261310 - make it easier to cache factories

Status: RESOLVED FIXED

(Core :: XPCOM, defect)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

I'd like to add some functions that make it easier to cache factories and use
them in a typesafe way.  This is a useful trick for improving the performance of
callers that do lots of CreateInstance calls for the same type of object.  (The
view manager does it for regions, and I'm doing it for script errors in bug 261283.)

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: work in progress

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: patch

Comment 3

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Comment on attachment 160601 [details] [diff] [review]
patch

Note that I am adding to nsComponentManagerObsolete, but I don't see any better
alternative.

Comment 4

[Darin Fisher]

Comment on attachment 160601 [details] [diff] [review]
patch

>Index: xpcom/glue/nsComponentManagerUtils.cpp

>+nsCreateInstanceFromFactory::operator()( const nsIID& aIID, void** aInstancePtr ) const
...
>+    if (NS_FAILED(status))
>+        *aInstancePtr = 0;
>+    if ( mErrorPtr )

nit: whitespace inconsistency (same goes for other methods in this file
or so it would appear)


nice patch, r=darin :)

Comment 5

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Fix checked in to trunk, 2004-10-01 17:44 -0700.

Comment 6

[Christian :Biesinger (don't email me, ping me on IRC)]

sounds like this caused bug 262596

Comment 7

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

FWIW, codesize numbers from luna:

  libxpcom.so
  	Total:	       +548 (+548/+0)
  	Code:	       +484 (+484/+0)
  	Data:	        +64 (+64/+0)
  	       +484 (+484/+0)	text (CODE)
  		       +484 (+484/+0)	UNDEF:libxpcom.so:text
  			       +158	nsGetClassObjectByContractID::operator()(nsID const&, void**) const
  			       +145	nsGetClassObjectByCID::operator()(nsID const&, void**) const
  			       +101	nsComponentManager::GetClassObjectByContractID(char const*,
nsID const&, void**)
  			        +80	nsCreateInstanceFromFactory::operator()(nsID const&, void**) const
  	        +64 (+64/+0)	data (DATA)
  		        +64 (+64/+0)	UNDEF:libxpcom.so:data
  			        +28	.nosyms.data
  			        +12	vtable for nsCreateInstanceFromFactory
  			        +12	vtable for nsGetClassObjectByCID
  			        +12	vtable for nsGetClassObjectByContractID
  
  libgklayout.so
  	Total:	        -96 (+25/-121)
  	Code:	        -93 (+0/+0)
  	Data:	         -3 (+25/-121)
  	        -96 (+25/-121)	text (DATA)
  		        -96 (+25/-121)	UNDEF:libgklayout.so:text
  			        +25	nsCSSScanner::OutputError()
  			         -3	.nosyms.text
  			        -52	nsViewManager::CreateRegion(nsIRegion**)
  			        -66	nsCSSScanner::InitGlobals()

Comment 8

[Doug Turner (:dougt)]

dbaron, does this mean that the total bloat increased?