boost/beast/http/span_body.hpp
//
// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/beast
//
#ifndef BOOST_BEAST_HTTP_SPAN_BODY_HPP
#define BOOST_BEAST_HTTP_SPAN_BODY_HPP
#include <boost/beast/core/detail/config.hpp>
#include <boost/beast/core/buffer_traits.hpp>
#include <boost/beast/core/span.hpp>
#include <boost/beast/http/error.hpp>
#include <boost/beast/http/message.hpp>
#include <boost/optional.hpp>
namespace boost {
namespace beast {
namespace http {
/** A <em>Body</em> using @ref span
This body uses @ref span as a memory-based container for
holding message payloads. The container represents a
non-owning reference to a contiguous area of memory.
Messages using this body type may be serialized and
parsed.
Unlike @ref buffer_body, only one buffer may be provided
during a parse or serialize operation.
*/
template<class T>
struct span_body
{
private:
static_assert(
std::is_trivial<T>::value &&
std::is_standard_layout<T>::value,
"POD requirements not met");
public:
/** The type of container used for the body
This determines the type of @ref message::body
when this body type is used with a message container.
*/
using value_type = span<T>;
/** Returns the payload size of the body
When this body is used with @ref message::prepare_payload,
the Content-Length will be set to the payload size, and
any chunked Transfer-Encoding will be removed.
*/
static
std::uint64_t
size(value_type const& body)
{
return body.size();
}
/** The algorithm for parsing the body
Meets the requirements of <em>BodyReader</em>.
*/
#if BOOST_BEAST_DOXYGEN
using reader = __implementation_defined__;
#else
class reader
{
value_type& body_;
public:
template<bool isRequest, class Fields>
explicit
reader(header<isRequest, Fields>&, value_type& b)
: body_(b)
{
}
void
init(boost::optional<
std::uint64_t> const& length, error_code& ec)
{
if(length && *length > body_.size())
{
BOOST_BEAST_ASSIGN_EC(ec, error::buffer_overflow);
return;
}
ec = {};
}
template<class ConstBufferSequence>
std::size_t
put(ConstBufferSequence const& buffers,
error_code& ec)
{
auto const n = buffer_bytes(buffers);
auto const len = body_.size();
if(n > len)
{
BOOST_BEAST_ASSIGN_EC(ec, error::buffer_overflow);
return 0;
}
ec = {};
net::buffer_copy(net::buffer(
body_.data(), n), buffers);
body_ = value_type{
body_.data() + n, body_.size() - n};
return n;
}
void
finish(error_code& ec)
{
ec = {};
}
};
#endif
/** The algorithm for serializing the body
Meets the requirements of <em>BodyWriter</em>.
*/
#if BOOST_BEAST_DOXYGEN
using writer = __implementation_defined__;
#else
class writer
{
value_type const& body_;
public:
using const_buffers_type =
net::const_buffer;
template<bool isRequest, class Fields>
explicit
writer(header<isRequest, Fields> const&, value_type const& b)
: body_(b)
{
}
void
init(error_code& ec)
{
ec = {};
}
boost::optional<std::pair<const_buffers_type, bool>>
get(error_code& ec)
{
ec = {};
return {{
{ body_.data(),
body_.size() * sizeof(typename
value_type::value_type)},
false}};
}
};
#endif
};
} // http
} // beast
} // boost
#endif