From 927937d6105d17fbcd8c85bbf185477d87264bc4 Mon Sep 17 00:00:00 2001
From: attilamolnar <attilamolnar@hush.com>
Date: Thu, 4 Apr 2013 22:09:21 +0200
Subject: Rework dynamic_reference management, introduce
 dynamic_reference_nocheck

New dynamic references are now resolved at construction and all of them are re-resolved when a relevant service is added or removed; resolution is no longer done in operator->

dynamic_reference_nocheck is a variant of dynamic_reference that does not check for value being null in operator-> / operator*
dynamic_reference still throws an exception when used in this case

Both kinds of dynamic references support .check(): an exception is thrown if this is called when value is null
---
 include/modules.h | 39 ++++++++++++++++++++++++++++++++++-----
 src/inspircd.cpp  |  1 +
 src/modules.cpp   | 29 +++++++++++++----------------
 3 files changed, 48 insertions(+), 21 deletions(-)

diff --git a/include/modules.h b/include/modules.h
index e09245de9..ac90d60e7 100644
--- a/include/modules.h
+++ b/include/modules.h
@@ -286,32 +286,61 @@ class CoreExport dynamic_reference_base : public interfacebase
 {
  private:
 	std::string name;
+	void resolve();
  protected:
 	DataProvider* value;
  public:
 	ModuleRef creator;
 	dynamic_reference_base(Module* Creator, const std::string& Name);
 	~dynamic_reference_base();
-	inline void ClearCache() { value = NULL; }
 	inline const std::string& GetProvider() { return name; }
 	void SetProvider(const std::string& newname);
-	void lookup();
-	operator bool();
+	void check();
+	operator bool() { return (value != NULL); }
 	static void reset_all();
 };
 
+inline void dynamic_reference_base::check()
+{
+	if (!value)
+		throw ModuleException("Dynamic reference to '" + name + "' failed to resolve");
+}
+
 template<typename T>
 class dynamic_reference : public dynamic_reference_base
 {
  public:
 	dynamic_reference(Module* Creator, const std::string& Name)
 		: dynamic_reference_base(Creator, Name) {}
+
 	inline T* operator->()
 	{
-		if (!value)
-			lookup();
+		check();
 		return static_cast<T*>(value);
 	}
+
+	T* operator*()
+	{
+		return operator->();
+	}
+};
+
+template<typename T>
+class dynamic_reference_nocheck : public dynamic_reference_base
+{
+ public:
+	dynamic_reference_nocheck(Module* Creator, const std::string& Name)
+		: dynamic_reference_base(Creator, Name) {}
+
+	T* operator->()
+	{
+		return static_cast<T*>(value);
+	}
+
+	T* operator*()
+	{
+		return operator->();
+	}
 };
 
 /** Priority types which can be used by Module::Prioritize()
diff --git a/src/inspircd.cpp b/src/inspircd.cpp
index cccf3fe89..b3c4ca27d 100644
--- a/src/inspircd.cpp
+++ b/src/inspircd.cpp
@@ -347,6 +347,7 @@ InspIRCd::InspIRCd(int argc, char** argv) :
 	this->SNO = new SnomaskManager;
 	this->BanCache = new BanCacheManager;
 	this->Modules = new ModuleManager();
+	dynamic_reference_base::reset_all();
 	this->stats = new serverstats();
 	this->Timers = new TimerManager;
 	this->Parser = new CommandParser;
diff --git a/src/modules.cpp b/src/modules.cpp
index 56f50eb29..b09639b2e 100644
--- a/src/modules.cpp
+++ b/src/modules.cpp
@@ -37,13 +37,15 @@
 #endif
 
 static std::vector<dynamic_reference_base*>* dynrefs = NULL;
+static bool dynref_init_complete = false;
 
 void dynamic_reference_base::reset_all()
 {
+	dynref_init_complete = true;
 	if (!dynrefs)
 		return;
 	for(unsigned int i = 0; i < dynrefs->size(); i++)
-		(*dynrefs)[i]->ClearCache();
+		(*dynrefs)[i]->resolve();
 }
 
 // Version is a simple class for holding a modules version number
@@ -449,6 +451,7 @@ void ModuleManager::AddService(ServiceProvider& item)
 				DataProviders.insert(std::make_pair(item.name.substr(0, slash), &item));
 				DataProviders.insert(std::make_pair(item.name.substr(slash + 1), &item));
 			}
+			dynamic_reference_base::reset_all();
 			return;
 		}
 		default:
@@ -505,6 +508,8 @@ dynamic_reference_base::dynamic_reference_base(Module* Creator, const std::strin
 	if (!dynrefs)
 		dynrefs = new std::vector<dynamic_reference_base*>;
 	dynrefs->push_back(this);
+	if (dynref_init_complete)
+		resolve();
 }
 
 dynamic_reference_base::~dynamic_reference_base()
@@ -530,24 +535,16 @@ dynamic_reference_base::~dynamic_reference_base()
 void dynamic_reference_base::SetProvider(const std::string& newname)
 {
 	name = newname;
-	ClearCache();
-}
-
-void dynamic_reference_base::lookup()
-{
-	if (!*this)
-		throw ModuleException("Dynamic reference to '" + name + "' failed to resolve");
+	resolve();
 }
 
-dynamic_reference_base::operator bool()
+void dynamic_reference_base::resolve()
 {
-	if (!value)
-	{
-		std::multimap<std::string, ServiceProvider*>::iterator i = ServerInstance->Modules->DataProviders.find(name);
-		if (i != ServerInstance->Modules->DataProviders.end())
-			value = static_cast<DataProvider*>(i->second);
-	}
-	return (value != NULL);
+	std::multimap<std::string, ServiceProvider*>::iterator i = ServerInstance->Modules->DataProviders.find(name);
+	if (i != ServerInstance->Modules->DataProviders.end())
+		value = static_cast<DataProvider*>(i->second);
+	else
+		value = NULL;
 }
 
 void InspIRCd::SendMode(const std::vector<std::string>& parameters, User *user)
-- 
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