sync: allow a sync server to change the frequency of syncing to a min of 60 secs (#595)

Author: tburgin

Source/common/SNTSyncConstants.h

@@ -158,6 +158,7 @@ extern NSString *const kPostflightRulesProcessed;
 ///
 ///  Are represented in seconds
 ///
+extern const NSUInteger kMinimumFullSyncInterval;
 extern const NSUInteger kDefaultFullSyncInterval;
 extern const NSUInteger kDefaultPushNotificationsFullSyncInterval;
 extern const NSUInteger kDefaultPushNotificationsGlobalRuleSyncDeadline;

Source/common/SNTSyncConstants.mm

@@ -151,6 +151,7 @@
 NSString *const kPostflightRulesProcessed = @"rules_processed";
 
 const NSUInteger kDefaultEventBatchSize = 50;
+const NSUInteger kMinimumFullSyncInterval = 60;
 const NSUInteger kDefaultFullSyncInterval = 600;
 const NSUInteger kDefaultPushNotificationsFullSyncInterval = 14400;
 const NSUInteger kDefaultPushNotificationsGlobalRuleSyncDeadline = 600;

Source/santasyncservice/SNTSyncPreflight.mm

@@ -182,7 +182,7 @@ - (BOOL)sync {
   uint64_t value = resp.push_notification_full_sync_interval_seconds()
                        ?: resp.deprecated_fcm_full_sync_interval_seconds();
   self.syncState.pushNotificationsFullSyncInterval =
-      (value < kDefaultFullSyncInterval) ? kDefaultPushNotificationsFullSyncInterval : value;
+      (value < kMinimumFullSyncInterval) ? kMinimumFullSyncInterval : value;
 
   value = resp.push_notification_global_rule_sync_deadline_seconds()
               ?: resp.deprecated_fcm_global_rule_sync_deadline_seconds();
@@ -193,7 +193,8 @@ - (BOOL)sync {
 
   // Check if our sync interval has changed
   value = resp.full_sync_interval_seconds();
-  self.syncState.fullSyncInterval = (value < 60) ? kDefaultFullSyncInterval : value;
+  self.syncState.fullSyncInterval =
+      (value < kMinimumFullSyncInterval) ? kMinimumFullSyncInterval : value;
 
   switch (resp.client_mode()) {
     case ::pbv1::MONITOR: self.syncState.clientMode = SNTClientModeMonitor; break;