Use separate session pool for cellular connections -- resolves #11

twitter-archive · Jan 11, 2014 · 57d43ec · 57d43ec
1 parent 95a9ca5
commit 57d43ec
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Showing 5 changed files with 92 additions and 19 deletions.
diff --git a/SPDY/SPDYSession.h b/SPDY/SPDYSession.h
@@ -16,10 +16,17 @@
 @class SPDYOrigin;
 
 @interface SPDYSession : NSObject
+
 @property (nonatomic, readonly) SPDYOrigin *origin;
+@property (nonatomic, readonly) bool isCellular;
 @property (nonatomic, readonly) bool isOpen;
-- (id)initWithOrigin:(SPDYOrigin *)origin configuration:(SPDYConfiguration *)configuration error:(NSError **)pError;
+
+- (id)initWithOrigin:(SPDYOrigin *)origin
+       configuration:(SPDYConfiguration *)configuration
+            cellular:(bool)cellular
+               error:(NSError **)pError;
 - (void)issueRequest:(SPDYProtocol *)protocol;
 - (void)cancelRequest:(SPDYProtocol *)protocol;
 - (void)close;
+
 @end
diff --git a/SPDY/SPDYSession.m b/SPDY/SPDYSession.m
@@ -69,9 +69,13 @@ @implementation SPDYSession
     bool _enableSettingsMinorVersion;
     bool _receivedGoAwayFrame;
     bool _sentGoAwayFrame;
+    bool _cellular;
 }
 
-- (id)initWithOrigin:(SPDYOrigin *)origin configuration:(SPDYConfiguration *)configuration error:(NSError **)pError
+- (id)initWithOrigin:(SPDYOrigin *)origin
+       configuration:(SPDYConfiguration *)configuration
+            cellular:(bool)cellular
+               error:(NSError **)pError
 {
     NSParameterAssert(origin != nil);
 
@@ -98,6 +102,9 @@ - (id)initWithOrigin:(SPDYOrigin *)origin configuration:(SPDYConfiguration *)con
             _origin = origin;
             SPDY_INFO(@"session connecting to %@", _origin);
 
+            // TODO: for accuracy confirm this later from the socket
+            _cellular = cellular;
+
             if ([_origin.scheme isEqualToString:@"https"]) {
                 SPDY_DEBUG(@"session using TLS");
                 [_socket secureWithTLS:configuration.tlsSettings];
@@ -221,6 +228,11 @@ - (void)dealloc
     [_socket disconnect];
 }
 
+- (bool)isCellular
+{
+    return _cellular;
+}
+
 - (bool)isOpen
 {
     return (!_receivedGoAwayFrame && !_sentGoAwayFrame);

diff --git a/SPDY/SPDYSessionManager.h b/SPDY/SPDYSessionManager.h
@@ -15,7 +15,9 @@
 @class SPDYSession;
 
 @interface SPDYSessionManager : NSObject
-+ (void)setConfiguration:(SPDYConfiguration *)configuration;
+
 + (SPDYSession *)sessionForURL:(NSURL *)url error:(NSError **)pError;
 + (void)sessionClosed:(SPDYSession *)session;
++ (void)setConfiguration:(SPDYConfiguration *)configuration;
+
 @end
diff --git a/SPDY/SPDYSessionManager.m b/SPDY/SPDYSessionManager.m
@@ -13,34 +13,59 @@
 #error "This file requires ARC support."
 #endif
 
+#import <SystemConfiguration/SystemConfiguration.h>
+#import <arpa/inet.h>
+#import "SPDYCommonLogger.h"
 #import "SPDYOrigin.h"
-#import "SPDYSessionManager.h"
 #import "SPDYProtocol.h"
 #import "SPDYSession.h"
+#import "SPDYSessionManager.h"
 
 @interface SPDYSessionManager ()
-+ (NSMutableDictionary *)activeSessions;
++ (NSMutableDictionary *)_sessionPool:(bool)network;
 @end
 
 static NSString *const SPDYSessionManagerKey = @"com.twitter.SPDYSessionManager";
 static SPDYConfiguration *currentConfiguration;
+static volatile bool reachabilityIsWWAN;
+
+#if TARGET_OS_IPHONE
+static char *const SPDYReachabilityQueue = "com.twitter.SPDYReachabilityQueue";
+
+static SCNetworkReachabilityRef reachabilityRef;
+static dispatch_queue_t reachabilityQueue;
+
+static void SPDYReachabilityCallback(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags, void *info);
+#endif
 
 @implementation SPDYSessionManager
 
 + (void)initialize
 {
     currentConfiguration = [SPDYConfiguration defaultConfiguration];
-}
+    reachabilityIsWWAN = NO;
 
-+ (NSMutableDictionary *)activeSessions
-{
-    NSMutableDictionary *threadDictionary = [NSThread currentThread].threadDictionary;
-    NSMutableDictionary *activeSessions = threadDictionary[SPDYSessionManagerKey];
-    if (!activeSessions) {
-        activeSessions = [NSMutableDictionary new];
-        threadDictionary[SPDYSessionManagerKey] = activeSessions;
+#if TARGET_OS_IPHONE
+    struct sockaddr_in zeroAddress;
+    bzero(&zeroAddress, sizeof(zeroAddress));
+    zeroAddress.sin_len = (uint8_t)sizeof(zeroAddress);
+    zeroAddress.sin_family = AF_INET;
+
+    SCNetworkReachabilityContext context = {0, NULL, NULL, NULL, NULL};
+    reachabilityRef = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, (const struct sockaddr *)&zeroAddress);
+
+    if (SCNetworkReachabilitySetCallback(reachabilityRef, SPDYReachabilityCallback, &context)) {
+        reachabilityQueue = dispatch_queue_create(SPDYReachabilityQueue, DISPATCH_QUEUE_SERIAL);
+        SCNetworkReachabilitySetDispatchQueue(reachabilityRef, reachabilityQueue);
     }
-    return activeSessions;
+
+    dispatch_async(reachabilityQueue, ^{
+        SCNetworkReachabilityFlags flags;
+        if (SCNetworkReachabilityGetFlags(reachabilityRef, &flags)) {
+            SPDYReachabilityCallback(reachabilityRef, flags, NULL);
+        }
+    });
+#endif
 }
 
 + (void)setConfiguration:(SPDYConfiguration *)configuration
@@ -51,11 +76,12 @@ + (void)setConfiguration:(SPDYConfiguration *)configuration
 + (SPDYSession *)sessionForURL:(NSURL *)url error:(NSError **)pError
 {
     SPDYOrigin *origin = [[SPDYOrigin alloc] initWithURL:url error:pError];
-    NSMutableDictionary *activeSessions = [SPDYSessionManager activeSessions];
+    NSMutableDictionary *activeSessions = [SPDYSessionManager _sessionPool:reachabilityIsWWAN];
     SPDYSession *session = activeSessions[origin];
     if (!session || !session.isOpen) {
         session = [[SPDYSession alloc] initWithOrigin:origin
                                         configuration:currentConfiguration
+                                             cellular:reachabilityIsWWAN
                                                 error:pError];
         if (session) {
             activeSessions[origin] = session;
@@ -67,10 +93,36 @@ + (SPDYSession *)sessionForURL:(NSURL *)url error:(NSError **)pError
 + (void)sessionClosed:(SPDYSession *)session
 {
     SPDYOrigin *origin = session.origin;
-    NSMutableDictionary *activeSessions = [SPDYSessionManager activeSessions];
+    NSMutableDictionary *activeSessions = [SPDYSessionManager _sessionPool:session.isCellular];
     if (activeSessions[origin] == session) {
         [activeSessions removeObjectForKey:origin];
     }
 }
 
++ (NSMutableDictionary *)_sessionPool:(bool)cellular
+{
+    NSMutableDictionary *threadDictionary = [NSThread currentThread].threadDictionary;
+    NSArray *sessionPools = threadDictionary[SPDYSessionManagerKey];
+    if (!sessionPools) {
+        threadDictionary[SPDYSessionManagerKey] = @[
+            [NSMutableDictionary new],
+            [NSMutableDictionary new]  // WWAN
+        ];
+    }
+
+    SPDY_DEBUG(@"using %@ session pool", cellular ? @"cellular" : @"standard");
+    return sessionPools[cellular ? 1 : 0];
+}
+
 @end
+
+#if TARGET_OS_IPHONE
+static void SPDYReachabilityCallback(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags, void *info)
+{
+    // Only update if the network is actually reachable
+    if (flags & kSCNetworkReachabilityFlagsReachable) {
+        reachabilityIsWWAN = (flags & kSCNetworkReachabilityFlagsIsWWAN) != 0;
+        SPDY_DEBUG(@"reachability updated: %@", reachabilityIsWWAN ? @"WWAN" : @"WLAN");
+    }
+}
+#endif
diff --git a/SPDY/SPDYSocket.m b/SPDY/SPDYSocket.m
@@ -15,11 +15,11 @@
 #error "This file requires ARC support."
 #endif
 
+#import <arpa/inet.h>
+#import <netinet/in.h>
+#import <sys/socket.h>
 #import "SPDYSocket.h"
 #import "SPDYCommonLogger.h"
-#import <sys/socket.h>
-#import <netinet/in.h>
-#import <arpa/inet.h>
 
 #pragma mark Declarations