Binary buffer with bit-level read operations. More...

#include <input.h>

Public Member Functions
	Input (const std::string &in)
	Wrap a string iinto a Input. More...

void	scan_lead_sections ()
	Scan the message filling in the sec[] array of start offsets of sections 0 and 1. More...

void	scan_other_sections (bool has_optional)
	Scan the message filling in the sec[] array of section start offsets of all sections from 2 on. More...

unsigned	offset () const
	Return the current decoding byte offset.

unsigned	bits_left () const
	Return the number of bits left in the message to be decoded.

unsigned	read_byte (unsigned pos) const
	Read a byte value at offset pos.

unsigned	read_byte (unsigned section, unsigned pos) const
	Read a byte value at offset pos inside section section.

unsigned	read_number (unsigned pos, unsigned byte_len) const
	Read a big endian integer value byte_len bytes long, at offset pos.

unsigned	read_number (unsigned section, unsigned pos, unsigned byte_len) const
	Read a big endian integer value byte_len bytes long, at offset pos inside section section.

uint32_t	get_bits (unsigned n)
	Get the integer value of the next 'n' bits from the decode input n must be <= 32.

void	debug_dump_next_bits (const char *desc, int count) const
	Dump to stderr 'count' bits of 'buf', starting at the 'ofs-th' bit.

void	parse_error (const char *fmt,...) const WREPORT_THROWF_ATTRS(2
	Throw an error_parse at the current decoding location.

void void	parse_error (unsigned pos, const char *fmt,...) const WREPORT_THROWF_ATTRS(3
	Throw an error_parse at the given decoding location.

void void void	parse_error (unsigned section, unsigned pos, const char *fmt,...) const WREPORT_THROWF_ATTRS(4
	Throw an error_parse at the given decoding location inside the given section.

void void void void	check_available_data (unsigned pos, size_t datalen, const char *expected)
	Check that the input buffer contains at least datalen characters after offset pos; throw error_parse otherwise. More...

void	check_available_message_data (unsigned section, unsigned pos, size_t datalen, const char *expected)
	Check that the input buffer contains at least datalen characters after offset pos in section section; throw error_parse otherwise. More...

void	check_available_section_data (unsigned section, unsigned pos, size_t datalen, const char *expected)
	Check that the given section in the input buffer contains at least datalen characters after offset pos; throw error_parse otherwise. More...

void	decode_compressed_number (Var &dest, uint32_t base, unsigned diffbits)
	Decode a compressed number as described by dest.info(), ad set it as value for dest. More...

void	decode_number (Var &dest)
	Decode a number as described by dest.info(), and set it as value for dest. More...

bool	decode_compressed_base (Varinfo info, uint32_t &base, uint32_t &diffbits)

void	decode_compressed_number (Varinfo info, unsigned subsets, std::function< void(unsigned, Var &&)> dest)
	Decode a number as described by info from a compressed bufr with subsets subsets, and send the resulting variables to dest.

void	decode_string (Varinfo info, unsigned subsets, DispatchToSubsets &dest)

void	decode_compressed_number (Varinfo info, unsigned subsets, DispatchToSubsets &dest)

void	decode_compressed_number (Varinfo info, const bulletin::AssociatedField &afield, unsigned subsets, std::function< void(unsigned, Var &&)> dest)
	Decode a number as described by info from a compressed bufr with subsets subsets, and send the resulting variables to dest.

void	decode_compressed_semantic_number (Var &dest, unsigned subsets)
	Decode a number as described by dest.info(), and set it as value for dest. More...

bool	decode_string (unsigned bit_len, char *str, size_t &len)
	Read a string from the data section. More...

void	decode_string (Var &dest)
	Decode a string as described by dest.info(), ad set it as value for dest. More...

void	decode_string (Var &dest, unsigned subsets)
	Decode a string as described by dest.info(), and set it as value for dest. More...

void	decode_string (Varinfo info, unsigned subsets, std::function< void(unsigned, Var &&)> dest)
	Decode a string as described by info from a compressed bufr with subsets subsets, and send the resulting variables to dest.

void	decode_binary (Var &dest)
	Decode a generic binary value as-is, as described by dest.info(), ad set it as value for dest. More...

std::string	decode_uncompressed_bitmap (unsigned size)
	Decode an uncompressed bitmap of size bits. More...

std::string	decode_compressed_bitmap (unsigned size)
	Decode a "compressed" bitmap of size bits. More...

Data Fields
const uint8_t *	data
	Input buffer.

size_t	data_len
	Input buffer size.

const char *	fname = nullptr
	Input file name (optional). More...

size_t	start_offset = 0
	File offset of the start of the message. More...

unsigned	s4_cursor = 0
	Offset of the byte we are currently decoding.

uint8_t	pbyte = 0
	Byte we are currently decoding.

int	pbyte_len = 0
	Bits left in pbyte to decode.

unsigned	sec [6]
	Offsets of the start of BUFR sections.

Protected Member Functions
void	scan_section_length (unsigned sec_no)
	Scan length of section sec_no, filling in the start of the next section in sec[sec_no + 1].

Detailed Description

Binary buffer with bit-level read operations.

Constructor & Destructor Documentation

◆ Input()

wreport::bufr::Input::Input ( const std::string & in )

Wrap a string iinto a Input.

Parameters

in	String with the data to read

Member Function Documentation

◆ check_available_data()

void void void void wreport::bufr::Input::check_available_data	(	unsigned	pos,
		size_t	datalen,
		const char *	expected
	)

Check that the input buffer contains at least datalen characters after offset pos; throw error_parse otherwise.

Parameters

pos	Starting offset of the required data
datalen	Required amount of data expected starting from pos
expected	name of what we are about to decode, used for generating nice error messages

◆ check_available_message_data()

void wreport::bufr::Input::check_available_message_data	(	unsigned	section,
		unsigned	pos,
		size_t	datalen,
		const char *	expected
	)

Check that the input buffer contains at least datalen characters after offset pos in section section; throw error_parse otherwise.

Parameters

section	Number of the section to check
pos	Starting offset inside the section of the required data
datalen	Required amount of data expected starting from pos
expected	Name of what we are about to decode, used for generating nice error messages

◆ check_available_section_data()

void wreport::bufr::Input::check_available_section_data	(	unsigned	section,
		unsigned	pos,
		size_t	datalen,
		const char *	expected
	)

Check that the given section in the input buffer contains at least datalen characters after offset pos; throw error_parse otherwise.

Parameters

section	Number of the section to check
pos	Starting offset inside the section of the required data
datalen	Required amount of data expected starting from pos
expected	Name of what we are about to decode, used for generating nice error messages

◆ decode_binary()

void wreport::bufr::Input::decode_binary ( Var & dest )

Decode a generic binary value as-is, as described by dest.info(), ad set it as value for dest.

It is assumed that dest is not set, therefore in case we decode a missing value, dest will not be touched.

Parameters

dest	Variable which holds the decoding information and that will hold the decoded value

◆ decode_compressed_bitmap()

std::string wreport::bufr::Input::decode_compressed_bitmap ( unsigned size )

Decode a "compressed" bitmap of size bits.

The result will be a string size bytes long, with a '+' where the bitmap reports that data is present, and a '-' where the bitmap reports that data is not present.

It would be more correct to say that it decodes a bitmap from a compressed BUFR message, because bitmaps in compressed messages are actually encoded with 7 bits per bit instead of one, because after each bit they need to send 6 bits saying that it will be followed by 0 bits of difference values.

◆ decode_compressed_number()

void wreport::bufr::Input::decode_compressed_number	(	Var &	dest,
		uint32_t	base,
		unsigned	diffbits
	)

Decode a compressed number as described by dest.info(), ad set it as value for dest.

Parameters

dest	Variable which holds the decoding information and that will hold the decoded value
base	The base value for the compressed number
diffbits	The number of bits used to encode the difference from base

◆ decode_compressed_semantic_number()

void wreport::bufr::Input::decode_compressed_semantic_number	(	Var &	dest,
		unsigned	subsets
	)

Decode a number as described by dest.info(), and set it as value for dest.

The number is decoded for subsets compressed datasets, and an exception is thrown if the values differ.

Parameters

dest	Variable which holds the decoding information and that will hold the decoded value
subsets	Number of subsets in the compressed data section

◆ decode_number()

void wreport::bufr::Input::decode_number ( Var & dest )

Decode a number as described by dest.info(), and set it as value for dest.

Parameters

dest	Variable which holds the decoding information and that will hold the decoded value

◆ decode_string() [1/3]

bool wreport::bufr::Input::decode_string	(	unsigned	bit_len,
		char *	str,
		size_t &	len
	)

Read a string from the data section.

Parameters

bit_len Number of bits (not bytes) to read. It is normally a multiple of 8, and when it is not, the last character will contain the partial byte read.

Return values

str	Buffer where the string is written. Must be big enough to contain the longest string described by info, plus 2 bytes
len	The string length

Returns: true if we decoded a real string, false if we decoded a missing string value

◆ decode_string() [2/3]

void wreport::bufr::Input::decode_string ( Var & dest )

Decode a string as described by dest.info(), ad set it as value for dest.

It is assumed that dest is not set, therefore in case we decode a missing value, dest will not be touched.

Parameters

dest	Variable which holds the decoding information and that will hold the decoded value

◆ decode_string() [3/3]

void wreport::bufr::Input::decode_string	(	Var &	dest,
		unsigned	subsets
	)

Decode a string as described by dest.info(), and set it as value for dest.

The string is decoded for subsets compressed datasets, and an exception is thrown if the values differ.

Parameters

dest	Variable which holds the decoding information and that will hold the decoded value
subsets	Number of subsets in the compressed data section

◆ decode_uncompressed_bitmap()

std::string wreport::bufr::Input::decode_uncompressed_bitmap ( unsigned size )

Decode an uncompressed bitmap of size bits.

The result will be a string size bytes long, with a '+' where the bitmap reports that data is present, and a '-' where the bitmap reports that data is not present.

◆ scan_lead_sections()

void wreport::bufr::Input::scan_lead_sections ( )

Scan the message filling in the sec[] array of start offsets of sections 0 and 1.

We cannot scan past section 1 until we decode it, because we need to know if section 2 is present or not

◆ scan_other_sections()

void wreport::bufr::Input::scan_other_sections ( bool has_optional )

Scan the message filling in the sec[] array of section start offsets of all sections from 2 on.

It also initialises points s4_cursor to the begin of the data in section 4.

Parameters

has_optional True if the optional section is present, false if it should be skipped.

Field Documentation

◆ fname

const char* wreport::bufr::Input::fname = nullptr

Input file name (optional).

If available, it will be used to generate better error messages.

If not available, it is NULL.

◆ start_offset

size_t wreport::bufr::Input::start_offset = 0

File offset of the start of the message.

If available, it will be used to generate better error messages.

If not available, it is 0.

The documentation for this class was generated from the following file:

input.h

Public Member Functions

Data Fields

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ Input()

Member Function Documentation

◆ check_available_data()

◆ check_available_message_data()

◆ check_available_section_data()

◆ decode_binary()

◆ decode_compressed_bitmap()

◆ decode_compressed_number()

◆ decode_compressed_semantic_number()

◆ decode_number()

◆ decode_string() [1/3]

◆ decode_string() [2/3]

◆ decode_string() [3/3]

◆ decode_uncompressed_bitmap()

◆ scan_lead_sections()

◆ scan_other_sections()

Field Documentation

◆ fname

◆ start_offset