| /* |
| * HPACK compressor (RFC7541) |
| * |
| * Copyright (C) 2014-2017 Willy Tarreau <willy@haproxy.org> |
| * Copyright (C) 2017 HAProxy Technologies |
| * |
| * 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 _COMMON_HPACK_ENC_H |
| #define _COMMON_HPACK_ENC_H |
| |
| #include <stdint.h> |
| #include <common/buf.h> |
| #include <common/config.h> |
| #include <common/ist.h> |
| |
| int hpack_encode_header(struct buffer *out, const struct ist n, |
| const struct ist v); |
| |
| /* Returns the number of bytes required to encode the string length <len>. The |
| * number of usable bits is an integral multiple of 7 plus 6 for the last byte. |
| * The maximum number of bytes returned is 4 (2097279 max length). Larger values |
| * return 0. |
| */ |
| static inline int hpack_len_to_bytes(size_t len) |
| { |
| ssize_t slen = len; |
| |
| slen -= 127; |
| if (__builtin_expect(slen < 0, 1)) |
| return 1; |
| if (slen < (1 << 14)) { |
| if (__builtin_expect(slen < (1 << 7), 1)) |
| return 2; |
| else |
| return 3; |
| } |
| if (slen < (1 << 21)) |
| return 4; |
| return 0; |
| } |
| |
| /* Encodes <len> into <out>+<pos> and return the new position. The caller is |
| * responsible for checking for available room using hpack_len_to_bytes() |
| * first. |
| */ |
| static inline int hpack_encode_len(char *out, int pos, int len) |
| { |
| int code = len - 127; |
| |
| if (code < 0) { |
| out[pos++] = len; |
| } else { |
| out[pos++] = 127; |
| for (; code >= 128; code >>= 7) |
| out[pos++] = code | 128; |
| out[pos++] = code; |
| } |
| return pos; |
| } |
| |
| #endif /* _COMMON_HPACK_ENC_H */ |