The plssvm::detail::file_reader class is responsible for reading a file and splitting it into its lines. More...

#include <file_reader.hpp>

Public Member Functions
	file_reader ()=default
	Creates a new file_reader without associating it to a file.

	file_reader (const char *filename)
	Create a new file_reader and associate it to the `filename` by opening it (possibly memory mapping it). More...

	file_reader (const std::string &filename)
	Create a new file_reader and associate it to the `filename` by opening it (possibly memory mapping it). More...

	file_reader (const std::filesystem::path &filename)
	Create a new file_reader and associate it to the `filename` by opening it (possibly memory mapping it). More...

	~file_reader ()
	Closes the associated file. More...

	file_reader (const file_reader &)=delete
	Delete the copy-constructor since file_reader is move-only.

	file_reader (file_reader &&other) noexcept
	Implement the move-constructor since file_reader is move-only. More...

file_reader &	operator= (const file_reader &)=delete
	Delete the copy-assignment operator since file_reader is move-only. More...

file_reader &	operator= (file_reader &&other) noexcept
	Implement the move-assignment operator since file_reader is move-only. More...

void	open (const char *filename)
	Associates the current file_reader with the file denoted by `filename`, i.e., opens the file `filename` (possible memory mapping it). More...

void	open (const std::string &filename)
	Associates the current file_reader with the file denoted by `filename`, i.e., opens the file `filename` (possible memory mapping it). More...

void	open (const std::filesystem::path &filename)
	Associates the current file_reader with the file denoted by `filename`, i.e., opens the file `filename` (possible memory mapping it). More...

bool	is_open () const noexcept
	Checks whether this file_reader is currently associated with a file. More...

void	close ()
	Closes the associated file. More...

void	swap (file_reader &other)
	Element-wise swap all contents of `*this` with `other`. More...

const std::vector< std::string_view > &	read_lines (std::string_view comment={ "\n" })
	Read the content of the associated file and split it into lines, ignoring empty lines and lines starting with the `comment`. More...

const std::vector< std::string_view > &	read_lines (char comment)
	Read the content of the associated file and split it into lines, ignoring empty lines and lines starting with the `comment`. More...

std::vector< std::string_view >::size_type	num_lines () const noexcept
	Return the number of parsed lines (where all empty lines or lines starting with a comment are ignored). More...

std::string_view	line (typename std::vector< std::string_view >::size_type pos) const
	Return the `pos` line of the parsed file. More...

const std::vector< std::string_view > &	lines () const noexcept
	Return all lines present after the preprocessing. More...

const char *	buffer () const noexcept
	Return the underlying file content as one large string. More...

Private Member Functions
void	open_memory_mapped_file_unix (const char *filename)
	Try to open the file `filename` and "read" its content using memory mapped IO on UNIX systems. More...

void	open_memory_mapped_file_windows (const char *filename)
	Try to open the file `filename` and "read" its content using memory mapped IO on Windows systems. More...

void	open_file (const char *filename)
	Read open the file and read its content in one buffer using a normal std::ifstream. More...

Private Attributes
char *	file_content_ { nullptr }
	The content of the file. Pointer to the memory mapped area or to a separately allocated memory area holding the file's content. If the file is empty, corresponds to a `nullptr`!

std::streamsize	num_bytes_ { 0 }
	The number of bytes stored in file_content_.

std::vector< std::string_view >	lines_ {}
	The parsed content of file_content_: a vector of all lines that are not empty and do not start with the provided comment.

bool	is_open_ { false }
	`true` if a file is currently associated wih this file_reader, `false` otherwise.

Detailed Description

The plssvm::detail::file_reader class is responsible for reading a file and splitting it into its lines.

If the necessary headers are present, the class tries to memory map the given file. If this fails or if the headers are not present, the file is read as one blob using std::ifstream::read.

Constructor & Destructor Documentation

◆ file_reader() [1/4]

plssvm::detail::io::file_reader::file_reader ( const char * filename )

explicit

Create a new file_reader and associate it to the filename by opening it (possibly memory mapping it).

Parameters

[in] filename the file to open

Exceptions

plssvm::file_not_found_exception if the filename couldn't be found

◆ file_reader() [2/4]

plssvm::detail::io::file_reader::file_reader ( const std::string & filename )

explicit

Create a new file_reader and associate it to the filename by opening it (possibly memory mapping it).

Parameters

[in] filename the file to open

Exceptions

plssvm::file_not_found_exception if the filename couldn't be found

◆ file_reader() [3/4]

plssvm::detail::io::file_reader::file_reader ( const std::filesystem::path & filename )

explicit

Create a new file_reader and associate it to the filename by opening it (possibly memory mapping it).

Parameters

[in] filename the file to open

Exceptions

plssvm::file_not_found_exception if the filename couldn't be found

◆ ~file_reader()

plssvm::detail::io::file_reader::~file_reader ( )

Closes the associated file.

If memory mapped IO has been used, unmap the file and close the file descriptor, and delete the allocated buffer.

◆ file_reader() [4/4]

plssvm::detail::io::file_reader::file_reader ( file_reader && other )

noexcept

Implement the move-constructor since file_reader is move-only.

Parameters

[in,out] other the file_reader to move the values from

Member Function Documentation

◆ operator=() [1/2]

file_reader& plssvm::detail::io::file_reader::operator= ( const file_reader & )

delete

Delete the copy-assignment operator since file_reader is move-only.

Returns: *this

◆ operator=() [2/2]

file_reader& plssvm::detail::io::file_reader::operator= ( file_reader && other )

noexcept

Implement the move-assignment operator since file_reader is move-only.

Parameters

[in,out] other the file_reader to move the values from

Returns: *this

◆ open() [1/3]

void plssvm::detail::io::file_reader::open ( const char * filename )

Associates the current file_reader with the file denoted by filename, i.e., opens the file filename (possible memory mapping it).

This function is called by the constructor of file_reader accepting a std::string and is not usually invoked directly.

Parameters

[in] filename the file to open

Exceptions

plssvm::file_reader_exception	if the file_reader has already opened another file
plssvm::file_not_found_exception	if the `filename` couldn't be found

◆ open() [2/3]

void plssvm::detail::io::file_reader::open ( const std::string & filename )

Associates the current file_reader with the file denoted by filename, i.e., opens the file filename (possible memory mapping it).

This function is called by the constructor of file_reader accepting a std::string and is not usually invoked directly.

Parameters

[in] filename the file to open

Exceptions

plssvm::file_reader_exception	if the file_reader has already opened another file
plssvm::file_not_found_exception	if the `filename` couldn't be found

◆ open() [3/3]

void plssvm::detail::io::file_reader::open ( const std::filesystem::path & filename )

Associates the current file_reader with the file denoted by filename, i.e., opens the file filename (possible memory mapping it).

This function is called by the constructor of file_reader accepting a std::string and is not usually invoked directly.

Parameters

[in] filename the file to open

Exceptions

plssvm::file_reader_exception	if the file_reader has already opened another file
plssvm::file_not_found_exception	if the `filename` couldn't be found

◆ is_open()

bool plssvm::detail::io::file_reader::is_open ( ) const

noexcept

Checks whether this file_reader is currently associated with a file.

Returns: true if a file is currently open, false otherwise ([[nodiscard]])

◆ close()

void plssvm::detail::io::file_reader::close ( )

Closes the associated file.

If memory mapped IO has been used, unmap the file and close the file descriptor, and delete the allocated buffer. This function is called by the destructor of file_reader when the object goes out of scope and is not usually invoked directly.

◆ swap()

void plssvm::detail::io::file_reader::swap ( file_reader & other )

Element-wise swap all contents of *this with other.

Parameters

[in,out] other the other file_reader to swap the contents with

◆ read_lines() [1/2]

const std::vector<std::string_view>& plssvm::detail::io::file_reader::read_lines ( std::string_view comment = { "\n" } )

Read the content of the associated file and split it into lines, ignoring empty lines and lines starting with the comment.

Parameters

[in] comment a character (sequence) at the beginning of a line that causes this line to be ignored (used to filter comments)

Exceptions

plssvm::file_reader_exception if no file is currently associated to this file_reader

Returns: the split lines, ignoring empty lines and lines starting with the comment

◆ read_lines() [2/2]

const std::vector<std::string_view>& plssvm::detail::io::file_reader::read_lines ( char comment )

Read the content of the associated file and split it into lines, ignoring empty lines and lines starting with the comment.

Parameters

[in] comment a character (sequence) at the beginning of a line that causes this line to be ignored (used to filter comments)

Exceptions

plssvm::file_reader_exception if no file is currently associated to this file_reader

Returns: the split lines, ignoring empty lines and lines starting with the comment

◆ num_lines()

std::vector<std::string_view>::size_type plssvm::detail::io::file_reader::num_lines ( ) const

noexcept

Return the number of parsed lines (where all empty lines or lines starting with a comment are ignored).

Returns 0 if no file is currently associated with this file_reader or the read_lines() function has not been called yet.

Returns: the number of lines after preprocessing ([[nodiscard]])

◆ line()

std::string_view plssvm::detail::io::file_reader::line ( typename std::vector< std::string_view >::size_type pos ) const

Return the pos line of the parsed file.

Returns 0 if no file is currently associated with this file_reader or the read_lines() function has not been called yet.

Parameters

[in] pos the line to return

Returns: the line without leading whitespaces ([[nodiscard]])

◆ lines()

const std::vector<std::string_view>& plssvm::detail::io::file_reader::lines ( ) const

noexcept

Return all lines present after the preprocessing.

Returns 0 if no file is currently associated with this file_reader or the read_lines() function has not been called yet.

Returns: all lines after preprocessing ([[nodiscard]])

◆ buffer()

const char* plssvm::detail::io::file_reader::buffer ( ) const

noexcept

Return the underlying file content as one large string.

Returns: the file content ([[nodiscard]])

◆ open_memory_mapped_file_unix()

void plssvm::detail::io::file_reader::open_memory_mapped_file_unix ( const char * filename )

private

Try to open the file filename and "read" its content using memory mapped IO on UNIX systems.

If the file could not be memory mapped, automatically falls back to open_file().

Parameters

[in] filename the file to open

Exceptions

plssvm::file_not_found_exception if the filename couldn't be found

◆ open_memory_mapped_file_windows()

void plssvm::detail::io::file_reader::open_memory_mapped_file_windows ( const char * filename )

private

Try to open the file filename and "read" its content using memory mapped IO on Windows systems.

If the file could not be memory mapped, automatically falls back to open_file().

Parameters

[in] filename the file to open

Exceptions

plssvm::file_not_found_exception if the filename couldn't be found

◆ open_file()

void plssvm::detail::io::file_reader::open_file ( const char * filename )

private

Read open the file and read its content in one buffer using a normal std::ifstream.

Parameters

[in] filename the file to open

Exceptions

plssvm::file_not_found_exception	if the `filename` couldn't be found
plssvm::invalid_file_format_exception	if an error occurs while reading the contents of the `filename`

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

include/plssvm/detail/io/file_reader.hpp

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ file_reader() [1/4]

◆ file_reader() [2/4]

◆ file_reader() [3/4]

◆ ~file_reader()

◆ file_reader() [4/4]

Member Function Documentation

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ open() [1/3]

◆ open() [2/3]

◆ open() [3/3]

◆ is_open()

◆ close()

◆ swap()

◆ read_lines() [1/2]

◆ read_lines() [2/2]

◆ num_lines()

◆ line()

◆ lines()

◆ buffer()

◆ open_memory_mapped_file_unix()

◆ open_memory_mapped_file_windows()

◆ open_file()