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Diffstat (limited to 'erts/doc/src/erl_nif.xml')
| -rw-r--r-- | erts/doc/src/erl_nif.xml | 329 |
1 files changed, 234 insertions, 95 deletions
diff --git a/erts/doc/src/erl_nif.xml b/erts/doc/src/erl_nif.xml index 3de94be9ff..2d8706169f 100644 --- a/erts/doc/src/erl_nif.xml +++ b/erts/doc/src/erl_nif.xml @@ -4,20 +4,21 @@ <cref> <header> <copyright> - <year>2001</year><year>2013</year> + <year>2001</year><year>2015</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> - The contents of this file are subject to the Erlang Public License, - Version 1.1, (the "License"); you may not use this file except in - compliance with the License. You should have received a copy of the - Erlang Public License along with this software. If not, it can be - retrieved online at http://www.erlang.org/. - - Software distributed under the License is distributed on an "AS IS" - basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See - the License for the specific language governing rights and limitations - under the License. + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. </legalnotice> @@ -66,34 +67,6 @@ </list> </warning> - <p>The NIF concept is officially supported from R14B. NIF source code - written for earlier experimental versions might need adaption to run on R14B - or later versions:</p> - <list> - <item>No incompatible changes between <em>R14B</em> and R14A.</item> - <item>Incompatible changes between <em>R14A</em> and R13B04: - <list> - <item>Environment argument removed for <c>enif_alloc</c>, - <c>enif_realloc</c>, <c>enif_free</c>, <c>enif_alloc_binary</c>, - <c>enif_realloc_binary</c>, <c>enif_release_binary</c>, - <c>enif_alloc_resource</c>, <c>enif_release_resource</c>, - <c>enif_is_identical</c> and <c>enif_compare</c>.</item> - <item>Character encoding argument added to <c>enif_get_atom</c> - and <c>enif_make_existing_atom</c>.</item> - <item>Module argument added to <c>enif_open_resource_type</c> - while changing name spaces of resource types from global to module local.</item> - </list> - </item> - <item>Incompatible changes between <em>R13B04</em> and R13B03: - <list> - <item>The function prototypes of the NIFs have changed to expect <c>argc</c> and <c>argv</c> - arguments. The arity of a NIF is by that no longer limited to 3.</item> - <item><c>enif_get_data</c> renamed as <c>enif_priv_data</c>.</item> - <item><c>enif_make_string</c> got a third argument for character encoding.</item> - </list> - </item> - </list> - <p>A minimal example of a NIF library can look like this:</p> <p/> <code type="none"> @@ -489,8 +462,9 @@ ok independent environment with all its terms is valid until you explicitly invalidates it with <seealso marker="#enif_free_env">enif_free_env</seealso> or <c>enif_send</c>.</p> - <p>All elements of a list/tuple must belong to the same environment as the - list/tuple itself. Terms can be copied between environments with + <p>All contained terms of a list/tuple/map must belong to the same + environment as the list/tuple/map itself. Terms can be copied between + environments with <seealso marker="#enif_make_copy">enif_make_copy</seealso>.</p> </item> <tag><marker id="ErlNifFunc"/>ErlNifFunc</tag> @@ -592,11 +566,11 @@ typedef enum { <funcs> <func><name><ret>void *</ret><nametext>enif_alloc(size_t size)</nametext></name> - <fsummary>Allocate dynamic memory.</fsummary> + <fsummary>Allocate dynamic memory</fsummary> <desc><p>Allocate memory of <c>size</c> bytes. Return NULL if allocation failed.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_alloc_binary(size_t size, ErlNifBinary* bin)</nametext></name> - <fsummary>Create a new binary.</fsummary> + <fsummary>Create a new binary</fsummary> <desc><p>Allocate a new binary of size <c>size</c> bytes. Initialize the structure pointed to by <c>bin</c> to refer to the allocated binary. The binary must either be released by @@ -623,7 +597,7 @@ typedef enum { <desc><p>Allocate a memory managed resource object of type <c>type</c> and size <c>size</c> bytes.</p></desc> </func> <func><name><ret>void</ret><nametext>enif_clear_env(ErlNifEnv* env)</nametext></name> - <fsummary>Clear an environment for reuse.</fsummary> + <fsummary>Clear an environment for reuse</fsummary> <desc><p>Free all terms in an environment and clear it for reuse. The environment must have been allocated with <seealso marker="#enif_alloc_env">enif_alloc_env</seealso>. </p></desc> @@ -711,14 +685,14 @@ typedef enum { <c>size-1</c>.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_get_atom_length(ErlNifEnv* env, ERL_NIF_TERM term, unsigned* len, ErlNifCharEncoding encode)</nametext></name> - <fsummary>Get the length of atom <c>term</c>.</fsummary> + <fsummary>Get the length of atom <c>term</c></fsummary> <desc><p>Set <c>*len</c> to the length (number of bytes excluding terminating null character) of the atom <c>term</c> with encoding <c>encode</c>. Return true on success or false if <c>term</c> is not an atom.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_get_double(ErlNifEnv* env, ERL_NIF_TERM term, double* dp)</nametext></name> - <fsummary>Read a floating-point number term.</fsummary> + <fsummary>Read a floating-point number term</fsummary> <desc><p>Set <c>*dp</c> to the floating point value of <c>term</c>. Return true on success or false if <c>term</c> is not a float.</p></desc> </func> @@ -747,17 +721,28 @@ typedef enum { non-empty list.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_get_list_length(ErlNifEnv* env, ERL_NIF_TERM term, unsigned* len)</nametext></name> - <fsummary>Get the length of list <c>term</c>.</fsummary> + <fsummary>Get the length of list <c>term</c></fsummary> <desc><p>Set <c>*len</c> to the length of list <c>term</c> and return true, or return false if <c>term</c> is not a list.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_get_long(ErlNifEnv* env, ERL_NIF_TERM term, long int* ip)</nametext></name> - <fsummary>Read an long integer term.</fsummary> + <fsummary>Read an long integer term</fsummary> <desc><p>Set <c>*ip</c> to the long integer value of <c>term</c> and return true, or return false if <c>term</c> is not an integer or is outside the bounds of type <c>long int</c>.</p></desc> </func> - <func><name><ret>int</ret><nametext>enif_get_resource(ErlNifEnv* env, ERL_NIF_TERM term, ErlNifResourceType* type, void** objp)</nametext></name> + <func><name><ret>int</ret><nametext>enif_get_map_size(ErlNifEnv* env, ERL_NIF_TERM term, size_t *size)</nametext></name> + <fsummary>Read the size of a map term</fsummary> + <desc><p>Set <c>*size</c> to the number of key-value pairs in the map <c>term</c> and + return true, or return false if <c>term</c> is not a map.</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_get_map_value(ErlNifEnv* env, ERL_NIF_TERM map, ERL_NIF_TERM key, ERL_NIF_TERM* value)</nametext></name> + <fsummary>Get the value of a key in a map</fsummary> + <desc><p>Set <c>*value</c> to the value associated with <c>key</c> in the + map <c>map</c> and return true. Return false if <c>map</c> is not a map + or if <c>map</c> does not contain <c>key</c>.</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_get_resource(ErlNifEnv* env, ERL_NIF_TERM term, ErlNifResourceType* type, void** objp)</nametext></name> <fsummary>Get the pointer to a resource object</fsummary> <desc><p>Set <c>*objp</c> to point to the resource object referred to by <c>term</c>.</p> <p>Return true on success or false if <c>term</c> is not a handle to a resource object @@ -766,7 +751,7 @@ typedef enum { <func><name><ret>int</ret><nametext>enif_get_string(ErlNifEnv* env, ERL_NIF_TERM list, char* buf, unsigned size, ErlNifCharEncoding encode)</nametext></name> - <fsummary>Get a C-string from a list.</fsummary> + <fsummary>Get a C-string from a list</fsummary> <desc><p>Write a null-terminated string, in the buffer pointed to by <c>buf</c> with size <c>size</c>, consisting of the characters in the string <c>list</c>. The characters are written using encoding @@ -779,7 +764,7 @@ typedef enum { <c>size</c> is less than 1.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_get_tuple(ErlNifEnv* env, ERL_NIF_TERM term, int* arity, const ERL_NIF_TERM** array)</nametext></name> - <fsummary>Inspect the elements of a tuple.</fsummary> + <fsummary>Inspect the elements of a tuple</fsummary> <desc><p>If <c>term</c> is a tuple, set <c>*array</c> to point to an array containing the elements of the tuple and set <c>*arity</c> to the number of elements. Note that the array @@ -789,23 +774,40 @@ typedef enum { tuple.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_get_uint(ErlNifEnv* env, ERL_NIF_TERM term, unsigned int* ip)</nametext></name> - <fsummary>Read an unsigned integer term.</fsummary> + <fsummary>Read an unsigned integer term</fsummary> <desc><p>Set <c>*ip</c> to the unsigned integer value of <c>term</c> and return true, or return false if <c>term</c> is not an unsigned integer or is outside the bounds of type <c>unsigned int</c>.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_get_uint64(ErlNifEnv* env, ERL_NIF_TERM term, ErlNifUInt64* ip)</nametext></name> - <fsummary>Read an unsigned 64-bit integer term.</fsummary> + <fsummary>Read an unsigned 64-bit integer term</fsummary> <desc><p>Set <c>*ip</c> to the unsigned integer value of <c>term</c> and return true, or return false if <c>term</c> is not an unsigned integer or is outside the bounds of an unsigned 64-bit integer.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_get_ulong(ErlNifEnv* env, ERL_NIF_TERM term, unsigned long* ip)</nametext></name> - <fsummary>Read an unsigned integer term.</fsummary> + <fsummary>Read an unsigned integer term</fsummary> <desc><p>Set <c>*ip</c> to the unsigned long integer value of <c>term</c> and return true, or return false if <c>term</c> is not an unsigned integer or is outside the bounds of type <c>unsigned long</c>.</p></desc> </func> + <func><name><ret>int</ret><nametext>enif_getenv(const char* key, char* value, size_t *value_size)</nametext></name> + <fsummary>Get the value of an environment variable</fsummary> + <desc><p>Same as <seealso marker="erl_driver#erl_drv_getenv">erl_drv_getenv</seealso>.</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_has_pending_exception(ErlNifEnv* env, ERL_NIF_TERM* reason)</nametext></name> + <fsummary>Check if an exception has been raised</fsummary> + <desc><p>Return true if a pending exception is associated + with the environment <c>env</c>. If <c>reason</c> is a null pointer, ignore it. + Otherwise, if there's a pending exception associated with <c>env</c>, set the ERL_NIF_TERM + to which <c>reason</c> points to the value of the exception's term. For example, if + <seealso marker="#enif_make_badarg">enif_make_badarg</seealso> is called to set a + pending <c>badarg</c> exception, a subsequent call to <c>enif_has_pending_exception(env, &reason)</c> + will set <c>reason</c> to the atom <c>badarg</c>, then return true.</p> + <p>See also: <seealso marker="#enif_make_badarg">enif_make_badarg</seealso> + and <seealso marker="#enif_raise_exception">enif_raise_exception</seealso>.</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> <desc><p>Initialize the structure pointed to by <c>bin</c> with @@ -835,9 +837,14 @@ typedef enum { <fsummary>Determine if a term is an empty list</fsummary> <desc><p>Return true if <c>term</c> is an empty list.</p></desc> </func> - <marker id="enif_is_exception"/><func><name><ret>int</ret><nametext>enif_is_exception(ErlNifEnv* env, ERL_NIF_TERM term)</nametext></name> + <func><name><ret>int</ret><nametext>enif_is_exception(ErlNifEnv* env, ERL_NIF_TERM term)</nametext></name> <fsummary>Determine if a term is an exception</fsummary> - <desc><p>Return true if <c>term</c> is an exception.</p></desc> + <desc><marker id="enif_is_exception"/> + <p>Return true if <c>term</c> is an exception.</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_is_map(ErlNifEnv* env, ERL_NIF_TERM term)</nametext></name> + <fsummary>Determine if a term is a map</fsummary> + <desc><p>Return true if <c>term</c> is a map, false otherwise.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_is_number(ErlNifEnv* env, ERL_NIF_TERM term)</nametext></name> <fsummary>Determine if a term is a number (integer or float)</fsummary> @@ -898,40 +905,58 @@ typedef enum { <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_atom(ErlNifEnv* env, const char* name)</nametext></name> <fsummary>Create an atom term</fsummary> <desc><p>Create an atom term from the null-terminated C-string <c>name</c> - with iso-latin-1 encoding.</p></desc> + with iso-latin-1 encoding. If the length of <c>name</c> exceeds the maximum length + allowed for an atom (255 characters), <c>enif_make_atom</c> invokes + <seealso marker="#enif_make_badarg">enif_make_badarg</seealso>. + </p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_atom_len(ErlNifEnv* env, const char* name, size_t len)</nametext></name> <fsummary>Create an atom term</fsummary> <desc><p>Create an atom term from the string <c>name</c> with length <c>len</c>. - Null-characters are treated as any other characters.</p></desc> + Null-characters are treated as any other characters. If <c>len</c> is greater than the maximum length + allowed for an atom (255 characters), <c>enif_make_atom</c> invokes + <seealso marker="#enif_make_badarg">enif_make_badarg</seealso>. + </p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_badarg(ErlNifEnv* env)</nametext></name> - <fsummary>Make a badarg exception.</fsummary> - <desc><p>Make a badarg exception to be returned from a NIF, and set - an associated exception reason in <c>env</c>. If - <c>enif_make_badarg</c> is called, the term it returns <em>must</em> - be returned from the function that called it. No other return value - is allowed. Also, the term returned from <c>enif_make_badarg</c> may - be passed only to - <seealso marker="#enif_is_exception">enif_is_exception</seealso> and - not to any other NIF API function.</p></desc> + <fsummary>Make a badarg exception</fsummary> + <desc><p>Make a badarg exception to be returned from a NIF, and associate + it with the environment <c>env</c>. Once a NIF or any function + it calls invokes <c>enif_make_badarg</c>, the runtime ensures that a + <c>badarg</c> exception is raised when the NIF returns, even if the NIF + attempts to return a non-exception term instead. + The return value from <c>enif_make_badarg</c> may be used only as the + return value from the NIF that invoked it (directly or indirectly) + or be passed to + <seealso marker="#enif_is_exception">enif_is_exception</seealso>, but + not to any other NIF API function.</p> + <p>See also: <seealso marker="#enif_has_pending_exception">enif_has_pending_exception</seealso> + and <seealso marker="#enif_raise_exception">enif_raise_exception</seealso> + </p> + <note><p>In earlier versions (older than erts-7.0, OTP 18) the return value + from <c>enif_make_badarg</c> had to be returned from the NIF. This + requirement is now lifted as the return value from the NIF is ignored + if <c>enif_make_badarg</c> has been invoked.</p></note></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_binary(ErlNifEnv* env, ErlNifBinary* bin)</nametext></name> - <fsummary>Make a binary term.</fsummary> + <fsummary>Make a binary term</fsummary> <desc><p>Make a binary term from <c>bin</c>. Any ownership of the binary data will be transferred to the created term and <c>bin</c> should be considered read-only for the rest of the NIF call and then as released.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_copy(ErlNifEnv* dst_env, ERL_NIF_TERM src_term)</nametext></name> - <fsummary>Make a copy of a term.</fsummary> + <fsummary>Make a copy of a term</fsummary> <desc><p>Make a copy of term <c>src_term</c>. The copy will be created in environment <c>dst_env</c>. The source term may be located in any environment.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_double(ErlNifEnv* env, double d)</nametext></name> <fsummary>Create a floating-point term</fsummary> - <desc><p>Create a floating-point term from a <c>double</c>.</p></desc> + <desc><p>Create a floating-point term from a <c>double</c>. If the <c>double</c> argument is + not finite or is NaN, <c>enif_make_double</c> invokes + <seealso marker="#enif_make_badarg">enif_make_badarg</seealso>. + </p></desc> </func> <func><name><ret>int</ret><nametext>enif_make_existing_atom(ErlNifEnv* env, const char* name, ERL_NIF_TERM* atom, ErlNifCharEncoding encode)</nametext></name> <fsummary>Create an existing atom term</fsummary> @@ -939,7 +964,9 @@ typedef enum { the null-terminated C-string <c>name</c> with encoding <seealso marker="#ErlNifCharEncoding">encode</seealso>. If the atom already exists store the term in <c>*atom</c> and return true, otherwise - return false.</p></desc> + return false. If the length of <c>name</c> exceeds the maximum length + allowed for an atom (255 characters), <c>enif_make_existing_atom</c> + returns false.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_make_existing_atom_len(ErlNifEnv* env, const char* name, size_t len, ERL_NIF_TERM* atom, ErlNifCharEncoding encoding)</nametext></name> <fsummary>Create an existing atom term</fsummary> @@ -947,7 +974,9 @@ typedef enum { string <c>name</c> with length <c>len</c> and encoding <seealso marker="#ErlNifCharEncoding">encode</seealso>. Null-characters are treated as any other characters. If the atom already exists store the term - in <c>*atom</c> and return true, otherwise return false.</p></desc> + in <c>*atom</c> and return true, otherwise return false. If <c>len</c> is greater + than the maximum length allowed for an atom (255 characters), + <c>enif_make_existing_atom_len</c> returns false.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_int(ErlNifEnv* env, int i)</nametext></name> <fsummary>Create an integer term</fsummary> @@ -958,7 +987,7 @@ typedef enum { <desc><p>Create an integer term from a signed 64-bit integer.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list(ErlNifEnv* env, unsigned cnt, ...)</nametext></name> - <fsummary>Create a list term.</fsummary> + <fsummary>Create a list term</fsummary> <desc><p>Create an ordinary list term of length <c>cnt</c>. Expects <c>cnt</c> number of arguments (after <c>cnt</c>) of type ERL_NIF_TERM as the elements of the list. An empty list is returned if <c>cnt</c> is 0.</p></desc> @@ -972,28 +1001,21 @@ typedef enum { <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list7(ErlNifEnv* env, ERL_NIF_TERM e1, ..., ERL_NIF_TERM e7)</nametext></name> <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list8(ErlNifEnv* env, ERL_NIF_TERM e1, ..., ERL_NIF_TERM e8)</nametext></name> <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list9(ErlNifEnv* env, ERL_NIF_TERM e1, ..., ERL_NIF_TERM e9)</nametext></name> - <fsummary>Create a list term.</fsummary> + <fsummary>Create a list term</fsummary> <desc><p>Create an ordinary list term with length indicated by the function name. Prefer these functions (macros) over the variadic <c>enif_make_list</c> to get a compile time error if the number of arguments does not match.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list_cell(ErlNifEnv* env, ERL_NIF_TERM head, ERL_NIF_TERM tail)</nametext></name> - <fsummary>Create a list cell.</fsummary> + <fsummary>Create a list cell</fsummary> <desc><p>Create a list cell <c>[head | tail]</c>.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_list_from_array(ErlNifEnv* env, const ERL_NIF_TERM arr[], unsigned cnt)</nametext></name> - <fsummary>Create a list term from an array.</fsummary> + <fsummary>Create a list term from an array</fsummary> <desc><p>Create an ordinary list containing the elements of array <c>arr</c> of length <c>cnt</c>. An empty list is returned if <c>cnt</c> is 0.</p></desc> </func> - <func><name><ret>int</ret><nametext>enif_make_reverse_list(ErlNifEnv* env, ERL_NIF_TERM term, ERL_NIF_TERM *list)</nametext></name> - <fsummary>Create the reverse list of the list <c>term</c>.</fsummary> - <desc><p>Set <c>*list</c> to the reverse list of the list <c>term</c> and return true, - or return false if <c>term</c> is not a list. This function should only be used on - short lists as a copy will be created of the list which will not be released until after the - nif returns.</p></desc> - </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_long(ErlNifEnv* env, long int i)</nametext></name> <fsummary>Create an integer term from a long int</fsummary> <desc><p>Create an integer term from a <c>long int</c>.</p></desc> @@ -1008,12 +1030,42 @@ typedef enum { reallocated.</p><p>Return a pointer to the raw binary data and set <c>*termp</c> to the binary term.</p></desc> </func> + <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_new_map(ErlNifEnv* env)</nametext></name> + <fsummary>Make an empty map term</fsummary> + <desc><p>Make an empty map term.</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_make_map_put(ErlNifEnv* env, ERL_NIF_TERM map_in, ERL_NIF_TERM key, ERL_NIF_TERM value, ERL_NIF_TERM* map_out)</nametext></name> + <fsummary>Insert key-value pair in map</fsummary> + <desc><p>Make a copy of map <c>map_in</c> and insert <c>key</c> with + <c>value</c>. If <c>key</c> already exists in <c>map_in</c>, the old + associated value is replaced by <c>value</c>. If successful set + <c>*map_out</c> to the new map and return true. Return false if + <c>map_in</c> is not a map.</p> + <p>The <c>map_in</c> term must belong to the environment <c>env</c>.</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_make_map_update(ErlNifEnv* env, ERL_NIF_TERM map_in, ERL_NIF_TERM key, ERL_NIF_TERM new_value, ERL_NIF_TERM* map_out)</nametext></name> + <fsummary>Replace value for key in map</fsummary> + <desc><p>Make a copy of map <c>map_in</c> and replace the old associated + value for <c>key</c> with <c>new_value</c>. If successful set + <c>*map_out</c> to the new map and return true. Return false if + <c>map_in</c> is not a map or if it does no contain <c>key</c>.</p> + <p>The <c>map_in</c> term must belong to the environment <c>env</c>.</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_make_map_remove(ErlNifEnv* env, ERL_NIF_TERM map_in, ERL_NIF_TERM key, ERL_NIF_TERM* map_out)</nametext></name> + <fsummary>Remove key from map</fsummary> + <desc><p>If map <c>map_in</c> contains <c>key</c>, make a copy of + <c>map_in</c> in <c>*map_out</c> and remove <c>key</c> and associated + value. If map <c>map_in</c> does not contain <c>key</c>, set + <c>*map_out</c> to <c>map_in</c>. Return true for success or false if + <c>map_in</c> is not a map.</p> + <p>The <c>map_in</c> term must belong to the environment <c>env</c>.</p></desc> + </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_pid(ErlNifEnv* env, const ErlNifPid* pid)</nametext></name> <fsummary>Make a pid term</fsummary> <desc><p>Make a pid term from <c>*pid</c>.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_ref(ErlNifEnv* env)</nametext></name> - <fsummary>Create a reference.</fsummary> + <fsummary>Create a reference</fsummary> <desc><p>Create a reference like <seealso marker="erlang#make_ref-0">erlang:make_ref/0</seealso>.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_resource(ErlNifEnv* env, void* obj)</nametext></name> @@ -1051,20 +1103,28 @@ typedef enum { <seealso marker="#enif_release_resource">enif_release_resource</seealso>.</p> </desc> </func> + <func><name><ret>int</ret><nametext>enif_make_reverse_list(ErlNifEnv* env, ERL_NIF_TERM list_in, ERL_NIF_TERM *list_out)</nametext></name> + <fsummary>Create the reverse of a list</fsummary> + <desc><p>Set <c>*list_out</c> to the reverse list of the list <c>list_in</c> and return true, + or return false if <c>list_in</c> is not a list. This function should only be used on + short lists as a copy will be created of the list which will not be released until after the + nif returns.</p> + <p>The <c>list_in</c> term must belong to the environment <c>env</c>.</p></desc> + </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_string(ErlNifEnv* env, const char* string, ErlNifCharEncoding encoding)</nametext></name> - <fsummary>Create a string.</fsummary> + <fsummary>Create a string</fsummary> <desc><p>Create a list containing the characters of the null-terminated string <c>string</c> with encoding <seealso marker="#ErlNifCharEncoding">encoding</seealso>.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_string_len(ErlNifEnv* env, const char* string, size_t len, ErlNifCharEncoding encoding)</nametext></name> - <fsummary>Create a string.</fsummary> + <fsummary>Create a string</fsummary> <desc><p>Create a list containing the characters of the string <c>string</c> with length <c>len</c> and encoding <seealso marker="#ErlNifCharEncoding">encoding</seealso>. Null-characters are treated as any other characters.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_sub_binary(ErlNifEnv* env, ERL_NIF_TERM bin_term, size_t pos, size_t size)</nametext></name> - <fsummary>Make a subbinary term.</fsummary> + <fsummary>Make a subbinary term</fsummary> <desc><p>Make a subbinary of binary <c>bin_term</c>, starting at zero-based position <c>pos</c> with a length of <c>size</c> bytes. <c>bin_term</c> must be a binary or bitstring and @@ -1072,7 +1132,7 @@ typedef enum { bytes in <c>bin_term</c>.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple(ErlNifEnv* env, unsigned cnt, ...)</nametext></name> - <fsummary>Create a tuple term.</fsummary> + <fsummary>Create a tuple term</fsummary> <desc><p>Create a tuple term of arity <c>cnt</c>. Expects <c>cnt</c> number of arguments (after <c>cnt</c>) of type ERL_NIF_TERM as the elements of the tuple.</p></desc> @@ -1086,14 +1146,14 @@ typedef enum { <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple7(ErlNifEnv* env, ERL_NIF_TERM e1, ..., ERL_NIF_TERM e7)</nametext></name> <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple8(ErlNifEnv* env, ERL_NIF_TERM e1, ..., ERL_NIF_TERM e8)</nametext></name> <name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple9(ErlNifEnv* env, ERL_NIF_TERM e1, ..., ERL_NIF_TERM e9)</nametext></name> - <fsummary>Create a tuple term.</fsummary> + <fsummary>Create a tuple term</fsummary> <desc><p>Create a tuple term with length indicated by the function name. Prefer these functions (macros) over the variadic <c>enif_make_tuple</c> to get a compile time error if the number of arguments does not match.</p></desc> </func> <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_make_tuple_from_array(ErlNifEnv* env, const ERL_NIF_TERM arr[], unsigned cnt)</nametext></name> - <fsummary>Create a tuple term from an array.</fsummary> + <fsummary>Create a tuple term from an array</fsummary> <desc><p>Create a tuple containing the elements of array <c>arr</c> of length <c>cnt</c>.</p></desc> </func> @@ -1109,6 +1169,72 @@ typedef enum { <fsummary>Create an integer term from an unsigned long int</fsummary> <desc><p>Create an integer term from an <c>unsigned long int</c>.</p></desc> </func> + <func><name><ret>int</ret><nametext>enif_map_iterator_create(ErlNifEnv *env, ERL_NIF_TERM map, ErlNifMapIterator *iter, ErlNifMapIteratorEntry entry)</nametext></name> + <fsummary>Create a map iterator</fsummary> + <desc><p>Create an iterator for the map <c>map</c> by initializing the + structure pointed to by <c>iter</c>. The <c>entry</c> argument determines + the start position of the iterator: <c>ERL_NIF_MAP_ITERATOR_FIRST</c> or + <c>ERL_NIF_MAP_ITERATOR_LAST</c>. Return true on success or false if + <c>map</c> is not a map.</p> + <p>A map iterator is only useful during the lifetime of the environment + <c>env</c> that the <c>map</c> belongs to. The iterator must be destroyed by + calling <seealso marker="#enif_map_iterator_destroy"> + enif_map_iterator_destroy</seealso>.</p> + <code type="none"> +ERL_NIF_TERM key, value; +ErlNifMapIterator iter; +enif_map_iterator_create(env, my_map, &iter, ERL_NIF_MAP_ITERATOR_FIRST); + +while (enif_map_iterator_get_pair(env, &iter, &key, &value)) { + do_something(key,value); + enif_map_iterator_next(env, &iter); +} +enif_map_iterator_destroy(env, &iter); + </code> + <note><p>The key-value pairs of a map have no defined iteration + order. The only guarantee is that the iteration order of a single map + instance is preserved during the lifetime of the environment that the map + belongs to.</p> + </note> + </desc> + </func> + <func><name><ret>void</ret><nametext>enif_map_iterator_destroy(ErlNifEnv *env, ErlNifMapIterator *iter)</nametext></name> + <fsummary>Destroy a map iterator</fsummary> + <desc><p>Destroy a map iterator created by + <seealso marker="#enif_map_iterator_create">enif_map_iterator_create</seealso>. + </p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_map_iterator_get_pair(ErlNifEnv *env, ErlNifMapIterator *iter, ERL_NIF_TERM *key, ERL_NIF_TERM *value)</nametext></name> + <fsummary>Get key and value at current map iterator position</fsummary> + <desc><p>Get key and value terms at current map iterator position. + On success set <c>*key</c> and <c>*value</c> and return true. + Return false if the iterator is positioned at head (before first entry) + or tail (beyond last entry).</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_map_iterator_is_head(ErlNifEnv *env, ErlNifMapIterator *iter)</nametext></name> + <fsummary>Check if map iterator is positioned before first</fsummary> + <desc><p>Return true if map iterator <c>iter</c> is positioned + before first entry.</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_map_iterator_is_tail(ErlNifEnv *env, ErlNifMapIterator *iter)</nametext></name> + <fsummary>Check if map iterator is positioned after last</fsummary> + <desc><p>Return true if map iterator <c>iter</c> is positioned + after last entry.</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_map_iterator_next(ErlNifEnv *env, ErlNifMapIterator *iter)</nametext></name> + <fsummary>Increment map iterator to point to next entry</fsummary> + <desc><p>Increment map iterator to point to next key-value entry. + Return true if the iterator is now positioned at a valid key-value entry, + or false if the iterator is positioned at the tail (beyond the last + entry).</p></desc> + </func> + <func><name><ret>int</ret><nametext>enif_map_iterator_prev(ErlNifEnv *env, ErlNifMapIterator *iter)</nametext></name> + <fsummary>Decrement map iterator to point to previous entry</fsummary> + <desc><p>Decrement map iterator to point to previous key-value entry. + Return true if the iterator is now positioned at a valid key-value entry, + or false if the iterator is positioned at the head (before the first + entry).</p></desc> + </func> <func><name><ret>ErlNifMutex *</ret><nametext>enif_mutex_create(char *name)</nametext></name> <fsummary></fsummary> <desc><p>Same as <seealso marker="erl_driver#erl_drv_mutex_create">erl_drv_mutex_create</seealso>. @@ -1169,19 +1295,32 @@ typedef enum { <c>reload</c> or <c>upgrade</c>.</p> <p>Was previously named <c>enif_get_data</c>.</p></desc> </func> + <func><name><ret>ERL_NIF_TERM</ret><nametext>enif_raise_exception(ErlNifEnv* env, ERL_NIF_TERM reason)</nametext></name> + <fsummary>Raise a NIF error exception</fsummary> + <desc><p>Create an error exception with the term <c>reason</c> to be returned from a NIF, + and associate it with the environment <c>env</c>. Once a NIF or any function it calls + invokes <c>enif_raise_exception</c>, the runtime ensures that the exception it creates + is raised when the NIF returns, even if the NIF attempts to return a non-exception + term instead. The return value from <c>enif_raise_exception</c> may be used only as + the return value from the NIF that invoked it (directly or indirectly) or be passed + to <seealso marker="#enif_is_exception">enif_is_exception</seealso>, but + not to any other NIF API function.</p> + <p>See also: <seealso marker="#enif_has_pending_exception">enif_has_pending_exception</seealso> + and <seealso marker="#enif_make_badarg">enif_make_badarg</seealso>.</p></desc> + </func> <func><name><ret>int</ret><nametext>enif_realloc_binary(ErlNifBinary* bin, size_t size)</nametext></name> - <fsummary>Change the size of a binary.</fsummary> + <fsummary>Change the size of a binary</fsummary> <desc><p>Change the size of a binary <c>bin</c>. The source binary may be read-only, in which case it will be left untouched and a mutable copy is allocated and assigned to <c>*bin</c>. Return true on success, false if memory allocation failed.</p></desc> </func> <func><name><ret>void</ret><nametext>enif_release_binary(ErlNifBinary* bin)</nametext></name> - <fsummary>Release a binary.</fsummary> + <fsummary>Release a binary</fsummary> <desc><p>Release a binary obtained from <c>enif_alloc_binary</c>.</p></desc> </func> <func><name><ret>void</ret><nametext>enif_release_resource(void* obj)</nametext></name> - <fsummary>Release a resource object.</fsummary> + <fsummary>Release a resource object</fsummary> <desc><p>Remove a reference to resource object <c>obj</c>obtained from <seealso marker="#enif_alloc_resource">enif_alloc_resource</seealso>. The resource object will be destructed when the last reference is removed. @@ -1257,12 +1396,12 @@ typedef enum { </desc> </func> <func><name><ret>ErlNifPid *</ret><nametext>enif_self(ErlNifEnv* caller_env, ErlNifPid* pid)</nametext></name> - <fsummary>Get the pid of the calling process.</fsummary> + <fsummary>Get the pid of the calling process</fsummary> <desc><p>Initialize the pid variable <c>*pid</c> to represent the calling process. Return <c>pid</c>.</p></desc> </func> <func><name><ret>int</ret><nametext>enif_send(ErlNifEnv* env, ErlNifPid* to_pid, ErlNifEnv* msg_env, ERL_NIF_TERM msg)</nametext></name> - <fsummary>Send a message to a process.</fsummary> + <fsummary>Send a message to a process</fsummary> <desc><p>Send a message to a process.</p> <taglist> <tag><c>env</c></tag> |