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construct/include/ircd/buffer.h
Jason Volk d9a4f06bf6 ircd: Employ namespace scope extensions from c++1z/gnu++14.
This is not a move to c++17. If the compiler happens to have support
for c++17 namespace scope resolution, they have been kind enough to
backport it to gnu++14. This limits our support for really old c++14
compilers, but that was limited anyway. GCC 6.1 and clang 3.6 tested.
2017-09-08 03:47:46 -07:00

345 lines
8.1 KiB
C++

/*
* charybdis5
* Copyright (C) 2016 Jason Volk <jason@zemos.net>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice is present in all copies.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#define HAVE_IRCD_BUFFER_H
namespace ircd::buffer
{
template<class it> struct buffer;
struct const_buffer;
struct mutable_buffer;
template<class buffer, size_t align> struct unique_buffer;
template<class T> using buffers = std::initializer_list<T>;
using const_buffers = buffers<const_buffer>;
using mutable_buffers = buffers<mutable_buffer>;
extern const mutable_buffer null_buffer;
extern const mutable_buffers null_buffers;
template<class it> it rend(const buffer<it> &buffer);
template<class it> it end(const buffer<it> &buffer);
template<class it> it rbegin(const buffer<it> &buffer);
template<class it> it begin(const buffer<it> &buffer);
template<class it> size_t size(const buffer<it> &buffer);
template<class T> size_t size(const buffers<T> &buffers);
template<class it> it data(const buffer<it> &buffer);
template<class it> size_t consume(buffer<it> &buffer, const size_t &bytes);
template<class T> size_t consume(buffers<T> &buffers, const size_t &bytes);
template<class it> char *copy(char *&dest, char *const &stop, const buffer<it> &buffer);
template<class it> size_t copy(char *const &dest, const size_t &max, const buffer<it> &buffer);
template<class T> char *copy(char *&dest, char *const &stop, const buffers<T> &buffer);
template<class T> size_t copy(char *const &dest, const size_t &max, const buffers<T> &buffer);
template<class it> std::ostream &operator<<(std::ostream &s, const buffer<it> &buffer);
template<class T> std::ostream &operator<<(std::ostream &s, const buffers<T> &buffers);
}
// Export these important aliases down to main ircd namespace
namespace ircd
{
using buffer::const_buffer;
using buffer::mutable_buffer;
using buffer::unique_buffer;
using buffer::const_buffers;
using buffer::mutable_buffers;
using buffer::null_buffer;
using buffer::null_buffers;
}
template<class it>
struct ircd::buffer::buffer
:std::tuple<it, it>
{
using value_type = it;
operator string_view() const;
operator std::string_view() const;
explicit operator std::string() const;
buffer(const it &start = nullptr, const it &stop = nullptr)
:std::tuple<it, it>{start, stop}
{}
buffer(const it &start, const size_t &size)
:buffer{start, start + size}
{}
};
struct ircd::buffer::const_buffer
:buffer<const char *>
{
operator boost::asio::const_buffer() const;
using buffer<const char *>::buffer;
const_buffer(const string_view &s)
:buffer<const char *>{begin(s), end(s)}
{}
};
struct ircd::buffer::mutable_buffer
:buffer<char *>
{
operator boost::asio::mutable_buffer() const;
using buffer<char *>::buffer;
};
template<class buffer,
size_t align = 16>
struct ircd::buffer::unique_buffer
:buffer
{
unique_buffer(std::unique_ptr<uint8_t[]> &&, const size_t &size);
unique_buffer(const size_t &size);
unique_buffer() = default;
unique_buffer(unique_buffer &&) noexcept;
unique_buffer(const unique_buffer &) = delete;
~unique_buffer() noexcept;
};
template<class T>
std::ostream &
ircd::buffer::operator<<(std::ostream &s, const buffers<T> &buffers)
{
std::for_each(begin(buffers), end(buffers), [&s]
(const auto &buffer)
{
s << buffer;
});
return s;
}
template<class it>
std::ostream &
ircd::buffer::operator<<(std::ostream &s, const buffer<it> &buffer)
{
s.write(data(buffer), size(buffer));
return s;
}
template<class T>
size_t
ircd::buffer::copy(char *const &dest,
const size_t &max,
const buffers<T> &buffers)
{
size_t ret(0);
for(const auto &buffer : buffers)
ret += copy(dest + ret, max - ret, buffer);
return ret;
}
template<class it>
size_t
ircd::buffer::copy(char *const &dest,
const size_t &max,
const buffer<it> &buffer)
{
if(!max)
return 0;
char *out(dest);
char *const stop(dest + max - 1);
copy(out, stop, buffer);
*out = '\0';
return std::distance(dest, out);
}
template<class T>
char *
ircd::buffer::copy(char *&dest,
char *const &stop,
const buffers<T> &buffers)
{
char *const ret(dest);
for(const auto &buffer : buffers)
copy(dest, stop, buffer);
return ret;
}
template<class it>
char *
ircd::buffer::copy(char *&dest,
char *const &stop,
const buffer<it> &buffer)
{
char *const ret(dest);
const size_t remain(stop - dest);
dest += std::min(size(buffer), remain);
memcpy(ret, data(buffer), dest - ret);
return ret;
}
template<class T>
size_t
ircd::buffer::consume(buffers<T> &buffers,
const size_t &bytes)
{
size_t remain(bytes);
for(auto it(begin(buffers)); it != end(buffers) && remain > 0; ++it)
{
using buffer = typename buffers<T>::value_type;
using iterator = typename buffer::value_type;
buffer &b(const_cast<buffer &>(*it));
remain -= consume(b, remain);
}
return bytes - remain;
}
template<class it>
size_t
ircd::buffer::consume(buffer<it> &buffer,
const size_t &bytes)
{
get<0>(buffer) += std::min(size(buffer), bytes);
return bytes - size(buffer);
}
template<class it>
it
ircd::buffer::data(const buffer<it> &buffer)
{
return get<0>(buffer);
}
template<class T>
size_t
ircd::buffer::size(const buffers<T> &buffers)
{
return std::accumulate(std::begin(buffers), std::end(buffers), size_t(0), []
(auto ret, const auto &buffer)
{
return ret += size(buffer);
});
}
template<class it>
size_t
ircd::buffer::size(const buffer<it> &buffer)
{
assert(get<0>(buffer) <= get<1>(buffer));
return std::distance(get<0>(buffer), get<1>(buffer));
}
template<class it>
it
ircd::buffer::begin(const buffer<it> &buffer)
{
return get<0>(buffer);
}
template<class it>
it
ircd::buffer::rbegin(const buffer<it> &buffer)
{
return std::reverse_iterator<it>(get<0>(buffer) + size(buffer));
}
template<class it>
it
ircd::buffer::end(const buffer<it> &buffer)
{
return get<1>(buffer);
}
template<class it>
it
ircd::buffer::rend(const buffer<it> &buffer)
{
return std::reverse_iterator<it>(get<0>(buffer));
}
template<class buffer,
size_t alignment>
ircd::buffer::unique_buffer<buffer, alignment>::unique_buffer(std::unique_ptr<uint8_t[]> &&b,
const size_t &size)
:buffer
{
typename buffer::value_type(b.release()), size
}
{
}
template<class buffer,
size_t alignment>
ircd::buffer::unique_buffer<buffer, alignment>::unique_buffer(const size_t &size)
:unique_buffer<buffer, alignment>
{
std::unique_ptr<uint8_t[]>
{
new __attribute__((aligned(alignment))) uint8_t[size]
},
size
}
{
}
template<class buffer,
size_t alignment>
ircd::buffer::unique_buffer<buffer, alignment>::unique_buffer(unique_buffer &&other)
noexcept
:buffer
{
std::move(other)
}
{
get<0>(other) = nullptr;
}
template<class buffer,
size_t alignment>
ircd::buffer::unique_buffer<buffer, alignment>::~unique_buffer()
noexcept
{
delete[] data(*this);
}
template<class it>
ircd::buffer::buffer<it>::operator std::string()
const
{
return { get<0>(*this), size(*this) };
}
template<class it>
ircd::buffer::buffer<it>::operator std::string_view()
const
{
return { get<0>(*this), size(*this) };
}
template<class it>
ircd::buffer::buffer<it>::operator string_view()
const
{
return { get<0>(*this), get<1>(*this) };
}