Modify error to allow for libpq resource cleanup

2 files changed, 54 insertions, 25 deletions

diff --git a/odb/pgsql/error.cxx b/odb/pgsql/error.cxx
index 2dd4f03..ba14b9a 100644
--- a/odb/pgsql/error.cxx
+++ b/odb/pgsql/error.cxx
@@ -8,6 +8,7 @@
 
 #include <odb/pgsql/error.hxx>
 #include <odb/pgsql/exceptions.hxx>
+#include <odb/pgsql/connection.hxx>
 
 using namespace std;
 
@@ -16,9 +17,9 @@ namespace odb
   namespace pgsql
   {
     void
-    translate_error (connection& c)
+    translate_connection_error (connection& c)
     {
-      PGconn* h (0); // @@ c.handle ();
+      PGconn* h (c.handle ());
 
       assert (CONNECTION_BAD == PQstatus (h));
 
@@ -29,50 +30,68 @@ namespace odb
     }
 
     void
-    translate_error (connection& c, PGresult* r)
+    translate_result_error_ (connection& c,
+                             ExecStatusType status = PGRES_EMPTY_QUERY,
+                             const char* sqlstate = 0,
+                             const char* error_message = 0)
     {
-      PGconn* h (0); // @@ c.handle ();
+      PGconn* h (c.handle ());
 
-      if (!r)
-      {
-        if (CONNECTION_BAD == PQstatus (h))
-          throw connection_lost ();
-        else
-          throw bad_alloc ();
-      }
-
-      switch (PQresultStatus (r))
+      switch (status)
       {
       case PGRES_BAD_RESPONSE:
         {
-          if (const char* m = PQresultErrorMessage (r))
-            throw database_exception (m);
+          if (error_message != 0)
+            throw database_exception (error_message);
           else
             throw database_exception ("bad server response");
         }
 
       case PGRES_FATAL_ERROR:
         {
-          // PG_DIAG_SQLSTATE field is always present.
-          //
-          string s (PQresultErrorField (r, PG_DIAG_SQLSTATE));
+          assert (sqlstate);
+          assert (error_message);
 
           // Deadlock detected.
           //
-          if ("40P01" == s)
+          if (std::string ("40P01") == sqlstate)
             throw deadlock ();
 
           else if (CONNECTION_BAD == PQstatus (h))
             throw connection_lost ();
 
           else
-            throw database_exception (s, PQresultErrorMessage (r));
+            throw database_exception (sqlstate, error_message);
         }
 
       default:
-        assert (0);
-        break;
+        {
+          if (CONNECTION_BAD == PQstatus (h))
+            throw connection_lost ();
+          else
+            throw bad_alloc ();
+        }
       };
     }
+
+    void
+    translate_result_error (connection& c,
+                            PGresult* r,
+                            ExecStatusType s,
+                            bool clear_result)
+    {
+      if (!r)
+        translate_result_error_ (c);
+      else
+      {
+        const char* ss = PQresultErrorField (r, PG_DIAG_SQLSTATE);
+        const char* m = PQresultErrorMessage (r);
+
+        if (clear_result)
+          PQclear (r);
+
+        translate_result_error_ (c, s, ss, m);
+      }
+    }
   }
 }
diff --git a/odb/pgsql/error.hxx b/odb/pgsql/error.hxx
index 3de9e78..7d2138b 100644
--- a/odb/pgsql/error.hxx
+++ b/odb/pgsql/error.hxx
@@ -21,10 +21,20 @@ namespace odb
     class connection;
 
     LIBODB_PGSQL_EXPORT void
-    translate_error (connection&);
-
+    translate_connection_error (connection&);
+
+    // Translate an error condition involving a PGresult*. If r is null, it is
+    // assumed that the error was caused due to a bad connection or a memory
+    // allocation error. All remaining parameters except c are ignored.  If r
+    // is non-null, the error is translated using the provided result status,
+    // s. Error descriptions are obtained using r. If clear_result is true,
+    // the resources associated with r are released via PQclear().
+    //
     LIBODB_PGSQL_EXPORT void
-    translate_error (connection& c, PGresult* r);
+    translate_result_error (connection& c,
+                            PGresult* r = 0,
+                            ExecStatusType s = PGRES_EMPTY_QUERY,
+                            bool clear_result = true);
   }
 }