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/*
*
* Copyright 2016 gRPC authors.
*
* 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 "GRPCConnectivityMonitor.h"
#include <netinet/in.h>
NSString *kGRPCConnectivityNotification = @"kGRPCConnectivityNotification";
static SCNetworkReachabilityRef reachability;
static GRPCConnectivityStatus currentStatus;
// Aggregate information in flags into network status.
GRPCConnectivityStatus CalculateConnectivityStatus(SCNetworkReachabilityFlags flags) {
GRPCConnectivityStatus result = GRPCConnectivityUnknown;
if (((flags & kSCNetworkReachabilityFlagsReachable) == 0) ||
((flags & kSCNetworkReachabilityFlagsConnectionRequired) != 0)) {
return GRPCConnectivityNoNetwork;
}
result = GRPCConnectivityWiFi;
#if TARGET_OS_IPHONE
if (flags & kSCNetworkReachabilityFlagsIsWWAN) {
return result = GRPCConnectivityCellular;
}
#endif
return result;
}
static void ReachabilityCallback(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags,
void *info) {
GRPCConnectivityStatus newStatus = CalculateConnectivityStatus(flags);
if (newStatus != currentStatus) {
[[NSNotificationCenter defaultCenter] postNotificationName:kGRPCConnectivityNotification
object:nil];
currentStatus = newStatus;
}
}
@implementation GRPCConnectivityMonitor
+ (void)initialize {
if (self == [GRPCConnectivityMonitor self]) {
struct sockaddr_in addr = {0};
addr.sin_len = sizeof(addr);
addr.sin_family = AF_INET;
reachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *)&addr);
currentStatus = GRPCConnectivityUnknown;
SCNetworkConnectionFlags flags;
if (SCNetworkReachabilityGetFlags(reachability, &flags)) {
currentStatus = CalculateConnectivityStatus(flags);
}
SCNetworkReachabilityContext context = {0, (__bridge void *)(self), NULL, NULL, NULL};
if (!SCNetworkReachabilitySetCallback(reachability, ReachabilityCallback, &context) ||
!SCNetworkReachabilityScheduleWithRunLoop(reachability, CFRunLoopGetMain(),
kCFRunLoopCommonModes)) {
NSLog(@"gRPC connectivity monitor fail to set");
}
}
}
+ (void)registerObserver:(id)observer selector:(SEL)selector {
[[NSNotificationCenter defaultCenter] addObserver:observer
selector:selector
name:kGRPCConnectivityNotification
object:nil];
}
+ (void)unregisterObserver:(id)observer {
[[NSNotificationCenter defaultCenter] removeObserver:observer];
}
@end
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