The Tor Browser / file comparison
comparison: media/mtransport/simpletokenbucket.cpp
media/mtransport/simpletokenbucket.cpp
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
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| -1:000000000000 | 0:18ef96fb5831 |
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| 1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ | |
| 2 /* vim: set ts=2 et sw=2 tw=80: */ | |
| 3 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this file, | |
| 5 * You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 /* Original author: bcampen@mozilla.com */ | |
| 8 | |
| 9 #include "simpletokenbucket.h" | |
| 10 | |
| 11 #include <stdint.h> | |
| 12 | |
| 13 #include "prinrval.h" | |
| 14 | |
| 15 namespace mozilla { | |
| 16 | |
| 17 SimpleTokenBucket::SimpleTokenBucket(size_t bucket_size, | |
| 18 size_t tokens_per_second) : | |
| 19 max_tokens_(bucket_size), | |
| 20 num_tokens_(bucket_size), | |
| 21 tokens_per_second_(tokens_per_second), | |
| 22 last_time_tokens_added_(PR_IntervalNow()) { | |
| 23 } | |
| 24 | |
| 25 size_t SimpleTokenBucket::getTokens(size_t num_requested_tokens) { | |
| 26 // Only fill if there isn't enough to satisfy the request. | |
| 27 // If we get tokens so seldomly that we are able to roll the timer all | |
| 28 // the way around its range, then we lose that entire range of time | |
| 29 // for token accumulation. Probably not the end of the world. | |
| 30 if (num_requested_tokens > num_tokens_) { | |
| 31 PRIntervalTime now = PR_IntervalNow(); | |
| 32 | |
| 33 // If we roll over the max, since everything in this calculation is the same | |
| 34 // unsigned type, this will still yield the elapsed time (unless we've | |
| 35 // wrapped more than once). | |
| 36 PRIntervalTime elapsed_ticks = now - last_time_tokens_added_; | |
| 37 | |
| 38 uint32_t elapsed_milli_sec = PR_IntervalToMilliseconds(elapsed_ticks); | |
| 39 size_t tokens_to_add = (elapsed_milli_sec * tokens_per_second_)/1000; | |
| 40 | |
| 41 // Only update our timestamp if we added some tokens | |
| 42 // TODO:(bcampen@mozilla.com) Should we attempt to "save" leftover time? | |
| 43 if (tokens_to_add) { | |
| 44 num_tokens_ += tokens_to_add; | |
| 45 if (num_tokens_ > max_tokens_) { | |
| 46 num_tokens_ = max_tokens_; | |
| 47 } | |
| 48 | |
| 49 last_time_tokens_added_ = now; | |
| 50 } | |
| 51 | |
| 52 if (num_requested_tokens > num_tokens_) { | |
| 53 return num_tokens_; | |
| 54 } | |
| 55 } | |
| 56 | |
| 57 num_tokens_ -= num_requested_tokens; | |
| 58 return num_requested_tokens; | |
| 59 } | |
| 60 | |
| 61 } // namespace mozilla | |
| 62 |
