| /* |
| * 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_ |