xtd::io::binary_reader Class Reference

Inheritance diagram for xtd::io::binary_reader:

Definition

Reads primitive data types as binary values in a specific encoding.

class core_export_ binary_reader : public xtd::object

Inheritance

xtd::object → xtd::io::binary_reader

Header

#include <xtd/io/binary_reader>

Namespace

xtd::io

Library

xtd.core

Examples

The following code example demonstrates how to store and retrieve application settings in a file.

#include <xtd/io/binary_reader>
#include <xtd/io/binary_writer>
#include <xtd/io/file>
#include <xtd/block_scope>
#include <xtd/console>
#include <xtd/startup>
 
using namespace xtd;
using namespace xtd::io;
 
class program {
  inline static const string file_name = "app_settings.dat";
public:
  static auto main() {
    write_default_values();
    display_values();
  }
  
  static void write_default_values() {
    block_scope_(auto fs = file::open(file_name, std::ios::out | std::ios::binary | std::ios::trunc)) {
      auto writer = binary_writer {fs};
      writer.write(1.250F);
      writer.write(R"(c:\Temp)");
      writer.write(10);
      writer.write(true);
    }
  }
  
  static void display_values() {
    auto aspect_ratio = .0f;
    auto temp_directory = string::empty_string;
    auto auto_save_time = 0;
    auto show_status_bar = false;
    
    if (file::exists(file_name)) {
      block_scope_(auto fs = file::open(file_name, std::ios::in | std::ios::binary)) {
        auto reader = binary_reader {fs};
        aspect_ratio = reader.read_single();
        temp_directory = reader.read_string();
        auto_save_time = reader.read_int32();
        show_status_bar = reader.read_boolean();
      }
      
      console::write_line("Aspect ratio set to: {}", aspect_ratio);
      console::write_line("Temp directory is: {}", temp_directory);
      console::write_line("Auto save time set to: {}", auto_save_time);
      console::write_line("Show status bar: {}", show_status_bar);
    }
  }
};
 
startup_(program::main);
 
// This code produces the following output :
//
// Aspect ratio set to: 1.25
// Temp directory is: c:\Temp
// Auto save time set to: 10
// Show status bar: true
 

Examples

The same example with stream operators.

#include <xtd/io/binary_reader>
#include <xtd/io/binary_writer>
#include <xtd/io/file>
#include <xtd/block_scope>
#include <xtd/console>
#include <xtd/startup>
 
using namespace xtd;
using namespace xtd::io;
 
class program {
  inline static const string file_name = "app_settings.dat";
public:
  static auto main() {
    write_default_values();
    display_values();
  }
  
  static void write_default_values() {
    block_scope_(auto fs = file::open(file_name, std::ios::out | std::ios::binary | std::ios::trunc)) {
      auto writer = binary_writer {fs};
      writer << 1.250F;
      writer << R"(c:\Temp)";
      writer << 10;
      writer << true;
    }
  }
  
  static void display_values() {
    auto aspect_ratio = .0f;
    auto temp_directory = string::empty_string;
    auto auto_save_time = 0;
    auto show_status_bar = false;
 
    if (file::exists(file_name)) {
      block_scope_(auto fs = file::open(file_name, std::ios::in | std::ios::binary)) {
        auto reader = binary_reader {fs};
        reader >> aspect_ratio;
        reader >> temp_directory;
        reader >> auto_save_time;
        reader >> show_status_bar;
      }
      
      console::write_line("Aspect ratio set to: {}", aspect_ratio);
      console::write_line("Temp directory is: {}", temp_directory);
      console::write_line("Auto save time set to: {}", auto_save_time);
      console::write_line("Show status bar: {}", show_status_bar);
    }
  }
};
 
startup_(program::main);
 
// This code produces the following output :
//
// Aspect ratio set to: 1.25
// Temp directory is: c:\Temp
// Auto save time set to: 10
// Show status bar: true
 

Remarks

The xtd:io::binary_reader class provides methods that simplify reading primitive data types from a stream. For example, you can use the xtd:io::binary_reader::read_boolean method to read the next byte as a bool value and advance the current position in the stream by one byte. The class includes read methods that support different data types.

When you create a new instance of the xtd:io::binary_reader and whether to leave the stream open after disposing the xtd:io::binary_reader object.

Examples

binary_reader.cpp, binary_reader2.cpp, and binary_reader3.cpp.

Public Constructors
	binary_reader (const xtd::string &path)
	Initializes a new instance of the xtd::io::binary_reader class for the specified file name.
	binary_reader (std::istream &stream)
	Initializes a new instance of the xtd::io::binary_reader class for the specified stream.

Public Properties
std::optional< std::reference_wrapper< std::istream > >	base_stream () const
	Returns the underlying stream.
bool	end_of_stream () const
	Gets a value that indicates whether the current stream position is at the end of the stream.

Public Methods
void	close ()
	Closes the xtd::io::binary_reader object and the underlying stream, and releases any system resources associated with the reader.
int32	peek_char () const
	Returns the next available character and does not advance the byte or character position.
std::streampos	pop ()
	Pop the current top position.
void	push (std::streampos pos=0)
	Push the current position.
virtual int32	read ()
	Reads characters from the underlying stream and advances the current position of the stream in accordance with the Encoding used and the specific character being read from the stream.
virtual size_t	read (std::vector< xtd::byte > &buffer, size_t index, size_t count)
	Reads the specified number of bytes from the stream, starting from a specified point in the byte array.
virtual size_t	read (std::vector< char > &buffer, size_t index, size_t count)
	Reads the specified number of characters from the stream, starting from a specified point in the character array.
virtual bool	read_boolean ()
	Reads a boolean value from the current stream and advances the current position of the stream by one byte.
virtual xtd::byte	read_byte ()
	Reads the next byte from the current stream and advances the current position of the stream by one byte.
virtual std::vector< xtd::byte >	read_bytes (size_t count)
	Reads the specified number of bytes from the current stream into a byte array and advances the current position by that number of bytes.
virtual char	read_char ()
	Reads the next character from the current stream and advances the current position of the stream by one byte.
virtual std::vector< char >	read_chars (size_t count)
	Reads the specified number of characters from the current stream into a byte array and advances the current position by that number of bytes.
virtual double	read_double ()
	Reads an 8-byte floating point value from the current stream and advances the current position of the stream by eight bytes.
virtual int16	read_int16 ()
	Reads a 2-byte signed integer from the current stream and advances the current position of the stream by two bytes.
virtual int32	read_int32 ()
	Reads a 4-byte signed integer from the current stream and advances the current position of the stream by four bytes.
virtual int64	read_int64 ()
	Reads a 8-byte signed integer from the current stream and advances the current position of the stream by eight bytes.
virtual sbyte	read_sbyte ()
	Reads the a signed byte from the current stream and advances the current position of the stream by one byte.
virtual float	read_single ()
	Reads an 4-byte floating point value from the current stream and advances the current position of the stream by four bytes.
virtual string	read_string ()
	Reads a string from the current stream. The string is prefixed with the length.
virtual uint16	read_uint16 ()
	Reads a 2-byte unsigned integer from the current stream and advances the current position of the stream by two bytes.
virtual uint32	read_uint32 ()
	Reads a 4-byte unsigned integer from the current stream and advances the current position of the stream by four bytes.
virtual uint64	read_uint64 ()
	Reads a 8-byte unsigned integer from the current stream and advances the current position of the stream by eight bytes.
void	rewind ()
	Rewind stream.
void	seekg (std::streamoff off, std::ios_base::seekdir dir=std::ios_base::cur)
	Change the position of the readers stream.
std::streampos	tellg ()
	Tell the current seek position of the readers stream;.

Additional Inherited Members
Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.
virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current object.
virtual size_t	get_hash_code () const noexcept
	Serves as a hash function for a particular type.
virtual type_object	get_type () const noexcept
	Gets the type of the current instance.
template<typename object_t >
xtd::uptr< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.
virtual xtd::string	to_string () const noexcept
	Returns a xtd::string that represents the current object.
Static Public Member Functions inherited from xtd::object
template<typename object_a_t , typename object_b_t >
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.
template<typename object_a_t , typename object_b_t >
static bool	reference_equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are the same instance.

Constructor & Destructor Documentation

binary_reader() [1/2]

xtd::io::binary_reader::binary_reader ( const xtd::string &  path )

explicit

Initializes a new instance of the xtd::io::binary_reader class for the specified file name.

Parameters

path	The complete file path to be read.

Exceptions

xtd::argument_exception

path is a zero-length string, contains only white space, or contains one or more invalid characters as defined by xtd::io::path::invalid_path_chars.

Remarks

For a list of common I/O tasks, see Common I/O Tasks.

binary_reader() [2/2]

xtd::io::binary_reader::binary_reader ( std::istream &  stream )

explicit

Initializes a new instance of the xtd::io::binary_reader class for the specified stream.

Parameters

stream

The stream to be read.

Examples

The following code example demonstrates how to store and retrieve application settings in a file.

#include <xtd/io/binary_reader>
#include <xtd/io/binary_writer>
#include <xtd/io/file>
#include <xtd/block_scope>
#include <xtd/console>
#include <xtd/startup>
 
using namespace xtd;
using namespace xtd::io;
 
class program {
  inline static const string file_name = "app_settings.dat";
public:
  static auto main() {
    write_default_values();
    display_values();
  }
  
  static void write_default_values() {
    block_scope_(auto fs = file::open(file_name, std::ios::out | std::ios::binary | std::ios::trunc)) {
      auto writer = binary_writer {fs};
      writer.write(1.250F);
      writer.write(R"(c:\Temp)");
      writer.write(10);
      writer.write(true);
    }
  }
  
  static void display_values() {
    auto aspect_ratio = .0f;
    auto temp_directory = string::empty_string;
    auto auto_save_time = 0;
    auto show_status_bar = false;
    
    if (file::exists(file_name)) {
      block_scope_(auto fs = file::open(file_name, std::ios::in | std::ios::binary)) {
        auto reader = binary_reader {fs};
        aspect_ratio = reader.read_single();
        temp_directory = reader.read_string();
        auto_save_time = reader.read_int32();
        show_status_bar = reader.read_boolean();
      }
      
      console::write_line("Aspect ratio set to: {}", aspect_ratio);
      console::write_line("Temp directory is: {}", temp_directory);
      console::write_line("Auto save time set to: {}", auto_save_time);
      console::write_line("Show status bar: {}", show_status_bar);
    }
  }
};
 
startup_(program::main);
 
// This code produces the following output :
//
// Aspect ratio set to: 1.25
// Temp directory is: c:\Temp
// Auto save time set to: 10
// Show status bar: true
 

Remarks

For a list of common I/O tasks, see Common I/O Tasks.

Member Function Documentation

base_stream()

std::optional< std::reference_wrapper< std::istream > > xtd::io::binary_reader::base_stream

(

)

const

Returns the underlying stream.

Returns

The underlying stream.

Warning

Using the underlying stream while reading or while using the xtd::io::binary_reader can cause data loss and corruption. For example, the same bytes might be read more than once, bytes might be skipped, or character reading might become unpredictable.

Remarks

For a list of common I/O tasks, see Common I/O Tasks.

end_of_stream()

bool xtd::io::binary_reader::end_of_stream

(

)

const

Gets a value that indicates whether the current stream position is at the end of the stream.

Returns

true if the current stream position is at the end of the stream; otherwise false.

close()

void xtd::io::binary_reader::close

(

)

Closes the xtd::io::binary_reader object and the underlying stream, and releases any system resources associated with the reader.

peek_char()

int32 xtd::io::binary_reader::peek_char

(

)

const

Returns the next available character and does not advance the byte or character position.

Returns

The next available character, or EOF if no more characters are available or the stream does not support seeking.

Exceptions

xtd::io::io_exception

An I/O error occurred.

Remarks

For a list of common I/O tasks, see Common I/O Tasks.

pop()

std::streampos xtd::io::binary_reader::pop

(

)

Pop the current top position.

Examples

binary_reader3.cpp.

push()

void xtd::io::binary_reader::push

(

std::streampos

pos = 0

)

Push the current position.

Parameters

pos	The stream position to be push/saved relative to ios_base::beg direction

Examples

binary_reader3.cpp.

read() [1/3]

virtual int32 xtd::io::binary_reader::read ( )

virtual

Reads characters from the underlying stream and advances the current position of the stream in accordance with the Encoding used and the specific character being read from the stream.

Returns

The next character from the input stream, or EOF if no characters are currently available.

Exceptions

xtd::io::io_exception

An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read.

For a list of common I/O tasks, see Common I/O Tasks.

read() [2/3]

virtual size_t xtd::io::binary_reader::read ( std::vector< xtd::byte > &  buffer, size_t  index, size_t  count  )

virtual

Reads the specified number of bytes from the stream, starting from a specified point in the byte array.

Parameters

buffer	The buffer to read data into.
index	The starting point in the buffer at which to begin reading into the buffer.
count	The number of bytes to read.

Returns

The number of bytes read into buffer. This might be less than the number of bytes requested if that many bytes are not available, or it might be zero if the end of the stream is reached.

Exceptions

xtd::argument_exception	The buffer length minus index is less than count.
xtd::io_io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read() [3/3]

virtual size_t xtd::io::binary_reader::read ( std::vector< char > &  buffer, size_t  index, size_t  count  )

virtual

Reads the specified number of characters from the stream, starting from a specified point in the character array.

Parameters

buffer	The buffer to read data into.
index	The starting point in the buffer at which to begin reading into the buffer.
count	The number of characters to read.

Exceptions

xtd::argument_exception	The buffer length minus index is less than count.
xtd::io_io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_boolean()

virtual bool xtd::io::binary_reader::read_boolean ( )

virtual

Reads a boolean value from the current stream and advances the current position of the stream by one byte.

Returns

true if the byte is nonzero; otherwise, false.

Exceptions

EndOfStreamException	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_byte()

virtual xtd::byte xtd::io::binary_reader::read_byte ( )

virtual

Reads the next byte from the current stream and advances the current position of the stream by one byte.

Returns

The next byte read from the current stream.

Exceptions

EndOfStreamException	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_bytes()

virtual std::vector< xtd::byte > xtd::io::binary_reader::read_bytes ( size_t  count )

virtual

Reads the specified number of bytes from the current stream into a byte array and advances the current position by that number of bytes.

Parameters

count

The number of bytes to read. This value must be 0 or a non-negative number or an exception will occur.

Returns

A byte array containing data read from the underlying stream. This might be less than the number of bytes requested if the end of the stream is reached.

Exceptions

EndOfStreamException	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_char()

virtual char xtd::io::binary_reader::read_char ( )

virtual

Reads the next character from the current stream and advances the current position of the stream by one byte.

Returns

A character read from the current stream.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_chars()

virtual std::vector< char > xtd::io::binary_reader::read_chars ( size_t  count )

virtual

Reads the specified number of characters from the current stream into a byte array and advances the current position by that number of bytes.

Parameters

count

The number of characters to read. This value must be 0 or a non-negative number or an exception will occur.

Returns

A character array containing data read from the underlying stream. This might be less than the number of bytes requested if the end of the stream is reached.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_double()

virtual double xtd::io::binary_reader::read_double ( )

virtual

Reads an 8-byte floating point value from the current stream and advances the current position of the stream by eight bytes.

Returns

An 8-byte floating point value read from the current stream.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_int16()

virtual int16 xtd::io::binary_reader::read_int16 ( )

virtual

Reads a 2-byte signed integer from the current stream and advances the current position of the stream by two bytes.

Returns

A 2-byte signed integer read from the current stream.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_int32()

virtual int32 xtd::io::binary_reader::read_int32 ( )

virtual

Reads a 4-byte signed integer from the current stream and advances the current position of the stream by four bytes.

Returns

A 4-byte signed integer read from the current stream.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_int64()

virtual int64 xtd::io::binary_reader::read_int64 ( )

virtual

Reads a 8-byte signed integer from the current stream and advances the current position of the stream by eight bytes.

Returns

A 8-byte signed integer read from the current stream.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_sbyte()

virtual sbyte xtd::io::binary_reader::read_sbyte ( )

virtual

Reads the a signed byte from the current stream and advances the current position of the stream by one byte.

Returns

A signed byte read from the current stream.

Exceptions

EndOfStreamException	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_single()

virtual float xtd::io::binary_reader::read_single ( )

virtual

Reads an 4-byte floating point value from the current stream and advances the current position of the stream by four bytes.

Returns

An 4-byte floating point value read from the current stream.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

Examples

binary_reader.cpp.

read_string()

virtual string xtd::io::binary_reader::read_string ( )

virtual

Reads a string from the current stream. The string is prefixed with the length.

Returns

The string being read.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_uint16()

virtual uint16 xtd::io::binary_reader::read_uint16 ( )

virtual

Reads a 2-byte unsigned integer from the current stream and advances the current position of the stream by two bytes.

Returns

A 2-byte unsigned integer read from the current stream.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_uint32()

virtual uint32 xtd::io::binary_reader::read_uint32 ( )

virtual

Reads a 4-byte unsigned integer from the current stream and advances the current position of the stream by four bytes.

Returns

A 4-byte unsigned integer read from the current stream.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

read_uint64()

virtual uint64 xtd::io::binary_reader::read_uint64 ( )

virtual

Reads a 8-byte unsigned integer from the current stream and advances the current position of the stream by eight bytes.

Returns

A 8-byte unsigned integer read from the current stream.

Exceptions

xtd::io::end_of_stream_exception	The end of the stream is reached.
xtd::io::io_exception	An I/O error occurred.

Remarks

xtd::io::binary_reader does not restore the file position after an unsuccessful read operation.

For a list of common I/O tasks, see Common I/O Tasks.

rewind()

void xtd::io::binary_reader::rewind

(

)

Rewind stream.

Examples

binary_reader3.cpp.

seekg()

void xtd::io::binary_reader::seekg	(	std::streamoff	off,
		std::ios_base::seekdir	dir = std::ios_base::cur
	)

Change the position of the readers stream.

Parameters

off	The offset being added to the direction
dir	The seek direction. If ommited defaults to ios_base::cur

tellg()

std::streampos xtd::io::binary_reader::tellg

(

)

Tell the current seek position of the readers stream;.

Returns

The current seek position

Examples

binary_reader3.cpp.

---

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

• xtd.core/include/xtd/io/binary_reader.hpp