1 files changed, 247 insertions, 0 deletions
diff --git a/xpcom/glue/nsComponentManagerUtils.h b/xpcom/glue/nsComponentManagerUtils.h
new file mode 100644
index 0000000000..2a7a4fbd7c
--- /dev/null
+++ b/xpcom/glue/nsComponentManagerUtils.h
@@ -0,0 +1,247 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsComponentManagerUtils_h__
+#define nsComponentManagerUtils_h__
+
+#include "nscore.h"
+#include "nsCOMPtr.h"
+
+#include "nsIFactory.h"
+
+
+nsresult CallCreateInstance(const nsCID& aClass, nsISupports* aDelegate,
+                            const nsIID& aIID, void** aResult);
+
+nsresult CallCreateInstance(const char* aContractID, nsISupports* aDelegate,
+                            const nsIID& aIID, void** aResult);
+
+nsresult CallGetClassObject(const nsCID& aClass, const nsIID& aIID,
+                            void** aResult);
+
+nsresult CallGetClassObject(const char* aContractID, const nsIID& aIID,
+                            void** aResult);
+
+
+class MOZ_STACK_CLASS nsCreateInstanceByCID final : public nsCOMPtr_helper
+{
+public:
+  nsCreateInstanceByCID(const nsCID& aCID, nsresult* aErrorPtr)
+    : mCID(aCID)
+    , mErrorPtr(aErrorPtr)
+  {
+  }
+
+  virtual nsresult NS_FASTCALL operator()(const nsIID&, void**) const
+    override;
+
+private:
+  const nsCID&    mCID;
+  nsresult*       mErrorPtr;
+};
+
+class MOZ_STACK_CLASS nsCreateInstanceByContractID final : public nsCOMPtr_helper
+{
+public:
+  nsCreateInstanceByContractID(const char* aContractID, nsresult* aErrorPtr)
+    : mContractID(aContractID)
+    , mErrorPtr(aErrorPtr)
+  {
+  }
+
+  virtual nsresult NS_FASTCALL operator()(const nsIID&, void**) const override;
+
+private:
+  const char*   mContractID;
+  nsresult*     mErrorPtr;
+};
+
+class MOZ_STACK_CLASS nsCreateInstanceFromFactory final : public nsCOMPtr_helper
+{
+public:
+  nsCreateInstanceFromFactory(nsIFactory* aFactory, nsresult* aErrorPtr)
+    : mFactory(aFactory)
+    , mErrorPtr(aErrorPtr)
+  {
+  }
+
+  virtual nsresult NS_FASTCALL operator()(const nsIID&, void**) const override;
+
+private:
+  nsIFactory* MOZ_NON_OWNING_REF mFactory;
+  nsresult*     mErrorPtr;
+};
+
+
+inline const nsCreateInstanceByCID
+do_CreateInstance(const nsCID& aCID, nsresult* aError = 0)
+{
+  return nsCreateInstanceByCID(aCID, aError);
+}
+
+inline const nsCreateInstanceByContractID
+do_CreateInstance(const char* aContractID, nsresult* aError = 0)
+{
+  return nsCreateInstanceByContractID(aContractID, aError);
+}
+
+inline const nsCreateInstanceFromFactory
+do_CreateInstance(nsIFactory* aFactory, nsresult* aError = 0)
+{
+  return nsCreateInstanceFromFactory(aFactory, aError);
+}
+
+
+class MOZ_STACK_CLASS nsGetClassObjectByCID final : public nsCOMPtr_helper
+{
+public:
+  nsGetClassObjectByCID(const nsCID& aCID, nsresult* aErrorPtr)
+    : mCID(aCID)
+    , mErrorPtr(aErrorPtr)
+  {
+  }
+
+  virtual nsresult NS_FASTCALL operator()(const nsIID&, void**) const override;
+
+private:
+  const nsCID&    mCID;
+  nsresult*       mErrorPtr;
+};
+
+class MOZ_STACK_CLASS nsGetClassObjectByContractID final : public nsCOMPtr_helper
+{
+public:
+  nsGetClassObjectByContractID(const char* aContractID, nsresult* aErrorPtr)
+    : mContractID(aContractID)
+    , mErrorPtr(aErrorPtr)
+  {
+  }
+
+  virtual nsresult NS_FASTCALL operator()(const nsIID&, void**) const override;
+
+private:
+  const char*   mContractID;
+  nsresult*     mErrorPtr;
+};
+
+/**
+ * do_GetClassObject can be used to improve performance of callers
+ * that call |CreateInstance| many times.  They can cache the factory
+ * and call do_CreateInstance or CallCreateInstance with the cached
+ * factory rather than having the component manager retrieve it every
+ * time.
+ */
+inline const nsGetClassObjectByCID
+do_GetClassObject(const nsCID& aCID, nsresult* aError = 0)
+{
+  return nsGetClassObjectByCID(aCID, aError);
+}
+
+inline const nsGetClassObjectByContractID
+do_GetClassObject(const char* aContractID, nsresult* aError = 0)
+{
+  return nsGetClassObjectByContractID(aContractID, aError);
+}
+
+// type-safe shortcuts for calling |CreateInstance|
+template<class DestinationType>
+inline nsresult
+CallCreateInstance(const nsCID& aClass,
+                   nsISupports* aDelegate,
+                   DestinationType** aDestination)
+{
+  NS_PRECONDITION(aDestination, "null parameter");
+
+  return CallCreateInstance(aClass, aDelegate,
+                            NS_GET_TEMPLATE_IID(DestinationType),
+                            reinterpret_cast<void**>(aDestination));
+}
+
+template<class DestinationType>
+inline nsresult
+CallCreateInstance(const nsCID& aClass, DestinationType** aDestination)
+{
+  NS_PRECONDITION(aDestination, "null parameter");
+
+  return CallCreateInstance(aClass, nullptr,
+                            NS_GET_TEMPLATE_IID(DestinationType),
+                            reinterpret_cast<void**>(aDestination));
+}
+
+template<class DestinationType>
+inline nsresult
+CallCreateInstance(const char* aContractID,
+                   nsISupports* aDelegate,
+                   DestinationType** aDestination)
+{
+  NS_PRECONDITION(aContractID, "null parameter");
+  NS_PRECONDITION(aDestination, "null parameter");
+
+  return CallCreateInstance(aContractID,
+                            aDelegate,
+                            NS_GET_TEMPLATE_IID(DestinationType),
+                            reinterpret_cast<void**>(aDestination));
+}
+
+template<class DestinationType>
+inline nsresult
+CallCreateInstance(const char* aContractID, DestinationType** aDestination)
+{
+  NS_PRECONDITION(aContractID, "null parameter");
+  NS_PRECONDITION(aDestination, "null parameter");
+
+  return CallCreateInstance(aContractID, nullptr,
+                            NS_GET_TEMPLATE_IID(DestinationType),
+                            reinterpret_cast<void**>(aDestination));
+}
+
+template<class DestinationType>
+inline nsresult
+CallCreateInstance(nsIFactory* aFactory,
+                   nsISupports* aDelegate,
+                   DestinationType** aDestination)
+{
+  NS_PRECONDITION(aFactory, "null parameter");
+  NS_PRECONDITION(aDestination, "null parameter");
+
+  return aFactory->CreateInstance(aDelegate,
+                                  NS_GET_TEMPLATE_IID(DestinationType),
+                                  reinterpret_cast<void**>(aDestination));
+}
+
+template<class DestinationType>
+inline nsresult
+CallCreateInstance(nsIFactory* aFactory, DestinationType** aDestination)
+{
+  NS_PRECONDITION(aFactory, "null parameter");
+  NS_PRECONDITION(aDestination, "null parameter");
+
+  return aFactory->CreateInstance(nullptr,
+                                  NS_GET_TEMPLATE_IID(DestinationType),
+                                  reinterpret_cast<void**>(aDestination));
+}
+
+template<class DestinationType>
+inline nsresult
+CallGetClassObject(const nsCID& aClass, DestinationType** aDestination)
+{
+  NS_PRECONDITION(aDestination, "null parameter");
+
+  return CallGetClassObject(aClass, NS_GET_TEMPLATE_IID(DestinationType),
+                            reinterpret_cast<void**>(aDestination));
+}
+
+template<class DestinationType>
+inline nsresult
+CallGetClassObject(const char* aContractID, DestinationType** aDestination)
+{
+  NS_PRECONDITION(aDestination, "null parameter");
+
+  return CallGetClassObject(aContractID, NS_GET_TEMPLATE_IID(DestinationType),
+                            reinterpret_cast<void**>(aDestination));
+}
+
+#endif /* nsComponentManagerUtils_h__ */