From 0835f40ae25f97360dc393928796387d3cd6b16e Mon Sep 17 00:00:00 2001 From: Guilherme Andrade Date: Wed, 19 Apr 2017 00:43:37 +0100 Subject: erts: Add enif_phash2 and enif_phash2_ranged These allow one to hash VM terms from NIF code. --- erts/doc/src/erl_nif.xml | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'erts/doc/src') 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 @@ -2369,6 +2369,36 @@ enif_map_iterator_destroy(env, &iter); + + + unsigned long + enif_phash2(ERL_NIF_TERM term) + + Portable hash function. + +

Portable hash function that gives the same hash for the same Erlang term + regardless of machine architecture and ERTS version. Corresponds to + erlang:phash2/1.

+

Returns an unsigned integer within 0..2^27-1.

+ + + + + + unsigned long + enif_phash2_ranged(ERL_NIF_TERM term, unsigned long range) + + Portable hash function. + +

Similar to enif_phash2 + but hash range can be specified. Corresponds to + erlang:phash2/2.

+

Returns an unsigned integer within 0..range-1 + if 0 < range < 2^32, and within 0..2^32-1 otherwise. +

+ + + intenif_port_command(ErlNifEnv* env, const ErlNifPort* to_port, ErlNifEnv *msg_env, ERL_NIF_TERM msg) -- cgit v1.2.3 From 1b37d0b010ea31b04b9d0a15d0bec9c75a013dc9 Mon Sep 17 00:00:00 2001 From: Guilherme Andrade Date: Thu, 20 Apr 2017 21:35:54 +0100 Subject: erts: Remove enif_phash2_ranged --- erts/doc/src/erl_nif.xml | 16 ---------------- 1 file changed, 16 deletions(-) (limited to 'erts/doc/src') diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml index 34dae418ef..35c42ac517 100644 --- a/erts/doc/src/erl_nif.xml +++ b/erts/doc/src/erl_nif.xml @@ -2383,22 +2383,6 @@ enif_map_iterator_destroy(env, &iter); - - - unsigned long - enif_phash2_ranged(ERL_NIF_TERM term, unsigned long range) - - Portable hash function. - -

Similar to enif_phash2 - but hash range can be specified. Corresponds to - erlang:phash2/2.

-

Returns an unsigned integer within 0..range-1 - if 0 < range < 2^32, and within 0..2^32-1 otherwise. -

- - - intenif_port_command(ErlNifEnv* env, const ErlNifPort* to_port, ErlNifEnv *msg_env, ERL_NIF_TERM msg) -- cgit v1.2.3 From d8756f8665a42effa2f3515369058cff4441abeb Mon Sep 17 00:00:00 2001 From: Guilherme Andrade Date: Thu, 20 Apr 2017 22:44:04 +0100 Subject: erts: Refactor enif_phash2 into enif_hash A more generic hashing function which can also hash terms based on `make_internal_hash'. --- erts/doc/src/erl_nif.xml | 49 ++++++++++++++++++++++++++++++++++-------------- 1 file changed, 35 insertions(+), 14 deletions(-) (limited to 'erts/doc/src') 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 { + ErlNifHash + +

An enumeration of the supported hash types that can be generated + using enif_hash. +

+ + ERL_NIF_INTERNAL_HASH + +

Non-portable hash function that gives different hashes for the same Erlang + term depending on machine architecture and ERTS version.

+

Generated hash values within 0..2^32-1.

+ + ERL_NIF_PHASH2 + +

Portable hash function that gives the same hash for the same Erlang term + regardless of machine architecture and ERTS version. Corresponds to + erlang:phash2/1.

+

Slower than ERL_NIF_INTERNAL_HASH.

+

Generated hash values within 0..2^27-1.

+ + + @@ -1386,6 +1408,19 @@ typedef enum { + + + unsigned long + enif_hash(ErlNifHash type, ERL_NIF_TERM term) + + Hash terms. + +

Hash terms according to the specified + ErlNifHash type.

+

Range of returned value depends on the hash type.

+ + + intenif_inspect_binary(ErlNifEnv* env, ERL_NIF_TERM bin_term, ErlNifBinary* bin) @@ -2369,20 +2404,6 @@ enif_map_iterator_destroy(env, &iter); - - - unsigned long - enif_phash2(ERL_NIF_TERM term) - - Portable hash function. - -

Portable hash function that gives the same hash for the same Erlang term - regardless of machine architecture and ERTS version. Corresponds to - erlang:phash2/1.

-

Returns an unsigned integer within 0..2^27-1.

- - - intenif_port_command(ErlNifEnv* env, const ErlNifPort* to_port, ErlNifEnv *msg_env, ERL_NIF_TERM msg) -- cgit v1.2.3 From 21e1d879faaae2278a68200fe1085d7e73791fa0 Mon Sep 17 00:00:00 2001 From: Guilherme Andrade Date: Sat, 22 Apr 2017 17:22:32 +0100 Subject: erts: Support custom salt in enif_hash --- erts/doc/src/erl_nif.xml | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'erts/doc/src') diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml index 53b6fdeaa1..03c96dd3ca 100644 --- a/erts/doc/src/erl_nif.xml +++ b/erts/doc/src/erl_nif.xml @@ -827,11 +827,13 @@ typedef enum { ERL_NIF_PHASH2 -

Portable hash function that gives the same hash for the same Erlang term - regardless of machine architecture and ERTS version. Corresponds to - erlang:phash2/1.

-

Slower than ERL_NIF_INTERNAL_HASH.

+

Portable hash function that gives the same hash for the + same Erlang term regardless of machine architecture and ERTS version.

Generated hash values within 0..2^27-1.

+

Slower than ERL_NIF_INTERNAL_HASH. + When used with salt=0, + it corresponds to + erlang:phash2/1.

 @@ -1411,12 +1413,15 @@ typedef enum { unsigned long - enif_hash(ErlNifHash type, ERL_NIF_TERM term) + + enif_hash(ErlNifHash type, ERL_NIF_TERM term, unsigned long salt) + Hash terms. -

Hash terms according to the specified - ErlNifHash type.

+

Hash term according to the specified + ErlNifHash type + and using the least significant 32 bits of salt.

Range of returned value depends on the hash type.

 -- cgit v1.2.3 From d810cd2b1ce642703d4986ba26ba50fd7949fcab Mon Sep 17 00:00:00 2001 From: Guilherme Andrade Date: Sat, 22 Apr 2017 18:46:16 +0100 Subject: erts: Improve enif_hash documentation --- erts/doc/src/erl_nif.xml | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'erts/doc/src') diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml index 03c96dd3ca..5faf1a05fc 100644 --- a/erts/doc/src/erl_nif.xml +++ b/erts/doc/src/erl_nif.xml @@ -821,8 +821,8 @@ typedef enum { ERL_NIF_INTERNAL_HASH -

Non-portable hash function that gives different hashes for the same Erlang - term depending on machine architecture and ERTS version.

+

Non-portable hash function that only guarantees the same hash + for the same term within one Erlang VM instance.

Generated hash values within 0..2^32-1.

 ERL_NIF_PHASH2 @@ -831,8 +831,7 @@ typedef enum { same Erlang term regardless of machine architecture and ERTS version.

Generated hash values within 0..2^27-1.

Slower than ERL_NIF_INTERNAL_HASH. - When used with salt=0, - it corresponds to + When used with salt=0, it corresponds to erlang:phash2/1.

 -- cgit v1.2.3 From da9abd24a93ae8fe174cdd38fc9699bbc45fdf56 Mon Sep 17 00:00:00 2001 From: Guilherme Andrade Date: Sat, 22 Apr 2017 20:00:28 +0100 Subject: erts: Allow for easier future enif_hash expansion Allow for expanding support to 64-bit hashes without breaking the interface. --- erts/doc/src/erl_nif.xml | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) (limited to 'erts/doc/src') diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml index 5faf1a05fc..534c90cbdc 100644 --- a/erts/doc/src/erl_nif.xml +++ b/erts/doc/src/erl_nif.xml @@ -823,13 +823,13 @@ typedef enum {

Non-portable hash function that only guarantees the same hash for the same term within one Erlang VM instance.

-

Generated hash values within 0..2^32-1.

+

It takes 32-bit salt values and generates hashes within 0..2^32-1.

 ERL_NIF_PHASH2

Portable hash function that gives the same hash for the same Erlang term regardless of machine architecture and ERTS version.

-

Generated hash values within 0..2^27-1.

+

It takes 32-bit salt values and generates hashes within 0..2^27-1.

Slower than ERL_NIF_INTERNAL_HASH. When used with salt=0, it corresponds to erlang:phash2/1.

@@ -1411,17 +1411,14 @@ typedef enum { - unsigned long - - enif_hash(ErlNifHash type, ERL_NIF_TERM term, unsigned long salt) - + ErlNifUInt64 + enif_hash(ErlNifHash type, ERL_NIF_TERM term, ErlNifUInt64 salt) Hash terms. -

Hash term according to the specified - ErlNifHash type - and using the least significant 32 bits of salt.

-

Range of returned value depends on the hash type.

+

Hashes term according to the specified + ErlNifHash type.

+

Ranges of taken salt and returned value depend on the hash type.

 -- cgit v1.2.3 From 3d6b8e7fb68543713f1620a45b8a590ef4ed88a5 Mon Sep 17 00:00:00 2001 From: Guilherme Andrade Date: Mon, 24 Apr 2017 22:51:49 +0100 Subject: erts: Discontinue salted use of enif_hash/phash2 --- erts/doc/src/erl_nif.xml | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'erts/doc/src') diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml index 534c90cbdc..05b519fe7d 100644 --- a/erts/doc/src/erl_nif.xml +++ b/erts/doc/src/erl_nif.xml @@ -829,10 +829,10 @@ typedef enum {

Portable hash function that gives the same hash for the same Erlang term regardless of machine architecture and ERTS version.

-

It takes 32-bit salt values and generates hashes within 0..2^27-1.

+

It ignores salt values and generates hashes within 0..2^27-1.

Slower than ERL_NIF_INTERNAL_HASH. - When used with salt=0, it corresponds to - erlang:phash2/1.

+ It corresponds to erlang:phash2/1. +

@@ -1418,7 +1418,7 @@ typedef enum {

Hashes term according to the specified ErlNifHash type.

-

Ranges of taken salt and returned value depend on the hash type.

+

Ranges of taken salt (if any) and returned value depend on the hash type.

 -- cgit v1.2.3