From 8acd8baa33d404ed3cbf790f0f243c2df26bec59 Mon Sep 17 00:00:00 2001
From: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
Date: Mon, 24 Mar 2008 13:04:55 -0700
Subject: [PATCH] use FailSafe postfix in a more rigorous way.

---
 src/core/attribute-test.cc | 20 +++++++-------
 src/core/object-base.cc    | 55 +++++++++++++++++++++++++++++++++-----
 src/core/object-base.h     | 30 ++++++++++++++++++---
 3 files changed, 86 insertions(+), 19 deletions(-)

diff --git a/src/core/attribute-test.cc b/src/core/attribute-test.cc
index 45afc9a65..9a2a38a4a 100644
--- a/src/core/attribute-test.cc
+++ b/src/core/attribute-test.cc
@@ -231,20 +231,22 @@ private:
 };
 
 
-#define CHECK_GET_STR(p,name,value)		\
-  {						\
-    std::string expected = value;		\
-    std::string got;				\
-    bool ok = p->GetAttribute (name, got);	\
-    NS_TEST_ASSERT (ok);			\
-    NS_TEST_ASSERT_EQUAL (got, expected);	\
+#define CHECK_GET_STR(p,name,value)                             \
+  {                                                             \
+    std::string expected = value;                               \
+    std::string got;                                            \
+    bool ok = p->GetAttributeAsStringFailSafe (name, got);	\
+    NS_TEST_ASSERT (ok);                                        \
+    NS_TEST_ASSERT_EQUAL (got, expected);                       \
   }
 #define CHECK_GET_PARAM(p,name,type,value)		\
   {							\
     const type expected = value;			\
     type got = value;					\
-    Attribute v = p->GetAttribute (name);		\
-    got = v;						\
+    Attribute v;                                        \
+    bool ok = p->GetAttributeFailSafe (name, v);        \
+    NS_TEST_ASSERT (ok);                                \
+    got = v;                                            \
     NS_TEST_ASSERT_EQUAL (got.Get (), expected.Get ());	\
   }
 
diff --git a/src/core/object-base.cc b/src/core/object-base.cc
index 07518aaa4..9c3ea4f4b 100644
--- a/src/core/object-base.cc
+++ b/src/core/object-base.cc
@@ -156,26 +156,27 @@ ObjectBase::SetAttributeFailSafe (std::string name, Attribute value)
     }
   return DoSet (info.accessor, info.initialValue, info.checker, value);
 }
-bool 
-ObjectBase::GetAttribute (std::string name, std::string &value) const
+std::string
+ObjectBase::GetAttributeAsString (std::string name) const
 {
   struct TypeId::AttributeInfo info;
   TypeId tid = GetInstanceTypeId ();
   if (!tid.LookupAttributeByName (name, &info))
     {
-      return false;
+      NS_FATAL_ERROR ("Attribute name="<<name<<" does not exist for this object: tid="<<tid.GetName ());
     }
   if (!(info.flags & TypeId::ATTR_GET))
     {
-      return false;
+      NS_FATAL_ERROR ("Attribute name="<<name<<" is not gettable for this object: tid="<<tid.GetName ());
     }
   Attribute v = info.checker->Create ();
   bool ok = info.accessor->Get (this, v);
-  if (ok)
+  if (!ok)
     {
-      value = v.SerializeToString (info.checker);
+      NS_FATAL_ERROR ("Attribute name="<<name<<" is not gettable for this object: tid="<<tid.GetName ());
     }
-  return ok;
+  std::string value = v.SerializeToString (info.checker);
+  return value;
 }
 
 Attribute
@@ -200,6 +201,46 @@ ObjectBase::GetAttribute (std::string name) const
   return value;
 }
 
+bool
+ObjectBase::GetAttributeAsStringFailSafe (std::string name, std::string &value) const
+{
+  struct TypeId::AttributeInfo info;
+  TypeId tid = GetInstanceTypeId ();
+  if (!tid.LookupAttributeByName (name, &info))
+    {
+      return false;
+    }
+  if (!(info.flags & TypeId::ATTR_GET))
+    {
+      return false;
+    }
+  Attribute v = info.checker->Create ();
+  bool ok = info.accessor->Get (this, v);
+  if (ok)
+    {
+      value = v.SerializeToString (info.checker);
+    }
+  return ok;
+}
+
+bool
+ObjectBase::GetAttributeFailSafe (std::string name, Attribute &value) const
+{
+  struct TypeId::AttributeInfo info;
+  TypeId tid = GetInstanceTypeId ();
+  if (!tid.LookupAttributeByName (name, &info))
+    {
+      return false;
+    }
+  if (!(info.flags & TypeId::ATTR_GET))
+    {
+      return false;
+    }
+  value = info.checker->Create ();
+  bool ok = info.accessor->Get (this, value);
+  return ok;
+}
+
 bool 
 ObjectBase::TraceConnectWithoutContext (std::string name, const CallbackBase &cb)
 {
diff --git a/src/core/object-base.h b/src/core/object-base.h
index 188c7cdde..b19eb7f26 100644
--- a/src/core/object-base.h
+++ b/src/core/object-base.h
@@ -33,6 +33,15 @@ public:
   static TypeId GetTypeId (void);
 
   virtual ~ObjectBase ();
+
+  /**
+   * \returns the TypeId associated to the most-derived type
+   *          of this instance.
+   *
+   * This method is typically implemented by ns3::Object::GetInstanceTypeId
+   * but some classes which derive from ns3::ObjectBase directly
+   * have to implement it themselves.
+   */
   virtual TypeId GetInstanceTypeId (void) const = 0;
 
   /**
@@ -52,11 +61,11 @@ public:
   bool SetAttributeFailSafe (std::string name, Attribute value);
   /**
    * \param name the name of the attribute to read
-   * \param value a reference to the string where the value of the 
-   *        attribute should be stored.
    * \returns true if the requested attribute was found, false otherwise.
+   *
+   * If the input attribute name does not exist, this method crashes.
    */
-  bool GetAttribute (std::string name, std::string &value) const;
+  std::string GetAttributeAsString (std::string name) const;
   /**
    * \param name the name of the attribute to read
    * \returns the attribute read.
@@ -65,6 +74,21 @@ public:
    */
   Attribute GetAttribute (std::string name) const;
 
+  /**
+   * \param name the name of the attribute to read
+   * \param value the string where the result value should be stored
+   * \returns true if the requested attribute was found, false otherwise.
+   */
+  bool GetAttributeAsStringFailSafe (std::string name, std::string &value) const;
+  /**
+   * \param name the name of the attribute to read
+   * \param attribute the attribute where the result value should be stored
+   * \returns true if the requested attribute was found, false otherwise.
+   *
+   * If the input attribute name does not exist, this method crashes.
+   */
+  bool GetAttributeFailSafe (std::string name, Attribute &attribute) const;
+
   bool TraceConnectWithoutContext (std::string name, const CallbackBase &cb);
   bool TraceConnectWithoutContext (std::string name, std::string context, const CallbackBase &cb);
   bool TraceDisconnectWithoutContext (std::string name, const CallbackBase &cb);