spdlog/include/c11log/details/fast_oss.h

105 lines
2.1 KiB
C++

#pragma once
// Faster than ostringstream--returns its string by ref
#include <ostream>
#include "stack_buf.h"
namespace c11log
{
namespace details
{
class stack_devicebuf :public std::streambuf
{
public:
using Base = std::streambuf;
stack_devicebuf() = default;
~stack_devicebuf() = default;
stack_devicebuf& operator=(const stack_devicebuf&) = delete;
stack_devicebuf(const stack_devicebuf& other) :std::basic_streambuf<char>(), _stackbuf(other._stackbuf)
{}
stack_devicebuf(stack_devicebuf&& other) :std::basic_streambuf<char>(), _stackbuf(std::move(other._stackbuf))
{
other.clear();
}
bufpair_t buf() const
{
return _stackbuf.get();
}
std::size_t size() const
{
return _stackbuf.size();
}
void clear()
{
_stackbuf.clear();
}
protected:
// copy the give buffer into the accumulated fast buffer
std::streamsize xsputn(const char_type* s, std::streamsize count) override
{
_stackbuf.append(s, static_cast<unsigned int>(count));
return count;
}
int_type overflow(int_type ch) override
{
if (traits_type::not_eof(ch))
{
char c = traits_type::to_char_type(ch);
xsputn(&c, 1);
}
return ch;
}
private:
stack_buf<256> _stackbuf;
};
class fast_oss :public std::ostream
{
public:
fast_oss() :std::ostream(&_dev) {}
~fast_oss() = default;
fast_oss& operator=(const fast_oss& other) = delete;
fast_oss& operator=(const fast_oss&& other) = delete;
fast_oss(const fast_oss& other) :std::basic_ios<char>(), std::ostream(&_dev), _dev(other._dev)
{}
fast_oss(fast_oss&& other) :std::basic_ios<char>(), std::ostream(&_dev), _dev(std::move(other._dev))
{
other.clear();
}
std::string str()
{
auto buf = _dev.buf();
return std::string(buf.first, buf.second);
}
std::size_t size() const
{
return _dev.size();
}
void clear()
{
_dev.clear();
}
private:
stack_devicebuf _dev;
};
}
}