From 54c1538aee9691b7e106b04664156c3d7573eba1 Mon Sep 17 00:00:00 2001
From: Reinhard Pfau <reinhard.pfau@intra2net.com>
Date: Mon, 1 Sep 2008 07:35:53 +0000
Subject: [PATCH] libsimpleio: (reinhard) modified server connection to allow fill_buffer without a backend cycle.

---
 glue_t2n/simpleio_t2n.cpp |   46 ++++++++++++++++++++++++++++++++++++--------
 glue_t2n/simpleio_t2n.hpp |    3 ++
 2 files changed, 40 insertions(+), 9 deletions(-)

diff --git a/glue_t2n/simpleio_t2n.cpp b/glue_t2n/simpleio_t2n.cpp
index 6dfeacb..a2f55d6 100644
--- a/glue_t2n/simpleio_t2n.cpp
+++ b/glue_t2n/simpleio_t2n.cpp
@@ -621,11 +621,13 @@ void T2NServerConnection::real_write(const std::string& data)
  * Since this class uses the asnychronous SimpleIo framework, new data may already be read when
  * this method is called.
  *
+ * @param wait determines if we need to wait; if @a false it is just checked if new data
+ *  was received, but no backend cycle is executed.
  * @param usec_timeout 
  * @param usec_timeout_remaining 
  * @return @a true if new data is available.
  */
-bool T2NServerConnection::fill_buffer(long long usec_timeout,long long* usec_timeout_remaining)
+bool T2NServerConnection::low_fill_buffer(bool wait, long long usec_timeout, long long* usec_timeout_remaining)
 {
     SCOPETRACKER();
     if (is_closed())
@@ -633,10 +635,10 @@ bool T2NServerConnection::fill_buffer(long long usec_timeout,long long* usec_tim
         module_logger().debug(HERE) << "fill_buffer() called on closed connection";
         return false;
     }
-    SimpleIo::MilliTime t0,t1;
-    SimpleIo::get_current_monotonic_time(t0);
-    if (!m_got_new_data)
+    if (not m_got_new_data and wait)
     {
+        SimpleIo::MilliTime t0,t1;
+        SimpleIo::get_current_monotonic_time(t0);
         IOExportWrapperBasePtr ptr = boost::dynamic_pointer_cast< IOExportWrapperBase >(m_real_connection);
         if (!ptr)
         {
@@ -665,12 +667,19 @@ bool T2NServerConnection::fill_buffer(long long usec_timeout,long long* usec_tim
             }
         }
         Backend::getBackend()->doOneStep( timeout );
+        SimpleIo::get_current_monotonic_time(t1);
+        if (usec_timeout_remaining)
+        {
+            long long delta= ((long long)(t1 - t0).get_milliseconds())* 1000L;
+            *usec_timeout_remaining= (usec_timeout > delta ) ? (usec_timeout - delta) : 0L;
+        }
     }
-    SimpleIo::get_current_monotonic_time(t1);
-    if (usec_timeout_remaining)
+    else
     {
-        long long delta= ((long long)(t1 - t0).get_milliseconds())* 1000L;
-        *usec_timeout_remaining= (usec_timeout > delta ) ? (usec_timeout - delta) : 0L;
+        if (usec_timeout_remaining)
+        {
+            *usec_timeout_remaining= usec_timeout;
+        }
     }
     if (m_got_new_data)
     {
@@ -678,6 +687,22 @@ bool T2NServerConnection::fill_buffer(long long usec_timeout,long long* usec_tim
         return true;
     }
     return false;
+} // eo T2NServerConnection::low_fill_buffer(bool,long long,long long*)
+
+
+/**
+ * @brief called to fill the connection buffer.
+ *
+ * Since this class uses the asnychronous SimpleIo framework, new data may already be read when
+ * this method is called.
+ *
+ * @param usec_timeout 
+ * @param usec_timeout_remaining 
+ * @return @a true if new data is available.
+ */
+bool T2NServerConnection::fill_buffer(long long usec_timeout,long long* usec_timeout_remaining)
+{
+    return low_fill_buffer(true, usec_timeout, usec_timeout_remaining);
 } // eo T2NServerConnection::fill_buffer(long long,long long*)
 
 
@@ -806,7 +831,10 @@ bool T2NServerBase::fill_connection_buffers()
             }
             continue;
         }
-        result= result or conn->fill_buffer(0);
+        if ( conn->low_fill_buffer(false, 0) )
+        {
+            result= true;
+        }
     }
     return result;
 } // eo T2NServerBase::fill_connection_buffers()
diff --git a/glue_t2n/simpleio_t2n.hpp b/glue_t2n/simpleio_t2n.hpp
index 24b3594..c57fb8a 100644
--- a/glue_t2n/simpleio_t2n.hpp
+++ b/glue_t2n/simpleio_t2n.hpp
@@ -121,6 +121,8 @@ class T2NServerConnection
 
         void eofSlot();
 
+        bool low_fill_buffer(bool wait, long long usec_timeout=-1, long long* usec_timeout_remaining=NULL);
+
         /*
         ** overloaded methods from t2n classes:
         */
@@ -129,6 +131,7 @@ class T2NServerConnection
 
         virtual bool fill_buffer(long long usec_timeout=-1,long long* usec_timeout_remaining=NULL);
 
+
     protected:
 
         SimpleIo::IOImplementationPtr m_real_connection;
-- 
1.7.1