diff options
Diffstat (limited to 'lib/erl_interface/doc/src/ei.xml')
| -rw-r--r-- | lib/erl_interface/doc/src/ei.xml | 869 |
1 files changed, 435 insertions, 434 deletions
diff --git a/lib/erl_interface/doc/src/ei.xml b/lib/erl_interface/doc/src/ei.xml index 1177954eb9..7928e4f5d1 100644 --- a/lib/erl_interface/doc/src/ei.xml +++ b/lib/erl_interface/doc/src/ei.xml @@ -11,7 +11,7 @@ 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 @@ -30,7 +30,7 @@ <checked></checked> <date>2000-11-27</date> <rev>PA1</rev> - <file>ei.sgml</file> + <file>ei.xml</file> </header> <lib>ei</lib> <libsummary>routines for handling the erlang binary term format</libsummary> @@ -106,149 +106,265 @@ typedef enum { </taglist> </section> <funcs> + <func> + <name><ret>int</ret><nametext>ei_decode_atom(const char *buf, int *index, char *p)</nametext></name> + <fsummary>Decode an atom.</fsummary> + <desc> + <p>This function decodes an atom from the binary format. The + null terminated name of the atom is placed at <c><![CDATA[p]]></c>. There can be at most + <c><![CDATA[MAXATOMLEN]]></c> bytes placed in the buffer.</p> + </desc> + </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> + <fsummary>Decode an atom.</fsummary> + <desc> + <p>This function decodes an atom from the binary format. The + null terminated name of the atom is placed in buffer at <c>p</c> of length + <c>plen</c> bytes.</p> + <p>The wanted string encoding is specified by <seealso marker="#erlang_char_encoding"> + <c>want</c></seealso>. The original encoding used in the + binary format (latin1 or utf8) can be obtained from <c>*was</c>. The actual encoding of the resulting string + (7-bit ascii, latin1 or utf8) can be obtained from <c>*result</c>. Both <c>was</c> and <c>result</c> can be <c>NULL</c>. + + <c>*result</c> may differ from <c>want</c> if <c>want</c> is a bitwise-or'd combination like + <c>ERLANG_LATIN1|ERLANG_UTF8</c> or if <c>*result</c> turn out to be pure 7-bit ascii + (compatible with both latin1 and utf8).</p> + <p>This function fails if the atom is too long for the buffer + or if it can not be represented with encoding <c>want</c>.</p> + <p>This function was introduced in R16 release of Erlang/OTP as part of a first step + to support UTF8 atoms.</p> + </desc> + </func> + <func> + <name><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>This function decodes an integer in the binary format to a GMP <c><![CDATA[mpz_t]]></c> integer. + To use this function the ei library needs to be configured and compiled + to use the GMP library. </p> + </desc> + </func> + <func> + <name><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>This function decodes a binary from the binary format. The + <c><![CDATA[len]]></c> parameter is set to the actual size of the + binary. Note that <c><![CDATA[ei_decode_binary()]]></c> assumes that there + are enough room for the binary. The size required can be + fetched by <c><![CDATA[ei_get_type()]]></c>.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_decode_boolean(const char *buf, int *index, int *p)</nametext></name> + <fsummary>Decode a boolean.</fsummary> + <desc> + <p>This function decodes a boolean value from the binary + format. A boolean is actually an atom, <c><![CDATA[true]]></c> decodes 1 + and <c><![CDATA[false]]></c> decodes 0.</p> + </desc> + </func> + <func> + <name><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>This function decodes a char (8-bit) integer between 0-255 + from the binary format. + Note that for historical reasons the returned integer is of + type <c><![CDATA[char]]></c>. Your C code should consider the + returned value to be of type <c><![CDATA[unsigned char]]></c> even if + the C compilers and system may define <c><![CDATA[char]]></c> to be + signed.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_decode_double(const char *buf, int *index, double *p)</nametext></name> + <fsummary>Decode a double.</fsummary> + <desc> + <p>This function decodes an double-precision (64 bit) floating + point number from the binary format.</p> + </desc> + </func> <func> - <name><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> + <name><ret>int</ret><nametext>ei_decode_ei_term(const char* buf, int* index, ei_term* term)</nametext></name> + <fsummary>Decode a term, without prior knowledge of type.</fsummary> <desc> - <marker id="ei_set_compat_rel"></marker> - <p>By default, the <c><![CDATA[ei]]></c> library is only guaranteed - to be compatible with other Erlang/OTP components from the same - release as the <c><![CDATA[ei]]></c> library itself. For example, <c><![CDATA[ei]]></c> from - the OTP R10 release is not compatible with an Erlang emulator - from the OTP R9 release by default.</p> - <p>A call to <c><![CDATA[ei_set_compat_rel(release_number)]]></c> sets the - <c><![CDATA[ei]]></c> library in compatibility mode of release - <c><![CDATA[release_number]]></c>. Valid range of <c><![CDATA[release_number]]></c> - is [7, current release]. This makes it possible to - communicate with Erlang/OTP components from earlier releases.</p> - <note> - <p>If this function is called, it may only be called once - and must be called before any other functions in the <c><![CDATA[ei]]></c> - library is called.</p> - </note> - <warning> - <p>You may run into trouble if this feature is used - carelessly. Always make sure 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> + <p>This function decodes any term, or at least tries to. If the + term pointed at by <c><![CDATA[*index]]></c> in <c><![CDATA[buf]]></c> fits in the + <c><![CDATA[term]]></c> union, it is decoded, and the appropriate field + in <c><![CDATA[term->value]]></c> is set, and <c><![CDATA[*index]]></c> is + incremented by the term size.</p> + <p>The function returns 1 on successful decoding, -1 on error, + and 0 if the term seems alright, but does not fit in the + <c><![CDATA[term]]></c> structure. If it returns 1, the <c><![CDATA[index]]></c> + will be incremented, and the <c><![CDATA[term]]></c> contains the + decoded term.</p> + <p>The <c><![CDATA[term]]></c> structure will contain the arity for a tuple + or list, size for a binary, string or atom. It will contains + a term if it's any of the following: integer, float, atom, + pid, port or ref.</p> </desc> </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> - <fsummary>Encode version</fsummary> + <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> + <fsummary>Decode a fun.</fsummary> <desc> - <p>Encodes a version magic number for the binary format. Must - be the first token in a binary term.</p> + <p>This function decodes a fun from the binary format. The + <c><![CDATA[p]]></c> parameter should be NULL or point to an + <c><![CDATA[erlang_fun]]></c> structure. This is the only decode + function that allocates memory; when the <c><![CDATA[erlang_fun]]></c> + is no longer needed, it should be freed with + <c><![CDATA[free_fun]]></c>. (This has to do with the arbitrary size of + the environment for a fun.)</p> </desc> </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> - <fsummary>Encode integer</fsummary> + <name><ret>int</ret><nametext>ei_decode_list_header(const char *buf, int *index, int *arity)</nametext></name> + <fsummary>Decode a list.</fsummary> <desc> - <p>Encodes a long integer in the binary format. - Note that if the code is 64 bits the function ei_encode_long() is - exactly the same as ei_encode_longlong().</p> + <p>This function decodes a list header from the binary + format. The number of elements is returned in + <c><![CDATA[arity]]></c>. The <c><![CDATA[arity+1]]></c> elements follows (the last + one is the tail of the list, normally an empty list.) If + <c><![CDATA[arity]]></c> is <c><![CDATA[0]]></c>, it's an empty list.</p> + <p>Note that lists are encoded as strings, if they consist + entirely of integers in the range 0..255. This function will + not decode such strings, use <c><![CDATA[ei_decode_string()]]></c> + instead.</p> </desc> </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> - <fsummary>Encode unsigned integer</fsummary> + <name><ret>int</ret><nametext>ei_decode_long(const char *buf, int *index, long *p)</nametext></name> + <fsummary>Decode integer.</fsummary> <desc> - <p>Encodes an unsigned long integer in the binary format. - Note that if the code is 64 bits the function ei_encode_ulong() is - exactly the same as ei_encode_ulonglong().</p> + <p>This function decodes a long integer from the binary format. + Note that if the code is 64 bits the function ei_decode_long() is + exactly the same as ei_decode_longlong().</p> </desc> </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> - <fsummary>Encode integer</fsummary> + <name><ret>int</ret><nametext>ei_decode_longlong(const char *buf, int *index, long long *p)</nametext></name> + <fsummary>Decode integer.</fsummary> <desc> - <p>Encodes a GCC <c><![CDATA[long long]]></c> or Visual C++ <c><![CDATA[__int64]]></c> (64 bit) - integer in the binary format. Note that this function is missing - in the VxWorks port.</p> + <p>This function decodes a GCC <c><![CDATA[long long]]></c> or Visual C++ <c><![CDATA[__int64]]></c> + (64 bit) integer from the binary format. Note that this + function is missing in the VxWorks port.</p> </desc> </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> - <fsummary>Encode unsigned integer</fsummary> + <name><ret>int</ret><nametext>ei_decode_map_header(const char *buf, int *index, int *arity)</nametext></name> + <fsummary>Decode a map.</fsummary> <desc> - <p>Encodes a GCC <c><![CDATA[unsigned long long]]></c> or Visual C++ <c><![CDATA[unsigned __int64]]></c> (64 bit) integer in the binary format. Note that - this function is missing in the VxWorks port.</p> + <p>This function decodes a map header from the binary + format. The number of key-value pairs is returned in + <c>*arity</c>. Keys and values follow in the following order: + <c>K1, V1, K2, V2, ..., Kn, Vn</c>. This makes a total of + <c>arity*2</c> terms. If <c>arity</c> is zero, it's an empty map. + A correctly encoded map does not have duplicate keys.</p> </desc> </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> - <fsummary>Encode an arbitrary precision integer</fsummary> + <name><ret>int</ret><nametext>ei_decode_pid(const char *buf, int *index, erlang_pid *p)</nametext></name> + <fsummary>Decode a <c><![CDATA[pid]]></c>.</fsummary> <desc> - <p>Encodes a GMP <c><![CDATA[mpz_t]]></c> integer to binary format. - To use this function the ei library needs to be configured and compiled - to use the GMP library. </p> + <p>Decodes a pid, process identifier, from the binary format.</p> </desc> </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> - <fsummary>Encode a double float</fsummary> + <name><ret>int</ret><nametext>ei_decode_port(const char *buf, int *index, erlang_port *p)</nametext></name> + <fsummary>Decode a port.</fsummary> <desc> - <p>Encodes a double-precision (64 bit) floating point number in - the binary format.</p> - <p> - The function returns <c><![CDATA[-1]]></c> if the floating point number is not finite. - </p> + <p>This function decodes a port identifier from the binary + format.</p> </desc> </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> - <fsummary>Encode a boolean</fsummary> + <name><ret>int</ret><nametext>ei_decode_ref(const char *buf, int *index, erlang_ref *p)</nametext></name> + <fsummary>Decode a reference.</fsummary> <desc> - <p>Encodes a boolean value, as the atom <c><![CDATA[true]]></c> if p is not - zero or <c><![CDATA[false]]></c> if p is zero.</p> + <p>This function decodes a reference from the binary format.</p> </desc> </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> - <fsummary>Encode an 8-bit integer between 0-255</fsummary> + <name><ret>int</ret><nametext>ei_decode_string(const char *buf, int *index, char *p)</nametext></name> + <fsummary>Decode a string.</fsummary> <desc> - <p>Encodes a char (8-bit) as an integer between 0-255 in the binary format. - Note that for historical reasons the integer argument is of - type <c><![CDATA[char]]></c>. Your C code should consider the - given argument to be of type <c><![CDATA[unsigned char]]></c> even if - the C compilers and system may define <c><![CDATA[char]]></c> to be - signed.</p> + <p>This function decodes a string from the binary format. A + string in erlang is a list of integers between 0 and + 255. Note that since the string is just a list, sometimes + lists are encoded as strings by <c><![CDATA[term_to_binary/1]]></c>, + even if it was not intended.</p> + <p>The string is copied to <c><![CDATA[p]]></c>, and enough space must be + allocated. The returned string is null terminated so you + need to add an extra byte to the memory requirement.</p> </desc> </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> - <fsummary>Encode a string</fsummary> + <name><ret>int</ret><nametext>ei_decode_term(const char *buf, int *index, void *t)</nametext></name> + <fsummary>Decode a <c><![CDATA[ETERM]]></c>.</fsummary> <desc> - <p>Encodes a string in the binary format. (A string in erlang - is a list, but is encoded as a character array in the binary - format.) The string should be zero-terminated, except for - the <c><![CDATA[ei_x_encode_string_len()]]></c> function.</p> + <p>This function decodes a term from the binary format. The + term is return in <c><![CDATA[t]]></c> as a <c><![CDATA[ETERM*]]></c>, so <c><![CDATA[t]]></c> + is actually an <c><![CDATA[ETERM**]]></c> (see + <c><![CDATA[erl_interface(3)]]></c>. The term should later be + deallocated.</p> + <p>Note that this function is located in the erl_interface + library.</p> </desc> </func> <func> + <name><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> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_decode_tuple_header(const char *buf, int *index, int *arity)</nametext></name> + <fsummary>Decode a tuple.</fsummary> + <desc> + <p>This function decodes a tuple header, the number of elements + is returned in <c><![CDATA[arity]]></c>. The tuple elements follows in order in + the buffer.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_decode_ulong(const char *buf, int *index, unsigned long *p)</nametext></name> + <fsummary>Decode unsigned integer.</fsummary> + <desc> + <p>This function decodes an unsigned long integer from + the binary format. + Note that if the code is 64 bits the function ei_decode_ulong() is + exactly the same as ei_decode_ulonglong().</p> + </desc> + </func> + <func> + <name><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>This function decodes a GCC <c><![CDATA[unsigned long long]]></c> or Visual C++ + <c><![CDATA[unsigned __int64]]></c> (64 bit) integer from the binary format. + Note that this function is missing in the VxWorks port.</p> + </desc> + </func> + <func> + <name><ret>int</ret><nametext>ei_decode_version(const char *buf, int *index, int *version)</nametext></name> + <fsummary>Encode an empty list (<c><![CDATA[nil]]></c>).</fsummary> + <desc> + <p>This function decodes the version magic number for the + erlang binary term format. It must be the first token in a + binary term.</p> + </desc> + </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> - <fsummary>Encode an atom</fsummary> + <fsummary>Encode an atom.</fsummary> <desc> <p>Encodes an atom in the binary format. The <c><![CDATA[p]]></c> parameter is the name of the atom in latin1 encoding. Only upto <c>MAXATOMLEN-1</c> bytes @@ -261,7 +377,7 @@ typedef enum { <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> - <fsummary>Encode an atom</fsummary> + <fsummary>Encode an atom.</fsummary> <desc> <p>Encodes an atom in the binary format with character encoding <seealso marker="#erlang_char_encoding"><c>to_enc</c></seealso> (latin1 or utf8). @@ -279,105 +395,83 @@ typedef enum { </desc> </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> - <fsummary>Encode a binary</fsummary> - <desc> - <p>Encodes a binary in the binary format. The data is at - <c><![CDATA[p]]></c>, of <c><![CDATA[len]]></c> bytes length.</p> - </desc> - </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> - <fsummary>Encode a pid</fsummary> + <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> + <fsummary>Encode an arbitrary precision integer.</fsummary> <desc> - <p>Encodes an erlang process identifier, pid, in the binary - format. The <c><![CDATA[p]]></c> parameter points to an - <c><![CDATA[erlang_pid]]></c> structure (which should have been obtained - earlier with <c><![CDATA[ei_decode_pid()]]></c>).</p> + <p>Encodes a GMP <c><![CDATA[mpz_t]]></c> integer to binary format. + To use this function the ei library needs to be configured and compiled + to use the GMP library. </p> </desc> </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> - <fsummary>Encode a fun</fsummary> + <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> + <fsummary>Encode a binary.</fsummary> <desc> - <p>Encodes a fun in the binary format. The <c><![CDATA[p]]></c> parameter - points to an <c><![CDATA[erlang_fun]]></c> structure. The - <c><![CDATA[erlang_fun]]></c> is not freed automatically, the - <c><![CDATA[free_fun]]></c> should be called if the fun is not needed - after encoding.</p> + <p>Encodes a binary in the binary format. The data is at + <c><![CDATA[p]]></c>, of <c><![CDATA[len]]></c> bytes length.</p> </desc> </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> - <fsummary>Encodes a port</fsummary> + <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> + <fsummary>Encode a boolean.</fsummary> <desc> - <p>Encodes an erlang port in the binary format. The <c><![CDATA[p]]></c> - parameter points to a <c><![CDATA[erlang_port]]></c> structure (which - should have been obtained earlier with - <c><![CDATA[ei_decode_port()]]></c>.</p> + <p>Encodes a boolean value, as the atom <c><![CDATA[true]]></c> if p is not + zero or <c><![CDATA[false]]></c> if p is zero.</p> </desc> </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> - <fsummary>Encodes a ref</fsummary> + <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> + <fsummary>Encode an 8-bit integer between 0-255.</fsummary> <desc> - <p>Encodes an erlang reference in the binary format. The - <c><![CDATA[p]]></c> parameter points to a <c><![CDATA[erlang_ref]]></c> structure - (which should have been obtained earlier with - <c><![CDATA[ei_decode_ref()]]></c>.</p> + <p>Encodes a char (8-bit) as an integer between 0-255 in the binary format. + Note that for historical reasons the integer argument is of + type <c><![CDATA[char]]></c>. Your C code should consider the + given argument to be of type <c><![CDATA[unsigned char]]></c> even if + the C compilers and system may define <c><![CDATA[char]]></c> to be + signed.</p> </desc> </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> - <fsummary>Encode an <c><![CDATA[erl_interface]]></c>term</fsummary> + <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> + <fsummary>Encode a double float.</fsummary> <desc> - <p>This function encodes an <c><![CDATA[ETERM]]></c>, as obtained from - <c><![CDATA[erl_interface]]></c>. The <c><![CDATA[t]]></c> parameter is actually an - <c><![CDATA[ETERM]]></c> pointer. This function doesn't free the - <c><![CDATA[ETERM]]></c>.</p> + <p>Encodes a double-precision (64 bit) floating point number in + the binary format.</p> + <p> + The function returns <c><![CDATA[-1]]></c> if the floating point number is not finite. + </p> </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> - <fsummary>Encode a trace token</fsummary> + <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> + <fsummary>Encode an empty list (<c><![CDATA[nil]]></c>).</fsummary> <desc> - <p>This function encodes an erlang trace token in the binary - format. The <c><![CDATA[p]]></c> parameter points to a - <c><![CDATA[erlang_trace]]></c> structure (which should have been - obtained earlier with <c><![CDATA[ei_decode_trace()]]></c>.</p> + <p>This function encodes an empty list. It's often used at the + tail of a list.</p> </desc> </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> - <fsummary>Encode a tuple</fsummary> + <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> + <fsummary>Encode a fun.</fsummary> <desc> - <p>This function encodes a tuple header, with a specified - arity. The next <c><![CDATA[arity]]></c> terms encoded will be the - elements of the tuple. Tuples and lists are encoded - recursively, so that a tuple may contain another tuple or - list.</p> - <p>E.g. to encode the tuple <c><![CDATA[{a, {b, {}}}]]></c>:</p> - <pre> -ei_encode_tuple_header(buf, &i, 2); -ei_encode_atom(buf, &i, "a"); -ei_encode_tuple_header(buf, &i, 2); -ei_encode_atom(buf, &i, "b"); -ei_encode_tuple_header(buf, &i, 0); - </pre> + <p>Encodes a fun in the binary format. The <c><![CDATA[p]]></c> parameter + points to an <c><![CDATA[erlang_fun]]></c> structure. The + <c><![CDATA[erlang_fun]]></c> is not freed automatically, the + <c><![CDATA[free_fun]]></c> should be called if the fun is not needed + after encoding.</p> </desc> </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> - <fsummary>Encode a list</fsummary> + <fsummary>Encode a list.</fsummary> <desc> <p>This function encodes a list header, with a specified arity. The next <c><![CDATA[arity+1]]></c> terms are the elements @@ -412,18 +506,29 @@ ei_x_encode_empty_list(&x); </desc> </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> - <fsummary>Encode an empty list (<c><![CDATA[nil]]></c>)</fsummary> + <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> + <fsummary>Encode integer.</fsummary> <desc> - <p>This function encodes an empty list. It's often used at the - tail of a list.</p> + <p>Encodes a long integer in the binary format. + Note that if the code is 64 bits the function ei_encode_long() is + exactly the same as ei_encode_longlong().</p> + </desc> + </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> + <fsummary>Encode integer.</fsummary> + <desc> + <p>Encodes a GCC <c><![CDATA[long long]]></c> or Visual C++ <c><![CDATA[__int64]]></c> (64 bit) + integer in the binary format. Note that this function is missing + in the VxWorks port.</p> </desc> </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> - <fsummary>Encode a map</fsummary> + <fsummary>Encode a map.</fsummary> <desc> <p>This function encodes a map header, with a specified arity. The next <c>arity*2</c> terms encoded will be the keys and values of the map @@ -441,275 +546,139 @@ ei_x_encode_string(&x, "Banana"); </desc> </func> <func> - <name><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>This function returns the type in <c><![CDATA[type]]></c> and size in - <c><![CDATA[size]]></c> of the encoded term. - For strings and atoms, size - is the number of characters <em>not</em> including the - terminating 0. For binaries, <c><![CDATA[size]]></c> is the number of - bytes. For lists and tuples, <c><![CDATA[size]]></c> is the arity of the - object. For other types, <c><![CDATA[size]]></c> is 0. In all cases, - <c><![CDATA[index]]></c> is left unchanged.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_decode_version(const char *buf, int *index, int *version)</nametext></name> - <fsummary>Encode an empty list (<c><![CDATA[nil]]></c>)</fsummary> - <desc> - <p>This function decodes the version magic number for the - erlang binary term format. It must be the first token in a - binary term.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_decode_long(const char *buf, int *index, long *p)</nametext></name> - <fsummary>Decode integer</fsummary> - <desc> - <p>This function decodes a long integer from the binary format. - Note that if the code is 64 bits the function ei_decode_long() is - exactly the same as ei_decode_longlong().</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_decode_ulong(const char *buf, int *index, unsigned long *p)</nametext></name> - <fsummary>Decode unsigned integer</fsummary> - <desc> - <p>This function decodes an unsigned long integer from - the binary format. - Note that if the code is 64 bits the function ei_decode_ulong() is - exactly the same as ei_decode_ulonglong().</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_decode_longlong(const char *buf, int *index, long long *p)</nametext></name> - <fsummary>Decode integer</fsummary> - <desc> - <p>This function decodes a GCC <c><![CDATA[long long]]></c> or Visual C++ <c><![CDATA[__int64]]></c> - (64 bit) integer from the binary format. Note that this - function is missing in the VxWorks port.</p> - </desc> - </func> - <func> - <name><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>This function decodes a GCC <c><![CDATA[unsigned long long]]></c> or Visual C++ - <c><![CDATA[unsigned __int64]]></c> (64 bit) integer from the binary format. - Note that this function is missing in the VxWorks port.</p> - </desc> - </func> - <func> - <name><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>This function decodes an integer in the binary format to a GMP <c><![CDATA[mpz_t]]></c> integer. - To use this function the ei library needs to be configured and compiled - to use the GMP library. </p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_decode_double(const char *buf, int *index, double *p)</nametext></name> - <fsummary>Decode a double</fsummary> - <desc> - <p>This function decodes an double-precision (64 bit) floating - point number from the binary format.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_decode_boolean(const char *buf, int *index, int *p)</nametext></name> - <fsummary>Decode a boolean</fsummary> - <desc> - <p>This function decodes a boolean value from the binary - format. A boolean is actually an atom, <c><![CDATA[true]]></c> decodes 1 - and <c><![CDATA[false]]></c> decodes 0.</p> - </desc> - </func> - <func> - <name><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>This function decodes a char (8-bit) integer between 0-255 - from the binary format. - Note that for historical reasons the returned integer is of - type <c><![CDATA[char]]></c>. Your C code should consider the - returned value to be of type <c><![CDATA[unsigned char]]></c> even if - the C compilers and system may define <c><![CDATA[char]]></c> to be - signed.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_decode_string(const char *buf, int *index, char *p)</nametext></name> - <fsummary>Decode a string</fsummary> - <desc> - <p>This function decodes a string from the binary format. A - string in erlang is a list of integers between 0 and - 255. Note that since the string is just a list, sometimes - lists are encoded as strings by <c><![CDATA[term_to_binary/1]]></c>, - even if it was not intended.</p> - <p>The string is copied to <c><![CDATA[p]]></c>, and enough space must be - allocated. The returned string is null terminated so you - need to add an extra byte to the memory requirement.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_decode_atom(const char *buf, int *index, char *p)</nametext></name> - <fsummary>Decode an atom</fsummary> - <desc> - <p>This function decodes an atom from the binary format. The - null terminated name of the atom is placed at <c><![CDATA[p]]></c>. There can be at most - <c><![CDATA[MAXATOMLEN]]></c> bytes placed in the buffer.</p> - </desc> - </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> - <fsummary>Decode an atom</fsummary> - <desc> - <p>This function decodes an atom from the binary format. The - null terminated name of the atom is placed in buffer at <c>p</c> of length - <c>plen</c> bytes.</p> - <p>The wanted string encoding is specified by <seealso marker="#erlang_char_encoding"> - <c>want</c></seealso>. The original encoding used in the - binary format (latin1 or utf8) can be obtained from <c>*was</c>. The actual encoding of the resulting string - (7-bit ascii, latin1 or utf8) can be obtained from <c>*result</c>. Both <c>was</c> and <c>result</c> can be <c>NULL</c>. - - <c>*result</c> may differ from <c>want</c> if <c>want</c> is a bitwise-or'd combination like - <c>ERLANG_LATIN1|ERLANG_UTF8</c> or if <c>*result</c> turn out to be pure 7-bit ascii - (compatible with both latin1 and utf8).</p> - <p>This function fails if the atom is too long for the buffer - or if it can not be represented with encoding <c>want</c>.</p> - <p>This function was introduced in R16 release of Erlang/OTP as part of a first step - to support UTF8 atoms.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_decode_binary(const char *buf, int *index, void *p, long *len)</nametext></name> - <fsummary>Decode a binary</fsummary> + <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> + <fsummary>Encode a pid.</fsummary> <desc> - <p>This function decodes a binary from the binary format. The - <c><![CDATA[len]]></c> parameter is set to the actual size of the - binary. Note that <c><![CDATA[ei_decode_binary()]]></c> assumes that there - are enough room for the binary. The size required can be - fetched by <c><![CDATA[ei_get_type()]]></c>.</p> + <p>Encodes an erlang process identifier, pid, in the binary + format. The <c><![CDATA[p]]></c> parameter points to an + <c><![CDATA[erlang_pid]]></c> structure (which should have been obtained + earlier with <c><![CDATA[ei_decode_pid()]]></c>).</p> </desc> </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> - <fsummary>Decode a fun</fsummary> + <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> + <fsummary>Encodes a port.</fsummary> <desc> - <p>This function decodes a fun from the binary format. The - <c><![CDATA[p]]></c> parameter should be NULL or point to an - <c><![CDATA[erlang_fun]]></c> structure. This is the only decode - function that allocates memory; when the <c><![CDATA[erlang_fun]]></c> - is no longer needed, it should be freed with - <c><![CDATA[free_fun]]></c>. (This has to do with the arbitrary size of - the environment for a fun.)</p> + <p>Encodes an erlang port in the binary format. The <c><![CDATA[p]]></c> + parameter points to a <c><![CDATA[erlang_port]]></c> structure (which + should have been obtained earlier with + <c><![CDATA[ei_decode_port()]]></c>.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_pid(const char *buf, int *index, erlang_pid *p)</nametext></name> - <fsummary>Decode a <c><![CDATA[pid]]></c></fsummary> + <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> + <fsummary>Encodes a ref.</fsummary> <desc> - <p>Decodes a pid, process identifier, from the binary format.</p> + <p>Encodes an erlang reference in the binary format. The + <c><![CDATA[p]]></c> parameter points to a <c><![CDATA[erlang_ref]]></c> structure + (which should have been obtained earlier with + <c><![CDATA[ei_decode_ref()]]></c>.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_port(const char *buf, int *index, erlang_port *p)</nametext></name> - <fsummary>Decode a port</fsummary> + <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> + <fsummary>Encode a string.</fsummary> <desc> - <p>This function decodes a port identifier from the binary - format.</p> + <p>Encodes a string in the binary format. (A string in erlang + is a list, but is encoded as a character array in the binary + format.) The string should be zero-terminated, except for + the <c><![CDATA[ei_x_encode_string_len()]]></c> function.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_ref(const char *buf, int *index, erlang_ref *p)</nametext></name> - <fsummary>Decode a reference</fsummary> + <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> + <fsummary>Encode an <c><![CDATA[erl_interface]]></c>term.</fsummary> <desc> - <p>This function decodes a reference from the binary format.</p> + <p>This function encodes an <c><![CDATA[ETERM]]></c>, as obtained from + <c><![CDATA[erl_interface]]></c>. The <c><![CDATA[t]]></c> parameter is actually an + <c><![CDATA[ETERM]]></c> pointer. This function doesn't free the + <c><![CDATA[ETERM]]></c>.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_trace(const char *buf, int *index, erlang_trace *p)</nametext></name> - <fsummary>Decode a trace token</fsummary> + <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> + <fsummary>Encode a trace token.</fsummary> <desc> - <p>Decodes an erlang trace token from the binary format.</p> + <p>This function encodes an erlang trace token in the binary + format. The <c><![CDATA[p]]></c> parameter points to a + <c><![CDATA[erlang_trace]]></c> structure (which should have been + obtained earlier with <c><![CDATA[ei_decode_trace()]]></c>.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_tuple_header(const char *buf, int *index, int *arity)</nametext></name> - <fsummary>Decode a tuple</fsummary> + <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> + <fsummary>Encode a tuple.</fsummary> <desc> - <p>This function decodes a tuple header, the number of elements - is returned in <c><![CDATA[arity]]></c>. The tuple elements follows in order in - the buffer.</p> + <p>This function encodes a tuple header, with a specified + arity. The next <c><![CDATA[arity]]></c> terms encoded will be the + elements of the tuple. Tuples and lists are encoded + recursively, so that a tuple may contain another tuple or + list.</p> + <p>E.g. to encode the tuple <c><![CDATA[{a, {b, {}}}]]></c>:</p> + <pre> +ei_encode_tuple_header(buf, &i, 2); +ei_encode_atom(buf, &i, "a"); +ei_encode_tuple_header(buf, &i, 2); +ei_encode_atom(buf, &i, "b"); +ei_encode_tuple_header(buf, &i, 0); + </pre> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_list_header(const char *buf, int *index, int *arity)</nametext></name> - <fsummary>Decode a list</fsummary> + <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> + <fsummary>Encode unsigned integer.</fsummary> <desc> - <p>This function decodes a list header from the binary - format. The number of elements is returned in - <c><![CDATA[arity]]></c>. The <c><![CDATA[arity+1]]></c> elements follows (the last - one is the tail of the list, normally an empty list.) If - <c><![CDATA[arity]]></c> is <c><![CDATA[0]]></c>, it's an empty list.</p> - <p>Note that lists are encoded as strings, if they consist - entirely of integers in the range 0..255. This function will - not decode such strings, use <c><![CDATA[ei_decode_string()]]></c> - instead.</p> + <p>Encodes an unsigned long integer in the binary format. + Note that if the code is 64 bits the function ei_encode_ulong() is + exactly the same as ei_encode_ulonglong().</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_map_header(const char *buf, int *index, int *arity)</nametext></name> - <fsummary>Decode a map</fsummary> + <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> + <fsummary>Encode unsigned integer.</fsummary> <desc> - <p>This function decodes a map header from the binary - format. The number of key-value pairs is returned in - <c>*arity</c>. Keys and values follow in the following order: - <c>K1, V1, K2, V2, ..., Kn, Vn</c>. This makes a total of - <c>arity*2</c> terms. If <c>arity</c> is zero, it's an empty map. - A correctly encoded map does not have duplicate keys.</p> + <p>Encodes a GCC <c><![CDATA[unsigned long long]]></c> or Visual C++ <c><![CDATA[unsigned __int64]]></c> (64 bit) integer in the binary format. Note that + this function is missing in the VxWorks port.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_ei_term(const char* buf, int* index, ei_term* term)</nametext></name> - <fsummary>Decode a term, without prior knowledge of type</fsummary> + <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> + <fsummary>Encode version.</fsummary> <desc> - <p>This function decodes any term, or at least tries to. If the - term pointed at by <c><![CDATA[*index]]></c> in <c><![CDATA[buf]]></c> fits in the - <c><![CDATA[term]]></c> union, it is decoded, and the appropriate field - in <c><![CDATA[term->value]]></c> is set, and <c><![CDATA[*index]]></c> is - incremented by the term size.</p> - <p>The function returns 1 on successful decoding, -1 on error, - and 0 if the term seems alright, but does not fit in the - <c><![CDATA[term]]></c> structure. If it returns 1, the <c><![CDATA[index]]></c> - will be incremented, and the <c><![CDATA[term]]></c> contains the - decoded term.</p> - <p>The <c><![CDATA[term]]></c> structure will contain the arity for a tuple - or list, size for a binary, string or atom. It will contains - a term if it's any of the following: integer, float, atom, - pid, port or ref.</p> + <p>Encodes a version magic number for the binary format. Must + be the first token in a binary term.</p> </desc> </func> <func> - <name><ret>int</ret><nametext>ei_decode_term(const char *buf, int *index, void *t)</nametext></name> - <fsummary>Decode a <c><![CDATA[ETERM]]></c></fsummary> + <name><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>This function decodes a term from the binary format. The - term is return in <c><![CDATA[t]]></c> as a <c><![CDATA[ETERM*]]></c>, so <c><![CDATA[t]]></c> - is actually an <c><![CDATA[ETERM**]]></c> (see - <c><![CDATA[erl_interface(3)]]></c>. The term should later be - deallocated.</p> - <p>Note that this function is located in the erl_interface - library.</p> + <p>This function returns the type in <c><![CDATA[type]]></c> and size in + <c><![CDATA[size]]></c> of the encoded term. + For strings and atoms, size + is the number of characters <em>not</em> including the + terminating 0. For binaries, <c><![CDATA[size]]></c> is the number of + bytes. For lists and tuples, <c><![CDATA[size]]></c> is the arity of the + object. For other types, <c><![CDATA[size]]></c> is 0. In all cases, + <c><![CDATA[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> - <fsummary>Print a term in clear text</fsummary> + <fsummary>Print a term in clear text.</fsummary> <desc> <p>This function prints a term, in clear text, to the file given by <c><![CDATA[fp]]></c>, or the buffer pointed to by <c><![CDATA[s]]></c>. It @@ -730,6 +699,67 @@ ei_x_encode_string(&x, "Banana"); </desc> </func> <func> + <name><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><![CDATA[ei]]></c> library is only guaranteed + to be compatible with other Erlang/OTP components from the same + release as the <c><![CDATA[ei]]></c> library itself. For example, <c><![CDATA[ei]]></c> from + the OTP R10 release is not compatible with an Erlang emulator + from the OTP R9 release by default.</p> + <p>A call to <c><![CDATA[ei_set_compat_rel(release_number)]]></c> sets the + <c><![CDATA[ei]]></c> library in compatibility mode of release + <c><![CDATA[release_number]]></c>. Valid range of <c><![CDATA[release_number]]></c> + is [7, current release]. This makes it possible to + communicate with Erlang/OTP components from earlier releases.</p> + <note> + <p>If this function is called, it may only be called once + and must be called before any other functions in the <c><![CDATA[ei]]></c> + library is called.</p> + </note> + <warning> + <p>You may run into trouble if this feature is used + carelessly. Always make sure 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> + <fsummary>skip a term.</fsummary> + <desc> + <p>This function skips a term in the given buffer, it + recursively skips elements of lists and tuples, so that a + full term is skipped. This is a way to get the size of an + erlang term.</p> + <p><c><![CDATA[buf]]></c> is the buffer.</p> + <p><c><![CDATA[index]]></c> is updated to point right after the term in the + buffer.</p> + <note> + <p>This can be useful when you want to hold arbitrary + terms: just skip them and copy the binary term data to some + buffer.</p> + </note> + <p>The function returns <c><![CDATA[0]]></c> on success and <c><![CDATA[-1]]></c> on + failure.</p> + </desc> + </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> + <fsummary>Appends a buffer at the end.</fsummary> + <desc> + <p>These functions appends data at the end of the buffer <c><![CDATA[x]]></c>.</p> + </desc> + </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> <fsummary>Format a term from a format string and parameters.</fsummary> @@ -761,9 +791,17 @@ encodes the tuple {numbers,12,3.14159} </desc> </func> <func> + <name><ret>int</ret><nametext>ei_x_free(ei_x_buff* x)</nametext></name> + <fsummary>Frees a buffer.</fsummary> + <desc> + <p>This function frees an <c><![CDATA[ei_x_buff]]></c> buffer. The memory + used by the buffer is returned to the OS.</p> + </desc> + </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> - <fsummary>Allocate a new buffer</fsummary> + <fsummary>Allocate a new buffer.</fsummary> <desc> <p>This function allocates a new <c><![CDATA[ei_x_buff]]></c> buffer. The fields of the structure pointed to by <c><![CDATA[x]]></c> parameter is @@ -773,43 +811,7 @@ encodes the tuple {numbers,12,3.14159} <c><![CDATA[ei_x_encode_version()]]></c> won't be needed.)</p> </desc> </func> - <func> - <name><ret>int</ret><nametext>ei_x_free(ei_x_buff* x)</nametext></name> - <fsummary>Frees a buffer</fsummary> - <desc> - <p>This function frees an <c><![CDATA[ei_x_buff]]></c> buffer. The memory - used by the buffer is returned to the OS.</p> - </desc> - </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> - <fsummary>Appends a buffer at the end</fsummary> - <desc> - <p>These functions appends data at the end of the buffer <c><![CDATA[x]]></c>.</p> - </desc> - </func> - <func> - <name><ret>int</ret><nametext>ei_skip_term(const char* buf, int* index)</nametext></name> - <fsummary>skip a term</fsummary> - <desc> - <p>This function skips a term in the given buffer, it - recursively skips elements of lists and tuples, so that a - full term is skipped. This is a way to get the size of an - erlang term.</p> - <p><c><![CDATA[buf]]></c> is the buffer.</p> - <p><c><![CDATA[index]]></c> is updated to point right after the term in the - buffer.</p> - <note> - <p>This can be useful when you want to hold arbitrary - terms: just skip them and copy the binary term data to some - buffer.</p> - </note> - <p>The function returns <c><![CDATA[0]]></c> on success and <c><![CDATA[-1]]></c> on - failure.</p> - </desc> - </func> - </funcs> + </funcs> <section> <title>Debug Information</title> @@ -828,4 +830,3 @@ encodes the tuple {numbers,12,3.14159} <p>erl_interface(3)</p> </section> </cref> - |