Analytics/SFAnalyticsMultiSampler.m

   1 /*
   2  * Copyright (c) 2017 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #if __OBJC2__
  25
  26 #import "SFAnalyticsMultiSampler+Internal.h"
  27 #import "SFAnalytics+Internal.h"
  28 #import "SFAnalyticsDefines.h"
  29 #import "utilities/debugging.h"
  30 #include <notify.h>
  31 #include <dispatch/dispatch.h>
  32
  33 @implementation SFAnalyticsMultiSampler {
  34     NSTimeInterval _samplingInterval;
  35     dispatch_source_t _timer;
  36     NSString* _name;
  37     MultiSamplerDictionary (^_block)(void);
  38     int _notificationToken;
  39     Class _clientClass;
  40     BOOL _oncePerReport;
  41     BOOL _activeTimer;
  42 }
  43
  44 @synthesize name = _name;
  45 @synthesize samplingInterval = _samplingInterval;
  46
  47 - (instancetype)initWithName:(NSString*)name interval:(NSTimeInterval)interval block:(MultiSamplerDictionary (^)(void))block clientClass:(Class)clientClass
  48 {
  49     if (self = [super init]) {
  50         if (![clientClass isSubclassOfClass:[SFAnalytics class]]) {
  51             secerror("SFAnalyticsSampler created without valid client class (%@)", clientClass);
  52             return nil;
  53         }
  54
  55         if (!name || (interval < 1.0f && interval != SFAnalyticsSamplerIntervalOncePerReport) || !block) {
  56             secerror("SFAnalyticsSampler created without proper data");
  57             return nil;
  58         }
  59
  60         _clientClass = clientClass;
  61         _block = block;
  62         _name = name;
  63         _samplingInterval = interval;
  64         [self newTimer];
  65     }
  66     return self;
  67 }
  68
  69 - (void)newTimer
  70 {
  71     if (_activeTimer) {
  72         [self pauseSampling];
  73     }
  74
  75     _oncePerReport = (_samplingInterval == SFAnalyticsSamplerIntervalOncePerReport);
  76     if (_oncePerReport) {
  77         [self setupOnceTimer];
  78     } else {
  79         [self setupPeriodicTimer];
  80     }
  81 }
  82
  83 - (void)setupOnceTimer
  84 {
  85     __weak __typeof(self) weakSelf = self;
  86     notify_register_dispatch(SFAnalyticsFireSamplersNotification, &_notificationToken, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^(int token) {
  87         __strong __typeof(self) strongSelf = weakSelf;
  88         if (!strongSelf) {
  89             secnotice("SFAnalyticsSampler", "sampler went away before we could run its once-per-report block");
  90             notify_cancel(token);
  91             return;
  92         }
  93
  94         MultiSamplerDictionary data = strongSelf->_block();
  95         [data enumerateKeysAndObjectsUsingBlock:^(NSString * _Nonnull key, NSNumber * _Nonnull obj, BOOL * _Nonnull stop) {
  96             [[strongSelf->_clientClass logger] logMetric:obj withName:key oncePerReport:strongSelf->_oncePerReport];
  97         }];
  98     });
  99     _activeTimer = YES;
 100 }
 101
 102 - (void)setupPeriodicTimer
 103 {
 104     _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0));
 105     dispatch_source_set_timer(_timer, dispatch_walltime(0, _samplingInterval * NSEC_PER_SEC), _samplingInterval * NSEC_PER_SEC, _samplingInterval * NSEC_PER_SEC / 50.0);    // give 2% leeway on timer
 106
 107     __weak __typeof(self) weakSelf = self;
 108     dispatch_source_set_event_handler(_timer, ^{
 109         __strong __typeof(self) strongSelf = weakSelf;
 110         if (!strongSelf) {
 111             secnotice("SFAnalyticsSampler", "sampler went away before we could run its once-per-report block");
 112             return;
 113         }
 114
 115         MultiSamplerDictionary data = strongSelf->_block();
 116         [data enumerateKeysAndObjectsUsingBlock:^(NSString * _Nonnull key, NSNumber * _Nonnull obj, BOOL * _Nonnull stop) {
 117             [[strongSelf->_clientClass logger] logMetric:obj withName:key oncePerReport:strongSelf->_oncePerReport];
 118         }];
 119     });
 120     dispatch_resume(_timer);
 121
 122     _activeTimer = YES;
 123 }
 124
 125 - (void)setSamplingInterval:(NSTimeInterval)interval
 126 {
 127     if (interval < 1.0f && !(interval == SFAnalyticsSamplerIntervalOncePerReport)) {
 128         secerror("SFAnalyticsSampler: interval %f is not supported", interval);
 129         return;
 130     }
 131
 132     _samplingInterval = interval;
 133     [self newTimer];
 134 }
 135
 136 - (NSTimeInterval)samplingInterval {
 137     return _samplingInterval;
 138 }
 139
 140 - (MultiSamplerDictionary)sampleNow
 141 {
 142     MultiSamplerDictionary data = _block();
 143     [data enumerateKeysAndObjectsUsingBlock:^(NSString * _Nonnull key, NSNumber * _Nonnull obj, BOOL * _Nonnull stop) {
 144         [[self->_clientClass logger] logMetric:obj withName:key oncePerReport:self->_oncePerReport];
 145     }];
 146     return data;
 147 }
 148
 149 - (void)pauseSampling
 150 {
 151     if (!_activeTimer) {
 152         return;
 153     }
 154
 155     if (_oncePerReport) {
 156         notify_cancel(_notificationToken);
 157         _notificationToken = 0;
 158     } else {
 159         dispatch_source_cancel(_timer);
 160     }
 161     _activeTimer = NO;
 162 }
 163
 164 - (void)resumeSampling
 165 {
 166     [self newTimer];
 167 }
 168
 169 - (void)dealloc
 170 {
 171     [self pauseSampling];
 172 }
 173
 174 @end
 175
 176 #endif