| henrike@webrtc.org | 0e118e7 | 2013-07-10 00:45:36 +0000 | [diff] [blame] | 1 | /* |
| 2 | * libjingle |
| 3 | * Copyright 2004--2010, Google Inc. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions are met: |
| 7 | * |
| 8 | * 1. Redistributions of source code must retain the above copyright notice, |
| 9 | * this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
| 11 | * this list of conditions and the following disclaimer in the documentation |
| 12 | * and/or other materials provided with the distribution. |
| 13 | * 3. The name of the author may not be used to endorse or promote products |
| 14 | * derived from this software without specific prior written permission. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 17 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 18 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
| 19 | * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 20 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 21 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
| 22 | * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| 23 | * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
| 24 | * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| 25 | * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | #include "talk/base/ratetracker.h" |
| 29 | #include "talk/base/timeutils.h" |
| 30 | |
| 31 | namespace talk_base { |
| 32 | |
| 33 | RateTracker::RateTracker() |
| 34 | : total_units_(0), units_second_(0), |
| 35 | last_units_second_time_(static_cast<uint32>(-1)), |
| 36 | last_units_second_calc_(0) { |
| 37 | } |
| 38 | |
| 39 | size_t RateTracker::total_units() const { |
| 40 | return total_units_; |
| 41 | } |
| 42 | |
| 43 | size_t RateTracker::units_second() { |
| 44 | // Snapshot units / second calculator. Determine how many seconds have |
| 45 | // elapsed since our last reference point. If over 1 second, establish |
| 46 | // a new reference point that is an integer number of seconds since the |
| 47 | // last one, and compute the units over that interval. |
| 48 | uint32 current_time = Time(); |
| 49 | if (last_units_second_time_ != static_cast<uint32>(-1)) { |
| 50 | int delta = talk_base::TimeDiff(current_time, last_units_second_time_); |
| 51 | if (delta >= 1000) { |
| 52 | int fraction_time = delta % 1000; |
| 53 | int seconds = delta / 1000; |
| 54 | int fraction_units = |
| 55 | static_cast<int>(total_units_ - last_units_second_calc_) * |
| 56 | fraction_time / delta; |
| 57 | // Compute "units received during the interval" / "seconds in interval" |
| 58 | units_second_ = |
| 59 | (total_units_ - last_units_second_calc_ - fraction_units) / seconds; |
| 60 | last_units_second_time_ = current_time - fraction_time; |
| 61 | last_units_second_calc_ = total_units_ - fraction_units; |
| 62 | } |
| 63 | } |
| 64 | if (last_units_second_time_ == static_cast<uint32>(-1)) { |
| 65 | last_units_second_time_ = current_time; |
| 66 | last_units_second_calc_ = total_units_; |
| 67 | } |
| 68 | |
| 69 | return units_second_; |
| 70 | } |
| 71 | |
| 72 | void RateTracker::Update(size_t units) { |
| 73 | total_units_ += units; |
| 74 | } |
| 75 | |
| 76 | uint32 RateTracker::Time() const { |
| 77 | return talk_base::Time(); |
| 78 | } |
| 79 | |
| 80 | } // namespace talk_base |