perlapi.pod

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

=for hackers
Found in file handy.h

=item savesharedpv
X<savesharedpv>

A version of C<savepv()> which allocates the duplicate string in memory
which is shared between threads.

	char*	savesharedpv(const char* pv)

=for hackers
Found in file util.c

=item savesharedpvn
X<savesharedpvn>

A version of C<savepvn()> which allocates the duplicate string in memory
which is shared between threads. (With the specific difference that a NULL
pointer is not acceptable)

	char*	savesharedpvn(const char *const pv, const STRLEN len)

=for hackers
Found in file util.c

=item savesvpv
X<savesvpv>

A version of C<savepv()>/C<savepvn()> which gets the string to duplicate from
the passed in SV using C<SvPV()>

	char*	savesvpv(SV* sv)

=for hackers
Found in file util.c

=item StructCopy
X<StructCopy>

This is an architecture-independent macro to copy one structure to another.

	void	StructCopy(type src, type dest, type)

=for hackers
Found in file handy.h

=item Zero
X<Zero>

The XSUB-writer's interface to the C C<memzero> function.  The C<dest> is the
destination, C<nitems> is the number of items, and C<type> is the type.

	void	Zero(void* dest, int nitems, type)

=for hackers
Found in file handy.h

=item ZeroD
X<ZeroD>

Like C<Zero> but returns dest. Useful for encouraging compilers to tail-call
optimise.

	void *	ZeroD(void* dest, int nitems, type)

=for hackers
Found in file handy.h


=back

=head1 Miscellaneous Functions

=over 8

=item fbm_compile
X<fbm_compile>

Analyses the string in order to make fast searches on it using fbm_instr()
-- the Boyer-Moore algorithm.

	void	fbm_compile(SV* sv, U32 flags)

=for hackers
Found in file util.c

=item fbm_instr
X<fbm_instr>

Returns the location of the SV in the string delimited by C<str> and
C<strend>.  It returns C<NULL> if the string can't be found.  The C<sv>
does not have to be fbm_compiled, but the search will not be as fast
then.

	char*	fbm_instr(unsigned char* big, unsigned char* bigend, SV* littlesv, U32 flags)

=for hackers
Found in file util.c

=item form
X<form>

Takes a sprintf-style format pattern and conventional
(non-SV) arguments and returns the formatted string.

    (char *) Perl_form(pTHX_ const char* pat, ...)

can be used any place a string (char *) is required:

    char * s = Perl_form("%d.%d",major,minor);

Uses a single private buffer so if you want to format several strings you
must explicitly copy the earlier strings away (and free the copies when you
are done).

	char*	form(const char* pat, ...)

=for hackers
Found in file util.c

=item getcwd_sv
X<getcwd_sv>

Fill the sv with current working directory

	int	getcwd_sv(SV* sv)

=for hackers
Found in file util.c

=item my_snprintf
X<my_snprintf>

The C library C<snprintf> functionality, if available and
standards-compliant (uses C<vsnprintf>, actually).  However, if the
C<vsnprintf> is not available, will unfortunately use the unsafe
C<vsprintf> which can overrun the buffer (there is an overrun check,
but that may be too late).  Consider using C<sv_vcatpvf> instead, or
getting C<vsnprintf>.

	int	my_snprintf(char *buffer, const Size_t len, const char *format, ...)

=for hackers
Found in file util.c

=item my_sprintf
X<my_sprintf>

The C library C<sprintf>, wrapped if necessary, to ensure that it will return
the length of the string written to the buffer. Only rare pre-ANSI systems
need the wrapper function - usually this is a direct call to C<sprintf>.

	int	my_sprintf(char *buffer, const char *pat, ...)

=for hackers
Found in file util.c

=item my_vsnprintf
X<my_vsnprintf>

The C library C<vsnprintf> if available and standards-compliant.
However, if if the C<vsnprintf> is not available, will unfortunately
use the unsafe C<vsprintf> which can overrun the buffer (there is an
overrun check, but that may be too late).  Consider using
C<sv_vcatpvf> instead, or getting C<vsnprintf>.

	int	my_vsnprintf(char *buffer, const Size_t len, const char *format, va_list ap)

=for hackers
Found in file util.c

=item new_version
X<new_version>

Returns a new version object based on the passed in SV:

    SV *sv = new_version(SV *ver);

Does not alter the passed in ver SV.  See "upg_version" if you
want to upgrade the SV.

	SV*	new_version(SV *ver)

=for hackers
Found in file util.c

=item scan_version
X<scan_version>

Returns a pointer to the next character after the parsed
version string, as well as upgrading the passed in SV to
an RV.

Function must be called with an already existing SV like

    sv = newSV(0);
    s = scan_version(s, SV *sv, bool qv);

Performs some preprocessing to the string to ensure that
it has the correct characteristics of a version.  Flags the
object if it contains an underscore (which denotes this
is an alpha version).  The boolean qv denotes that the version
should be interpreted as if it had multiple decimals, even if
it doesn't.

	const char*	scan_version(const char *vstr, SV *sv, bool qv)

=for hackers
Found in file util.c

=item strEQ
X<strEQ>

Test two strings to see if they are equal.  Returns true or false.

	bool	strEQ(char* s1, char* s2)

=for hackers
Found in file handy.h

=item strGE
X<strGE>

Test two strings to see if the first, C<s1>, is greater than or equal to
the second, C<s2>.  Returns true or false.

	bool	strGE(char* s1, char* s2)

=for hackers
Found in file handy.h

=item strGT
X<strGT>

Test two strings to see if the first, C<s1>, is greater than the second,
C<s2>.  Returns true or false.

	bool	strGT(char* s1, char* s2)

=for hackers
Found in file handy.h

=item strLE
X<strLE>

Test two strings to see if the first, C<s1>, is less than or equal to the
second, C<s2>.  Returns true or false.

	bool	strLE(char* s1, char* s2)

=for hackers
Found in file handy.h

=item strLT
X<strLT>

Test two strings to see if the first, C<s1>, is less than the second,
C<s2>.  Returns true or false.

	bool	strLT(char* s1, char* s2)

=for hackers
Found in file handy.h

=item strNE
X<strNE>

Test two strings to see if they are different.  Returns true or
false.

	bool	strNE(char* s1, char* s2)

=for hackers
Found in file handy.h

=item strnEQ
X<strnEQ>

Test two strings to see if they are equal.  The C<len> parameter indicates
the number of bytes to compare.  Returns true or false. (A wrapper for
C<strncmp>).

	bool	strnEQ(char* s1, char* s2, STRLEN len)

=for hackers
Found in file handy.h

=item strnNE
X<strnNE>

Test two strings to see if they are different.  The C<len> parameter
indicates the number of bytes to compare.  Returns true or false. (A
wrapper for C<strncmp>).

	bool	strnNE(char* s1, char* s2, STRLEN len)

=for hackers
Found in file handy.h

=item sv_destroyable
X<sv_destroyable>

Dummy routine which reports that object can be destroyed when there is no
sharing module present.  It ignores its single SV argument, and returns
'true'.  Exists to avoid test for a NULL function pointer and because it
could potentially warn under some level of strict-ness.

	bool	sv_destroyable(SV *sv)

=for hackers
Found in file util.c

=item sv_nosharing
X<sv_nosharing>

Dummy routine which "shares" an SV when there is no sharing module present.
Or "locks" it. Or "unlocks" it. In other words, ignores its single SV argument.
Exists to avoid test for a NULL function pointer and because it could
potentially warn under some level of strict-ness.

	void	sv_nosharing(SV *sv)

=for hackers
Found in file util.c

=item upg_version
X<upg_version>

In-place upgrade of the supplied SV to a version object.

    SV *sv = upg_version(SV *sv, bool qv);

Returns a pointer to the upgraded SV.  Set the boolean qv if you want
to force this SV to be interpreted as an "extended" version.

	SV*	upg_version(SV *ver, bool qv)

=for hackers
Found in file util.c

=item vcmp
X<vcmp>

Version object aware cmp.  Both operands must already have been 
converted into version objects.

	int	vcmp(SV *lvs, SV *rvs)

=for hackers
Found in file util.c

=item vnormal
X<vnormal>

Accepts a version object and returns the normalized string
representation.  Call like:

    sv = vnormal(rv);

NOTE: you can pass either the object directly or the SV
contained within the RV.

	SV*	vnormal(SV *vs)

=for hackers
Found in file util.c

=item vnumify
X<vnumify>

Accepts a version object and returns the normalized floating
point representation.  Call like:

    sv = vnumify(rv);

NOTE: you can pass either the object directly or the SV
contained within the RV.

	SV*	vnumify(SV *vs)

=for hackers
Found in file util.c

=item vstringify
X<vstringify>

In order to maintain maximum compatibility with earlier versions
of Perl, this function will return either the floating point
notation or the multiple dotted notation, depending on whether
the original version contained 1 or more dots, respectively

	SV*	vstringify(SV *vs)

=for hackers
Found in file util.c

=item vverify
X<vverify>

Validates that the SV contains a valid version object.

    bool vverify(SV *vobj);

Note that it only confirms the bare minimum structure (so as not to get
confused by derived classes which may contain additional hash entries):

	bool	vverify(SV *vs)

=for hackers
Found in file util.c


=back

=head1 MRO Functions

=over 8

=item mro_get_linear_isa
X<mro_get_linear_isa>

Returns either C<mro_get_linear_isa_c3> or
C<mro_get_linear_isa_dfs> for the given stash,
dependant upon which MRO is in effect
for that stash.  The return value is a
read-only AV*.

You are responsible for C<SvREFCNT_inc()> on the
return value if you plan to store it anywhere
semi-permanently (otherwise it might be deleted
out from under you the next time the cache is
invalidated).

	AV*	mro_get_linear_isa(HV* stash)

=for hackers
Found in file mro.c

=item mro_method_changed_in
X<mro_method_changed_in>

Invalidates method caching on any child classes
of the given stash, so that they might notice
the changes in this one.

Ideally, all instances of C<PL_sub_generation++> in
perl source outside of C<mro.c> should be
replaced by calls to this.

Perl automatically handles most of the common
ways a method might be redefined.  However, there
are a few ways you could change a method in a stash
without the cache code noticing, in which case you
need to call this method afterwards:

1) Directly manipulating the stash HV entries from
XS code.

2) Assigning a reference to a readonly scalar
constant into a stash entry in order to create
a constant subroutine (like constant.pm
does).

This same method is available from pure perl
via, C<mro::method_changed_in(classname)>.

	void	mro_method_changed_in(HV* stash)

=for hackers
Found in file mro.c


=back

=head1 Multicall Functions

=over 8

=item dMULTICALL
X<dMULTICALL>

Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.

		dMULTICALL;

=for hackers
Found in file cop.h

=item MULTICALL
X<MULTICALL>

Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.

		MULTICALL;

=for hackers
Found in file cop.h

=item POP_MULTICALL
X<POP_MULTICALL>

Closing bracket for a lightweight callback.
See L<perlcall/Lightweight Callbacks>.

		POP_MULTICALL;

=for hackers
Found in file cop.h

=item PUSH_MULTICALL
X<PUSH_MULTICALL>

Opening bracket for a lightweight callback.
See L<perlcall/Lightweight Callbacks>.

		PUSH_MULTICALL;

=for hackers
Found in file cop.h


=back

=head1 Numeric functions

=over 8

=item grok_bin
X<grok_bin>

converts a string representing a binary number to numeric form.

On entry I<start> and I<*len> give the string to scan, I<*flags> gives
conversion flags, and I<result> should be NULL or a pointer to an NV.
The scan stops at the end of the string, or the first invalid character.
Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
invalid character will also trigger a warning.
On return I<*len> is set to the length of the scanned string,
and I<*flags> gives output flags.

If the value is <= C<UV_MAX> it is returned as a UV, the output flags are clear,
and nothing is written to I<*result>. If the value is > UV_MAX C<grok_bin>
returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
and writes the value to I<*result> (or the value is discarded if I<result>
is NULL).

The binary number may optionally be prefixed with "0b" or "b" unless
C<PERL_SCAN_DISALLOW_PREFIX> is set in I<*flags> on entry. If
C<PERL_SCAN_ALLOW_UNDERSCORES> is set in I<*flags> then the binary
number may use '_' characters to separate digits.

	UV	grok_bin(const char* start, STRLEN* len_p, I32* flags, NV *result)

=for hackers
Found in file numeric.c

=item grok_hex
X<grok_hex>

converts a string representing a hex number to numeric form.

On entry I<start> and I<*len> give the string to scan, I<*flags> gives
conversion flags, and I<result> should be NULL or a pointer to an NV.
The scan stops at the end of the string, or the first invalid character.
Unless C<PERL_SCAN_SILENT_ILLDIGIT> is set in I<*flags>, encountering an
invalid character will also trigger a warning.
On return I<*len> is set to the length of the scanned string,
and I<*flags> gives output flags.

If the value is <= UV_MAX it is returned as a UV, the output flags are clear,
and nothing is written to I<*result>. If the value is > UV_MAX C<grok_hex>
returns UV_MAX, sets C<PERL_SCAN_GREATER_THAN_UV_MAX> in the output flags,
and writes the value to I<*result> (or the value is discarded if