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-rw-r--r--erts/doc/src/erl_nif.xml30
-rw-r--r--erts/emulator/beam/bif.c17
-rw-r--r--erts/emulator/beam/erl_nif.c20
-rw-r--r--erts/emulator/beam/erl_nif_api_funcs.h4
-rw-r--r--erts/emulator/beam/erl_utils.h1
-rw-r--r--erts/emulator/beam/utils.c10
-rw-r--r--erts/emulator/test/nif_SUITE.erl85
-rw-r--r--erts/emulator/test/nif_SUITE_data/nif_SUITE.c19
8 files changed, 173 insertions, 13 deletions
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml
index 6bb1109415..34dae418ef 100644
--- a/erts/doc/src/erl_nif.xml
+++ b/erts/doc/src/erl_nif.xml
@@ -2370,6 +2370,36 @@ 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>unsigned long</ret>
+ <nametext>enif_phash2_ranged(ERL_NIF_TERM term, unsigned long range)</nametext>
+ </name>
+ <fsummary>Portable hash function.</fsummary>
+ <desc>
+ <p>Similar to <seealso marker="#enif_phash2"><c>enif_phash2</c></seealso>
+ but hash range can be specified. Corresponds to
+ <seealso marker="erlang#phash2-2"><c>erlang:phash2/2</c></seealso>.</p>
+ <p>Returns an unsigned integer within <c>0..range-1</c>
+ if <c>0 &lt; range &lt; 2^32</c>, and within <c>0..2^32-1</c> otherwise.
+ </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/bif.c b/erts/emulator/beam/bif.c
index 214de3652f..d59adc18d6 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -4888,7 +4888,6 @@ BIF_RETTYPE phash2_1(BIF_ALIST_1)
BIF_RETTYPE phash2_2(BIF_ALIST_2)
{
Uint32 hash;
- Uint32 final_hash;
Uint32 range;
/* Check for special case 2^32 */
@@ -4901,23 +4900,19 @@ BIF_RETTYPE phash2_2(BIF_ALIST_2)
}
range = (Uint32) u;
}
- hash = make_hash2(BIF_ARG_1);
- if (range) {
- final_hash = hash % range; /* [0..range-1] */
- } else {
- final_hash = hash;
- }
+ hash = make_hash2_within_range(BIF_ARG_1, range);
+
/*
* Return either a small or a big. Use the heap for bigs if there is room.
*/
#if defined(ARCH_64)
- BIF_RET(make_small(final_hash));
+ BIF_RET(make_small(hash));
#else
- if (IS_USMALL(0, final_hash)) {
- BIF_RET(make_small(final_hash));
+ if (IS_USMALL(0, hash)) {
+ BIF_RET(make_small(hash));
} else {
Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
- BIF_RET(uint_to_big(final_hash, hp));
+ BIF_RET(uint_to_big(hash, hp));
}
#endif
}
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index f86b9739fa..14abf461a3 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -55,6 +55,7 @@
#include "dtrace-wrapper.h"
#include "erl_process.h"
#include "erl_bif_unique.h"
+#include "erl_utils.h"
#undef ERTS_WANT_NFUNC_SCHED_INTERNALS__
#define ERTS_WANT_NFUNC_SCHED_INTERNALS__
#include "erl_nfunc_sched.h"
@@ -1213,6 +1214,25 @@ int enif_compare(Eterm lhs, Eterm rhs)
return result;
}
+#if SIZEOF_LONG < 4
+/* This *really* shouldn't happen */
+# error Incompatible long word size
+#endif
+
+unsigned long enif_phash2(Eterm term)
+{
+ return make_hash2(term) & ((1 << 27) - 1);
+}
+
+unsigned long enif_phash2_ranged(Eterm term, unsigned long range)
+{
+#if SIZEOF_LONG > 4
+ if (range > (unsigned long) UINT32_MAX)
+ range = 0;
+#endif
+ return make_hash2_within_range(term, range);
+}
+
int enif_get_tuple(ErlNifEnv* env, Eterm tpl, int* arity, const Eterm** array)
{
Eterm* ptr;
diff --git a/erts/emulator/beam/erl_nif_api_funcs.h b/erts/emulator/beam/erl_nif_api_funcs.h
index 01d9e386ed..8a3f9165d9 100644
--- a/erts/emulator/beam/erl_nif_api_funcs.h
+++ b/erts/emulator/beam/erl_nif_api_funcs.h
@@ -47,6 +47,8 @@ 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_phash2_ranged,(ERL_NIF_TERM term, unsigned long));
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));
@@ -208,6 +210,8 @@ 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_phash2_ranged ERL_NIF_API_FUNC_MACRO(enif_phash2_ranged)
# 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/beam/erl_utils.h b/erts/emulator/beam/erl_utils.h
index 47289a0af1..75578c26d6 100644
--- a/erts/emulator/beam/erl_utils.h
+++ b/erts/emulator/beam/erl_utils.h
@@ -119,6 +119,7 @@ Sint erts_list_length(Eterm);
int erts_is_builtin(Eterm, Eterm, int);
Uint32 block_hash(byte *, unsigned, Uint32);
Uint32 make_hash2(Eterm);
+Uint32 make_hash2_within_range(Eterm, Uint32);
Uint32 make_hash(Eterm);
Uint32 make_internal_hash(Eterm);
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index 8f3f48f38f..72c59b33c6 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -1552,6 +1552,16 @@ make_hash2(Eterm term)
}
}
+Uint32
+make_hash2_within_range(Eterm term, Uint32 range)
+{
+ Uint32 hash = make_hash2(term);
+ if (range)
+ return hash % range; /* [0..range-1] */
+ else
+ return hash; /* Special case: 2**32 */
+}
+
/* Term hash function for internal use.
*
* Limitation #1: Is not "portable" in any way between different VM instances.
diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl
index 693db42e58..780fe0a5ee 100644
--- a/erts/emulator/test/nif_SUITE.erl
+++ b/erts/emulator/test/nif_SUITE.erl
@@ -56,7 +56,9 @@
nif_is_process_alive/1, nif_is_port_alive/1,
nif_term_to_binary/1, nif_binary_to_term/1,
nif_port_command/1,
- nif_snprintf/1
+ nif_snprintf/1,
+ nif_phash2/1,
+ nif_phash2_ranged/1
]).
-export([many_args_100/100]).
@@ -90,7 +92,9 @@ all() ->
nif_is_process_alive, nif_is_port_alive,
nif_term_to_binary, nif_binary_to_term,
nif_port_command,
- nif_snprintf].
+ nif_snprintf,
+ nif_phash2,
+ nif_phash2_ranged].
groups() ->
[{G, [], api_repeaters()} || G <- api_groups()]
@@ -2610,6 +2614,81 @@ nif_snprintf(Config) ->
<<"{{hello,world,-33},",0>> = format_term_nif(20,{{hello,world, -33}, 3.14, self()}),
ok.
+nif_phash2(Config) ->
+ ensure_lib_loaded(Config),
+ Terms =
+ [random_term() || _ <- lists:seq(1, 1000)],
+
+ lists:foreach(
+ fun (Term) ->
+ HashValue = erlang:phash2(Term),
+ NifHashValue = phash2_nif(Term),
+ (HashValue =:= NifHashValue
+ orelse ct:fail("Expected: ~p\nActual: ~p",
+ [HashValue, NifHashValue]))
+ end,
+ Terms).
+
+nif_phash2_ranged(Config) ->
+ ensure_lib_loaded(Config),
+ RandomRangedTerms =
+ [{random_term(), rand:uniform((1 bsl 32) - 1)}
+ || _ <- lists:seq(1, 1000)],
+
+ lists:foreach(
+ fun ({Term, Range}) ->
+ HashValue = erlang:phash2(Term, Range),
+ NifHashValue = phash2_ranged_nif(Term, Range),
+ (HashValue =:= NifHashValue
+ orelse ct:fail("Expected: ~p\nActual: ~p",
+ [HashValue, NifHashValue]))
+ end,
+ RandomRangedTerms),
+
+ EdgeCaseTerm = random_term(),
+ EdgeCaseHashValue = erlang:phash2(EdgeCaseTerm, 1 bsl 32),
+ EdgeCaseNifHashValue = phash2_ranged_nif(EdgeCaseTerm, 0),
+ (EdgeCaseHashValue =:= EdgeCaseNifHashValue
+ orelse ct:fail("Expected: ~p\nActual: ~p",
+ [EdgeCaseHashValue, EdgeCaseNifHashValue])).
+
+-define(HALF_DBL_EPSILON, 1.1102230246251565e-16). % math:pow(2, -53)
+
+random_term() ->
+ case rand:uniform(6) of
+ 1 -> rand:uniform(1 bsl 27) - 1; % small
+ 2 -> (1 bsl 27) + rand:uniform(1 bsl 128); % big
+ 3 -> random_sign() * (rand:uniform() * ?HALF_DBL_EPSILON); % float
+ 4 -> random_binary();
+ 5 -> random_pid();
+ 6 ->
+ Length = rand:uniform(10),
+ List = [random_term() || _ <- lists:seq(1, Length)],
+ case rand:uniform(2) of
+ 1 ->
+ List;
+ 2 ->
+ list_to_tuple(List)
+ end
+ end.
+
+random_sign() ->
+ case rand:uniform(2) of
+ 1 -> -1.0;
+ 2 -> 1.0
+ end.
+
+random_binary() ->
+ list_to_binary(random_bytes(rand:uniform(32) - 1)).
+
+random_bytes(0) ->
+ [];
+random_bytes(N) when N > 0 ->
+ [rand:uniform(256) - 1 | random_bytes(N - 1)].
+
+random_pid() ->
+ Processes = erlang:processes(),
+ lists:nth(rand:uniform(length(Processes)), Processes).
%% The NIFs:
lib_version() -> undefined.
@@ -2621,6 +2700,8 @@ type_test() -> ?nif_stub.
tuple_2_list(_) -> ?nif_stub.
is_identical(_,_) -> ?nif_stub.
compare(_,_) -> ?nif_stub.
+phash2_nif(_) -> ?nif_stub.
+phash2_ranged_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 8fe5ee809a..3bdd4d93c7 100644
--- a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
+++ b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
@@ -687,6 +687,23 @@ 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[])
+{
+ if (argc != 1) {
+ return enif_make_badarg(env);
+ }
+ return enif_make_ulong(env, enif_phash2(argv[0]));
+}
+
+static ERL_NIF_TERM phash2_ranged_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+ unsigned long range;
+ if (argc != 2 || !enif_get_ulong(env, argv[1], &range)) {
+ return enif_make_badarg(env);
+ }
+ return enif_make_ulong(env, enif_phash2_ranged(argv[0], range));
+}
+
static ERL_NIF_TERM many_args_100(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
{
int i, k;
@@ -2864,6 +2881,8 @@ static ErlNifFunc nif_funcs[] =
{"tuple_2_list", 1, tuple_2_list},
{"is_identical",2,is_identical},
{"compare",2,compare},
+ {"phash2_nif",1,phash2_nif},
+ {"phash2_ranged_nif",2,phash2_ranged_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 2024-11-16 03:40:28 +0000