nghttp2/src/buffer.h

69 lines
2.3 KiB
C++

/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2014 Tatsuhiro Tsujikawa
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef BUFFER_H
#define BUFFER_H
#include "nghttp2_config.h"
#include <cstring>
#include <algorithm>
#include <array>
namespace nghttp2 {
template <size_t N> struct Buffer {
Buffer() : pos(std::begin(buf)), last(pos) {}
// Returns the number of bytes to read.
size_t rleft() const { return last - pos; }
// Returns the number of bytes this buffer can store.
size_t wleft() const { return std::end(buf) - last; }
// Writes up to min(wleft(), |count|) bytes from buffer pointed by
// |src|. Returns number of bytes written.
size_t write(const void *src, size_t count) {
count = std::min(count, wleft());
auto p = static_cast<const uint8_t *>(src);
last = std::copy_n(p, count, last);
return count;
}
size_t write(size_t count) {
count = std::min(count, wleft());
last += count;
return count;
}
// Drains min(rleft(), |count|) bytes from start of the buffer.
size_t drain(size_t count) {
count = std::min(count, rleft());
pos += count;
return count;
}
void reset() { pos = last = std::begin(buf); }
std::array<uint8_t, N> buf;
uint8_t *pos, *last;
};
} // namespace nghttp2
#endif // BUFFER_H