mirror of https://github.com/nodejs/node.git
76 lines
2.0 KiB
C
76 lines
2.0 KiB
C
/*
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* nghttp2 - HTTP/2 C Library
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*
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* Copyright (c) 2023 nghttp2 contributors
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include "nghttp2_ratelim.h"
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#include "nghttp2_helper.h"
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void nghttp2_ratelim_init(nghttp2_ratelim *rl, uint64_t burst, uint64_t rate) {
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rl->val = rl->burst = burst;
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rl->rate = rate;
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rl->tstamp = 0;
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}
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void nghttp2_ratelim_update(nghttp2_ratelim *rl, uint64_t tstamp) {
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uint64_t d, gain;
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if (tstamp == rl->tstamp) {
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return;
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}
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if (tstamp > rl->tstamp) {
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d = tstamp - rl->tstamp;
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} else {
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d = 1;
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}
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rl->tstamp = tstamp;
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if (UINT64_MAX / d < rl->rate) {
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rl->val = rl->burst;
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return;
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}
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gain = rl->rate * d;
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if (UINT64_MAX - gain < rl->val) {
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rl->val = rl->burst;
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return;
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}
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rl->val += gain;
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rl->val = nghttp2_min_uint64(rl->val, rl->burst);
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}
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int nghttp2_ratelim_drain(nghttp2_ratelim *rl, uint64_t n) {
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if (rl->val < n) {
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return -1;
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}
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rl->val -= n;
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return 0;
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}
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