Avoid long viewer freezes when region doesn't have reverse DNS.

Some opensim servers might not have a reverse DNS, which causes
a stall of up to 5 seconds for each call. This means that
every time you up the parcel music stream (or any other media)
the viewer would freeze six times 5 seconds.. 30 seconds.

With this patch it only freeze once ;) (when you enter a region).
It already did that before (too), but after that opening the
parcel media doesn't freeze the viewer at all anymore.

indra/llmessage/llhost.cpp

@@ -59,11 +59,12 @@ LLHost::LLHost(const std::string& ip_and_port)
 		mIP = ip_string_to_u32(ip_str.c_str());
 		mPort = atol(port_str.c_str());
 	}
+	mHostNotFound = 0;
 }
 
 std::string LLHost::getString() const
 {
-	return llformat("%s:%u", u32_to_ip_string(mIP), mPort);
+	return llformat("%s:%hu", u32_to_ip_string(mIP), mPort);
 }
 
 
@@ -87,16 +88,27 @@ std::string LLHost::getHostName() const
 		llwarns << "LLHost::getHostName() : Invalid IP address" << llendl;
 		return std::string();
 	}
+	if (mHostNotFound)
+	{
+		// We already checked this... avoid freezing the viewer 5 seconds again and again.
+		llwarns << "LLHost::getHostName() : Returning cached HOST_NOT_FOUND." << llendl;
+		return std::string();
+	}
 	he = gethostbyaddr((char *)&mIP, sizeof(mIP), AF_INET);
 	if (!he)
 	{
 #if LL_WINDOWS
-		llwarns << "LLHost::getHostName() : Couldn't find host name for address " << mIP << ", Error: " 
-			<< WSAGetLastError() << llendl;
+		int err = WSAGetLastError();
+		int err_host_not_found = WSAHOST_NOT_FOUND;
 #else
-		llwarns << "LLHost::getHostName() : Couldn't find host name for address " << mIP << ", Error: " 
-			<< h_errno << llendl;
+		int err = h_errno;
+		int err_host_not_found = HOST_NOT_FOUND;
 #endif
+		llwarns << "LLHost::getHostName() : Couldn't find host name for address " << mIP << ", Error: " << err << llendl;
+		if (err == err_host_not_found)
+		{
+			mHostNotFound = 1;
+		}
 		return std::string();
 	}
 	else
@@ -125,6 +137,7 @@ BOOL LLHost::setHostByName(const std::string& hostname)
 	if (he)
 	{
 		mIP = *(U32 *)he->h_addr_list[0];
+		mHostNotFound = 0;
 		return TRUE;
 	}
 	else 

indra/llmessage/llhost.h

@@ -38,7 +38,8 @@ const U32 INVALID_HOST_IP_ADDRESS = 0x0;
 
 class LLHost {
 protected:
-	U32			mPort;
+	U16			mPort;
+	mutable U16	mHostNotFound;			// Singularity addition; caches a failed IP -> hostname lookup.
 	U32         mIP;
 public:
 	
@@ -47,17 +48,20 @@ public:
 	// CREATORS
 	LLHost()
 	:	mPort(INVALID_PORT),
+		mHostNotFound(1),
 		mIP(INVALID_HOST_IP_ADDRESS)
 	{ } // STL's hash_map expect this T()
 
 	LLHost( U32 ipv4_addr, U32 port )
-	:	mPort( port ) 
+	:	mPort(port),
+		mHostNotFound(0)
 	{
 		mIP = ipv4_addr;
 	}
 
 	LLHost( const std::string& ipv4_addr, U32 port )
-	:	mPort( port )
+	:	mPort(port),
+		mHostNotFound(0)
 	{ 
 		mIP = ip_string_to_u32(ipv4_addr.c_str());
 	}
@@ -68,6 +72,7 @@ public:
 		U32 port = (U32)(ip_port & (U64)0xFFFFFFFF);
 		mIP = ip;
 		mPort = port;
+		mHostNotFound = 0;
 	}
 
 	explicit LLHost(const std::string& ip_and_port);
@@ -76,15 +81,15 @@ public:
 	{ }
 
 	// MANIPULATORS
-	void	set( U32 ip, U32 port )				{ mIP = ip; mPort = port; }
-	void	set( const std::string& ipstr, U32 port )	{ mIP = ip_string_to_u32(ipstr.c_str()); mPort = port; }
-	void	setAddress( const std::string& ipstr )		{ mIP = ip_string_to_u32(ipstr.c_str()); }
-	void	setAddress( U32 ip )				{ mIP = ip; }
+	void	set( U32 ip, U32 port )				{ mIP = ip; mPort = port; mHostNotFound = 0; }
+	void	set( const std::string& ipstr, U32 port )	{ mIP = ip_string_to_u32(ipstr.c_str()); mPort = port; mHostNotFound = 0; }
+	void	setAddress( const std::string& ipstr )		{ mIP = ip_string_to_u32(ipstr.c_str()); mHostNotFound = 0; }
+	void	setAddress( U32 ip )				{ mIP = ip; mHostNotFound = 0; }
 	void	setPort( U32 port )					{ mPort = port; }
 	BOOL    setHostByName(const std::string& hname);
 
 	LLHost&	operator=(const LLHost &rhs);
-	void    invalidate()                        { mIP = INVALID_HOST_IP_ADDRESS; mPort = INVALID_PORT;};
+	void    invalidate()                        { mIP = INVALID_HOST_IP_ADDRESS; mPort = INVALID_PORT; mHostNotFound = 1; }
 
 	// READERS
 	U32		getAddress() const							{ return mIP; }

indra/newview/llviewerparcelmedia.cpp

@@ -1071,7 +1071,11 @@ std::string LLViewerParcelMedia::extractDomain(std::string url)
 		url = url.substr(pos + 1, count);
 	}
 
-	if (url.find(gAgent.getRegion()->getHost().getHostName()) == 0 || url.find(last_region) == 0)
+	//Singu note: The call to getHostName() freezes the viewer for a few seconds if the region has no reverse DNS...
+	// Avoid calling it three times therefore -- not to mention that if it fails, it returns an empty string which
+	// does NOT mean that it should match the current url as if the current url contains the current regions hostname!
+	std::string const hostname = gAgent.getRegion()->getHost().getHostName();
+	if ((!hostname.empty() && url.find(hostname) == 0) || url.find(last_region) == 0)
 	{
 		// This must be a scripted object rezzed in the region:
 		// extend the concept of "domain" to encompass the
@@ -1080,7 +1084,7 @@ std::string LLViewerParcelMedia::extractDomain(std::string url)
 
 		// Get rid of any port number
 		pos = url.find('/');		// We earlier made sure that there's one
-		url = gAgent.getRegion()->getHost().getHostName() + url.substr(pos);
+		url = hostname + url.substr(pos);
 
 		pos = url.find('?');
 		if (pos != std::string::npos)
@@ -1111,10 +1115,12 @@ std::string LLViewerParcelMedia::extractDomain(std::string url)
 		}
 	}
 
-		
 	// Remember this region, so to cope with requests occuring just after a
 	// TP out of it.
-	last_region = gAgent.getRegion()->getHost().getHostName();
+	if (!hostname.empty())	// Singu note: also make sure that last_region doesn't become empty.
+	{
+		last_region = hostname;
+	}
 
 	return url;
 }