Files
boost_beast/examples/file_body.hpp
2017-07-20 08:12:15 -07:00

98 lines
2.3 KiB
C++

//
// Copyright (c) 2013-2017 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)
//
#ifndef BEAST_EXAMPLE_FILE_BODY_H_INCLUDED
#define BEAST_EXAMPLE_FILE_BODY_H_INCLUDED
#include <beast/core/error.hpp>
#include <beast/http/message.hpp>
#include <boost/asio/buffer.hpp>
#include <boost/assert.hpp>
#include <boost/filesystem.hpp>
#include <cstdio>
#include <cstdint>
namespace beast {
namespace http {
struct file_body
{
using value_type = std::string;
class writer
{
std::uint64_t size_ = 0;
std::uint64_t offset_ = 0;
std::string const& path_;
FILE* file_ = nullptr;
char buf_[4096];
std::size_t buf_len_;
public:
writer(writer const&) = delete;
writer& operator=(writer const&) = delete;
template<bool isRequest, class Fields>
writer(message<isRequest,
file_body, Fields> const& m) noexcept
: path_(m.body)
{
}
~writer()
{
if(file_)
fclose(file_);
}
void
init(error_code& ec) noexcept
{
file_ = fopen(path_.c_str(), "rb");
if(! file_)
ec = error_code{errno,
system_category()};
else
size_ = boost::filesystem::file_size(path_);
}
std::uint64_t
content_length() const noexcept
{
return size_;
}
template<class WriteFunction>
bool
write(error_code& ec, WriteFunction&& wf) noexcept
{
if(size_ - offset_ < sizeof(buf_))
buf_len_ = static_cast<std::size_t>(
size_ - offset_);
else
buf_len_ = sizeof(buf_);
auto const nread = fread(
buf_, 1, sizeof(buf_), file_);
if(ferror(file_))
{
ec = error_code(errno,
system_category());
return true;
}
BOOST_ASSERT(nread != 0);
offset_ += nread;
wf(boost::asio::buffer(buf_, nread));
return offset_ >= size_;
}
};
};
} // http
} // beast
#endif