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author | Guilherme Andrade <[email protected]> | 2017-04-20 22:44:04 +0100 |
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committer | Guilherme Andrade <[email protected]> | 2017-04-20 22:54:17 +0100 |
commit | d8756f8665a42effa2f3515369058cff4441abeb (patch) | |
tree | bce1d8701307f9389c098c3316a6f7a8dee50127 /erts/emulator/test | |
parent | 5ad95cca3f3c6802cd71fdd35dd397c3a37dc239 (diff) | |
download | otp-d8756f8665a42effa2f3515369058cff4441abeb.tar.gz otp-d8756f8665a42effa2f3515369058cff4441abeb.tar.bz2 otp-d8756f8665a42effa2f3515369058cff4441abeb.zip |
erts: Refactor enif_phash2 into enif_hash
A more generic hashing function which can also hash terms based on
`make_internal_hash'.
Diffstat (limited to 'erts/emulator/test')
-rw-r--r-- | erts/emulator/test/nif_SUITE.erl | 47 | ||||
-rw-r--r-- | erts/emulator/test/nif_SUITE_data/nif_SUITE.c | 20 |
2 files changed, 60 insertions, 7 deletions
diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl index 9127a5eae9..e177fa4963 100644 --- a/erts/emulator/test/nif_SUITE.erl +++ b/erts/emulator/test/nif_SUITE.erl @@ -57,6 +57,7 @@ nif_term_to_binary/1, nif_binary_to_term/1, nif_port_command/1, nif_snprintf/1, + nif_internal_hash/1, nif_phash2/1 ]). @@ -92,6 +93,7 @@ all() -> nif_term_to_binary, nif_binary_to_term, nif_port_command, nif_snprintf, + nif_internal_hash, nif_phash2]. groups() -> @@ -2612,15 +2614,54 @@ nif_snprintf(Config) -> <<"{{hello,world,-33},",0>> = format_term_nif(20,{{hello,world, -33}, 3.14, self()}), ok. +nif_internal_hash(Config) -> + ensure_lib_loaded(Config), + Terms = + [random_term() || _ <- lists:seq(1, 5000)], + + % Unlike the phash2 hash, in this case we + % have nothing to compare to, so let's try + % and at least make sure the distribution + % isn't outright wrong, statistical nuances + % aside. + + OnesPerBit = + lists:foldl( + fun (Term, Acc) -> + NifHashValue = hash_nif(internal, Term), + lists:foldl( + fun (BitIndex, AccB) -> + BitValue = (NifHashValue band (1 bsl BitIndex)) bsr BitIndex, + dict:update_counter(BitIndex, BitValue, AccB) + end, + Acc, + lists:seq(0, 31)) + end, + dict:new(), + Terms), + + ExpectedNrOfOnes = length(Terms) div 2, + dict:fold( + fun (BitIndex, NrOfOnes, Acc) -> + RelativeDeviation = abs(NrOfOnes - ExpectedNrOfOnes) / ExpectedNrOfOnes, + (RelativeDeviation < 0.10 + orelse ct:fail("Unreasonable deviation on number of set bits (i=~p): " + "expected ~p, got ~p (relative dev. ~.3f)", + [BitIndex, ExpectedNrOfOnes, NrOfOnes, RelativeDeviation])), + Acc + end, + ok, + OnesPerBit). + nif_phash2(Config) -> ensure_lib_loaded(Config), Terms = - [random_term() || _ <- lists:seq(1, 1000)], + [random_term() || _ <- lists:seq(1, 5000)], lists:foreach( fun (Term) -> HashValue = erlang:phash2(Term), - NifHashValue = phash2_nif(Term), + NifHashValue = hash_nif(phash2, Term), (HashValue =:= NifHashValue orelse ct:fail("Expected: ~p\nActual: ~p", [HashValue, NifHashValue])) @@ -2673,7 +2714,7 @@ type_test() -> ?nif_stub. tuple_2_list(_) -> ?nif_stub. is_identical(_,_) -> ?nif_stub. compare(_,_) -> ?nif_stub. -phash2_nif(_) -> ?nif_stub. +hash_nif(_, _) -> ?nif_stub. many_args_100(_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_,_) -> ?nif_stub. clone_bin(_) -> ?nif_stub. make_sub_bin(_,_,_) -> ?nif_stub. diff --git a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c index dac6d02e9d..9d65b9c09b 100644 --- a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c +++ b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c @@ -687,12 +687,24 @@ static ERL_NIF_TERM compare(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) return enif_make_int(env, enif_compare(argv[0],argv[1])); } -static ERL_NIF_TERM phash2_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) +static ERL_NIF_TERM hash_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) { - if (argc != 1) { + if (argc != 2) { + return enif_make_badarg(env); + } + + ErlNifHash type; + if (enif_is_identical(argv[0], enif_make_atom(env, "internal"))) { + type = ERL_NIF_INTERNAL_HASH; + } + else if (enif_is_identical(argv[0], enif_make_atom(env, "phash2"))) { + type = ERL_NIF_PHASH2; + } + else { return enif_make_badarg(env); } - return enif_make_ulong(env, enif_phash2(argv[0])); + + return enif_make_ulong(env, enif_hash(type, argv[1])); } static ERL_NIF_TERM many_args_100(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]) @@ -2872,7 +2884,7 @@ static ErlNifFunc nif_funcs[] = {"tuple_2_list", 1, tuple_2_list}, {"is_identical",2,is_identical}, {"compare",2,compare}, - {"phash2_nif",1,phash2_nif}, + {"hash_nif",2,hash_nif}, {"many_args_100", 100, many_args_100}, {"clone_bin", 1, clone_bin}, {"make_sub_bin", 3, make_sub_bin}, |