81 lines
2.8 KiB
C
81 lines
2.8 KiB
C
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/*
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* libjingle
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* Copyright 2012, Google Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
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* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef TALK_BASE_RATELIMITER_H_
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#define TALK_BASE_RATELIMITER_H_
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#include <stdlib.h>
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#include "talk/base/basictypes.h"
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namespace talk_base {
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// Limits the rate of use to a certain maximum quantity per period of
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// time. Use, for example, for simple bandwidth throttling.
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//
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// It's implemented like a diet plan: You have so many calories per
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// day. If you hit the limit, you can't eat any more until the next
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// day.
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class RateLimiter {
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public:
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// For example, 100kb per second.
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RateLimiter(size_t max, double period)
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: max_per_period_(max),
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period_length_(period),
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used_in_period_(0),
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period_start_(0.0),
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period_end_(period) {
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}
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virtual ~RateLimiter() {}
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// Returns true if if the desired quantity is available in the
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// current period (< (max - used)). Once the given time passes the
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// end of the period, used is set to zero and more use is available.
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bool CanUse(size_t desired, double time);
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// Increment the quantity used this period. If past the end of a
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// period, a new period is started.
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void Use(size_t used, double time);
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size_t used_in_period() const {
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return used_in_period_;
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}
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size_t max_per_period() const {
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return max_per_period_;
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}
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private:
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size_t max_per_period_;
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double period_length_;
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size_t used_in_period_;
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double period_start_;
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double period_end_;
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};
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} // namespace talk_base
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#endif // TALK_BASE_RATELIMITER_H_
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