Added a hack to de-duplicate hosts and some more checks when adding a host to minimize the chances for dupes

Limelight/Network/CleanupCrew.h

@@ -0,0 +1,22 @@
+//
+//  CleanupCrew.h
+//  Limelight
+//
+//  Created by Diego Waxemberg on 4/5/15.
+//  Copyright (c) 2015 Limelight Stream. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+#import "Host.h"
+
+@protocol CleanupCallback <NSObject>
+
+- (void) cleanedUpHosts:(NSSet*) host;
+
+@end
+
+@interface CleanupCrew : NSOperation
+
+- (id) initWithHostList:(NSArray*) hostList andCallback:(id<CleanupCallback>)callback;
+
+@end

Limelight/Network/CleanupCrew.m

@@ -0,0 +1,54 @@
+//
+//  CleanupCrew.m
+//  Limelight
+//
+//  Created by Diego Waxemberg on 4/5/15.
+//  Copyright (c) 2015 Limelight Stream. All rights reserved.
+//
+
+#import "CleanupCrew.h"
+
+@implementation CleanupCrew {
+    NSArray* _hostList;
+    id<CleanupCallback> _callback;
+}
+
+static const int CLEANUP_RATE = 2;
+
+
+- (id) initWithHostList:(NSArray *)hostList andCallback:(id<CleanupCallback>)callback {
+    self = [super init];
+    _hostList = hostList;
+    _callback = callback;
+    return self;
+}
+
+- (void) main {
+    while (!self.isCancelled) {
+        NSMutableSet* dirtyHosts = [[NSMutableSet alloc] init];
+        
+        for (Host* host in _hostList) {
+            for (Host* other in _hostList) {
+                if (self.isCancelled) {
+                    break;
+                }
+                
+                // We check the name as well as a hack to remove duplicates
+                if (host != other && ([host.uuid isEqualToString:other.uuid]
+                                      || [host.name isEqualToString:other.name]))  {
+                    [dirtyHosts addObject:other];
+                }
+            }
+        }
+        
+        if (dirtyHosts.count > 0) {
+            [_callback cleanedUpHosts:dirtyHosts];
+        }
+        
+        if (!self.cancelled) {
+            [NSThread sleepForTimeInterval:CLEANUP_RATE];
+        }
+    }
+}
+
+@end

Limelight/Network/DiscoveryManager.h

@@ -9,6 +9,7 @@
 #import <Foundation/Foundation.h>
 #import "MDNSManager.h"
 #import "Host.h"
+#import "CleanupCrew.h"
 
 @protocol DiscoveryCallback <NSObject>
 
@@ -16,7 +17,7 @@
 
 @end
 
-@interface DiscoveryManager : NSObject <MDNSCallback>
+@interface DiscoveryManager : NSObject <MDNSCallback, CleanupCallback>
 
 - (id) initWithHosts:(NSArray*)hosts andCallback:(id<DiscoveryCallback>) callback;
 - (void) startDiscovery;

Limelight/Network/DiscoveryManager.m

@@ -15,7 +15,7 @@
 #import "ServerInfoResponse.h"
 
 @implementation DiscoveryManager {
-    NSMutableArray* _hostQueue;
+    NSMutableArray* _hostList;
     NSMutableArray* _discoveredHosts;
     id<DiscoveryCallback> _callback;
     MDNSManager* _mdnsMan;
@@ -27,7 +27,7 @@
 
 - (id)initWithHosts:(NSArray *)hosts andCallback:(id<DiscoveryCallback>)callback {
     self = [super init];
-    _hostQueue = [NSMutableArray arrayWithArray:hosts];
+    _hostList = [NSMutableArray arrayWithArray:hosts];
     _callback = callback;
     _opQueue = [[NSOperationQueue alloc] init];
     _mdnsMan = [[MDNSManager alloc] initWithCallback:self];
@@ -66,9 +66,11 @@
     Log(LOG_I, @"Starting discovery");
     shouldDiscover = YES;
     [_mdnsMan searchForHosts];
-    for (Host* host in _hostQueue) {
+    for (Host* host in _hostList) {
         [_opQueue addOperation:[self createWorkerForHost:host]];
     }
+    CleanupCrew* cleanup = [[CleanupCrew alloc] initWithHostList:_hostList andCallback:self];
+    [_opQueue addOperation:cleanup];
 }
 
 - (void) stopDiscovery {
@@ -88,8 +90,8 @@
 }
 
 - (BOOL) addHostToDiscovery:(Host *)host {
-    if (![self isHostInDiscovery:host]) {
+    if (host.uuid.length > 0 && ![self isHostInDiscovery:host]) {
-        [_hostQueue addObject:host];
+        [_hostList addObject:host];
         if (shouldDiscover) {
             [_opQueue addOperation:[self createWorkerForHost:host]];
         }
@@ -104,7 +106,16 @@
             [worker cancel];
         }
     }
-    [_hostQueue removeObject:host];
+    [_hostList removeObject:host];
+}
+
+// Override from CleanupCallback
+- (void) cleanedUpHosts:(NSSet*)dirtyHosts {
+    for (Host* host in dirtyHosts) {
+        Log(LOG_I, @"Cleaning up duplicate host: %@", host.name);
+        [self removeHostFromDiscovery:host];
+    }
+    [_callback updateAllHosts:_hostList];
 }
 
 // Override from MDNSCallback
@@ -119,7 +130,7 @@
             [worker discoverHost];
             if ([self addHostToDiscovery:host]) {
                 Log(LOG_I, @"Adding host to discovery: %@", host.name);
-                [_callback updateAllHosts:_hostQueue];
+                [_callback updateAllHosts:_hostList];
             } else {
                 Log(LOG_I, @"Not adding host to discovery: %@", host.name);
                 [dataMan removeHost:host];
@@ -129,8 +140,8 @@
 }
 
 - (BOOL) isHostInDiscovery:(Host*)host {
-    for (int i = 0; i < _hostQueue.count; i++) {
+    for (int i = 0; i < _hostList.count; i++) {
-        Host* discoveredHost = [_hostQueue objectAtIndex:i];
+        Host* discoveredHost = [_hostList objectAtIndex:i];
         if (discoveredHost.uuid.length > 0 && [discoveredHost.uuid isEqualToString:host.uuid]) {
             return YES;
         }