libt2n: (gerd) more documentation-polishing

[libt2n] / src / command_server.cpp

diff --git a/src/command_server.cpp b/src/command_server.cpp
index 3bfc0e3..91011fd 100644 (file)
--- a/src/command_server.cpp
+++ b/src/command_server.cpp
@@ -20,6 +20,7 @@
 #include <string>
 #include <sstream>
 #include <stdexcept>
+#include <iostream>
 
 #include <boost/archive/binary_oarchive.hpp>
 #include <boost/archive/binary_iarchive.hpp>
@@ -27,61 +28,123 @@
 #include <boost/archive/xml_iarchive.hpp>
 #include <boost/serialization/serialization.hpp>
 
+#include <boost/bind.hpp>
+
 #include "command_server.hxx"
 #include "container.hxx"
 #include "log.hxx"
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 using namespace std;
 
 namespace libt2n
 {
 
+command_server::command_server(server& _s)
+    : s(_s), guard_handle(0)
+{
+    // register callback
+    s.add_callback(new_connection,bind(&command_server::send_hello, boost::ref(*this), _1));
+}
+
+/// send a hello message to a new connection
+void command_server::send_hello(unsigned int conn_id)
+{
+    server_connection* sc=s.get_connection(conn_id);
+
+    std::ostringstream hello;
+
+    hello << "T2Nv" << PROTOCOL_VERSION << ';';
+
+    int byteordercheck=1;
+    hello.write((char*)&byteordercheck,sizeof(byteordercheck));
+
+    hello << ';';
+
+    sc->write(hello.str());
+}
+
 /// handle a command including deserialization and answering
 void command_server::handle_packet(const std::string& packet, server_connection* conn)
 {
     OBJLOGSTREAM(s,debug,"handling packet from connection " << conn->get_id());
 
     // deserialize packet
-    istringstream ifs(packet);
+    std::istringstream ifs(packet);
     boost::archive::binary_iarchive ia(ifs);
     command_container ccont;
+    result_container res;
 
-    // TODO: catch
-    ia >> ccont;
-
-    std::ostream* ostr;
-    if ((ostr=s.get_logstream(fulldebug))!=NULL)
+    try
     {
-        (*ostr) << "decoded packet data: " << std::endl;
-        boost::archive::xml_oarchive xo(*ostr);
-        xo << BOOST_SERIALIZATION_NVP(ccont);
+        ia >> ccont;
+    }
+    catch(boost::archive::archive_exception &e)
+    {
+        std::ostringstream msg;
+        msg << "archive_exception while deserializing on server-side, "
+               "code " << e.code << " (" << e.what() << ")";
+        res.set_exception(new t2n_serialization_error(msg.str()));
     }
+    catch(...)
+        { throw; }
 
-    // TODO: cast to command subclass (template)
-    command *cmd=ccont.get_command();
+    if (!res.has_exception())
+    {
+        std::ostream* ostr;
+        if ((ostr=s.get_logstream(fulldebug))!=NULL)
+        {
+            (*ostr) << "decoded packet data: " << std::endl;
+            boost::archive::xml_oarchive xo(*ostr);
+            xo << BOOST_SERIALIZATION_NVP(ccont);
+        }
 
-    result_container res;
+        command* cmd=cast_command(ccont.get_command());
 
-    if (cmd)
-    {
-        try
+        if (cmd)
+        {
+            try
+            {
+                res.set_result((*cmd)());
+            }
+            catch (t2n_exception &e)
+                { res.set_exception(e.clone()); }
+            catch (...)
+                { throw; }
+        }
+        else
         {
-            res.set_result((*cmd)());
+            std::ostringstream msg;
+            if (ccont.get_command()!=NULL)
+                msg << "illegal command of type " << typeid(ccont.get_command()).name() << " called";
+            else
+                msg << "NULL command called";
+            res.set_exception(new t2n_command_error(msg.str()));
         }
-        catch (t2n_exception &e)
-            { res.set_exception(e.clone()); }
-        catch (...)
-            { throw; }
     }
-    else
-        throw logic_error("uninitialized command called");
 
-    ostringstream ofs;
+    std::ostringstream ofs;
     boost::archive::binary_oarchive oa(ofs);
 
-    // TODO: catch
-    oa << res;
+    try
+    {
+        oa << res;
+    }
+    catch(boost::archive::archive_exception &e)
+    {
+        std::ostringstream msg;
+        msg << "archive_exception while serializing on server-side, "
+               "code " << e.code << " (" << e.what() << ")";
+        res.set_exception(new t2n_serialization_error(msg.str()));
+        oa << res;
+    }
+    catch(...)
+        { throw; }
 
+    std::ostream* ostr;
     if ((ostr=s.get_logstream(fulldebug))!=NULL)
     {
         (*ostr) << "returning result, decoded data: " << std::endl;
@@ -93,20 +156,48 @@ void command_server::handle_packet(const std::string& packet, server_connection*
 }
 
 /** @brief handle incoming commands
-    @param usec_timeout wait until new data is found, max timeout usecs.
-            -1: wait endless, 0: no timeout
+    @param[in,out] usec_timeout wait until new data is found, max timeout usecs.
+            -1: wait endless, 0: instant return
+    @param[out] usec_timeout_remaining microseconds from the timeout that were not used
 */
-void command_server::handle(long long usec_timeout)
+void command_server::handle(long long usec_timeout, long long* usec_timeout_remaining)
 {
-    if (s.fill_buffer(usec_timeout))
+    guard_handle++;
+    try
     {
-        string packet;
-        unsigned int conn_id;
-
-        while (s.get_packet(packet,conn_id))
-            handle_packet(packet,s.get_connection(conn_id)); 
+        if (s.fill_buffer(usec_timeout,usec_timeout_remaining))
+        {
+            std::string packet;
+            unsigned int conn_id;
+
+            while (s.get_packet(packet,conn_id))
+            {
+                server_connection* conn=s.get_connection(conn_id);
+                if (!conn)
+                    EXCEPTIONSTREAM(error,logic_error,"illegal connection id " << conn_id << " received");
+
+                try
+                    { handle_packet(packet,conn); }
+                catch (t2n_transfer_error &e)
+                {
+                    // shut down a connection with transfer errors (usually write errors)
+                    conn->close();
+                }
+                catch(...)
+                    { throw; }
+            }
+        }
+    }
+    catch(...)
+    {
+        guard_handle--;
+        throw;
     }
-    s.cleanup();
+    guard_handle--;
+
+    // don't call cleanup on re-entered handle-calls
+    if (guard_handle == 0)
+        s.cleanup();
 }
 
 }