diff options
Diffstat (limited to 'lib/erl_interface/doc/src/ei.xml')
| -rw-r--r-- | lib/erl_interface/doc/src/ei.xml | 329 |
1 files changed, 215 insertions, 114 deletions
diff --git a/lib/erl_interface/doc/src/ei.xml b/lib/erl_interface/doc/src/ei.xml index 9502fb1ee7..70af5642da 100644 --- a/lib/erl_interface/doc/src/ei.xml +++ b/lib/erl_interface/doc/src/ei.xml @@ -35,6 +35,9 @@ <lib>ei</lib> <libsummary>Routines for handling the Erlang binary term format.</libsummary> <description> + <note><p>The support for VxWorks is deprecated as of OTP 22, and + will be removed in OTP 23.</p></note> + <p>The library <c>ei</c> contains macros and functions to encode and decode the Erlang binary term format.</p> @@ -124,7 +127,7 @@ typedef enum { <funcs> <func> - <name><ret>int</ret><nametext>ei_decode_atom(const char *buf, int *index, char *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_atom(const char *buf, int *index, char *p)</nametext></name> <fsummary>Decode an atom.</fsummary> <desc> <p>Decodes an atom from the binary format. The <c>NULL</c>-terminated @@ -134,7 +137,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_atom_as(const char *buf, int *index, char *p, int plen, erlang_char_encoding want, erlang_char_encoding* was, erlang_char_encoding* result)</nametext></name> + <name since="OTP R16B"><ret>int</ret><nametext>ei_decode_atom_as(const char *buf, int *index, char *p, int plen, erlang_char_encoding want, erlang_char_encoding* was, erlang_char_encoding* result)</nametext></name> <fsummary>Decode an atom.</fsummary> <desc> <p>Decodes an atom from the binary format. The <c>NULL</c>-terminated @@ -158,7 +161,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_bignum(const char *buf, int *index, mpz_t obj)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_bignum(const char *buf, int *index, mpz_t obj)</nametext></name> <fsummary>Decode a GMP arbitrary precision integer.</fsummary> <desc> <p>Decodes an integer in the binary format to a GMP @@ -168,7 +171,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_binary(const char *buf, int *index, void *p, long *len)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_binary(const char *buf, int *index, void *p, long *len)</nametext></name> <fsummary>Decode a binary.</fsummary> <desc> <p>Decodes a binary from the binary format. Parameter @@ -180,7 +183,44 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_boolean(const char *buf, int *index, int *p)</nametext></name> + <name since="OTP 22.0"><ret>int</ret><nametext>ei_decode_bitstring(const char *buf, int *index, const char **pp, unsigned int *bitoffsp, size_t *nbitsp)</nametext></name> + <fsummary>Decode a bitstring.</fsummary> + <desc> + <p>Decodes a bit string from the binary format.</p> + <taglist> + <tag><c>pp</c></tag> + <item><p>Either <c>NULL</c> or <c>*pp</c> returns a pointer to + the first byte of the bit string. The returned bit string is + readable as long as the buffer pointed to by <c>buf</c> is + readable and not written to.</p> + </item> + <tag><c>bitoffsp</c></tag> + <item><p>Either <c>NULL</c> or <c>*bitoffsp</c> returns the + number of unused bits in the first byte pointed to by + <c>*pp</c>. The value of <c>*bitoffsp</c> is between 0 and 7. + Unused bits in the first byte are the most significant bits.</p> + </item> + <tag><c>nbitsp</c></tag> + <item><p>Either <c>NULL</c> or <c>*nbitsp</c> returns the length + of the bit string in <em>bits</em>.</p> + </item> + </taglist> + <p>Returns <c>0</c> if it was a bit string term.</p> + <p>The number of <em>bytes</em> pointed to by <c>*pp</c>, which are + part of the bit string, is <c>(*bitoffsp + *nbitsp + 7)/8</c>. If + <c>(*bitoffsp + *bitsp)%8 > 0</c> then only <c>(*bitoffsp + + *bitsp)%8</c> bits of the last byte are used. Unused bits in + the last byte are the least significant bits.</p> + <p>The values of unused bits in the first and last byte are undefined + and cannot be relied on.</p> + <p>Number of bits may be divisible by 8, which means a binary + decodable by <c>ei_decode_binary</c> is also decodable by + <c>ei_decode_bitstring</c>.</p> + </desc> + </func> + + <func> + <name since=""><ret>int</ret><nametext>ei_decode_boolean(const char *buf, int *index, int *p)</nametext></name> <fsummary>Decode a boolean.</fsummary> <desc> <p>Decodes a boolean value from the binary format. @@ -190,7 +230,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_char(const char *buf, int *index, char *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_char(const char *buf, int *index, char *p)</nametext></name> <fsummary>Decode an 8-bit integer between 0-255.</fsummary> <desc> <p>Decodes a char (8-bit) integer between 0-255 from the binary format. @@ -203,7 +243,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_double(const char *buf, int *index, double *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_double(const char *buf, int *index, double *p)</nametext></name> <fsummary>Decode a double.</fsummary> <desc> <p>Decodes a double-precision (64-bit) floating @@ -212,7 +252,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_ei_term(const char* buf, int* index, ei_term* term)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_ei_term(const char* buf, int* index, ei_term* term)</nametext></name> <fsummary>Decode a term, without previous knowledge of type.</fsummary> <desc> <p>Decodes any term, or at least tries to. If the term @@ -233,8 +273,8 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_fun(const char *buf, int *index, erlang_fun *p)</nametext></name> - <name><ret>void</ret><nametext>free_fun(erlang_fun* f)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_fun(const char *buf, int *index, erlang_fun *p)</nametext></name> + <name since=""><ret>void</ret><nametext>free_fun(erlang_fun* f)</nametext></name> <fsummary>Decode a fun.</fsummary> <desc> <p>Decodes a fun from the binary format. Parameter @@ -248,7 +288,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_list_header(const char *buf, int *index, int *arity)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_list_header(const char *buf, int *index, int *arity)</nametext></name> <fsummary>Decode a list.</fsummary> <desc> <p>Decodes a list header from the binary @@ -265,7 +305,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_long(const char *buf, int *index, long *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_long(const char *buf, int *index, long *p)</nametext></name> <fsummary>Decode integer.</fsummary> <desc> <p>Decodes a long integer from the binary format. @@ -275,7 +315,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_longlong(const char *buf, int *index, long long *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_longlong(const char *buf, int *index, long long *p)</nametext></name> <fsummary>Decode integer.</fsummary> <desc> <p>Decodes a GCC <c>long long</c> or Visual C++ @@ -286,7 +326,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_map_header(const char *buf, int *index, int *arity)</nametext></name> + <name since="OTP 17.0"><ret>int</ret><nametext>ei_decode_map_header(const char *buf, int *index, int *arity)</nametext></name> <fsummary>Decode a map.</fsummary> <desc> <p>Decodes a map header from the binary @@ -299,7 +339,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_pid(const char *buf, int *index, erlang_pid *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_pid(const char *buf, int *index, erlang_pid *p)</nametext></name> <fsummary>Decode a <c>pid</c>.</fsummary> <desc> <p>Decodes a process identifier (pid) from the binary format.</p> @@ -307,7 +347,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_port(const char *buf, int *index, erlang_port *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_port(const char *buf, int *index, erlang_port *p)</nametext></name> <fsummary>Decode a port.</fsummary> <desc> <p>Decodes a port identifier from the binary format.</p> @@ -315,7 +355,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_ref(const char *buf, int *index, erlang_ref *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_ref(const char *buf, int *index, erlang_ref *p)</nametext></name> <fsummary>Decode a reference.</fsummary> <desc> <p>Decodes a reference from the binary format.</p> @@ -323,7 +363,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_string(const char *buf, int *index, char *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_string(const char *buf, int *index, char *p)</nametext></name> <fsummary>Decode a string.</fsummary> <desc> <p>Decodes a string from the binary format. A @@ -338,7 +378,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_term(const char *buf, int *index, void *t)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_term(const char *buf, int *index, void *t)</nametext></name> <fsummary>Decode a <c>ETERM</c>.</fsummary> <desc> <p>Decodes a term from the binary format. The term @@ -346,13 +386,15 @@ typedef enum { <c>t</c> is actually an <c>ETERM**</c> (see <seealso marker="erl_eterm"><c>erl_eterm</c></seealso>). The term is later to be deallocated.</p> - <p>Notice that this function is located in the <c>Erl_Interface</c> - library.</p> + <note><p>This function is deprecated as of OTP 22 and will be removed in + OTP 23 together with the old legacy <c>erl_interface</c> library (functions + with prefix <c>erl_</c>).</p> + </note> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_trace(const char *buf, int *index, erlang_trace *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_trace(const char *buf, int *index, erlang_trace *p)</nametext></name> <fsummary>Decode a trace token.</fsummary> <desc> <p>Decodes an Erlang trace token from the binary format.</p> @@ -360,7 +402,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_tuple_header(const char *buf, int *index, int *arity)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_tuple_header(const char *buf, int *index, int *arity)</nametext></name> <fsummary>Decode a tuple.</fsummary> <desc> <p>Decodes a tuple header, the number of elements @@ -370,7 +412,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_ulong(const char *buf, int *index, unsigned long *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_ulong(const char *buf, int *index, unsigned long *p)</nametext></name> <fsummary>Decode unsigned integer.</fsummary> <desc> <p>Decodes an unsigned long integer from the binary format. @@ -380,7 +422,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_ulonglong(const char *buf, int *index, unsigned long long *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_ulonglong(const char *buf, int *index, unsigned long long *p)</nametext></name> <fsummary>Decode unsigned integer.</fsummary> <desc> <p>Decodes a GCC <c>unsigned long long</c> or Visual C++ @@ -390,7 +432,7 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_decode_version(const char *buf, int *index, int *version)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_decode_version(const char *buf, int *index, int *version)</nametext></name> <fsummary>Decode an empty list (<c>nil</c>).</fsummary> <desc> <p>Decodes the version magic number for the @@ -400,10 +442,10 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_atom(char *buf, int *index, const char *p)</nametext></name> - <name><ret>int</ret><nametext>ei_encode_atom_len(char *buf, int *index, const char *p, int len)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_atom(ei_x_buff* x, const char *p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_atom_len(ei_x_buff* x, const char *p, int len)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_atom(char *buf, int *index, const char *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_atom_len(char *buf, int *index, const char *p, int len)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_atom(ei_x_buff* x, const char *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_atom_len(ei_x_buff* x, const char *p, int len)</nametext></name> <fsummary>Encode an atom.</fsummary> <desc> <p>Encodes an atom in the binary format. Parameter <c>p</c> @@ -415,10 +457,10 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_atom_as(char *buf, int *index, const char *p, erlang_char_encoding from_enc, erlang_char_encoding to_enc)</nametext></name> - <name><ret>int</ret><nametext>ei_encode_atom_len_as(char *buf, int *index, const char *p, int len, erlang_char_encoding from_enc, erlang_char_encoding to_enc)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_atom_as(ei_x_buff* x, const char *p, erlang_char_encoding from_enc, erlang_char_encoding to_enc)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_atom_len_as(ei_x_buff* x, const char *p, int len, erlang_char_encoding from_enc, erlang_char_encoding to_enc)</nametext></name> + <name since="OTP R16B"><ret>int</ret><nametext>ei_encode_atom_as(char *buf, int *index, const char *p, erlang_char_encoding from_enc, erlang_char_encoding to_enc)</nametext></name> + <name since="OTP R16B"><ret>int</ret><nametext>ei_encode_atom_len_as(char *buf, int *index, const char *p, int len, erlang_char_encoding from_enc, erlang_char_encoding to_enc)</nametext></name> + <name since="OTP R16B"><ret>int</ret><nametext>ei_x_encode_atom_as(ei_x_buff* x, const char *p, erlang_char_encoding from_enc, erlang_char_encoding to_enc)</nametext></name> + <name since="OTP R16B"><ret>int</ret><nametext>ei_x_encode_atom_len_as(ei_x_buff* x, const char *p, int len, erlang_char_encoding from_enc, erlang_char_encoding to_enc)</nametext></name> <fsummary>Encode an atom.</fsummary> <desc> <p>Encodes an atom in the binary format. Parameter <c>p</c> is the name of the atom with @@ -435,8 +477,8 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_bignum(char *buf, int *index, mpz_t obj)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_bignum(ei_x_buff *x, mpz_t obj)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_bignum(char *buf, int *index, mpz_t obj)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_bignum(ei_x_buff *x, mpz_t obj)</nametext></name> <fsummary>Encode an arbitrary precision integer.</fsummary> <desc> <p>Encodes a GMP <c>mpz_t</c> integer to binary format. @@ -446,8 +488,8 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_binary(char *buf, int *index, const void *p, long len)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_binary(ei_x_buff* x, const void *p, long len)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_binary(char *buf, int *index, const void *p, long len)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_binary(ei_x_buff* x, const void *p, long len)</nametext></name> <fsummary>Encode a binary.</fsummary> <desc> <p>Encodes a binary in the binary format. The data is at @@ -456,8 +498,30 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_boolean(char *buf, int *index, int p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_boolean(ei_x_buff* x, int p)</nametext></name> + <name since="OTP 22.0"><ret>int</ret> + <nametext>ei_encode_bitstring(char *buf, int *index, const char *p, size_t bitoffs, size_t nbits)</nametext></name> + <name since="OTP 22.0"><ret>int</ret> + <nametext>ei_x_encode_bitstring(ei_x_buff* x, const char *p, size_t bitoffs, size_t nbits)</nametext></name> + <fsummary>Encode a bitstring.</fsummary> + <desc> + <p>Encodes a bit string in the binary format.</p> + <p>The data is at <c>p</c>. The length of the bit string is <c>nbits</c> + bits. The first <c>bitoffs</c> bits of the data at <c>p</c> are unused. + The first byte which is part of the bit string is + <c>p[bitoffs/8]</c>. The <c>bitoffs%8</c> most significant bits of + the first byte <c>p[bitoffs/8]</c> are unused.</p> + <p>The number of bytes which is part of the bit string is <c>(bitoffs + + nbits + 7)/8</c>. If <c>(bitoffs + nbits)%8 > 0</c> then only <c>(bitoffs + + nbits)%8</c> bits of the last byte are used. Unused bits in + the last byte are the least significant bits.</p> + <p>The values of unused bits are disregarded and does not need to be + cleared.</p> + </desc> + </func> + + <func> + <name since=""><ret>int</ret><nametext>ei_encode_boolean(char *buf, int *index, int p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_boolean(ei_x_buff* x, int p)</nametext></name> <fsummary>Encode a boolean.</fsummary> <desc> <p>Encodes a boolean value as the atom <c>true</c> if @@ -467,8 +531,8 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_char(char *buf, int *index, char p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_char(ei_x_buff* x, char p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_char(char *buf, int *index, char p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_char(ei_x_buff* x, char p)</nametext></name> <fsummary>Encode an 8-bit integer between 0-255.</fsummary> <desc> <p>Encodes a char (8-bit) as an integer between 0-255 in the binary @@ -481,8 +545,8 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_double(char *buf, int *index, double p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_double(ei_x_buff* x, double p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_double(char *buf, int *index, double p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_double(ei_x_buff* x, double p)</nametext></name> <fsummary>Encode a double float.</fsummary> <desc> <p>Encodes a double-precision (64-bit) floating point number in @@ -493,8 +557,8 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_empty_list(char* buf, int* index)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_empty_list(ei_x_buff* x)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_empty_list(char* buf, int* index)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_empty_list(ei_x_buff* x)</nametext></name> <fsummary>Encode an empty list (<c>nil</c>).</fsummary> <desc> <p>Encodes an empty list. It is often used at the tail of a list.</p> @@ -502,8 +566,8 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_fun(char *buf, int *index, const erlang_fun *p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_fun(ei_x_buff* x, const erlang_fun* fun)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_fun(char *buf, int *index, const erlang_fun *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_fun(ei_x_buff* x, const erlang_fun* fun)</nametext></name> <fsummary>Encode a fun.</fsummary> <desc> <p>Encodes a fun in the binary format. Parameter <c>p</c> @@ -515,8 +579,8 @@ typedef enum { </func> <func> - <name><ret>int</ret><nametext>ei_encode_list_header(char *buf, int *index, int arity)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_list_header(ei_x_buff* x, int arity)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_list_header(char *buf, int *index, int arity)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_list_header(ei_x_buff* x, int arity)</nametext></name> <fsummary>Encode a list.</fsummary> <desc> <p>Encodes a list header, with a specified @@ -552,8 +616,8 @@ ei_x_encode_empty_list(&x);</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_long(char *buf, int *index, long p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_long(ei_x_buff* x, long p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_long(char *buf, int *index, long p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_long(ei_x_buff* x, long p)</nametext></name> <fsummary>Encode integer.</fsummary> <desc> <p>Encodes a long integer in the binary format. @@ -563,8 +627,8 @@ ei_x_encode_empty_list(&x);</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_longlong(char *buf, int *index, long long p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_longlong(ei_x_buff* x, long long p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_longlong(char *buf, int *index, long long p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_longlong(ei_x_buff* x, long long p)</nametext></name> <fsummary>Encode integer.</fsummary> <desc> <p>Encodes a GCC <c>long long</c> or Visual C++ @@ -574,8 +638,8 @@ ei_x_encode_empty_list(&x);</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_map_header(char *buf, int *index, int arity)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_map_header(ei_x_buff* x, int arity)</nametext></name> + <name since="OTP 17.0"><ret>int</ret><nametext>ei_encode_map_header(char *buf, int *index, int arity)</nametext></name> + <name since="OTP 17.0"><ret>int</ret><nametext>ei_x_encode_map_header(ei_x_buff* x, int arity)</nametext></name> <fsummary>Encode a map.</fsummary> <desc> <p>Encodes a map header, with a specified arity. The next @@ -595,8 +659,8 @@ ei_x_encode_string(&x, "Banana");</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_pid(char *buf, int *index, const erlang_pid *p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_pid(ei_x_buff* x, const erlang_pid *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_pid(char *buf, int *index, const erlang_pid *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_pid(ei_x_buff* x, const erlang_pid *p)</nametext></name> <fsummary>Encode a pid.</fsummary> <desc> <p>Encodes an Erlang process identifier (pid) in the binary @@ -607,8 +671,8 @@ ei_x_encode_string(&x, "Banana");</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_port(char *buf, int *index, const erlang_port *p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_port(ei_x_buff* x, const erlang_port *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_port(char *buf, int *index, const erlang_port *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_port(ei_x_buff* x, const erlang_port *p)</nametext></name> <fsummary>Encode a port.</fsummary> <desc> <p>Encodes an Erlang port in the binary format. Parameter @@ -619,8 +683,8 @@ ei_x_encode_string(&x, "Banana");</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_ref(char *buf, int *index, const erlang_ref *p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_ref(ei_x_buff* x, const erlang_ref *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_ref(char *buf, int *index, const erlang_ref *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_ref(ei_x_buff* x, const erlang_ref *p)</nametext></name> <fsummary>Encode a ref.</fsummary> <desc> <p>Encodes an Erlang reference in the binary format. Parameter @@ -631,10 +695,10 @@ ei_x_encode_string(&x, "Banana");</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_string(char *buf, int *index, const char *p)</nametext></name> - <name><ret>int</ret><nametext>ei_encode_string_len(char *buf, int *index, const char *p, int len)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_string(ei_x_buff* x, const char *p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_string_len(ei_x_buff* x, const char* s, int len)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_string(char *buf, int *index, const char *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_string_len(char *buf, int *index, const char *p, int len)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_string(ei_x_buff* x, const char *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_string_len(ei_x_buff* x, const char* s, int len)</nametext></name> <fsummary>Encode a string.</fsummary> <desc> <p>Encodes a string in the binary format. (A string in Erlang @@ -645,19 +709,23 @@ ei_x_encode_string(&x, "Banana");</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_term(char *buf, int *index, void *t)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_term(ei_x_buff* x, void *t)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_term(char *buf, int *index, void *t)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_term(ei_x_buff* x, void *t)</nametext></name> <fsummary>Encode an <c>erl_interface</c> term.</fsummary> <desc> <p>Encodes an <c>ETERM</c>, as obtained from <c>erl_interface</c>. Parameter <c>t</c> is actually an <c>ETERM</c> pointer. This function does not free the <c>ETERM</c>.</p> + <note><p>These functions are deprecated as of OTP 22 and will be removed in + OTP 23 together with the old legacy <c>erl_interface</c> library + (functions with prefix <c>erl_</c>).</p> + </note> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_encode_trace(char *buf, int *index, const erlang_trace *p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_trace(ei_x_buff* x, const erlang_trace *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_trace(char *buf, int *index, const erlang_trace *p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_trace(ei_x_buff* x, const erlang_trace *p)</nametext></name> <fsummary>Encode a trace token.</fsummary> <desc> <p>Encodes an Erlang trace token in the binary format. @@ -668,8 +736,8 @@ ei_x_encode_string(&x, "Banana");</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_tuple_header(char *buf, int *index, int arity)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_tuple_header(ei_x_buff* x, int arity)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_tuple_header(char *buf, int *index, int arity)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_tuple_header(ei_x_buff* x, int arity)</nametext></name> <fsummary>Encode a tuple.</fsummary> <desc> <p>Encodes a tuple header, with a specified @@ -687,8 +755,8 @@ ei_encode_tuple_header(buf, &i, 0);</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_ulong(char *buf, int *index, unsigned long p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_ulong(ei_x_buff* x, unsigned long p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_ulong(char *buf, int *index, unsigned long p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_ulong(ei_x_buff* x, unsigned long p)</nametext></name> <fsummary>Encode unsigned integer.</fsummary> <desc> <p>Encodes an unsigned long integer in the binary format. @@ -698,8 +766,8 @@ ei_encode_tuple_header(buf, &i, 0);</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_ulonglong(char *buf, int *index, unsigned long long p)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_ulonglong(ei_x_buff* x, unsigned long long p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_ulonglong(char *buf, int *index, unsigned long long p)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_ulonglong(ei_x_buff* x, unsigned long long p)</nametext></name> <fsummary>Encode unsigned integer.</fsummary> <desc> <p>Encodes a GCC <c>unsigned long long</c> or Visual C++ @@ -709,8 +777,8 @@ ei_encode_tuple_header(buf, &i, 0);</pre> </func> <func> - <name><ret>int</ret><nametext>ei_encode_version(char *buf, int *index)</nametext></name> - <name><ret>int</ret><nametext>ei_x_encode_version(ei_x_buff* x)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_encode_version(char *buf, int *index)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_encode_version(ei_x_buff* x)</nametext></name> <fsummary>Encode version.</fsummary> <desc> <p>Encodes a version magic number for the binary format. Must @@ -719,22 +787,37 @@ ei_encode_tuple_header(buf, &i, 0);</pre> </func> <func> - <name><ret>int</ret><nametext>ei_get_type(const char *buf, const int *index, int *type, int *size)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_get_type(const char *buf, const int *index, int *type, int *size)</nametext></name> <fsummary>Fetch the type and size of an encoded term.</fsummary> <desc> - <p>Returns the type in <c>type</c> and size in - <c>size</c> of the encoded term. For strings and atoms, + <p>Returns the type in <c>*type</c> and size in + <c>*size</c> of the encoded term. For strings and atoms, size is the number of characters <em>not</em> including the - terminating <c>NULL</c>. For binaries, <c>size</c> is the number of - bytes. For lists and tuples, <c>size</c> is the arity of - the object. For other types, <c>size</c> is 0. In all + terminating <c>NULL</c>. For binaries and bitstrings, <c>*size</c> is + the number of bytes. For lists, tuples and maps, <c>*size</c> is the + arity of the object. For other types, <c>*size</c> is 0. In all cases, <c>index</c> is left unchanged.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_print_term(FILE* fp, const char* buf, int* index)</nametext></name> - <name><ret>int</ret><nametext>ei_s_print_term(char** s, const char* buf, int* index)</nametext></name> + <name since="OTP 21.3"><ret>int</ret><nametext>ei_init(void)</nametext></name> + <fsummary>Initialize the ei library.</fsummary> + <desc> + <p>Initialize the <c>ei</c> library. This function should be called once + (and only once) before calling any other functionality in the <c>ei</c> + library. However, note the exception below.</p> + <p>If the <c>ei</c> library is used together with the <c>erl_interface</c> + library, this function should <em>not</em> be called directly. It will be + called by the <c>erl_init()</c> function which should be used to initialize + the combination of the two libraries instead.</p> + <p>On success zero is returned. On failure a posix error code is returned.</p> + </desc> + </func> + + <func> + <name since=""><ret>int</ret><nametext>ei_print_term(FILE* fp, const char* buf, int* index)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_s_print_term(char** s, const char* buf, int* index)</nametext></name> <fsummary>Print a term in clear text.</fsummary> <desc> <p>Prints a term, in clear text, to the file @@ -759,42 +842,60 @@ ei_encode_tuple_header(buf, &i, 0);</pre> </func> <func> - <name><ret>void</ret><nametext>ei_set_compat_rel(release_number)</nametext></name> + <name since=""><ret>void</ret><nametext>ei_set_compat_rel(release_number)</nametext></name> <fsummary>Set the ei library in compatibility mode.</fsummary> <type> <v>unsigned release_number;</v> </type> <desc> <marker id="ei_set_compat_rel"></marker> - <p>By default, the <c>ei</c> library is only guaranteed - to be compatible with other Erlang/OTP components from the same - release as the <c>ei</c> library itself. For example, - <c>ei</c> from - Erlang/OTP R10 is not compatible with an Erlang emulator - from Erlang/OTP R9 by default.</p> - <p>A call to <c>ei_set_compat_rel(release_number)</c> sets - the <c>ei</c> library in compatibility mode of release - <c>release_number</c>. Valid range of - <c>release_number</c> - is <c>[7, current release]</c>. This makes it possible to - communicate with Erlang/OTP components from earlier releases.</p> + <p>In general, the <c>ei</c> library is guaranteed + to be compatible with other Erlang/OTP components that are 2 major + releases older or newer than the <c>ei</c> library itself.</p> + <p>Sometimes an exception to the above rule has to be made to make new + features (or even bug fixes) possible. A call to + <c>ei_set_compat_rel(release_number)</c> sets + the <c>ei</c> library in compatibility mode of OTP release + <c>release_number</c>.</p> + <p>The only useful value for <c>release_number</c> is currently + <c>21</c>. This will only be useful and have an effect if <em>bit + strings</em> or <em>export funs</em> are received from a connected + node. Before OTP 22, bit strings and export funs were not supported by + <c>ei</c>. They were instead encoded using an undocumented fallback + tuple format when sent from the emulator to <c>ei</c>:</p> + <taglist> + <tag><c>Bit string</c></tag> + <item><p>The term <c><<42, 1:1>></c> was encoded as + <c>{<<42, 128>>, 1}</c>. The first element of the tuple is a + binary and the second element denotes how many bits of the last bytes + are part of the bit string. In this example only the most significant + bit of the last byte (128) is part of the bit string.</p> + </item> + <tag><c>Export fun</c></tag> + <item><p>The term <c>fun lists:map/2</c> was encoded as + <c>{lists,map}</c>. A tuple with the module, function and a missing + arity.</p> + </item> + </taglist> + <p>If <c>ei_set_compat_rel(21)</c> is <em>not</em> called then a connected + emulator will send bit strings and export funs correctly encoded. The + functions <seealso marker="#ei_decode_bitstring"><c>ei_decode_bitstring</c></seealso> + and <seealso marker="#ei_decode_fun"><c>ei_decode_fun</c></seealso> + has to be used to decode such terms. Calling + <c>ei_set_compat_rel(21)</c> should only be done as a workaround to + keep an old implementation alive, which expects to receive the + undocumented tuple formats for bit strings and/or export funs. + </p> <note> <p>If this function is called, it can only be called once and must be called before any other functions in the <c>ei</c> library are called.</p> </note> - <warning> - <p>You can run into trouble if this feature is used - carelessly. Always ensure that all communicating - components are either from the same Erlang/OTP release, or - from release X and release Y where all components - from release Y are in compatibility mode of release X.</p> - </warning> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_skip_term(const char* buf, int* index)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_skip_term(const char* buf, int* index)</nametext></name> <fsummary>Skip a term.</fsummary> <desc> <p>Skips a term in the specified buffer; @@ -815,8 +916,8 @@ ei_encode_tuple_header(buf, &i, 0);</pre> </func> <func> - <name><ret>int</ret><nametext>ei_x_append(ei_x_buff* x, const ei_x_buff* x2)</nametext></name> - <name><ret>int</ret><nametext>ei_x_append_buf(ei_x_buff* x, const char* buf, int len)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_append(ei_x_buff* x, const ei_x_buff* x2)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_append_buf(ei_x_buff* x, const char* buf, int len)</nametext></name> <fsummary>Append a buffer at the end.</fsummary> <desc> <p>Appends data at the end of buffer <c>x</c>.</p> @@ -824,8 +925,8 @@ ei_encode_tuple_header(buf, &i, 0);</pre> </func> <func> - <name><ret>int</ret><nametext>ei_x_format(ei_x_buff* x, const char* fmt, ...)</nametext></name> - <name><ret>int</ret><nametext>ei_x_format_wo_ver(ei_x_buff* x, const char *fmt, ... )</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_format(ei_x_buff* x, const char* fmt, ...)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_format_wo_ver(ei_x_buff* x, const char *fmt, ... )</nametext></name> <fsummary>Format a term from a format string and parameters.</fsummary> <desc> <p>Formats a term, given as a string, to a buffer. @@ -853,7 +954,7 @@ encodes the tuple {numbers,12,3.14159}</pre> </func> <func> - <name><ret>int</ret><nametext>ei_x_free(ei_x_buff* x)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_free(ei_x_buff* x)</nametext></name> <fsummary>Free a buffer.</fsummary> <desc> <p>Frees an <c>ei_x_buff</c> buffer. @@ -862,8 +963,8 @@ encodes the tuple {numbers,12,3.14159}</pre> </func> <func> - <name><ret>int</ret><nametext>ei_x_new(ei_x_buff* x)</nametext></name> - <name><ret>int</ret><nametext>ei_x_new_with_version(ei_x_buff* x)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_new(ei_x_buff* x)</nametext></name> + <name since=""><ret>int</ret><nametext>ei_x_new_with_version(ei_x_buff* x)</nametext></name> <fsummary>Allocate a new buffer.</fsummary> <desc> <p>Allocates a new <c>ei_x_buff</c> buffer. The |