz2 |
Get rid of the superstitious "~" in dict hashing's "i = (~hash) & mask".
The comment following used to say:
/* We use ~hash instead of hash, as degenerate hash functions, such
as for ints <sigh>, can have lots of leading zeros. It's not
really a performance risk, but better safe than sorry.
12-Dec-00 tim: so ~hash produces lots of leading ones instead --
what's the gain? */
That is, there was never a good reason for doing it. And to the contrary,
as explained on Python-Dev last December, it tended to make the *sum*
(i + incr) & mask (which is the first table index examined in case of
collison) the same "too often" across distinct hashes.
Changing to the simpler "i = hash & mask" reduced the number of string-dict
collisions (== # number of times we go around the lookup for-loop) from about
6 million to 5 million during a full run of the test suite (these are
approximate because the test suite does some random stuff from run to run).
The number of collisions in non-string dicts also decreased, but not as
dramatically.
Note that this may, for a given dict, change the order (wrt previous
releases) of entries exposed by .keys(), .values() and .items(). A number
of std tests suffered bogus failures as a result. For dicts keyed by
small ints, or (less so) by characters, the order is much more likely to be
in increasing order of key now; e.g.,
>>> d = {}
>>> for i in range(10):
... d[i] = i
...
>>> d
{0: 0, 1: 1, 2: 2, 3: 3, 4: 4, 5: 5, 6: 6, 7: 7, 8: 8, 9: 9}
>>>
Unfortunately. people may latch on to that in small examples and draw a
bogus conclusion.
test_support.py
Moved test_extcall's sortdict() into test_support, made it stronger,
and imported sortdict into other std tests that needed it.
test_unicode.py
Excluced cp875 from the "roundtrip over range(128)" test, because
cp875 doesn't have a well-defined inverse for unicode("?", "cp875").
See Python-Dev for excruciating details.
Cookie.py
Chaged various output functions to sort dicts before building
strings from them.
test_extcall
Fiddled the expected-result file. This remains sensitive to native
dict ordering, because, e.g., if there are multiple errors in a
keyword-arg dict (and test_extcall sets up many cases like that), the
specific error Python complains about first depends on native dict
ordering.
Diffstat (limited to 'Lib/test/output')
-rw-r--r-- | Lib/test/output/test_cookie | 6 | ||||
-rw-r--r-- | Lib/test/output/test_extcall | 20 |
2 files changed, 13 insertions, 13 deletions
diff --git a/Lib/test/output/test_cookie b/Lib/test/output/test_cookie index 64b9d04..221c72a 100644 --- a/Lib/test/output/test_cookie +++ b/Lib/test/output/test_cookie @@ -1,11 +1,11 @@ test_cookie -<SimpleCookie: vienna='finger' chips='ahoy'> -Set-Cookie: vienna=finger; +<SimpleCookie: chips='ahoy' vienna='finger'> Set-Cookie: chips=ahoy; - vienna 'finger' 'finger' Set-Cookie: vienna=finger; chips 'ahoy' 'ahoy' Set-Cookie: chips=ahoy; + vienna 'finger' 'finger' +Set-Cookie: vienna=finger; <SimpleCookie: keebler='E=mc2; L="Loves"; fudge=\n;'> Set-Cookie: keebler="E=mc2; L=\"Loves\"; fudge=\012;"; keebler 'E=mc2; L="Loves"; fudge=\n;' 'E=mc2; L="Loves"; fudge=\n;' diff --git a/Lib/test/output/test_extcall b/Lib/test/output/test_extcall index 58f52d4..24e8c8c 100644 --- a/Lib/test/output/test_extcall +++ b/Lib/test/output/test_extcall @@ -40,7 +40,7 @@ za () {} -> za() takes exactly 1 argument (0 given) za () {'a': 'aa'} -> ok za aa B D E V a za () {'d': 'dd'} -> za() got an unexpected keyword argument 'd' za () {'a': 'aa', 'd': 'dd'} -> za() got an unexpected keyword argument 'd' -za () {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> za() got an unexpected keyword argument 'd' +za () {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> za() got an unexpected keyword argument 'b' za (1, 2) {} -> za() takes exactly 1 argument (2 given) za (1, 2) {'a': 'aa'} -> za() takes exactly 1 non-keyword argument (2 given) za (1, 2) {'d': 'dd'} -> za() takes exactly 1 non-keyword argument (2 given) @@ -59,8 +59,8 @@ zade () {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zade() got an unexpected zade (1, 2) {} -> ok zade 1 B 2 e V e zade (1, 2) {'a': 'aa'} -> zade() got multiple values for keyword argument 'a' zade (1, 2) {'d': 'dd'} -> zade() got multiple values for keyword argument 'd' -zade (1, 2) {'a': 'aa', 'd': 'dd'} -> zade() got multiple values for keyword argument 'd' -zade (1, 2) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zade() got multiple values for keyword argument 'd' +zade (1, 2) {'a': 'aa', 'd': 'dd'} -> zade() got multiple values for keyword argument 'a' +zade (1, 2) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zade() got multiple values for keyword argument 'a' zade (1, 2, 3, 4, 5) {} -> zade() takes at most 3 arguments (5 given) zade (1, 2, 3, 4, 5) {'a': 'aa'} -> zade() takes at most 3 non-keyword arguments (5 given) zade (1, 2, 3, 4, 5) {'d': 'dd'} -> zade() takes at most 3 non-keyword arguments (5 given) @@ -75,7 +75,7 @@ zabk (1, 2) {} -> ok zabk 1 2 D E V {} zabk (1, 2) {'a': 'aa'} -> zabk() got multiple values for keyword argument 'a' zabk (1, 2) {'d': 'dd'} -> ok zabk 1 2 D E V {'d': 'dd'} zabk (1, 2) {'a': 'aa', 'd': 'dd'} -> zabk() got multiple values for keyword argument 'a' -zabk (1, 2) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabk() got multiple values for keyword argument 'b' +zabk (1, 2) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabk() got multiple values for keyword argument 'a' zabk (1, 2, 3, 4, 5) {} -> zabk() takes exactly 2 arguments (5 given) zabk (1, 2, 3, 4, 5) {'a': 'aa'} -> zabk() takes exactly 2 non-keyword arguments (5 given) zabk (1, 2, 3, 4, 5) {'d': 'dd'} -> zabk() takes exactly 2 non-keyword arguments (5 given) @@ -90,12 +90,12 @@ zabdv (1, 2) {} -> ok zabdv 1 2 d E () e zabdv (1, 2) {'a': 'aa'} -> zabdv() got multiple values for keyword argument 'a' zabdv (1, 2) {'d': 'dd'} -> ok zabdv 1 2 dd E () d zabdv (1, 2) {'a': 'aa', 'd': 'dd'} -> zabdv() got multiple values for keyword argument 'a' -zabdv (1, 2) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabdv() got an unexpected keyword argument 'e' +zabdv (1, 2) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabdv() got multiple values for keyword argument 'a' zabdv (1, 2, 3, 4, 5) {} -> ok zabdv 1 2 3 E (4, 5) e zabdv (1, 2, 3, 4, 5) {'a': 'aa'} -> zabdv() got multiple values for keyword argument 'a' zabdv (1, 2, 3, 4, 5) {'d': 'dd'} -> zabdv() got multiple values for keyword argument 'd' -zabdv (1, 2, 3, 4, 5) {'a': 'aa', 'd': 'dd'} -> zabdv() got multiple values for keyword argument 'd' -zabdv (1, 2, 3, 4, 5) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabdv() got multiple values for keyword argument 'd' +zabdv (1, 2, 3, 4, 5) {'a': 'aa', 'd': 'dd'} -> zabdv() got multiple values for keyword argument 'a' +zabdv (1, 2, 3, 4, 5) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabdv() got multiple values for keyword argument 'a' zabdevk () {} -> zabdevk() takes at least 2 arguments (0 given) zabdevk () {'a': 'aa'} -> zabdevk() takes at least 2 non-keyword arguments (1 given) zabdevk () {'d': 'dd'} -> zabdevk() takes at least 2 non-keyword arguments (0 given) @@ -105,9 +105,9 @@ zabdevk (1, 2) {} -> ok zabdevk 1 2 d e () {} zabdevk (1, 2) {'a': 'aa'} -> zabdevk() got multiple values for keyword argument 'a' zabdevk (1, 2) {'d': 'dd'} -> ok zabdevk 1 2 dd e () {} zabdevk (1, 2) {'a': 'aa', 'd': 'dd'} -> zabdevk() got multiple values for keyword argument 'a' -zabdevk (1, 2) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabdevk() got multiple values for keyword argument 'b' +zabdevk (1, 2) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabdevk() got multiple values for keyword argument 'a' zabdevk (1, 2, 3, 4, 5) {} -> ok zabdevk 1 2 3 4 (5,) {} zabdevk (1, 2, 3, 4, 5) {'a': 'aa'} -> zabdevk() got multiple values for keyword argument 'a' zabdevk (1, 2, 3, 4, 5) {'d': 'dd'} -> zabdevk() got multiple values for keyword argument 'd' -zabdevk (1, 2, 3, 4, 5) {'a': 'aa', 'd': 'dd'} -> zabdevk() got multiple values for keyword argument 'd' -zabdevk (1, 2, 3, 4, 5) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabdevk() got multiple values for keyword argument 'd' +zabdevk (1, 2, 3, 4, 5) {'a': 'aa', 'd': 'dd'} -> zabdevk() got multiple values for keyword argument 'a' +zabdevk (1, 2, 3, 4, 5) {'a': 'aa', 'b': 'bb', 'd': 'dd', 'e': 'ee'} -> zabdevk() got multiple values for keyword argument 'a' |