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/*
* 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 <algorithm>
#include "template.h"
namespace nghttp2 {
template <size_t N> struct Buffer {
constexpr Buffer() noexcept : pos(buf), last(pos) {}
// Returns the number of bytes to read.
constexpr size_t rleft() const noexcept { return as_unsigned(last - pos); }
// Returns the number of bytes this buffer can store.
constexpr size_t wleft() const noexcept {
return as_unsigned(&buf[N] - last);
}
// Writes up to min(wleft(), |count|) bytes from buffer pointed by
// |src|. Returns number of bytes written.
constexpr size_t write(const void *src, size_t count) {
count = std::min(count, wleft());
auto p = static_cast<const uint8_t *>(src);
last = std::ranges::copy_n(p, as_signed(count), last).out;
return count;
}
constexpr 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.
constexpr size_t drain(size_t count) {
count = std::min(count, rleft());
pos += count;
return count;
}
constexpr size_t drain_reset(size_t count) {
count = std::min(count, rleft());
last = std::ranges::copy(pos + count, last, buf).out;
pos = buf;
return count;
}
constexpr void reset() noexcept { pos = last = buf; }
constexpr uint8_t *begin() noexcept { return buf; }
constexpr uint8_t &operator[](size_t n) { return buf[n]; }
constexpr const uint8_t &operator[](size_t n) const { return buf[n]; }
uint8_t buf[N];
uint8_t *pos, *last;
};
} // namespace nghttp2
#endif // !defined(BUFFER_H)