lan plugin config option for transmitting duplicate packets

RJ · Jul 18, 2009 · eaffd19 · eaffd19
1 parent c0d064f
commit eaffd19
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Showing 2 changed files with 23 additions and 11 deletions.
diff --git a/resolvers/lan/README.txt b/resolvers/lan/README.txt
@@ -2,13 +2,15 @@ The LAN plugin broadcasts searches using UDP multicast.
 Results are streamed over HTTP using the address the UDP result came from.
 It should just automatically work on home/small office networks.
 --
-By default you don't need anything in the config file for this plugin, however:
+By default you don't need anything in the config file for this plugin, however
+the following options are valid if you need any of them:
 
  "lan" : 
  {
      "listenip" : "your.lan.ip.address",
      "listenport" : 8888,
-     "endpoints" : ["239.255.0.1", "10.1.2.3", "192.168.1.1"]
+     "endpoints" : ["239.255.0.1", "10.1.2.3", "192.168.1.1"],
+     "numcopies" : 3
  }
 
 * If you change the "listenport", it'll only work with others on the same port.
@@ -23,3 +25,6 @@ By default you don't need anything in the config file for this plugin, however:
   machine you can reach on the LAN, despite multicast not working.
 
 * to change endpoint ports too: "endpoints" : [ ["10.1.2.3",1234], [..] ]
+
+* for lossy networks, set copies to more than 1, so your UDP packets stand a 
+  better chance of being received. default is 1.
diff --git a/resolvers/lan/lan.cpp b/resolvers/lan/lan.cpp
@@ -219,15 +219,22 @@ lan::async_send(boost::asio::ip::udp::endpoint * remote_endpoint,
     //cout << "UDPsend[" << remote_endpoint.address() 
     //     << ":" << remote_endpoint.port() << "]"
     //     << "(" << message << ")" << endl;
-    char * buf = (char*)malloc(message.length());
+
-    memcpy(buf, message.data(), message.length());
+    // you can set numcopies to 2 or 3 for lossy networks:
-    socket_->async_send_to(     
+    int copies = m_pap->get<int>("plugins.lan.numcopies", 1);
-            boost::asio::buffer(buf,message.length()), 
+    if(copies<1) copies=1;
-            *remote_endpoint,
+    for(int j = 0; j<copies; j++)
-            boost::bind(&lan::handle_send, this,
+    {
-                boost::asio::placeholders::error,
+        char * buf = (char*)malloc(message.length());
-                boost::asio::placeholders::bytes_transferred,
+        memcpy(buf, message.data(), message.length());
-                buf));
+        socket_->async_send_to(     
+                boost::asio::buffer(buf,message.length()), 
+                *remote_endpoint,
+                boost::bind(&lan::handle_send, this,
+                    boost::asio::placeholders::error,
+                    boost::asio::placeholders::bytes_transferred,
+                    buf));
+    }
 }
 
 void lan::handle_send(   const boost::system::error_code& error,