pqxx::internal Namespace Reference

Internal items for libpqxx' own use. Do not use these yourself. More...

Namespaces
	gate

Classes
class	basic_robusttransaction
	Helper base class for the robusttransaction class template. More...
class	basic_transaction
	Helper base class for the transaction class template. More...
struct	enum_traits
	Helper class for defining enum conversions. More...
class	result_iter

Functions
void	wait_read (internal::pq::PGconn const *)
void	wait_read (internal::pq::PGconn const *, std::time_t seconds, long microseconds)
void	wait_write (internal::pq::PGconn const *)
void	clear_result (pq::PGresult const *)
	C++ wrapper for libpq's PQclear. More...
std::string	demangle_type_name (char const [])
	Attempt to demangle std::type_info::name() to something human-readable. More...
std::string	cat2 (std::string_view x, std::string_view y)
	Efficiently concatenate two strings. More...
std::string	describe_object (std::string_view class_name, std::string_view name)
	Describe an object for humans, based on class name and optional name. More...
void	check_unique_register (void const *old_guest, std::string_view old_class, std::string_view old_name, void const *new_guest, std::string_view new_class, std::string_view new_name)
	Check validity of registering a new "guest" in a "host.". More...
void	check_unique_unregister (void const *old_guest, std::string_view old_class, std::string_view old_name, void const *new_guest, std::string_view new_class, std::string_view new_name)
	Like check_unique_register, but for un-registering a guest. More...
constexpr std::size_t	size_esc_bin (std::size_t binary_bytes) noexcept
	Compute buffer size needed to escape binary data for use as a BYTEA. More...
constexpr std::size_t	size_unesc_bin (std::size_t escaped_bytes) noexcept
	Compute binary size from the size of its escaped version. More...
void	esc_bin (std::string_view binary_data, char buffer[]) noexcept
	Hex-escape binary data into a buffer. More...
std::string	esc_bin (std::string_view binary_data)
	Hex-escape binary data into a std::string. More...
void	unesc_bin (std::string_view escaped_data, std::byte buffer[])
	Reconstitute binary data from its escaped version. More...
std::string	unesc_bin (std::string_view escaped_data)
	Reconstitute binary data from its escaped version. More...
template<typename T >
auto	ssize (T const &c)
	Transitional: std::ssize(), or custom implementation if not available. More...
void	wait_for (unsigned int microseconds)
	Wait. More...
int	PQXX_VERSION_CHECK () noexcept
	Library version check stub. More...
constexpr char const *	as_c_string (char const str[]) noexcept
	Get a raw C string pointer. More...
template<std::size_t N>
constexpr char const *	as_c_string (char(&str)[N]) noexcept
	Get a raw C string pointer. More...
constexpr char const *	as_c_string (pqxx::zview str) noexcept
	Get a raw C string pointer. More...
char const *	as_c_string (std::string const &str) noexcept
	Get a raw C string pointer. More...
PQXX_PURE char const *	name_encoding (int encoding_id)
encoding_group	enc_group (int libpq_enc_id)
encoding_group	enc_group (std::string_view encoding_name)
template<template< encoding_group > class T, typename F >
constexpr F *	for_encoding (encoding_group enc)
	Look up instantiation T<enc>::call at runtime. More...
PQXX_PURE glyph_scanner_func *	get_glyph_scanner (encoding_group enc)
PQXX_PURE std::size_t	find_with_encoding (encoding_group enc, std::string_view haystack, char needle, std::size_t start)
PQXX_PURE std::size_t	find_with_encoding (encoding_group enc, std::string_view haystack, std::string_view needle, std::size_t start)
void	throw_null_conversion (std::string const &type)
std::string	state_buffer_overrun (int have_bytes, int need_bytes)
template<typename F >
std::string	to_dumb_stringstream (dumb_stringstream< F > &s, F value)
template<typename T >
std::string	to_string_float (T value)
	Floating-point implementations for pqxx::to_string(). More...
template std::string	to_string_float (float)
template std::string	to_string_float (double)
template std::string	to_string_float (long double)

Variables
constexpr char	empty_composite_str [] {"()"}
template<pqxx::isolation_level isolation, pqxx::write_policy rw>
const zview	begin_cmd
	The SQL command for starting a given type of transaction. More...

Detailed Description

Internal items for libpqxx' own use. Do not use these yourself.

Private namespace for libpqxx's internal use; do not access.

This namespace hides definitions internal to libpqxx. These are not supposed to be used by client programs, and they may change at any time without notice.

Conversely, if you find something in this namespace tremendously useful, by all means do lodge a request for its publication.

Warning

Here be dragons!

Version check.

Copyright (c) 2000-2021, Jeroen T. Vermeulen.

See COPYING for copyright license. If you did not receive a file called COPYING with this source code, please notify the distributor of this mistake, or contact the author.

Function Documentation

as_c_string() [1/4]

constexpr char const* pqxx::internal::as_c_string ( char const  str[] )

noexcept

Get a raw C string pointer.

References as_c_string().

Referenced by as_c_string(), and pqxx::connection::quote_columns().

as_c_string() [2/4]

template<std::size_t N>

constexpr char const* pqxx::internal::as_c_string ( char(&)  str[N] )

noexcept

Get a raw C string pointer.

References as_c_string().

as_c_string() [3/4]

constexpr char const* pqxx::internal::as_c_string ( pqxx::zview  str )

noexcept

Get a raw C string pointer.

References as_c_string().

as_c_string() [4/4]

char const* pqxx::internal::as_c_string ( std::string const &  str )

noexcept

Get a raw C string pointer.

References as_c_string().

cat2()

std::string pqxx::internal::cat2	(	std::string_view	x,
		std::string_view	y
	)

Efficiently concatenate two strings.

This is a special case of concatenate(), needed because dependency management does not let us use that function here.

Referenced by pqxx::check_cast().

check_unique_register()

void pqxx::internal::check_unique_register	(	void const *	old_guest,
		std::string_view	old_class,
		std::string_view	old_name,
		void const *	new_guest,
		std::string_view	new_class,
		std::string_view	new_name
	)

Check validity of registering a new "guest" in a "host.".

The host might be e.g. a connection, and the guest a transaction. The host can only have one guest at a time, so it is an error to register a new guest while the host already has a guest.

If the new registration is an error, this function throws a descriptive exception.

Pass the old guest (if any) and the new guest (if any), for both, a type name (at least if the guest is not null), and optionally an object name (but which may be omitted if the caller did not assign one).

References describe_object().

Referenced by pqxx::transaction_base::close(), and pqxx::connection::close().

check_unique_unregister()

void pqxx::internal::check_unique_unregister	(	void const *	old_guest,
		std::string_view	old_class,
		std::string_view	old_name,
		void const *	new_guest,
		std::string_view	new_class,
		std::string_view	new_name
	)

Like check_unique_register, but for un-registering a guest.

Pass the guest which was registered, as well as the guest which is being unregistered, so that the function can check that they are the same one.

References describe_object().

Referenced by pqxx::transaction_base::close(), and pqxx::connection::close().

clear_result()

void pqxx::internal::clear_result

(

pq::PGresult const *

data

)

C++ wrapper for libpq's PQclear.

References pqxx::result::result().

Referenced by pqxx::result::table_column().

demangle_type_name()

std::string pqxx::internal::demangle_type_name

(

char const

raw[]

)

Attempt to demangle std::type_info::name() to something human-readable.

describe_object()

std::string pqxx::internal::describe_object	(	std::string_view	class_name,
		std::string_view	name
	)

Describe an object for humans, based on class name and optional name.

Interprets an empty name as "no name given."

Referenced by check_unique_register(), check_unique_unregister(), pqxx::connection::close(), pqxx::transaction_focus::description(), and pqxx::transaction_base::direct_exec().

enc_group() [1/2]

encoding_group pqxx::internal::enc_group

(

int

libpq_enc_id

)

References name_encoding().

Referenced by pqxx::connection::esc_like(), and pqxx::connection::operator=().

enc_group() [2/2]

encoding_group pqxx::internal::enc_group

(

std::string_view

encoding_name

)

esc_bin() [1/2]

void pqxx::internal::esc_bin ( std::string_view  binary_data, char  buffer[]  )

noexcept

Hex-escape binary data into a buffer.

The buffer must be able to accommodate size_esc_bin(std::size(binary_data)) bytes, and the function will write exactly that number of bytes into the buffer. This includes a trailing zero.

Referenced by esc_bin(), pqxx::connection::esc_raw(), pqxx::string_traits< binarystring >::into_buf(), and size_unesc_bin().

esc_bin() [2/2]

std::string pqxx::internal::esc_bin

(

std::string_view

binary_data

)

Hex-escape binary data into a std::string.

References esc_bin(), and size_esc_bin().

find_with_encoding() [1/2]

PQXX_PURE std::size_t pqxx::internal::find_with_encoding	(	encoding_group	enc,
		std::string_view	haystack,
		char	needle,
		std::size_t	start
	)

find_with_encoding() [2/2]

PQXX_PURE std::size_t pqxx::internal::find_with_encoding	(	encoding_group	enc,
		std::string_view	haystack,
		std::string_view	needle,
		std::size_t	start
	)

for_encoding()

template<template< encoding_group > class T, typename F >

constexpr F* pqxx::internal::for_encoding

(

encoding_group

enc

)

Look up instantiation T<enc>::call at runtime.

Here, "T" is a struct template with a static member function "call", whose type is "F".

The return value is a pointer to the "call" member function for the instantiation of T for encoding group enc.

get_glyph_scanner()

PQXX_PURE glyph_scanner_func* pqxx::internal::get_glyph_scanner

(

encoding_group

enc

)

Referenced by pqxx::parse_composite().

name_encoding()

PQXX_PURE char const* pqxx::internal::name_encoding

(

int

encoding_id

)

Referenced by enc_group(), and pqxx::connection::get_client_encoding().

PQXX_VERSION_CHECK()

int pqxx::internal::PQXX_VERSION_CHECK ( )

noexcept

Library version check stub.

Helps detect version mismatches between libpqxx headers and the libpqxx library binary.

Sometimes users run into trouble linking their code against libpqxx because they build their own libpqxx, but the system also has a different version installed. The declarations in the headers against which they compile their code will differ from the ones used to build the libpqxx version they're using, leading to confusing link errors. The solution is to generate a link error when the libpqxx binary is not the same version as the libpqxx headers used to compile the code.

This function's definition is in the libpqxx binary, so it's based on the version as found in the binary. The headers contain a call to the function, whose name contains the libpqxx version as found in the headers. (The library build process will use its own local headers even if another version of the headers is installed on the system.)

If the libpqxx binary was compiled for a different version than the user's code, linking will fail with an error: check_library_version will not exist for the given version number.

Referenced by pqxx::check_version().

size_esc_bin()

constexpr std::size_t pqxx::internal::size_esc_bin ( std::size_t  binary_bytes )

noexcept

Compute buffer size needed to escape binary data for use as a BYTEA.

This uses the hex-escaping format. The return value includes room for the "\x" prefix.

Referenced by esc_bin(), and pqxx::string_traits< binarystring >::size_buffer().

size_unesc_bin()

constexpr std::size_t pqxx::internal::size_unesc_bin ( std::size_t  escaped_bytes )

noexcept

Compute binary size from the size of its escaped version.

Do not include a terminating zero in escaped_bytes.

References esc_bin(), and unesc_bin().

Referenced by pqxx::string_traits< binarystring >::from_string(), and unesc_bin().

ssize()

template<typename T >

auto pqxx::internal::ssize

(

T const &

c

)

Transitional: std::ssize(), or custom implementation if not available.

References wait_for().

Referenced by pqxx::connection::close(), pqxx::params::make_c_params(), and pqxx::params::ssize().

state_buffer_overrun()

std::string pqxx::internal::state_buffer_overrun	(	int	have_bytes,
		int	need_bytes
	)

References pqxx::text, pqxx::to_buf(), and to_string_float().

throw_null_conversion()

void pqxx::internal::throw_null_conversion

(

std::string const &

type

)

Referenced by pqxx::field::as(), pqxx::field::as< std::string_view >(), pqxx::from_string(), and pqxx::stream_from::operator>>().

to_dumb_stringstream()

template<typename F >

std::string pqxx::internal::to_dumb_stringstream	(	dumb_stringstream< F > &	s,
		F	value
	)

Referenced by to_string_float().

to_string_float() [1/4]

template<typename T >

std::string pqxx::internal::to_string_float

(

T

value

)

Floating-point implementations for pqxx::to_string().

References pqxx::from_string(), pqxx::size_buffer(), pqxx::text, pqxx::to_buf(), and to_dumb_stringstream().

Referenced by state_buffer_overrun().

to_string_float() [2/4]

template std::string pqxx::internal::to_string_float

(

float

)

to_string_float() [3/4]

template std::string pqxx::internal::to_string_float

(

double

)

to_string_float() [4/4]

template std::string pqxx::internal::to_string_float

(

long

double

)

unesc_bin() [1/2]

void pqxx::internal::unesc_bin	(	std::string_view	escaped_data,
		std::byte	buffer[]
	)

Reconstitute binary data from its escaped version.

Referenced by pqxx::string_traits< binarystring >::from_string(), size_unesc_bin(), unesc_bin(), and pqxx::connection::unesc_raw().

unesc_bin() [2/2]

std::string pqxx::internal::unesc_bin

(

std::string_view

escaped_data

)

Reconstitute binary data from its escaped version.

References size_unesc_bin(), and unesc_bin().

wait_for()

void pqxx::internal::wait_for

(

unsigned int

microseconds

)

Wait.

This is normally std::this_thread::sleep_for(). But MinGW's <thread> doesn't work, so we must be careful about including it.

Referenced by pqxx::internal::basic_robusttransaction::basic_robusttransaction(), and ssize().

wait_read() [1/2]

void pqxx::internal::wait_read

(

internal::pq::PGconn const *

c

)

Referenced by pqxx::connection::quote_columns(), pqxx::connection::unesc_raw(), and wait_write().

wait_read() [2/2]

void pqxx::internal::wait_read	(	internal::pq::PGconn const *	c,
		std::time_t	seconds,
		long	microseconds
	)

References pqxx::check_cast().

wait_write()

void pqxx::internal::wait_write

(

internal::pq::PGconn const *

c

)

References wait_read().

Referenced by pqxx::connection::quote_columns().

Variable Documentation

begin_cmd

template<pqxx::isolation_level isolation, pqxx::write_policy rw>

const zview pqxx::internal::begin_cmd

The SQL command for starting a given type of transaction.

empty_composite_str

constexpr char pqxx::internal::empty_composite_str[] {"()"}

Referenced by pqxx::composite_size_buffer().