From 932cd7a53b3996468fee5cfa63c2b2998dbe971a Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Mon, 4 Jul 2011 17:53:47 +0200 Subject: Implement support for database operations callbacks New object pragma: callback. New test: common/callback. New manual section: 10.1.4, "callback". --- NEWS | 8 +++ doc/manual.xhtml | 126 +++++++++++++++++++++++++++++++++++++++++++++- odb/header.cxx | 1 + odb/pragma.cxx | 38 +++++++++++++- odb/relational/header.hxx | 11 ++++ odb/relational/inline.hxx | 90 +++++++++++++++++++++++++++++++++ odb/relational/source.hxx | 6 ++- odb/tracer/header.cxx | 10 ++++ odb/tracer/inline.cxx | 14 ++++++ odb/validator.cxx | 43 ++++++++++++++++ 10 files changed, 343 insertions(+), 4 deletions(-) diff --git a/NEWS b/NEWS index 8dde908..7851416 100644 --- a/NEWS +++ b/NEWS @@ -1,5 +1,13 @@ Version 1.5.0 + * Support for database operations callbacks. Now a persistent class can + register a callback function that will be called before and after every + database operation, such as persist, load, update, or erase, is performed + on an object of this class. A database operations callback can be used to + implement object-specific pre and post initializations, registrations, + and cleanups. For more information and an example refer to Section 10.1.4, + "Callback" in the ODB manual. + * New option, --include-regex, allows the modification of the #include directive paths generated by the ODB compiler. This is primarily useful when placing the generating code into subdirectories and the #include diff --git a/doc/manual.xhtml b/doc/manual.xhtml index b60eafc..a06bfa6 100644 --- a/doc/manual.xhtml +++ b/doc/manual.xhtml @@ -414,6 +414,7 @@ for consistency. 10.1.1table 10.1.2pointer 10.1.3abstract + 10.1.4callback @@ -5749,8 +5750,13 @@ class person 10.1.3 - + + callback + database operations callback + 10.1.4 + +

10.1.1 table

@@ -5851,6 +5857,124 @@ class contractor: public person discussion of persistent class inheritance, refer to Chapter 8, "Inheritance".

+

10.1.4 callback

+ +

The callback specifier specifies the persist class + member function that should be called before and after a + database operation is performed on an object of this class. + For example:

+ + 
+#include <odb/callback.hxx>
+
+#pragma db object callback(init)
+class person
+{
+  ...
+
+  void
+  init (odb::callback_event, odb::database&);
+};
+
+ +

The callback function has the following signature and can be + overloaded for constant objects:

+ + 
+void
+name (odb::callback_event, odb::database&);
+
+void
+name (odb::callback_event, odb::database&) const;
+
+ +

The first argument to the callback function is the event that + triggered this call. The odb::callback_event + enum-like type is defined in the <odb/callback.hxx> + header file and has the following interface:

+ + 
+namespace odb
+{
+  struct callback_event
+  {
+    enum value
+    {
+      pre_persist,
+      post_persist,
+      pre_load,
+      post_load,
+      pre_update,
+      post_update,
+      pre_erase,
+      post_erase
+    };
+
+    callback_event (value v);
+    operator value () const;
+  };
+}
+
+ +

The second argument to the callback function is the database + on which the operation is about to be performed or has just + been performed.

+ +

If only the non-const version of the callback function + is provided, then only database operations that are performed on + unrestricted objects will trigger callback calls. If only the + const version is provided, then the database + operations on both constant and unrestricted objects will trigger + callback calls but the object will always be passed as constant. + Finally, if both versions are provided, then the const + overload will be called for constant objects and the non-const + overload for unrestricted objects. These rules are modeled after + the standard C++ overload resolution rules. A callback function can + be inline or virtual.

+ +

A database operations callback can be used to implement object-specific + pre and post initializations, registrations, and cleanups. As an example, + the following code fragment outlines an implementation of a + person class that maintains the transient age + data member in addition to the persistent date of birth. A callback + is used to calculate the value of the former from the latter every + time a person object is loaded from the database.

+ + 
+#include <odb/core.hxx>
+#include <odb/callback.hxx>
+
+#pragma db object callback(init)
+class person
+{
+  ...
+
+private:
+  friend class odb::access;
+
+  date born_;
+
+  #pragma db transient
+  unsigned short age_;
+
+  void
+  init (odb::callback_event e, odb::database&)
+  {
+    switch (e)
+    {
+    case odb::callback_event::post_load:
+    {
+      // Calculate age from the date of birth.
+      ...
+      break;
+    }
+    default:
+      break;
+    }
+  }
+};
+
+

10.2 Value Type Pragmas

A pragma with the value qualifier describes a value diff --git a/odb/header.cxx b/odb/header.cxx index 140a781..62902f6 100644 --- a/odb/header.cxx +++ b/odb/header.cxx @@ -88,6 +88,7 @@ namespace header os << "#include " << endl << "#include " << endl + << "#include " << endl << "#include " << endl; // In case of a boost TR1 implementation, we cannot distinguish diff --git a/odb/pragma.cxx b/odb/pragma.cxx index a22c1d1..3b8d222 100644 --- a/odb/pragma.cxx +++ b/odb/pragma.cxx @@ -127,7 +127,8 @@ check_decl_type (tree d, string const& name, string const& p, location_t l) } else if (p == "object" || p == "pointer" || - p == "abstract") + p == "abstract" || + p == "callback") { if (tc != RECORD_TYPE) { @@ -374,6 +375,41 @@ handle_pragma (cpp_reader* reader, tt = pragma_lex (&t); } + else if (p == "callback") + { + // callback (name) + // + + // Make sure we've got the correct declaration type. + // + if (decl != 0 && !check_decl_type (decl, decl_name, p, loc)) + return; + + if (pragma_lex (&t) != CPP_OPEN_PAREN) + { + error () << "'(' expected after db pragma '" << p << "'" << endl; + return; + } + + tt = pragma_lex (&t); + + if (tt != CPP_NAME) + { + error () << "member function name expected in db pragma '" << p + << "'" << endl; + return; + } + + val = IDENTIFIER_POINTER (t); + + if (pragma_lex (&t) != CPP_CLOSE_PAREN) + { + error () << "')' expected at the end of db pragma '" << p << "'" << endl; + return; + } + + tt = pragma_lex (&t); + } else if (p == "id") { // id diff --git a/odb/relational/header.hxx b/odb/relational/header.hxx index 16c7855..62c2e92 100644 --- a/odb/relational/header.hxx +++ b/odb/relational/header.hxx @@ -940,6 +940,16 @@ namespace relational // Functions (concrete). // + // callback () + // + os << "static void" << endl + << "callback (database&, object_type&, callback_event);" + << endl; + + os << "static void" << endl + << "callback (database&, const object_type&, callback_event);" + << endl; + // persist () // os << "static void" << endl @@ -1090,6 +1100,7 @@ namespace relational generate () { os << "#include " << endl + << "#include " << endl << endl; os << "#include " << endl diff --git a/odb/relational/inline.hxx b/odb/relational/inline.hxx index 856965c..89fc720 100644 --- a/odb/relational/inline.hxx +++ b/odb/relational/inline.hxx @@ -13,6 +13,67 @@ namespace relational { namespace inline_ { + // + // + struct callback_calls: traversal::class_, virtual context + { + typedef callback_calls base; + + callback_calls () + { + *this >> inherits_ >> *this; + } + + callback_calls (callback_calls const&) + : root_context (), //@@ -Wextra + context () + { + *this >> inherits_ >> *this; + } + + virtual void + traverse (type& c, bool constant) + { + const_ = constant; + traverse (c); + } + + virtual void + traverse (type& c) + { + // Ignore transient bases. + // + if (!c.count ("object")) + return; + + if (c.count ("callback")) + { + string name (c.get ("callback")); + + // In case of the const object, we only generate the call if + // there is a const callback. + // + if (const_) + { + if (c.count ("callback-const")) + os << "static_cast< const " << c.fq_name () << "& > (obj)." << + name << " (e, db);"; + } + else + os << "static_cast< " << c.fq_name () << "& > (obj)." << + name << " (e, db);"; + } + else + inherits (c); + } + + protected: + bool const_; + traversal::inherits inherits_; + }; + + // + // struct class_: traversal::class_, virtual context { typedef class_ base; @@ -113,6 +174,32 @@ namespace relational if (abst) return; + // callback () + // + os << "inline" << endl + << "void " << traits << "::" << endl + << "callback (database& db, object_type& obj, callback_event e)" + << endl + << "{" + << "ODB_POTENTIALLY_UNUSED (db);" + << "ODB_POTENTIALLY_UNUSED (obj);" + << "ODB_POTENTIALLY_UNUSED (e);" + << endl; + callback_calls_->traverse (c, false); + os << "}"; + + os << "inline" << endl + << "void " << traits << "::" << endl + << "callback (database& db, const object_type& obj, " << + "callback_event e)" + << "{" + << "ODB_POTENTIALLY_UNUSED (db);" + << "ODB_POTENTIALLY_UNUSED (obj);" + << "ODB_POTENTIALLY_UNUSED (e);" + << endl; + callback_calls_->traverse (c, true); + os << "}"; + // query_type // if (options.generate_query ()) @@ -164,6 +251,9 @@ namespace relational */ } + + private: + instance callback_calls_; }; } } diff --git a/odb/relational/source.hxx b/odb/relational/source.hxx index 4d2f10a..42d0f9b 100644 --- a/odb/relational/source.hxx +++ b/odb/relational/source.hxx @@ -2331,9 +2331,11 @@ namespace relational << endl << "if (l.locked ())" << "{" + << "callback (db, obj, callback_event::pre_load);" << "init (obj, sts.image (), db);" << "load_ (sts, obj);" << "sts.load_delayed ();" + << "callback (db, obj, callback_event::post_load);" << "l.unlock ();" << "}" << "else" << endl @@ -2367,9 +2369,11 @@ namespace relational << endl << "if (l.locked ())" << "{" + << "callback (db, obj, callback_event::pre_load);" << "init (obj, sts.image (), db);" << "load_ (sts, obj);" << "sts.load_delayed ();" + << "callback (db, obj, callback_event::post_load);" << "l.unlock ();" << "}" << "else" << endl @@ -2689,8 +2693,6 @@ namespace relational if (embedded_schema) os << "#include " << endl; - os << "#include " << endl; - if (options.generate_query ()) os << "#include " << endl; diff --git a/odb/tracer/header.cxx b/odb/tracer/header.cxx index 16bee82..ac89ec7 100644 --- a/odb/tracer/header.cxx +++ b/odb/tracer/header.cxx @@ -88,6 +88,16 @@ namespace tracer os << "static bool" << endl << "find (database&, const id_type&, object_type&);"; + // callback () + // + os << "static void" << endl + << "callback (database&, object_type&, callback_event);" + << endl; + + os << "static void" << endl + << "callback (database&, const object_type&, callback_event);" + << endl; + os << "};"; } }; diff --git a/odb/tracer/inline.cxx b/odb/tracer/inline.cxx index f4125a9..e8feec8 100644 --- a/odb/tracer/inline.cxx +++ b/odb/tracer/inline.cxx @@ -42,6 +42,20 @@ namespace tracer << "{" << "return obj." << id.name () << ";" << endl << "}"; + + // callback () + // + os << "inline" << endl + << "void " << traits << "::" << endl + << "callback (database&, object_type&, callback_event)" + << "{" + << "}"; + + os << "inline" << endl + << "void " << traits << "::" << endl + << "callback (database&, const object_type&, callback_event)" + << "{" + << "}"; } }; } diff --git a/odb/validator.cxx b/odb/validator.cxx index 998bd8b..487d69a 100644 --- a/odb/validator.cxx +++ b/odb/validator.cxx @@ -3,6 +3,8 @@ // copyright : Copyright (c) 2009-2011 Code Synthesis Tools CC // license : GNU GPL v3; see accompanying LICENSE file +#include + #include #include @@ -138,6 +140,47 @@ namespace virtual void traverse_object (type& c) { + // Check that the callback function exist. + // + if (c.count ("callback")) + { + string name (c.get ("callback")); + tree decl ( + lookup_qualified_name ( + c.tree_node (), get_identifier (name.c_str ()), false, false)); + + if (decl == error_mark_node || TREE_CODE (decl) != BASELINK) + { + cerr << c.file () << ":" << c.line () << ":" << c.column () << ": " + << "error: unable to resolve member function '" << name << "' " + << "specified with '#pragma db callback' for class '" + << c.name () << "'" << endl; + + valid_ = false; + } + + // Figure out if we have a const version of the callback. OVL_* + // macros work for both FUNCTION_DECL and OVERLOAD. + // + for (tree o (BASELINK_FUNCTIONS (decl)); o != 0; o = OVL_NEXT (o)) + { + tree f (OVL_CURRENT (o)); + if (DECL_CONST_MEMFUNC_P (f)) + { + c.set ("callback-const", true); + break; + } + } + + //@@ Would be nice to check the signature of the function(s) + // instead of postponing it until the C++ compilation. Though + // we may still get C++ compilation errors because of const + // mismatch. + // + } + + // Check bases. + // bool base (false); for (type::inherits_iterator i (c.inherits_begin ()); -- cgit v1.1