From b134d7b4f2c105870a98a67ec568c16c9f632aba Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Thu, 4 Oct 2012 11:33:49 +0200
Subject: Initial support for prepared queries

---
 odb/header.cxx                  |   3 +
 odb/options.cli                 |  10 ++
 odb/relational/header.cxx       |  26 ++-
 odb/relational/header.hxx       |  15 +-
 odb/relational/pgsql/source.cxx |   5 +-
 odb/relational/source.cxx       | 363 +++++++++++++++++++++++++++-------------
 odb/relational/source.hxx       |  24 +--
 7 files changed, 309 insertions(+), 137 deletions(-)

(limited to 'odb')

diff --git a/odb/header.cxx b/odb/header.cxx
index 8bf5453..32dc898 100644
--- a/odb/header.cxx
+++ b/odb/header.cxx
@@ -60,6 +60,9 @@ namespace header
 
     if (ctx.options.generate_query ())
     {
+      if (!ctx.options.omit_prepared ())
+        os << "#include <odb/prepared-query.hxx>" << endl;
+
       os << "#include <odb/result.hxx>" << endl;
 
       if (ctx.features.simple_object)
diff --git a/odb/options.cli b/odb/options.cli
index f61aa0e..ce990b0 100644
--- a/odb/options.cli
+++ b/odb/options.cli
@@ -58,6 +58,16 @@ class options
      and can only load objects via their ids."
   };
 
+  bool --omit-prepared
+  {
+    "Omit prepared query execution support code."
+  };
+
+  bool --omit-unprepared
+  {
+    "Omit un-prepared (once-off) query execution support code."
+  };
+
   bool --generate-session | -e
   {
     "Generate session support code. With this option session support will
diff --git a/odb/relational/header.cxx b/odb/relational/header.cxx
index 41b4960..a78697f 100644
--- a/odb/relational/header.cxx
+++ b/odb/relational/header.cxx
@@ -680,13 +680,27 @@ traverse_object (type& c)
   //
   if (options.generate_query ())
   {
-    os << "static result<object_type>" << endl
-       << "query (database&, const query_base_type&);"
-       << endl;
+    if (!options.omit_unprepared ())
+    {
+      os << "static result<object_type>" << endl
+         << "query (database&, const query_base_type&);"
+         << endl;
 
-    os << "static unsigned long long" << endl
-       << "erase_query (database&, const query_base_type&);"
-       << endl;
+      os << "static unsigned long long" << endl
+         << "erase_query (database&, const query_base_type&);"
+         << endl;
+    }
+
+    if (!options.omit_prepared ())
+    {
+      os << "static odb::details::shared_ptr<prepared_query_impl>" << endl
+         << "prepare_query (connection&, const char*, const query_base_type&);"
+         << endl;
+
+      os << "static odb::details::shared_ptr<result_impl>" << endl
+         << "execute_query (prepared_query_impl&);"
+         << endl;
+    }
   }
 
   // create_schema ()
diff --git a/odb/relational/header.hxx b/odb/relational/header.hxx
index 9d932ae..fe08a49 100644
--- a/odb/relational/header.hxx
+++ b/odb/relational/header.hxx
@@ -1124,9 +1124,10 @@ namespace relational
 
         // query ()
         //
-        os << "static result<view_type>" << endl
-           << "query (database&, const query_base_type&);"
-           << endl;
+        if (!options.omit_unprepared ())
+          os << "static result<view_type>" << endl
+             << "query (database&, const query_base_type&);"
+             << endl;
 
         view_public_extra_post (c);
 
@@ -1445,8 +1446,12 @@ namespace relational
       generate ()
       {
         os << "#include <odb/details/buffer.hxx>" << endl
-           << "#include <odb/details/unused.hxx>" << endl
-           << endl;
+           << "#include <odb/details/unused.hxx>" << endl;
+
+        if (options.generate_query ())
+          os << "#include <odb/details/shared-ptr.hxx>" << endl;
+
+        os << endl;
 
         os << "#include <odb/" << db << "/version.hxx>" << endl
            << "#include <odb/" << db << "/forward.hxx>" << endl
diff --git a/odb/relational/pgsql/source.cxx b/odb/relational/pgsql/source.cxx
index da07073..e771053 100644
--- a/odb/relational/pgsql/source.cxx
+++ b/odb/relational/pgsql/source.cxx
@@ -829,9 +829,10 @@ namespace relational
         }
 
         virtual void
-        post_query_ (type&)
+        post_query_ (type&, bool once_off)
         {
-          os << "st->deallocate ();";
+          if (once_off)
+            os << "st->deallocate ();";
         }
       };
       entry<class_> class_entry_;
diff --git a/odb/relational/source.cxx b/odb/relational/source.cxx
index 8981417..4e407b6 100644
--- a/odb/relational/source.cxx
+++ b/odb/relational/source.cxx
@@ -2564,92 +2564,227 @@ traverse_object (type& c)
 
   if (options.generate_query ())
   {
-    // query ()
-    //
-    os << "result< " << traits << "::object_type >" << endl
-       << traits << "::" << endl
-       << "query (database&, const query_base_type& q)"
-       << "{"
-       << "using namespace " << db << ";"
-       << "using odb::details::shared;"
-       << "using odb::details::shared_ptr;"
-       << endl
-       << db << "::connection& conn (" << endl
-       << db << "::transaction::current ().connection ());"
-       << endl
-       << "statements_type& sts (" << endl
-       << "conn.statement_cache ().find_object<object_type> ());"
-       << endl;
+    char const* result_type;
+    if (poly)
+      result_type = "polymorphic_object_result_impl<object_type>";
+    else if (id != 0)
+      result_type = "object_result_impl<object_type>";
+    else
+      result_type = "no_id_object_result_impl<object_type>";
 
-    // Rebind the image if necessary.
+    // Unprepared.
     //
-    os << "image_type& im (sts.image ());"
-       << "binding& imb (sts.select_image_binding (" <<
-      (poly_derived ? "depth" : "") << "));"
-       << endl;
-
-    if (poly_derived)
+    if (!options.omit_unprepared ())
     {
-      os << "if (imb.version == 0 ||" << endl
-         << "check_version (sts.select_image_versions (), im))"
+      // query ()
+      //
+      os << "result< " << traits << "::object_type >" << endl
+         << traits << "::" << endl
+         << "query (database&, const query_base_type& q)"
          << "{"
-         << "bind (imb.bind, 0, 0, im, statement_select);"
-         << "update_version (sts.select_image_versions ()," << endl
-         << "im," << endl
-         << "sts.select_image_bindings ());"
+         << "using namespace " << db << ";"
+         << "using odb::details::shared;"
+         << "using odb::details::shared_ptr;"
+         << endl
+         << db << "::connection& conn (" << endl
+         << db << "::transaction::current ().connection ());"
+         << endl
+         << "statements_type& sts (" << endl
+         << "conn.statement_cache ().find_object<object_type> ());"
+         << endl;
+
+      // Rebind the image if necessary.
+      //
+      os << "image_type& im (sts.image ());"
+         << "binding& imb (sts.select_image_binding (" <<
+        (poly_derived ? "depth" : "") << "));"
+         << endl;
+
+      if (poly_derived)
+      {
+        os << "if (imb.version == 0 ||" << endl
+           << "check_version (sts.select_image_versions (), im))"
+           << "{"
+           << "bind (imb.bind, 0, 0, im, statement_select);"
+           << "update_version (sts.select_image_versions ()," << endl
+           << "im," << endl
+           << "sts.select_image_bindings ());"
+           << "}";
+      }
+      else
+      {
+        os << "if (im.version != sts.select_image_version () ||" << endl
+           << "imb.version == 0)"
+           << "{"
+           << "bind (imb.bind, im, statement_select);"
+           << "sts.select_image_version (im.version);"
+           << "imb.version++;"
+           << "}";
+      }
+
+      os << "q.init_parameters ();"
+         << "shared_ptr<select_statement> st (" << endl
+         << "new (shared) select_statement (" << endl;
+      object_query_statement_ctor_args (c, "q");
+      os << "));" << endl
+         << "st->execute ();";
+
+      post_query_ (c, true);
+
+      os << endl
+         << "shared_ptr< odb::" << result_type << " > r (" << endl
+         << "new (shared) " << db << "::" << result_type << " (" << endl
+         << "q, st, sts));"
+         << endl
+         << "return result<object_type> (r);"
+         << "}";
+
+      // erase_query
+      //
+      os << "unsigned long long " << traits << "::" << endl
+         << "erase_query (database&, const query_base_type& q)"
+         << "{"
+         << "using namespace " << db << ";"
+         << endl
+         << db << "::connection& conn (" << endl
+         << db << "::transaction::current ().connection ());"
+         << endl
+         << "q.init_parameters ();"
+         << "delete_statement st (" << endl;
+      object_erase_query_statement_ctor_args (c, "q");
+      os << ");"
+         << endl
+         << "return st.execute ();"
          << "}";
     }
-    else
+
+    // Prepared. Very similar to unprepared but has some annoying variations
+    // that make it difficult to factor out something common.
+    //
+    if (!options.omit_prepared ())
     {
-      os << "if (im.version != sts.select_image_version () ||" << endl
-         << "imb.version == 0)"
+      os << "odb::details::shared_ptr<prepared_query_impl>" << endl
+         << traits << "::" << endl
+         << "prepare_query (connection& c, const char* n, " <<
+        "const query_base_type& q)"
          << "{"
-         << "bind (imb.bind, im, statement_select);"
-         << "sts.select_image_version (im.version);"
-         << "imb.version++;"
+         << "using namespace " << db << ";"
+         << "using odb::details::shared;"
+         << "using odb::details::shared_ptr;"
+         << endl
+         << db << "::connection& conn (" << endl
+         << "static_cast<" << db << "::connection&> (c));"
+         << endl
+         << "statements_type& sts (" << endl
+         << "conn.statement_cache ().find_object<object_type> ());"
+         << endl;
+
+      // Rebind the image if necessary.
+      //
+      os << "image_type& im (sts.image ());"
+         << "binding& imb (sts.select_image_binding (" <<
+        (poly_derived ? "depth" : "") << "));"
+         << endl;
+
+      if (poly_derived)
+      {
+        os << "if (imb.version == 0 ||" << endl
+           << "check_version (sts.select_image_versions (), im))"
+           << "{"
+           << "bind (imb.bind, 0, 0, im, statement_select);"
+           << "update_version (sts.select_image_versions ()," << endl
+           << "im," << endl
+           << "sts.select_image_bindings ());"
+           << "}";
+      }
+      else
+      {
+        os << "if (im.version != sts.select_image_version () ||" << endl
+           << "imb.version == 0)"
+           << "{"
+           << "bind (imb.bind, im, statement_select);"
+           << "sts.select_image_version (im.version);"
+           << "imb.version++;"
+           << "}";
+      }
+
+      os << "shared_ptr<" << db << "::prepared_query_impl> r (" << endl
+         << "new (shared) " << db << "::prepared_query_impl);"
+         << "r->name = n;"
+         << "r->execute = &execute_query;"
+         << "r->query = q;"
+         << "r->stmt.reset (" << endl
+         << "new (shared) select_statement (" << endl;
+      object_query_statement_ctor_args (c, "r->query");
+      os << "));"
+         << endl
+         << "return r;"
          << "}";
-    }
 
-    os << "shared_ptr<select_statement> st (" << endl
-       << "new (shared) select_statement (" << endl;
-    object_query_statement_ctor_args (c);
-    os << "));" << endl
-       << "st->execute ();";
+      os << "odb::details::shared_ptr<result_impl>" << endl
+         << traits << "::" << endl
+         << "execute_query (prepared_query_impl& q)"
+         << "{"
+         << "using namespace " << db << ";"
+         << "using odb::details::shared;"
+         << "using odb::details::shared_ptr;"
+         << endl
+         << db << "::prepared_query_impl& pq (" << endl
+         << "static_cast<" << db << "::prepared_query_impl&> (q));"
+         << "shared_ptr<select_statement>& st (pq.stmt);"
+         << endl
+         << db << "::connection& conn (" << endl
+         << db << "::transaction::current ().connection ());"
+         << endl
+         << "// The connection used by the current transaction and the" << endl
+         << "// one used to prepare this statement must be the same." << endl
+         << "//" << endl
+         << "assert (&conn == &st->connection ());"
+         << endl
+         << "statements_type& sts (" << endl
+         << "conn.statement_cache ().find_object<object_type> ());"
+         << endl;
 
-    post_query_ (c);
+      // Rebind the image if necessary.
+      //
+      os << "image_type& im (sts.image ());"
+         << "binding& imb (sts.select_image_binding (" <<
+        (poly_derived ? "depth" : "") << "));"
+         << endl;
 
-    char const* result_type;
-    if (poly)
-      result_type = "polymorphic_object_result_impl<object_type>";
-    else if (id != 0)
-      result_type = "object_result_impl<object_type>";
-    else
-      result_type = "no_id_object_result_impl<object_type>";
+      if (poly_derived)
+      {
+        os << "if (imb.version == 0 ||" << endl
+           << "check_version (sts.select_image_versions (), im))"
+           << "{"
+           << "bind (imb.bind, 0, 0, im, statement_select);"
+           << "update_version (sts.select_image_versions ()," << endl
+           << "im," << endl
+           << "sts.select_image_bindings ());"
+           << "}";
+      }
+      else
+      {
+        os << "if (im.version != sts.select_image_version () ||" << endl
+           << "imb.version == 0)"
+           << "{"
+           << "bind (imb.bind, im, statement_select);"
+           << "sts.select_image_version (im.version);"
+           << "imb.version++;"
+           << "}";
+      }
 
-    os << endl
-       << "shared_ptr< odb::" << result_type << " > r (" << endl
-       << "new (shared) " << db << "::" << result_type << " (" << endl
-       << "q, st, sts));"
-       << endl
-       << "return result<object_type> (r);"
-       << "}";
+      os << "pq.query.init_parameters ();"
+         << "st->execute ();";
+      post_query_ (c, false);
+
+      os << endl
+         << "return shared_ptr<result_impl> (" << endl
+         << "new (shared) " << db << "::" << result_type << " (" << endl
+         << "pq.query, st, sts));"
+         << "}";
+    }
 
-    // erase_query
-    //
-    os << "unsigned long long " << traits << "::" << endl
-       << "erase_query (database&, const query_base_type& q)"
-       << "{"
-       << "using namespace " << db << ";"
-       << endl
-       << db << "::connection& conn (" << endl
-       << db << "::transaction::current ().connection ());"
-       << endl
-       << "delete_statement st (" << endl;
-    object_erase_query_statement_ctor_args (c);
-    os << ");"
-       << endl
-       << "return st.execute ();"
-       << "}";
   }
 
   if (embedded_schema)
@@ -3396,52 +3531,56 @@ traverse_view (type& c)
 
   // query ()
   //
-  os << "result< " << traits << "::view_type >" << endl
-     << traits << "::" << endl
-     << "query (database&, const query_base_type& q)"
-     << "{"
-     << "using namespace " << db << ";"
-     << "using odb::details::shared;"
-     << "using odb::details::shared_ptr;"
-     << endl
-     << db << "::connection& conn (" << endl
-     << db << "::transaction::current ().connection ());"
-     << endl
-     << "view_statements< view_type >& sts (" << endl
-     << "conn.statement_cache ().find_view<view_type> ());"
-     << endl
-     << "image_type& im (sts.image ());"
-     << "binding& imb (sts.image_binding ());"
-     << endl
-     << "if (im.version != sts.image_version () || imb.version == 0)"
-     << "{"
-     << "bind (imb.bind, im);"
-     << "sts.image_version (im.version);"
-     << "imb.version++;"
-     << "}";
+  if (!options.omit_unprepared ())
+  {
+    os << "result< " << traits << "::view_type >" << endl
+       << traits << "::" << endl
+       << "query (database&, const query_base_type& q)"
+       << "{"
+       << "using namespace " << db << ";"
+       << "using odb::details::shared;"
+       << "using odb::details::shared_ptr;"
+       << endl
+       << db << "::connection& conn (" << endl
+       << db << "::transaction::current ().connection ());"
+       << endl
+       << "view_statements< view_type >& sts (" << endl
+       << "conn.statement_cache ().find_view<view_type> ());"
+       << endl
+       << "image_type& im (sts.image ());"
+       << "binding& imb (sts.image_binding ());"
+       << endl
+       << "if (im.version != sts.image_version () || imb.version == 0)"
+       << "{"
+       << "bind (imb.bind, im);"
+       << "sts.image_version (im.version);"
+       << "imb.version++;"
+       << "}";
 
-  if (vq.kind == view_query::runtime)
-    os << "const query_base_type& qs (q);";
-  else
-    os << "const query_base_type& qs (query_statement (q));";
+    if (vq.kind == view_query::runtime)
+      os << "const query_base_type& qs (q);";
+    else
+      os << "const query_base_type& qs (query_statement (q));";
 
-  os << "shared_ptr<select_statement> st (" << endl
-     << "new (shared) select_statement (" << endl;
+    os << "qs.init_parameters ();"
+       << "shared_ptr<select_statement> st (" << endl
+       << "new (shared) select_statement (" << endl;
 
-  view_query_statement_ctor_args (c);
+    view_query_statement_ctor_args (c);
 
-  os << "));" << endl
-     << "st->execute ();";
+    os << "));" << endl
+       << "st->execute ();";
 
-  post_query_ (c);
+    post_query_ (c, true);
 
-  os << endl
-     << "shared_ptr< odb::view_result_impl<view_type> > r (" << endl
-     << "new (shared) " << db << "::view_result_impl<view_type> (" << endl
-     << "qs, st, sts));"
-     << endl
-     << "return result<view_type> (r);"
-     << "}";
+    os << endl
+       << "shared_ptr< odb::view_result_impl<view_type> > r (" << endl
+       << "new (shared) " << db << "::view_result_impl<view_type> (" << endl
+       << "qs, st, sts));"
+       << endl
+       << "return result<view_type> (r);"
+       << "}";
+  }
 }
 
 namespace relational
diff --git a/odb/relational/source.hxx b/odb/relational/source.hxx
index 123ac55..4f1a9fc 100644
--- a/odb/relational/source.hxx
+++ b/odb/relational/source.hxx
@@ -3406,7 +3406,7 @@ namespace relational
       //
 
       virtual void
-      post_query_ (type&)
+      post_query_ (type&, bool /*once_off*/)
       {
       }
 
@@ -3425,20 +3425,20 @@ namespace relational
       }
 
       virtual void
-      object_query_statement_ctor_args (type&)
+      object_query_statement_ctor_args (type&, std::string const& q)
       {
-        os << "sts.connection ()," << endl
-           << "query_statement + q.clause ()," << endl
-           << "q.parameters_binding ()," << endl
+        os << "conn," << endl
+           << "query_statement + " << q << ".clause ()," << endl
+           << q << ".parameters_binding ()," << endl
            << "imb";
       }
 
       virtual void
-      object_erase_query_statement_ctor_args (type&)
+      object_erase_query_statement_ctor_args (type&, std::string const& q)
       {
         os << "conn," << endl
-           << "erase_query_statement + q.clause ()," << endl
-           << "q.parameters_binding ()";
+           << "erase_query_statement + " << q << ".clause ()," << endl
+           << q << ".parameters_binding ()";
       }
 
       virtual void
@@ -3456,7 +3456,7 @@ namespace relational
       virtual void
       view_query_statement_ctor_args (type&)
       {
-        os << "sts.connection ()," << endl
+        os << "conn," << endl
            << "qs.clause ()," << endl
            << "qs.parameters_binding ()," << endl
            << "imb";
@@ -3663,9 +3663,6 @@ namespace relational
         if (embedded_schema)
           os << "#include <odb/schema-catalog-impl.hxx>" << endl;
 
-        if (options.generate_query ())
-          os << "#include <odb/details/shared-ptr.hxx>" << endl;
-
         os << endl;
 
         os << "#include <odb/" << db << "/traits.hxx>" << endl
@@ -3692,6 +3689,9 @@ namespace relational
 
         if (options.generate_query ())
         {
+          if (!options.omit_prepared ())
+            os << "#include <odb/" << db << "/prepared-query.hxx>" << endl;
+
           if (features.simple_object)
             os << "#include <odb/" << db << "/simple-object-result.hxx>" << endl;
 
-- 
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