1 /* 2 * nghttp2 - HTTP/2 C Library 3 * 4 * Copyright (c) 2014 Tatsuhiro Tsujikawa 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining 7 * a copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sublicense, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be 15 * included in all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 20 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 21 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 22 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 23 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 24 */ 25 #ifndef BUFFER_H 26 #define BUFFER_H 27 28 #include "nghttp2_config.h" 29 30 #include <cstring> 31 #include <algorithm> 32 #include <array> 33 34 namespace nghttp2 { 35 36 template <size_t N> struct Buffer { BufferBuffer37 Buffer() : pos(std::begin(buf)), last(pos) {} 38 // Returns the number of bytes to read. rleftBuffer39 size_t rleft() const { return last - pos; } 40 // Returns the number of bytes this buffer can store. wleftBuffer41 size_t wleft() const { return std::end(buf) - last; } 42 // Writes up to min(wleft(), |count|) bytes from buffer pointed by 43 // |src|. Returns number of bytes written. writeBuffer44 size_t write(const void *src, size_t count) { 45 count = std::min(count, wleft()); 46 auto p = static_cast<const uint8_t *>(src); 47 last = std::copy_n(p, count, last); 48 return count; 49 } writeBuffer50 size_t write(size_t count) { 51 count = std::min(count, wleft()); 52 last += count; 53 return count; 54 } 55 // Drains min(rleft(), |count|) bytes from start of the buffer. drainBuffer56 size_t drain(size_t count) { 57 count = std::min(count, rleft()); 58 pos += count; 59 return count; 60 } drain_resetBuffer61 size_t drain_reset(size_t count) { 62 count = std::min(count, rleft()); 63 std::copy(pos + count, last, std::begin(buf)); 64 last = std::begin(buf) + (last - (pos + count)); 65 pos = std::begin(buf); 66 return count; 67 } resetBuffer68 void reset() { pos = last = std::begin(buf); } beginBuffer69 uint8_t *begin() { return std::begin(buf); } 70 uint8_t &operator[](size_t n) { return buf[n]; } 71 const uint8_t &operator[](size_t n) const { return buf[n]; } 72 std::array<uint8_t, N> buf; 73 uint8_t *pos, *last; 74 }; 75 76 } // namespace nghttp2 77 78 #endif // BUFFER_H 79