/src/h2o/include/h2o/absprio.h
Line | Count | Source |
1 | | /* |
2 | | * Copyright (c) 2019 Fastly |
3 | | * |
4 | | * Permission is hereby granted, free of charge, to any person obtaining a copy |
5 | | * of this software and associated documentation files (the "Software"), to |
6 | | * deal in the Software without restriction, including without limitation the |
7 | | * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or |
8 | | * sell copies of the Software, and to permit persons to whom the Software is |
9 | | * furnished to do so, subject to the following conditions: |
10 | | * |
11 | | * The above copyright notice and this permission notice shall be included in |
12 | | * all copies or substantial portions of the Software. |
13 | | * |
14 | | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
15 | | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
16 | | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
17 | | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
18 | | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
19 | | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
20 | | * IN THE SOFTWARE. |
21 | | */ |
22 | | #ifndef h2o__absprio_h |
23 | | #define h2o__absprio_h |
24 | | |
25 | | #include <assert.h> |
26 | | #include <stddef.h> |
27 | | #include <stdint.h> |
28 | | |
29 | | #define H2O_ABSPRIO_DEFAULT_URGENCY 3 |
30 | 144k | #define H2O_ABSPRIO_NUM_URGENCY_LEVELS 8 |
31 | | |
32 | | typedef struct h2o_absprio_t { |
33 | | uint8_t urgency : 3; |
34 | | uint8_t incremental : 1; |
35 | | } h2o_absprio_t; |
36 | | |
37 | | extern h2o_absprio_t h2o_absprio_default; |
38 | | |
39 | | void h2o_absprio_parse_priority(const char *s, size_t len, h2o_absprio_t *prio); |
40 | | /** |
41 | | * Convert urgency value in absolute priority header to HTTP2 weight, having Chromium as a client in mind. |
42 | | */ |
43 | | static uint16_t h2o_absprio_urgency_to_chromium_weight(uint8_t urgency); |
44 | | |
45 | | /* inline functions */ |
46 | | |
47 | | inline uint16_t h2o_absprio_urgency_to_chromium_weight(uint8_t urgency) |
48 | 0 | { |
49 | 0 | uint16_t weight; |
50 | 0 | assert(urgency < H2O_ABSPRIO_NUM_URGENCY_LEVELS); |
51 | | /* formula excerpted from: |
52 | | * https://quiche.googlesource.com/quiche/+/8cbe7bfa5c6efa7a42652e36fabf8d21879894be/spdy/core/spdy_protocol.cc#50 */ |
53 | 0 | const float ksteps = 255.9f / (float)(H2O_ABSPRIO_NUM_URGENCY_LEVELS - 1); |
54 | 0 | weight = (uint16_t)(ksteps * ((H2O_ABSPRIO_NUM_URGENCY_LEVELS - 1) - urgency)) + 1; |
55 | 0 | return weight; |
56 | 0 | } Unexecuted instantiation: connection.c:h2o_absprio_urgency_to_chromium_weight Unexecuted instantiation: stream.c:h2o_absprio_urgency_to_chromium_weight Unexecuted instantiation: server.c:h2o_absprio_urgency_to_chromium_weight Unexecuted instantiation: absprio.c:h2o_absprio_urgency_to_chromium_weight |
57 | | |
58 | | #endif |