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author | 2016-03-16 07:56:37 -0700 | |
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committer | 2016-03-16 07:56:37 -0700 | |
commit | 5ee157cd1184e34209d840947c3595864da891b4 (patch) | |
tree | dfc222fdd97fdbdc67b58053bd406468a27f155b /src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m | |
parent | 69f57b4672f1c14f39921cbe0b9419a2fc04e4ba (diff) | |
parent | 66e3b02d8a970f978c7907903f04094f802c7b44 (diff) |
Merge github.com:grpc/grpc into backoff_lib
Diffstat (limited to 'src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m')
-rw-r--r-- | src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m b/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m new file mode 100644 index 0000000000..b4061bd5ef --- /dev/null +++ b/src/objective-c/GRPCClient/private/GRPCConnectivityMonitor.m @@ -0,0 +1,192 @@ +/* + * + * Copyright 2016, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#import "GRPCConnectivityMonitor.h" + +#pragma mark Flags + +@implementation GRPCReachabilityFlags { + SCNetworkReachabilityFlags _flags; +} + ++ (instancetype)flagsWithFlags:(SCNetworkReachabilityFlags)flags { + return [[self alloc] initWithFlags:flags]; +} + +- (instancetype)initWithFlags:(SCNetworkReachabilityFlags)flags { + if ((self = [super init])) { + _flags = flags; + } + return self; +} + +/* + * One accessor method implementation per flag. Example: + +- (BOOL)isCell { \ + return !!(_flags & kSCNetworkReachabilityFlagsIsWWAN); \ +} + + */ +#define GRPC_XMACRO_ITEM(methodName, FlagName) \ +- (BOOL)methodName { \ + return !!(_flags & kSCNetworkReachabilityFlags ## FlagName); \ +} +#include "GRPCReachabilityFlagNames.xmacro.h" +#undef GRPC_XMACRO_ITEM + +- (BOOL)isHostReachable { + // Note: connectionOnDemand means it'll be reachable only if using the CFSocketStream API or APIs + // on top of it. + // connectionRequired means we can't tell until a connection is attempted (e.g. for VPN on + // demand). + return self.reachable && !self.interventionRequired && !self.connectionOnDemand; +} + +- (NSString *)description { + NSMutableArray *activeOptions = [NSMutableArray arrayWithCapacity:9]; + + /* + * For each flag, add its name to the array if it's ON. Example: + + if (self.isCell) { + [activeOptions addObject:@"isCell"]; + } + + */ +#define GRPC_XMACRO_ITEM(methodName, FlagName) \ + if (self.methodName) { \ + [activeOptions addObject:@#methodName]; \ + } +#include "GRPCReachabilityFlagNames.xmacro.h" +#undef GRPC_XMACRO_ITEM + + return activeOptions.count == 0 ? @"(none)" : [activeOptions componentsJoinedByString:@", "]; +} + +- (BOOL)isEqual:(id)object { + return [object isKindOfClass:[GRPCReachabilityFlags class]] && + _flags == ((GRPCReachabilityFlags *)object)->_flags; +} + +- (NSUInteger)hash { + return _flags; +} +@end + +#pragma mark Connectivity Monitor + +// Assumes the third argument is a block that accepts a GRPCReachabilityFlags object, and passes the +// received ones to it. +static void PassFlagsToContextInfoBlock(SCNetworkReachabilityRef target, + SCNetworkReachabilityFlags flags, + void *info) { + #pragma unused (target) + // This can be called many times with the same info. The info is retained by SCNetworkReachability + // while this function is being executed. + void (^handler)(GRPCReachabilityFlags *) = (__bridge void (^)(GRPCReachabilityFlags *))info; + handler([[GRPCReachabilityFlags alloc] initWithFlags:flags]); +} + +@implementation GRPCConnectivityMonitor { + SCNetworkReachabilityRef _reachabilityRef; +} + +- (nullable instancetype)initWithReachability:(nullable SCNetworkReachabilityRef)reachability { + if (!reachability) { + return nil; + } + if ((self = [super init])) { + _reachabilityRef = CFRetain(reachability); + _queue = dispatch_get_main_queue(); + } + return self; +} + ++ (nullable instancetype)monitorWithHost:(nonnull NSString *)host { + const char *hostName = host.UTF8String; + if (!hostName) { + [NSException raise:NSInvalidArgumentException + format:@"host.UTF8String returns NULL for %@", host]; + } + SCNetworkReachabilityRef reachability = + SCNetworkReachabilityCreateWithName(NULL, hostName); + + GRPCConnectivityMonitor *returnValue = [[self alloc] initWithReachability:reachability]; + if (reachability) { + CFRelease(reachability); + } + return returnValue; +} + +- (void)handleLossWithHandler:(void (^)())handler { + [self startListeningWithHandler:^(GRPCReachabilityFlags *flags) { + if (!flags.isHostReachable) { + handler(); + } + }]; +} + +- (void)startListeningWithHandler:(void (^)(GRPCReachabilityFlags *))handler { + // Copy to ensure the handler block is in the heap (and so can't be deallocated when this method + // returns). + void (^copiedHandler)(GRPCReachabilityFlags *) = [handler copy]; + SCNetworkReachabilityContext context = { + .version = 0, + .info = (__bridge void *)copiedHandler, + .retain = CFRetain, + .release = CFRelease, + }; + // The following will retain context.info, and release it when the callback is set to NULL. + SCNetworkReachabilitySetCallback(_reachabilityRef, PassFlagsToContextInfoBlock, &context); + SCNetworkReachabilitySetDispatchQueue(_reachabilityRef, _queue); +} + +- (void)stopListening { + // This releases the block on context.info. + SCNetworkReachabilitySetCallback(_reachabilityRef, NULL, NULL); + SCNetworkReachabilitySetDispatchQueue(_reachabilityRef, NULL); +} + +- (void)setQueue:(dispatch_queue_t)queue { + _queue = queue ?: dispatch_get_main_queue(); +} + +- (void)dealloc { + if (_reachabilityRef) { + [self stopListening]; + CFRelease(_reachabilityRef); + } +} + +@end |