obstream Class¶

Provides the functionality of Binary Writer.

Syntax¶

namespace yasio { 
using obstream = basic_obstream<endian::network_convert_tag>;

// The fast binary writer without byte order convertion.
using fast_obstream = basic_obstream<endian::host_convert_tag>;
}

Members¶

Public Constructors¶

Public Methods¶

Remarks¶

When write int16~int64 and float/double, will auto convert host byte order to network byte order.

Requirements¶

Header: obstream.hpp

obstream::obstream¶

Constructs a obstream object.

obstream(size_t capacity = 128);

obstream(const obstream& rhs);

obstream(obstream&& rhs);

Example¶

TODO:

obstream::write¶

Write number value to stream with byte order convertion.

template<typename _Nty>
void obstream::write(_Nty value);

Parameters¶

value
The value to be written.

Remarks¶

The type _Nty of value could be any (1~8bytes) integral or float types

Example¶

TODO:

obstream::write_ix¶

Write 7Bit Encoded Int compressed value.

template<typename _Intty>
void obstream::write_ix(_Intty value);

Parameters¶

value
The value to be written.

Remarks¶

The type _Intty of value must be one of follows

• int32_t
• int64_t

This function behavior is compatible with dotnet

• BinaryWriter.Write7BitEncodedInt
• BinaryWriter.Write7BitEncodedInt64

Example¶

TODO:

obstream::write_v¶

Write blob data with 7Bit Encoded Int length field.

void write_v(cxx17::string_view sv);

Parameters¶

sv
The string_view value to be written.

Remarks¶

This function will write length field with 7Bit Encoded first, then call write_bytes to write the value.

Example¶

TODO:

obstream::write_byte¶

Write 1 byte to stream.

void write_byte(uint8_t value);

Parameters¶

value
The value to be written.

Remarks¶

This function is identical to obstream::write

Example¶

TODO:

obstream::write_bytes¶

Write byte array to stream.

void write_bytes(cxx17::string_view sv);

void write_bytes(const void* data, int length);

void write_bytes(std::streamoff offset, const void* data, int length);

Parameters¶

sv
The string_view value to be written.

data
The data to be written.

length
The length data to be written.

offset
The offset of stream to be written.

Remarks¶

The value of offset + length must be less than obstream::length

Example¶

TODO:

obstream::empty¶

Tests whether the obstream is empty.

bool empty() const;

Return Value¶

true if the obstream empty; false if it has at least one byte.

Remarks¶

The member function is equivalent to length == 0.

Example¶

TODO:

obstream::data¶

Retrieves stream data pointer.

const char* data() const;

char* data();

Return Value¶

A pointer to the first byte in the stream.

Example¶

TODO:

obstream::length¶

Returns the number of bytes in the stream.

size_t length() const;

Return Value¶

The current length of the stream.

Example¶

TODO:

obstream::buffer¶

Retrieves internal buffer of stream.

const std::vector<char>& buffer() const;

std::vector<char>& buffer();

Return Value¶

The internal implementation buffer of the stream.

Example¶

// obstream_buffer.cpp
// compile with: /EHsc
#include "yasio/obstream.hpp"

int main( )
{
   using namespace yasio;
   using namespace cxx17;

   obstream obs;
   obs.write_v("hello world!");

   const auto& const_buffer = obs.buffer();

   // after this line, the obs will be empty
   auto move_buffer = std::move(obs.buffer());

   return 0;
}

obstream::save¶

Save the stream data to file.

void save(const char* filename) const;

Example¶

// obstream_save.cpp
// compile with: /EHsc
#include "yasio/obstream.hpp"
#include "yasio/ibstream.hpp"

int main( )
{
   using namespace yasio;
   using namespace cxx17;

   obstream obs;
   obs.write_v("hello world!");
   obs.save("obstream_save.bin");

   ibstream ibs;
   if(ibs.load("obstream_save.bin")) {
       // output should be: hello world!
       try {
           std::count << ibs.read_v() << "\n";
       }
       catch(const std::exception& ex) {
           std::count << "read_v fail: " <<
               << ex.message() << "\n";
       }
   }

   return 0;
}

See also¶

ibstream_view Class

ibstream Class