Add helper functions that make it easier to cache factories. b=261310 r=darin

content/html/style/src/nsCSSScanner.cpp

@@ -212,12 +212,7 @@ nsCSSScanner::~nsCSSScanner()
   nsresult rv = CallGetService(NS_CONSOLESERVICE_CONTRACTID, &gConsoleService);
   NS_ENSURE_SUCCESS(rv, PR_FALSE);
 
-  nsCOMPtr<nsIComponentManager> compMgr;
-  rv = NS_GetComponentManager(getter_AddRefs(compMgr));
-  NS_ENSURE_SUCCESS(rv, PR_FALSE);
-  rv = compMgr->GetClassObjectByContractID(NS_SCRIPTERROR_CONTRACTID,
-                                           NS_GET_IID(nsIFactory),
-                                           (void**)&gScriptErrorFactory);
+  rv = CallGetClassObject(NS_SCRIPTERROR_CONTRACTID, &gScriptErrorFactory);
   NS_ENSURE_SUCCESS(rv, PR_FALSE);
   NS_ASSERTION(gConsoleService && gScriptErrorFactory,
                "unexpected null pointer without failure");
@@ -287,10 +282,9 @@ void nsCSSScanner::OutputError()
   // Log it to the JavaScript console
 
   if (InitGlobals()) {
-    nsCOMPtr<nsIScriptError> errorObject;
-    nsresult rv =
-      gScriptErrorFactory->CreateInstance(nsnull, NS_GET_IID(nsIScriptError),
-                                          getter_AddRefs(errorObject));
+    nsresult rv;
+    nsCOMPtr<nsIScriptError> errorObject =
+      do_CreateInstance(gScriptErrorFactory, &rv);
     if (NS_SUCCEEDED(rv)) {
       rv = errorObject->Init(mError.get(),
                              NS_ConvertASCIItoUCS2(mFileName.get()).get(),

layout/style/nsCSSScanner.cpp

@@ -212,12 +212,7 @@ nsCSSScanner::~nsCSSScanner()
   nsresult rv = CallGetService(NS_CONSOLESERVICE_CONTRACTID, &gConsoleService);
   NS_ENSURE_SUCCESS(rv, PR_FALSE);
 
-  nsCOMPtr<nsIComponentManager> compMgr;
-  rv = NS_GetComponentManager(getter_AddRefs(compMgr));
-  NS_ENSURE_SUCCESS(rv, PR_FALSE);
-  rv = compMgr->GetClassObjectByContractID(NS_SCRIPTERROR_CONTRACTID,
-                                           NS_GET_IID(nsIFactory),
-                                           (void**)&gScriptErrorFactory);
+  rv = CallGetClassObject(NS_SCRIPTERROR_CONTRACTID, &gScriptErrorFactory);
   NS_ENSURE_SUCCESS(rv, PR_FALSE);
   NS_ASSERTION(gConsoleService && gScriptErrorFactory,
                "unexpected null pointer without failure");
@@ -287,10 +282,9 @@ void nsCSSScanner::OutputError()
   // Log it to the JavaScript console
 
   if (InitGlobals()) {
-    nsCOMPtr<nsIScriptError> errorObject;
-    nsresult rv =
-      gScriptErrorFactory->CreateInstance(nsnull, NS_GET_IID(nsIScriptError),
-                                          getter_AddRefs(errorObject));
+    nsresult rv;
+    nsCOMPtr<nsIScriptError> errorObject =
+      do_CreateInstance(gScriptErrorFactory, &rv);
     if (NS_SUCCEEDED(rv)) {
       rv = errorObject->Init(mError.get(),
                              NS_ConvertASCIItoUCS2(mFileName.get()).get(),

view/src/nsViewManager.cpp

@@ -533,22 +533,15 @@ nsViewManager::CreateRegion(nsIRegion* *result)
   nsresult rv;
 
   if (!mRegionFactory) {
-    nsCOMPtr<nsIComponentManager> compMgr;
-    rv = NS_GetComponentManager(getter_AddRefs(compMgr));
-
-    if (NS_SUCCEEDED(rv))
-      rv = compMgr->GetClassObject(kRegionCID,
-                                   NS_GET_IID(nsIFactory),
-                                   getter_AddRefs(mRegionFactory));
-
-    if (!mRegionFactory) {
+    mRegionFactory = do_GetClassObject(kRegionCID, &rv);
+    if (NS_FAILED(rv)) {
       *result = nsnull;
-      return NS_ERROR_FAILURE;
+      return rv;
     }
   }
 
   nsIRegion* region = nsnull;
-  rv = mRegionFactory->CreateInstance(nsnull, NS_GET_IID(nsIRegion), (void**)&region);
+  rv = CallCreateInstance(mRegionFactory, &region);
   if (NS_SUCCEEDED(rv)) {
     rv = region->Init();
     *result = region;

xpcom/components/nsComponentManagerObsolete.cpp

@@ -39,6 +39,7 @@
 // Global Static Component Manager Methods
 // (for when you need to link with xpcom)
 
+#include "nsXPCOM.h"
 #include "nsIComponentManagerObsolete.h"
 #include "nsComponentManagerObsolete.h"
 
@@ -69,6 +70,17 @@ nsComponentManager::GetClassObject(const nsCID &aClass, const nsIID &aIID,
     return cm->GetClassObject(aClass, aIID, aResult);
 }
 
+nsresult
+nsComponentManager::GetClassObjectByContractID(const char *aContractID,
+                                               const nsIID &aIID,
+                                               void **aResult)
+{
+    nsCOMPtr<nsIComponentManager> cm;
+    nsresult rv = NS_GetComponentManager(getter_AddRefs(cm));
+    if (NS_FAILED(rv)) return rv;
+    return cm->GetClassObjectByContractID(aContractID, aIID, aResult);
+}
+
 nsresult
 nsComponentManager::ContractIDToClassID(const char *aContractID,
                                   nsCID *aClass)

xpcom/components/nsComponentManagerObsolete.h

@@ -83,6 +83,11 @@ public:
   static nsresult GetClassObject(const nsCID &aClass, const nsIID &aIID,
                                  void **aResult);
 
+  // Get the singleton class object that implements the CID aClass
+  static nsresult GetClassObjectByContractID(const char *aContractID,
+                                             const nsIID &aIID,
+                                             void **aResult);
+
   // Finds a class ID for a specific Program ID
   static nsresult ContractIDToClassID(const char *aContractID,
                                 nsCID *aClass);

xpcom/components/nsComponentManagerUtils.h

@@ -73,9 +73,9 @@ public:
     virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
     
 private:
-    const nsCID&	mCID;
-    nsISupports*	mOuter;
-    nsresult*		mErrorPtr;
+    const nsCID&    mCID;
+    nsISupports*    mOuter;
+    nsresult*       mErrorPtr;
 };
 
 class NS_COM nsCreateInstanceByContractID : public nsCOMPtr_helper
@@ -85,18 +85,38 @@ public:
         : mContractID(aContractID),
           mOuter(aOuter),
           mErrorPtr(aErrorPtr)
-				{
-					// nothing else to do here
-				}
+    {
+        // nothing else to do here
+    }
     
     virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
     
 private:
-    const char*	  mContractID;
+    const char*   mContractID;
     nsISupports*  mOuter;
-    nsresult*	  mErrorPtr;
+    nsresult*     mErrorPtr;
 };
 
+class NS_COM nsCreateInstanceFromFactory : public nsCOMPtr_helper
+{
+public:
+    nsCreateInstanceFromFactory( nsIFactory* aFactory, nsISupports* aOuter, nsresult* aErrorPtr )
+        : mFactory(aFactory),
+          mOuter(aOuter),
+          mErrorPtr(aErrorPtr)
+    {
+        // nothing else to do here
+    }
+    
+    virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
+    
+private:
+    nsIFactory*   mFactory;
+    nsISupports*  mOuter;
+    nsresult*     mErrorPtr;
+};
+
+
 inline
 const nsCreateInstanceByCID
 do_CreateInstance( const nsCID& aCID, nsresult* error = 0 )
@@ -125,6 +145,74 @@ do_CreateInstance( const char* aContractID, nsISupports* aOuter, nsresult* error
     return nsCreateInstanceByContractID(aContractID, aOuter, error);
 }
 
+inline
+const nsCreateInstanceFromFactory
+do_CreateInstance( nsIFactory* aFactory, nsresult* error = 0 )
+{
+    return nsCreateInstanceFromFactory(aFactory, 0, error);
+}
+
+inline
+const nsCreateInstanceFromFactory
+do_CreateInstance( nsIFactory* aFactory, nsISupports* aOuter, nsresult* error = 0 )
+{
+    return nsCreateInstanceFromFactory(aFactory, aOuter, error);
+}
+
+
+class NS_COM nsGetClassObjectByCID : public nsCOMPtr_helper
+{
+public:
+    nsGetClassObjectByCID( const nsCID& aCID, nsresult* aErrorPtr )
+        : mCID(aCID),
+          mErrorPtr(aErrorPtr)
+    {
+        // nothing else to do here
+    }
+    
+    virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
+    
+private:
+    const nsCID&    mCID;
+    nsresult*       mErrorPtr;
+};
+
+class NS_COM nsGetClassObjectByContractID : public nsCOMPtr_helper
+{
+public:
+    nsGetClassObjectByContractID( const char* aContractID, nsresult* aErrorPtr )
+        : mContractID(aContractID),
+          mErrorPtr(aErrorPtr)
+    {
+        // nothing else to do here
+    }
+    
+    virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
+    
+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* error = 0 )
+{
+    return nsGetClassObjectByCID(aCID, error);
+}
+
+inline const nsGetClassObjectByContractID
+do_GetClassObject( const char* aContractID, nsresult* error = 0 )
+{
+    return nsGetClassObjectByContractID(aContractID, error);
+}
+
 // type-safe shortcuts for calling |CreateInstance|
 template <class DestinationType>
 inline
@@ -183,6 +271,59 @@ CallCreateInstance( const char *aContractID,
                                               NS_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_IID(DestinationType),
+                                    NS_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(nsnull,
+                                    NS_GET_IID(DestinationType),
+                                    NS_REINTERPRET_CAST(void**, aDestination));
+}
+
+template <class DestinationType>
+inline
+nsresult
+CallGetClassObject( const nsCID &aClass,
+                    DestinationType** aDestination )
+{
+    NS_PRECONDITION(aDestination, "null parameter");
+    
+    return nsComponentManager::GetClassObject(aClass,
+        NS_GET_IID(DestinationType), NS_REINTERPRET_CAST(void**, aDestination));
+}
+
+template <class DestinationType>
+inline
+nsresult
+CallGetClassObject( const char* aContractID,
+                    DestinationType** aDestination )
+{
+    NS_PRECONDITION(aDestination, "null parameter");
+    
+    return nsComponentManager::GetClassObjectByContractID(aContractID,
+        NS_GET_IID(DestinationType), NS_REINTERPRET_CAST(void**, aDestination));
+}
+
 /* keys for registry use */
 extern const char xpcomKeyName[];
 extern const char xpcomComponentsKeyName[];

xpcom/glue/nsComponentManagerUtils.cpp

@@ -87,6 +87,64 @@ nsCreateInstanceByContractID::operator()( const nsIID& aIID, void** aInstancePtr
     return status;
 }
 
+nsresult
+nsCreateInstanceFromFactory::operator()( const nsIID& aIID, void** aInstancePtr ) const
+{
+    nsresult status;
+    if ( mFactory )
+        status = mFactory->CreateInstance(mOuter, aIID, aInstancePtr);
+    else
+        status = NS_ERROR_NULL_POINTER;
+    
+    if ( NS_FAILED(status) )
+        *aInstancePtr = 0;
+    if ( mErrorPtr )
+        *mErrorPtr = status;
+    return status;
+}
+
+
+nsresult
+nsGetClassObjectByCID::operator()( const nsIID& aIID, void** aInstancePtr ) const
+{
+    nsCOMPtr<nsIComponentManager> compMgr;
+    nsresult status = NS_GetComponentManager(getter_AddRefs(compMgr));
+    if (compMgr)
+        status = compMgr->GetClassObject(mCID, aIID, aInstancePtr);
+    else if (NS_SUCCEEDED(status))
+        status = NS_ERROR_UNEXPECTED;
+
+    if ( NS_FAILED(status) )
+        *aInstancePtr = 0;
+    
+    if ( mErrorPtr )
+        *mErrorPtr = status;
+    return status;
+}
+
+nsresult
+nsGetClassObjectByContractID::operator()( const nsIID& aIID, void** aInstancePtr ) const
+{
+    nsresult status;
+    if ( mContractID ) {
+        nsCOMPtr<nsIComponentManager> compMgr;
+        status = NS_GetComponentManager(getter_AddRefs(compMgr));
+        if (compMgr)
+            status = compMgr->GetClassObjectByContractID(mContractID,
+                                                         aIID, aInstancePtr);
+        else if (NS_SUCCEEDED(status))
+            status = NS_ERROR_UNEXPECTED;
+    }
+    else
+        status = NS_ERROR_NULL_POINTER;
+    
+    if ( NS_FAILED(status) )
+        *aInstancePtr = 0;
+    if ( mErrorPtr )
+        *mErrorPtr = status;
+    return status;
+}
+
 
 nsresult
 nsGetServiceByCID::operator()( const nsIID& aIID, void** aInstancePtr ) const

xpcom/glue/nsComponentManagerUtils.h

@@ -73,9 +73,9 @@ public:
     virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
     
 private:
-    const nsCID&	mCID;
-    nsISupports*	mOuter;
-    nsresult*		mErrorPtr;
+    const nsCID&    mCID;
+    nsISupports*    mOuter;
+    nsresult*       mErrorPtr;
 };
 
 class NS_COM nsCreateInstanceByContractID : public nsCOMPtr_helper
@@ -85,18 +85,38 @@ public:
         : mContractID(aContractID),
           mOuter(aOuter),
           mErrorPtr(aErrorPtr)
-				{
-					// nothing else to do here
-				}
+    {
+        // nothing else to do here
+    }
     
     virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
     
 private:
-    const char*	  mContractID;
+    const char*   mContractID;
     nsISupports*  mOuter;
-    nsresult*	  mErrorPtr;
+    nsresult*     mErrorPtr;
 };
 
+class NS_COM nsCreateInstanceFromFactory : public nsCOMPtr_helper
+{
+public:
+    nsCreateInstanceFromFactory( nsIFactory* aFactory, nsISupports* aOuter, nsresult* aErrorPtr )
+        : mFactory(aFactory),
+          mOuter(aOuter),
+          mErrorPtr(aErrorPtr)
+    {
+        // nothing else to do here
+    }
+    
+    virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
+    
+private:
+    nsIFactory*   mFactory;
+    nsISupports*  mOuter;
+    nsresult*     mErrorPtr;
+};
+
+
 inline
 const nsCreateInstanceByCID
 do_CreateInstance( const nsCID& aCID, nsresult* error = 0 )
@@ -125,6 +145,74 @@ do_CreateInstance( const char* aContractID, nsISupports* aOuter, nsresult* error
     return nsCreateInstanceByContractID(aContractID, aOuter, error);
 }
 
+inline
+const nsCreateInstanceFromFactory
+do_CreateInstance( nsIFactory* aFactory, nsresult* error = 0 )
+{
+    return nsCreateInstanceFromFactory(aFactory, 0, error);
+}
+
+inline
+const nsCreateInstanceFromFactory
+do_CreateInstance( nsIFactory* aFactory, nsISupports* aOuter, nsresult* error = 0 )
+{
+    return nsCreateInstanceFromFactory(aFactory, aOuter, error);
+}
+
+
+class NS_COM nsGetClassObjectByCID : public nsCOMPtr_helper
+{
+public:
+    nsGetClassObjectByCID( const nsCID& aCID, nsresult* aErrorPtr )
+        : mCID(aCID),
+          mErrorPtr(aErrorPtr)
+    {
+        // nothing else to do here
+    }
+    
+    virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
+    
+private:
+    const nsCID&    mCID;
+    nsresult*       mErrorPtr;
+};
+
+class NS_COM nsGetClassObjectByContractID : public nsCOMPtr_helper
+{
+public:
+    nsGetClassObjectByContractID( const char* aContractID, nsresult* aErrorPtr )
+        : mContractID(aContractID),
+          mErrorPtr(aErrorPtr)
+    {
+        // nothing else to do here
+    }
+    
+    virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
+    
+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* error = 0 )
+{
+    return nsGetClassObjectByCID(aCID, error);
+}
+
+inline const nsGetClassObjectByContractID
+do_GetClassObject( const char* aContractID, nsresult* error = 0 )
+{
+    return nsGetClassObjectByContractID(aContractID, error);
+}
+
 // type-safe shortcuts for calling |CreateInstance|
 template <class DestinationType>
 inline
@@ -183,6 +271,59 @@ CallCreateInstance( const char *aContractID,
                                               NS_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_IID(DestinationType),
+                                    NS_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(nsnull,
+                                    NS_GET_IID(DestinationType),
+                                    NS_REINTERPRET_CAST(void**, aDestination));
+}
+
+template <class DestinationType>
+inline
+nsresult
+CallGetClassObject( const nsCID &aClass,
+                    DestinationType** aDestination )
+{
+    NS_PRECONDITION(aDestination, "null parameter");
+    
+    return nsComponentManager::GetClassObject(aClass,
+        NS_GET_IID(DestinationType), NS_REINTERPRET_CAST(void**, aDestination));
+}
+
+template <class DestinationType>
+inline
+nsresult
+CallGetClassObject( const char* aContractID,
+                    DestinationType** aDestination )
+{
+    NS_PRECONDITION(aDestination, "null parameter");
+    
+    return nsComponentManager::GetClassObjectByContractID(aContractID,
+        NS_GET_IID(DestinationType), NS_REINTERPRET_CAST(void**, aDestination));
+}
+
 /* keys for registry use */
 extern const char xpcomKeyName[];
 extern const char xpcomComponentsKeyName[];