projects / thirdparty / squid.git / blame
| Commit | Line | Data |
|---|---|---|
| b27668ec | 1 | /* |
| b8ae064d | 2 | * Copyright (C) 1996-2023 The Squid Software Foundation and contributors |
| b27668ec EB |
3 | * |
| 4 | * Squid software is distributed under GPLv2+ license and includes | |
| 5 | * contributions from numerous individuals and organizations. | |
| 6 | * Please see the COPYING and CONTRIBUTORS files for details. | |
| 7 | */ | |
| 8 | ||
| 9 | #include "squid.h" | |
| 10 | ||
| 11 | #if USE_DELAY_POOLS | |
| 12 | ||
| 13 | #include "BandwidthBucket.h" | |
| 14 | #include "ClientInfo.h" | |
| 15 | #include "comm/Connection.h" | |
| 675b8408 | 16 | #include "debug/Stream.h" |
| b27668ec EB |
17 | #include "fde.h" |
| 18 | ||
| 19 | BandwidthBucket::BandwidthBucket(const int speed, const int initialLevelPercent, const double sizeLimit) : | |
| 20 | bucketLevel( sizeLimit * (initialLevelPercent / 100.0)), | |
| 21 | selectWaiting(false), | |
| 22 | writeSpeedLimit(speed), | |
| 23 | bucketSizeLimit(sizeLimit) | |
| 24 | { | |
| 25 | getCurrentTime(); | |
| 26 | /* put current time to have something sensible here */ | |
| 27 | prevTime = current_dtime; | |
| 28 | } | |
| 29 | ||
| 30 | void | |
| 31 | BandwidthBucket::refillBucket() | |
| 32 | { | |
| 33 | if (noLimit()) | |
| 34 | return; | |
| 35 | // all these times are in seconds, with double precision | |
| 36 | const double currTime = current_dtime; | |
| 37 | const double timePassed = currTime - prevTime; | |
| 38 | ||
| 39 | // Calculate allowance for the time passed. Use double to avoid | |
| 40 | // accumulating rounding errors for small intervals. For example, always | |
| 41 | // adding 1 byte instead of 1.4 results in 29% bandwidth allocation error. | |
| 42 | const double gain = timePassed * writeSpeedLimit; | |
| 43 | ||
| 44 | // to further combat error accumulation during micro updates, | |
| 45 | // quit before updating time if we cannot add at least one byte | |
| 46 | if (gain < 1.0) | |
| 47 | return; | |
| 48 | ||
| 49 | prevTime = currTime; | |
| 50 | ||
| 51 | // for "first" connections, drain initial fat before refilling but keep | |
| 52 | // updating prevTime to avoid bursts after the fat is gone | |
| 53 | if (bucketLevel > bucketSizeLimit) { | |
| 54 | debugs(77, 4, "not refilling while draining initial fat"); | |
| 55 | return; | |
| 56 | } | |
| 57 | ||
| 58 | bucketLevel += gain; | |
| 59 | ||
| 60 | // obey quota limits | |
| 61 | if (bucketLevel > bucketSizeLimit) | |
| 62 | bucketLevel = bucketSizeLimit; | |
| 63 | } | |
| 64 | ||
| 65 | bool | |
| 66 | BandwidthBucket::applyQuota(int &nleft, Comm::IoCallback *state) | |
| 67 | { | |
| 68 | const int q = quota(); | |
| 69 | if (!q) | |
| 70 | return false; | |
| 71 | else if (q < 0) | |
| 72 | return true; | |
| 73 | const int nleft_corrected = min(nleft, q); | |
| 74 | if (nleft != nleft_corrected) { | |
| 75 | debugs(77, 5, state->conn << " writes only " << | |
| 76 | nleft_corrected << " out of " << nleft); | |
| 77 | nleft = nleft_corrected; | |
| 78 | } | |
| 79 | return true; | |
| 80 | } | |
| 81 | ||
| 82 | void | |
| 83 | BandwidthBucket::reduceBucket(const int len) | |
| 84 | { | |
| 85 | if (len <= 0 || noLimit()) | |
| 86 | return; | |
| 87 | bucketLevel -= len; | |
| 88 | if (bucketLevel < 0.0) { | |
| 89 | debugs(77, DBG_IMPORTANT, "drained too much"); // should not happen | |
| 90 | bucketLevel = 0; | |
| 91 | } | |
| 92 | } | |
| 93 | ||
| 94 | BandwidthBucket * | |
| 95 | BandwidthBucket::SelectBucket(fde *f) | |
| 96 | { | |
| 97 | BandwidthBucket *bucket = f->writeQuotaHandler.getRaw(); | |
| 98 | if (!bucket) { | |
| 99 | ClientInfo *clientInfo = f->clientInfo; | |
| 100 | if (clientInfo && clientInfo->writeLimitingActive) | |
| 101 | bucket = clientInfo; | |
| 102 | } | |
| 103 | return bucket; | |
| 104 | } | |
| 105 | ||
| 106 | #endif /* USE_DELAY_POOLS */ | |
| 107 |