webrtc/talk/base/ratelimiter.h
henrike@webrtc.org 28e2075280 Adds trunk/talk folder of revision 359 from libjingles google code to
trunk/talk


git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
2013-07-10 00:45:36 +00:00

81 lines
2.8 KiB
C++

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