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-rw-r--r--erts/doc/src/erl_nif.xml49
-rw-r--r--erts/emulator/beam/erl_nif.c11
-rw-r--r--erts/emulator/beam/erl_nif.h5
-rw-r--r--erts/emulator/beam/erl_nif_api_funcs.h4
-rw-r--r--erts/emulator/test/nif_SUITE.erl47
-rw-r--r--erts/emulator/test/nif_SUITE_data/nif_SUITE.c20
6 files changed, 111 insertions, 25 deletions
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml
index 35c42ac517..53b6fdeaa1 100644
--- a/erts/doc/src/erl_nif.xml
+++ b/erts/doc/src/erl_nif.xml
@@ -813,6 +813,28 @@ typedef enum {
</item>
</taglist>
</item>
+ <tag><marker id="ErlNifHash"/><c>ErlNifHash</c></tag>
+ <item>
+ <p>An enumeration of the supported hash types that can be generated
+ using <seealso marker="#enif_hash"><c>enif_hash</c></seealso>.
+ </p>
+ <taglist>
+ <tag><c>ERL_NIF_INTERNAL_HASH</c></tag>
+ <item>
+ <p>Non-portable hash function that gives different hashes for the same Erlang
+ term depending on machine architecture and ERTS version.</p>
+ <p>Generated hash values within <c>0..2^32-1</c>.</p>
+ </item>
+ <tag><c>ERL_NIF_PHASH2</c></tag>
+ <item>
+ <p>Portable hash function that gives the same hash for the same Erlang term
+ regardless of machine architecture and ERTS version. Corresponds to
+ <seealso marker="erlang#phash2-1"><c>erlang:phash2/1</c></seealso>.</p>
+ <p>Slower than <c>ERL_NIF_INTERNAL_HASH.</c></p>
+ <p>Generated hash values within <c>0..2^27-1</c>.</p>
+ </item>
+ </taglist>
+ </item>
</taglist>
</section>
@@ -1387,6 +1409,19 @@ typedef enum {
</func>
<func>
+ <name>
+ <ret>unsigned long</ret>
+ <nametext>enif_hash(ErlNifHash type, ERL_NIF_TERM term)</nametext>
+ </name>
+ <fsummary>Hash terms.</fsummary>
+ <desc>
+ <p>Hash terms according to the specified
+ <seealso marker="#ErlNifHash"><c>ErlNifHash</c></seealso> type.</p>
+ <p>Range of returned value depends on the hash type.</p>
+ </desc>
+ </func>
+
+ <func>
<name><ret>int</ret><nametext>enif_inspect_binary(ErlNifEnv* env,
ERL_NIF_TERM bin_term, ErlNifBinary* bin)</nametext></name>
<fsummary>Inspect the content of a binary.</fsummary>
@@ -2370,20 +2405,6 @@ enif_map_iterator_destroy(env, &amp;iter);</code>
</func>
<func>
- <name>
- <ret>unsigned long</ret>
- <nametext>enif_phash2(ERL_NIF_TERM term)</nametext>
- </name>
- <fsummary>Portable hash function.</fsummary>
- <desc>
- <p>Portable hash function that gives the same hash for the same Erlang term
- regardless of machine architecture and ERTS version. Corresponds to
- <seealso marker="erlang#phash2-1"><c>erlang:phash2/1</c></seealso>.</p>
- <p>Returns an unsigned integer within <c>0..2^27-1</c>.</p>
- </desc>
- </func>
-
- <func>
<name><ret>int</ret><nametext>enif_port_command(ErlNifEnv* env, const
ErlNifPort* to_port, ErlNifEnv *msg_env, ERL_NIF_TERM msg)</nametext>
</name>
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index f7777c8b92..3470cf3fd5 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -1214,13 +1214,20 @@ int enif_compare(Eterm lhs, Eterm rhs)
return result;
}
-unsigned long enif_phash2(Eterm term)
+unsigned long enif_hash(ErlNifHash type, Eterm term)
{
#if SIZEOF_LONG < 4
/* This *really* shouldn't happen */
# error Incompatible long word size
#endif
- return make_hash2(term) & ((1 << 27) - 1);
+ switch (type) {
+ case ERL_NIF_INTERNAL_HASH:
+ return make_internal_hash(term);
+ case ERL_NIF_PHASH2:
+ return make_hash2(term) & ((1 << 27) - 1);
+ default:
+ return 0;
+ }
}
int enif_get_tuple(ErlNifEnv* env, Eterm tpl, int* arity, const Eterm** array)
diff --git a/erts/emulator/beam/erl_nif.h b/erts/emulator/beam/erl_nif.h
index ac45f3ac81..5a81f5fbbb 100644
--- a/erts/emulator/beam/erl_nif.h
+++ b/erts/emulator/beam/erl_nif.h
@@ -236,6 +236,11 @@ typedef enum {
ERL_NIF_BIN2TERM_SAFE = 0x20000000
} ErlNifBinaryToTerm;
+typedef enum {
+ ERL_NIF_INTERNAL_HASH = 1,
+ ERL_NIF_PHASH2 = 2
+} ErlNifHash;
+
/*
* Return values from enif_thread_type(). Negative values
* reserved for specific types of non-scheduler threads.
diff --git a/erts/emulator/beam/erl_nif_api_funcs.h b/erts/emulator/beam/erl_nif_api_funcs.h
index c096b18f91..f52c841ed7 100644
--- a/erts/emulator/beam/erl_nif_api_funcs.h
+++ b/erts/emulator/beam/erl_nif_api_funcs.h
@@ -47,7 +47,7 @@ ERL_NIF_API_FUNC_DECL(int,enif_get_list_cell,(ErlNifEnv* env, ERL_NIF_TERM term,
ERL_NIF_API_FUNC_DECL(int,enif_get_tuple,(ErlNifEnv* env, ERL_NIF_TERM tpl, int* arity, const ERL_NIF_TERM** array));
ERL_NIF_API_FUNC_DECL(int,enif_is_identical,(ERL_NIF_TERM lhs, ERL_NIF_TERM rhs));
ERL_NIF_API_FUNC_DECL(int,enif_compare,(ERL_NIF_TERM lhs, ERL_NIF_TERM rhs));
-ERL_NIF_API_FUNC_DECL(unsigned long,enif_phash2,(ERL_NIF_TERM term));
+ERL_NIF_API_FUNC_DECL(unsigned long,enif_hash,(ErlNifHash type, ERL_NIF_TERM term));
ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_make_binary,(ErlNifEnv* env, ErlNifBinary* bin));
ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_make_badarg,(ErlNifEnv* env));
ERL_NIF_API_FUNC_DECL(ERL_NIF_TERM,enif_make_int,(ErlNifEnv* env, int i));
@@ -209,7 +209,7 @@ ERL_NIF_API_FUNC_DECL(int, enif_compare_monitors,(const ErlNifMonitor*,const Erl
# define enif_get_list_cell ERL_NIF_API_FUNC_MACRO(enif_get_list_cell)
# define enif_is_identical ERL_NIF_API_FUNC_MACRO(enif_is_identical)
# define enif_compare ERL_NIF_API_FUNC_MACRO(enif_compare)
-# define enif_phash2 ERL_NIF_API_FUNC_MACRO(enif_phash2)
+# define enif_hash ERL_NIF_API_FUNC_MACRO(enif_hash)
# define enif_make_binary ERL_NIF_API_FUNC_MACRO(enif_make_binary)
# define enif_make_badarg ERL_NIF_API_FUNC_MACRO(enif_make_badarg)
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},
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-24 14:04:23 +0000