Files
santa/Source/santad/SNTSyncdQueue.m
2019-07-29 08:29:04 -04:00

101 lines
3.6 KiB
Objective-C

/// Copyright 2016 Google Inc. All rights reserved.
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
/// http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
#import "Source/santad/SNTSyncdQueue.h"
#import <MOLXPCConnection/MOLXPCConnection.h>
#import "Source/common/SNTLogging.h"
#import "Source/common/SNTStoredEvent.h"
#import "Source/common/SNTXPCSyncdInterface.h"
@interface SNTSyncdQueue ()
@property NSCache<NSString *, NSDate *> *uploadBackoff;
@property dispatch_queue_t syncdQueue;
@property dispatch_semaphore_t sema;
@end
@implementation SNTSyncdQueue
- (instancetype)init {
self = [super init];
if (self) {
_uploadBackoff = [[NSCache alloc] init];
_uploadBackoff.countLimit = 128;
_syncdQueue = dispatch_queue_create("com.google.syncd_queue", DISPATCH_QUEUE_SERIAL);
_sema = dispatch_semaphore_create(0);
}
return self;
}
- (void)addEvents:(NSArray<SNTStoredEvent *> *)events isFromBundle:(BOOL)isFromBundle {
if (!events.count) return;
SNTStoredEvent *first = events.firstObject;
NSString *hash = isFromBundle ? first.fileBundleHash : first.fileSHA256;
if (![self backoffForPrimaryHash:hash]) return;
[self dispatchBlockOnSyncdQueue:^{
[self.syncdConnection.remoteObjectProxy postEventsToSyncServer:events
isFromBundle:isFromBundle];
}];
}
- (void)addBundleEvent:(SNTStoredEvent *)event reply:(void (^)(SNTBundleEventAction))reply {
if (![self backoffForPrimaryHash:event.fileBundleHash]) return;
[self dispatchBlockOnSyncdQueue:^{
[self.syncdConnection.remoteObjectProxy
postBundleEventToSyncServer:event reply:^(SNTBundleEventAction action) {
// Remove the backoff entry for the initial block event. The same event will be included in
// the related events synced using addEvents:isFromBundle:.
if (action == SNTBundleEventActionSendEvents) {
[self.uploadBackoff removeObjectForKey:event.fileBundleHash];
}
reply(action);
}];
}];
}
- (void)startSyncingEvents {
dispatch_semaphore_signal(self.sema);
}
- (void)stopSyncingEvents {
self.sema = dispatch_semaphore_create(0);
}
// Hold events for a few seconds to allow santad and santactl to establish connections.
// If the connections are not established in time drop the event from the queue.
// They will be uploaded during a full sync.
- (void)dispatchBlockOnSyncdQueue:(void (^)(void))block {
dispatch_async(self.syncdQueue, ^{
if (!dispatch_semaphore_wait(self.sema, dispatch_time(DISPATCH_TIME_NOW, 2 * NSEC_PER_SEC))) {
if (block) block();
dispatch_semaphore_signal(self.sema);
} else {
LOGD(@"Dropping block %@ from com.google.syncd_queue", block);
}
});
}
// The event upload is skipped if an event has been initiated for it in the last 10 minutes.
// The passed-in hash is fileBundleHash for a bundle event, or fileSHA256 for a normal event.
- (BOOL)backoffForPrimaryHash:(NSString *)hash {
NSDate *backoff = [self.uploadBackoff objectForKey:hash];
NSDate *now = [NSDate date];
if (([now timeIntervalSince1970] - [backoff timeIntervalSince1970]) < 600) return NO;
[self.uploadBackoff setObject:now forKey:hash];
return YES;
}
@end