From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 6 Apr 2015 22:19:21 +0000 (+0300)
Subject: Provide a signal to handle errors from Communicator
X-Git-Url: http://git.tdb.fi/?p=libs%2Fnet.git;a=commitdiff_plain;h=a0b7f9bcf0654a7a3f24bac95746ac587b71986b

Provide a signal to handle errors from Communicator

Since Communicator is typically used with an EventDispatcher, it can be
inconvenient to just throw exceptions out.  Handling them would require
wrapping the EventDispatcher's tick call in a try block, and the exact
source of the exception would be lost.
---

diff --git a/source/net/communicator.cpp b/source/net/communicator.cpp
index c9b277d..618e8b4 100644
--- a/source/net/communicator.cpp
+++ b/source/net/communicator.cpp
@@ -1,6 +1,8 @@
 #include <cstring>
 #include "communicator.h"
 
+using namespace std;
+
 namespace {
 
 using namespace Msp::Net;
@@ -85,9 +87,10 @@ void Communicator::data_available()
 	if(!good)
 		return;
 
-	in_end += socket.read(in_end, in_buf+buf_size-in_end);
 	try
 	{
+		in_end += socket.read(in_end, in_buf+buf_size-in_end);
+
 		bool more = true;
 		while(more)
 		{
@@ -114,10 +117,12 @@ void Communicator::data_available()
 			}
 		}
 	}
-	catch(...)
+	catch(const exception &e)
 	{
 		good = false;
-		throw;
+		if(signal_error.empty())
+			throw;
+		signal_error.emit(e);
 	}
 }
 
diff --git a/source/net/communicator.h b/source/net/communicator.h
index 8530db1..cd465a5 100644
--- a/source/net/communicator.h
+++ b/source/net/communicator.h
@@ -19,6 +19,7 @@ class Communicator
 {
 public:
 	sigc::signal<void> signal_handshake_done;
+	sigc::signal<void, const std::exception &> signal_error;
 
 private:
 	StreamSocket &socket;
@@ -47,7 +48,17 @@ public:
 		if(handshake_status!=2)
 			throw sequence_error("handshaking not done");
 		unsigned size = protocol.assemble(pkt, out_buf, buf_size);
-		socket.write(out_buf, size);
+		try
+		{
+			socket.write(out_buf, size);
+		}
+		catch(const std::exception &e)
+		{
+			good = false;
+			if(signal_error.empty())
+				throw;
+			signal_error.emit(e);
+		}
 	}
 
 private: