92617 - front-end cache for element factories in XML content sink

Status: VERIFIED DUPLICATE of bug 91241

(Core :: DOM: Core & HTML, defect)

Description

[Chris Waterson]

dp proposed doing a front-end cache in the XML content sink to avoid traffic to
the component manager:

r=waterson

Suresh Duddi wrote:

This patch eliminates 1500 calls to ContractID->CID and about 3000 string
copies. About 1/2 sec savings our of 22secs startup.

nsXMLContentSink:

When a elementfactory is required from the namespace, instead of going from
id->string->string->servicemanager, maintaining a map locally would save all the
translation and hash table lookup.

Patch  maintains a weak ref to a service. I think that is ok but if this needs
to be super super clean, then maybe those refs can be made owning and cleaned up
on say shutdown-listener.

dp


------------------------------------------------------------------------

Index: nsXMLContentSink.cpp
===================================================================
RCS file: /cvsroot/mozilla/content/xml/document/src/nsXMLContentSink.cpp,v
retrieving revision 1.166
diff -c -r1.166 nsXMLContentSink.cpp
*** nsXMLContentSink.cpp    2001/07/25 07:50:57    1.166
--- nsXMLContentSink.cpp    2001/07/26 09:41:37
***************
*** 94,99 ****
--- 94,102 ----
  nsINameSpaceManager* nsXMLContentSink::gNameSpaceManager = nsnull;
  PRUint32 nsXMLContentSink::gRefCnt = 0;
  + nsXMLContentSink::ElementFactoryMap
nsXMLContentSink::gElementFactoryMap[nsXMLContentSink::MAX_ELEMENTFACTORY_MAP];
+ int nsXMLContentSink::gNElementFactoryMap = 0;
+   // XXX Open Issues:
  // 1) what's not allowed - We need to figure out which HTML tags
  //    (prefixed with a HTML namespace qualifier) are explicitly not
***************
*** 1849,1855 ****
  void   nsXMLContentSink::GetElementFactory(PRInt32 aNameSpaceID,
nsIElementFactory** aResult)
  {
!   nsresult rv;
    nsAutoString nameSpace;
    gNameSpaceManager->GetNameSpaceURI(aNameSpaceID, nameSpace);
  --- 1852,1867 ----
  void   nsXMLContentSink::GetElementFactory(PRInt32 aNameSpaceID,
nsIElementFactory** aResult)
  {
!   // Check out mapping table. If it exists return.
!   int i;
!   for (i=0; i<gNElementFactoryMap; i++) {
!     if (gElementFactoryMap[i].nameSpaceID == aNameSpaceID) {
!       *aResult = gElementFactoryMap[i].factory;
!       NS_IF_ADDREF(*aResult);
!       return;
!     }
!   }
!     nsAutoString nameSpace;
    gNameSpaceManager->GetNameSpaceURI(aNameSpaceID, nameSpace);
  ***************
*** 1857,1864 ****
    contractID.AppendWithConversion(nameSpace);
      // Retrieve the appropriate factory.
!   nsCOMPtr<nsIElementFactory> elementFactory(do_GetService(contractID, &rv));
      *aResult = elementFactory;
    NS_IF_ADDREF(*aResult);
  }
--- 1869,1887 ----
    contractID.AppendWithConversion(nameSpace);
      // Retrieve the appropriate factory.
!   nsCOMPtr<nsIElementFactory> elementFactory(do_GetService(contractID));
      *aResult = elementFactory;
    NS_IF_ADDREF(*aResult);
+ +   // Update our element factory mapping
+   if (gNElementFactoryMap < MAX_ELEMENTFACTORY_MAP) {
+     gElementFactoryMap[gNElementFactoryMap].nameSpaceID = aNameSpaceID;
+     // WEAK
+     // These are services and we are trusting these will be around
+     // upto the point of shutdown. Beyond that creation of XMLContentSink
+     // will fail or even getservice will fail.
+     gElementFactoryMap[gNElementFactoryMap].factory = elementFactory;
+     gNElementFactoryMap++;
+   }
  }
Index: nsXMLContentSink.h
===================================================================
RCS file: /cvsroot/mozilla/content/xml/document/src/nsXMLContentSink.h,v
retrieving revision 1.47
diff -c -r1.47 nsXMLContentSink.h
*** nsXMLContentSink.h    2001/07/04 19:35:23    1.47
--- nsXMLContentSink.h    2001/07/26 09:41:38
***************
*** 169,174 ****
--- 169,182 ----
    static nsINameSpaceManager* gNameSpaceManager;
    static PRUint32 gRefCnt;
  +   static const int MAX_ELEMENTFACTORY_MAP = 8;
+   typedef struct {
+     PRInt32 nameSpaceID;
+     nsIElementFactory *factory;  // WEAK
+   } ElementFactoryMap;
+   static ElementFactoryMap gElementFactoryMap[MAX_ELEMENTFACTORY_MAP];
+   static int gNElementFactoryMap;
+     nsIDocument* mDocument;
    nsIURI* mDocumentURL;
    nsIURI* mDocumentBaseURL; // can be set via HTTP headers

namespace-patch.txt

Content-Type:

text/plain
Content-Encoding:

7bit

Comment 1

[Heikki Toivonen (remove -bugzilla when emailing directly)]

This is a dupe, and jst says he also has a fix...

*** This bug has been marked as a duplicate of 91241 ***

Comment 2

[[e-mail] (gone - use [e-mail] instead)]

verified dup.