iOS/Pods/FirebaseMessaging/Firebase/Messaging/FIRMessagingDelayedMessageQueue.m

   1 /*
   2  * Copyright 2017 Google
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #import "FIRMessagingDelayedMessageQueue.h"
  18
  19 #import "Protos/GtalkCore.pbobjc.h"
  20
  21 #import "FIRMessagingDefines.h"
  22 #import "FIRMessagingRmqManager.h"
  23 #import "FIRMessagingUtilities.h"
  24
  25 static const int kMaxQueuedMessageCount = 10;
  26
  27 @interface FIRMessagingDelayedMessageQueue ()
  28
  29 @property(nonatomic, readonly, weak) id<FIRMessagingRmqScanner> rmqScanner;
  30 @property(nonatomic, readonly, copy) FIRMessagingSendDelayedMessagesHandler sendDelayedMessagesHandler;
  31
  32 @property(nonatomic, readwrite, assign) int persistedMessageCount;
  33 // the scheduled timeout or -1 if not set
  34 @property(nonatomic, readwrite, assign) int64_t scheduledTimeoutMilliseconds;
  35 // The time  of the last scan of the message DB,
  36 // used to avoid retrieving messages more than once.
  37 @property(nonatomic, readwrite, assign) int64_t lastDBScanTimestampSeconds;
  38
  39 @property(nonatomic, readwrite, strong) NSMutableArray *messages;
  40 @property(nonatomic, readwrite, strong) NSTimer *sendTimer;
  41
  42 @end
  43
  44 @implementation FIRMessagingDelayedMessageQueue
  45
  46 - (instancetype)init {
  47   FIRMessagingInvalidateInitializer();
  48 }
  49
  50 - (instancetype)initWithRmqScanner:(id<FIRMessagingRmqScanner>)rmqScanner
  51         sendDelayedMessagesHandler:(FIRMessagingSendDelayedMessagesHandler)sendDelayedMessagesHandler {
  52   _FIRMessagingDevAssert(sendDelayedMessagesHandler, @"Invalid nil callback for delayed messages");
  53   self = [super init];
  54   if (self) {
  55     _rmqScanner = rmqScanner;
  56     _sendDelayedMessagesHandler = sendDelayedMessagesHandler;
  57     _messages = [NSMutableArray arrayWithCapacity:10];
  58     _scheduledTimeoutMilliseconds = -1;
  59   }
  60   return self;
  61 }
  62
  63 - (BOOL)queueMessage:(GtalkDataMessageStanza *)message {
  64   if (self.messages.count >= kMaxQueuedMessageCount) {
  65     return NO;
  66   }
  67   if (message.ttl == 0) {
  68     // ttl=0 messages aren't persisted, add it to memory
  69     [self.messages addObject:message];
  70   } else {
  71     self.persistedMessageCount++;
  72   }
  73   int64_t timeoutMillis = [self calculateTimeoutInMillisWithDelayInSeconds:message.maxDelay];
  74   if (![self isTimeoutScheduled] || timeoutMillis < self.scheduledTimeoutMilliseconds) {
  75     [self scheduleTimeoutInMillis:timeoutMillis];
  76   }
  77   return YES;
  78 }
  79
  80 - (NSArray *)removeDelayedMessages {
  81   [self cancelTimeout];
  82   if ([self messageCount] == 0) {
  83     return @[];
  84   }
  85
  86   NSMutableArray *delayedMessages = [NSMutableArray array];
  87   // add the ttl=0 messages
  88   if (self.messages.count) {
  89     [delayedMessages addObjectsFromArray:delayedMessages];
  90     [self.messages removeAllObjects];
  91   }
  92
  93   // add persistent messages
  94   if (self.persistedMessageCount > 0) {
  95     FIRMessaging_WEAKIFY(self);
  96     [self.rmqScanner scanWithRmqMessageHandler:nil
  97                             dataMessageHandler:^(int64_t rmqId, GtalkDataMessageStanza *stanza) {
  98                               FIRMessaging_STRONGIFY(self);
  99                               if ([stanza hasMaxDelay] &&
 100                                   [stanza sent] >= self.lastDBScanTimestampSeconds) {
 101                                 [delayedMessages addObject:stanza];
 102                               }
 103                             }];
 104     self.lastDBScanTimestampSeconds = FIRMessagingCurrentTimestampInSeconds();
 105     self.persistedMessageCount = 0;
 106   }
 107   return delayedMessages;
 108 }
 109
 110 - (void)sendMessages {
 111   if (self.sendDelayedMessagesHandler) {
 112     self.sendDelayedMessagesHandler([self removeDelayedMessages]);
 113   }
 114 }
 115
 116 #pragma mark - Private
 117
 118 - (NSInteger)messageCount {
 119   return self.messages.count + self.persistedMessageCount;
 120 }
 121
 122 - (BOOL)isTimeoutScheduled {
 123   return self.scheduledTimeoutMilliseconds > 0;
 124 }
 125
 126 - (int64_t)calculateTimeoutInMillisWithDelayInSeconds:(int)delay {
 127   return FIRMessagingCurrentTimestampInMilliseconds() + delay * 1000.0;
 128 }
 129
 130 - (void)scheduleTimeoutInMillis:(int64_t)time {
 131   [self cancelTimeout];
 132   self.scheduledTimeoutMilliseconds = time;
 133   double delay = (time - FIRMessagingCurrentTimestampInMilliseconds()) / 1000.0;
 134   [self performSelector:@selector(sendMessages) withObject:self afterDelay:delay];
 135 }
 136
 137 - (void)cancelTimeout {
 138   if ([self isTimeoutScheduled]) {
 139     [NSObject cancelPreviousPerformRequestsWithTarget:self
 140                                              selector:@selector(sendMessages)
 141                                                object:nil];
 142     self.scheduledTimeoutMilliseconds = -1;
 143   }
 144 }
 145
 146 @end