I have a recursive function and it uses the Notes objects. Please tell whether I should call recycle method for these objects, or I can leave that to garbage collector?
function getAllUsersInDepartmentAndSub (nd: NotesDocument, arrData: Array) {
var strSubPrefix = strTaskLibName + "getAllUsersInDepartmentAndSub/";
try {
var ndcResp: NotesDocumentCollection;
var ndResp: NotesDocument;
var ndNext: NotesDocument;
var strTemp: string;
if (nd) {
ndcResp = nd.getResponses();
if (ndcResp) {
if (ndcResp.getCount() > 0) {
ndResp = ndcResp.getFirstDocument();
while (ndResp) {
strTemp = #LowerCase(ndResp.getItemValueString("form"));
if (strTemp == "department") {
getAllUsersInDepartmentAndSub (ndResp, arrData);
} else if (strTemp == "person") {
strTemp = ndResp.getItemValueString("fullname");
if (#Member(strTemp, arrData) <= 0) {
arrData.push(strTemp);
}
}
ndNext = ndcResp.getNextDocument(ndResp);
ndResp.recycle();
ndResp = ndNext;
}
}
ndcResp.recycle();
}
}
} catch(e) {
writeInfo(strSubPrefix, e, true, true);
}
}
In short: Recycle Recycle, Recycle!
You have to recycle all Domino objects as soon as they are not needed anymore.
And you have to be carefull: If you miss an instance it is horrible to find a recycling problem in your code.
In your code above, your NotesDocumentCollection ndcResp is not recycled when an error is thrown, and your server runs into allocation problems sooner or later.
You should use the finally statement and recycle all objects used in your function, so they will be cleaned up even if something in your method goes wrong.
Related
I need to prevent/disable nested lists in text editor implemented in Angular. So far i wrote a hack that undos a nested list when created by the user. But if the user creates a normal list and presses the tab-key the list is shown as nested for a few milliseconds until my hack sets in back to a normal list. I need something like event.preventDefault() or stopPropagation() on tab-event keydown but unfortunately that event is not tracked for some reason. Also the froala settings with tabSpaces: falseis not showing any difference when it comes to nested list...in summary i want is: if the user creates a list and presses the tab-key that nothing happens, not even for a millisecond. Has anyone an idea about that?
Froala’s support told us, there’s no built-in way to suppress nested list creation. They result from TAB key getting hit with the caret on a list item. However we found a way to get around this using MutationObserver
Basically we move the now nested list item to his former sibling and remove the newly created list. Finally we take care of the caret position.
var observer = new MutationObserver(mutationObserverCallback);
observer.observe(editorNode, {
childList: true,
subtree: true
});
var mutationObserverCallback = function (mutationList) {
var setCaret = function (ele) {
if (ele.nextSibling) {
ele = ele.nextSibling;
}
var range = document.createRange();
var sel = window.getSelection();
range.setStart(ele, 0);
range.collapse(true);
sel.removeAllRanges();
sel.addRange(range);
};
var handleAddedListNode = function (listNode) {
if (! listNode.parentNode) {
return;
}
var parentListItem = listNode.parentNode.closest('li');
if (!parentListItem) {
return;
}
var idx = listNode.children.length - 1;
while (idx >= 0) {
var childNode = listNode.children[idx];
if (parentListItem.nextSibling) {
parentListItem.parentNode.insertBefore(childNode, parentListItem.nextSibling);
} else {
parentListItem.parentNode.appendChild(childNode);
}
--idx;
}
setCaret(parentListItem);
listNode.parentNode.removeChild(listNode);
};
mutationList.forEach(function (mutation) {
var addedNodes = mutation.addedNodes;
if (!addedNodes.length) {
return;
}
for (var i = 0; i < addedNodes.length; i++) {
var currentNode = addedNodes[i];
switch (currentNode.nodeName.toLowerCase()) {
case 'ol':
case 'ul':
handleAddedListNode(currentNode);
break;
// more optimizations
}
}
})
};
We have an MFC application that has been used and maintained for many years. Recently we made some administrative changes to some computers that are running the application. Now the software occasionally crashes when printing from the application.
We are using pretty standard MFC code to initiate the printing. We added try/catch blocks around what we felt like are the pertinent areas of the code with no luck. Whatever is failing does not seem to throw.
We get the typical dialog stating that "____ MFC Application has stopped working". Closing the program is the only option.
The windows event logger shows that our application is the Faulting application.
The exception code is 0xc0000005, which appears to be an Access Denied error.
The application is in the CView::OnFilePrint() code when the crash occurs.
We have added some logging, and we know that we get through DoPreparePrinting, and OnBeginPrinting.
We believe that CDC::StartDoc would be the next thing called, then CView::OnPrepareDC. We don't get to OnPrepareDC when we fail.
We don't seem to find the source code for CView::OnFilePrint, so we are not sure what it looks like. From research online, we think that things happen in this order in OnFilePrint:
// what we think is in OnFilePrint:
CView::OnFilePrint()
{
OnPreparePrinting(); <- we get through our override of this
OnBeginPrinting(); <- we get through our override of this
// loop back to here on multiple docs
CDC::StartDoc();
CView::OnPrepareDC(); <- we do not reach our override of this
CView::OnPaint();
CDC::EndPage();
// loop back on multiple docs
...
// finish if last doc...
}
I would like to have the source for it so we could attempt to rewrite it and try to gracefully fail instead of failing by crashing.
I'm looking for:
1) any suggestions as to how to figure out why the process of printing causes our application to crash.
2) A location for where the CView::OnFilePrint code is located, if available.
(the only idea I have left to narrow down the problem is to call our own version of this so that we can step through it and add logging and/or see if we can at least fail gracefully when it the problem occurs.)
The printer is Xerox Phaser 3610, for what its worth.
source code for CView::OnFilePrint should be in C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\atlmfc\src\mfc\viewprnt.cpp, depending on VS version. There could also be a problem with printer initialization/access.
If there is any error it is most likely due to printer initialization. You can override OnFilePrint and add CPrintInfo printInfo for testing. Example:
//ON_COMMAND(ID_FILE_PRINT, &CView::OnFilePrint)
//ON_COMMAND(ID_FILE_PRINT_DIRECT, &CView::OnFilePrint)
ON_COMMAND(ID_FILE_PRINT, OnFilePrint)
ON_COMMAND(ID_FILE_PRINT_DIRECT, OnFilePrint)
void CMyView::OnFilePrint()
{
try
{
CPrintInfo printInfo;
}
catch(...)
{
//log error
AfxMessageBox(L"error");
}
CView::OnFilePrint();
}
As noted in comments, another possibility is that there is a bug somewhere else in the code, which may not necessarily be related to printing.
Inside of CView::OnFilePrint, this occurs:
CWnd * hwndTemp = AfxGetMainWnd();
It turns out that if you don't call OnFilePrint from the main thread, this returns NULL.
Due to slight timing changes when the computers were logged onto a domain, OnFilePrint was being called from another thread. This causes the above call to return null, then when this line gets executed:
hwndTemp->EnableWindow(FALSE);
The application crashes.
There are several ways to fix this. One is to use this:
CWnd * hwndTemp = AfxGetApp()->GetMainWnd();
In place of this:
CWnd * hwndTemp = AfxGetMainWnd();
Another way is to assure that OnFilePrint is only called from the main thread.
A cut to the chase version of the code in CView::OnFilePrint is here:
// disable main window while printing & init printing status dialog
// Store the Handle of the Window in a temp so that it can be enabled
// once the printing is finished
CWnd * hwndTemp = AfxGetMainWnd(); // <--- CAN RETURN NULL HERE
hwndTemp->EnableWindow(FALSE); // <--- CRASH WILL OCCUR HERE
CPrintingDialog dlgPrintStatus(this);
Full version of CView::OnFilePrint is below.
The OnFilePrint code, with the problem area noted:
void CView::OnFilePrint()
{
// get default print info
CPrintInfo printInfo;
ASSERT(printInfo.m_pPD != NULL); // must be set
if (LOWORD(GetCurrentMessage()->wParam) == ID_FILE_PRINT_DIRECT)
{
CCommandLineInfo* pCmdInfo = AfxGetApp()->m_pCmdInfo;
if (pCmdInfo != NULL)
{
if (pCmdInfo->m_nShellCommand == CCommandLineInfo::FilePrintTo)
{
printInfo.m_pPD->m_pd.hDC = ::CreateDC(pCmdInfo->m_strDriverName,
pCmdInfo->m_strPrinterName, pCmdInfo->m_strPortName, NULL);
if (printInfo.m_pPD->m_pd.hDC == NULL)
{
AfxMessageBox(AFX_IDP_FAILED_TO_START_PRINT);
return;
}
}
}
printInfo.m_bDirect = TRUE;
}
if (OnPreparePrinting(&printInfo))
{
// hDC must be set (did you remember to call DoPreparePrinting?)
ASSERT(printInfo.m_pPD->m_pd.hDC != NULL);
// gather file to print to if print-to-file selected
CString strOutput;
if (printInfo.m_pPD->m_pd.Flags & PD_PRINTTOFILE && !printInfo.m_bDocObject)
{
// construct CFileDialog for browsing
CString strDef(MAKEINTRESOURCE(AFX_IDS_PRINTDEFAULTEXT));
CString strPrintDef(MAKEINTRESOURCE(AFX_IDS_PRINTDEFAULT));
CString strFilter(MAKEINTRESOURCE(AFX_IDS_PRINTFILTER));
CString strCaption(MAKEINTRESOURCE(AFX_IDS_PRINTCAPTION));
CFileDialog dlg(FALSE, strDef, strPrintDef,
OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT, strFilter, NULL, 0);
dlg.m_ofn.lpstrTitle = strCaption;
if (dlg.DoModal() != IDOK)
return;
// set output device to resulting path name
strOutput = dlg.GetPathName();
}
// set up document info and start the document printing process
CString strTitle;
CDocument* pDoc = GetDocument();
if (pDoc != NULL)
strTitle = pDoc->GetTitle();
else
EnsureParentFrame()->GetWindowText(strTitle);
DOCINFO docInfo;
memset(&docInfo, 0, sizeof(DOCINFO));
docInfo.cbSize = sizeof(DOCINFO);
docInfo.lpszDocName = strTitle;
CString strPortName;
if (strOutput.IsEmpty())
{
docInfo.lpszOutput = NULL;
strPortName = printInfo.m_pPD->GetPortName();
}
else
{
docInfo.lpszOutput = strOutput;
AfxGetFileTitle(strOutput,
strPortName.GetBuffer(_MAX_PATH), _MAX_PATH);
}
// setup the printing DC
CDC dcPrint;
if (!printInfo.m_bDocObject)
{
dcPrint.Attach(printInfo.m_pPD->m_pd.hDC); // attach printer dc
dcPrint.m_bPrinting = TRUE;
}
OnBeginPrinting(&dcPrint, &printInfo);
if (!printInfo.m_bDocObject)
dcPrint.SetAbortProc(_AfxAbortProc);
/**********************************************************************
Problem area.
If the calling thread is not the main thread, the call to AfxGetMainWnd
can return NULL. In this case, hwndTemp->EnableWindow(FALSE) will crash
the application.
**********************************************************************/
// disable main window while printing & init printing status dialog
// Store the Handle of the Window in a temp so that it can be enabled
// once the printing is finished
CWnd * hwndTemp = AfxGetMainWnd(); // <--- CAN RETURN NULL HERE
hwndTemp->EnableWindow(FALSE); // <--- CRASH WILL OCCUR HERE
CPrintingDialog dlgPrintStatus(this);
CString strTemp;
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_DOCNAME, strTitle);
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_PRINTERNAME,
printInfo.m_pPD->GetDeviceName());
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_PORTNAME, strPortName);
dlgPrintStatus.ShowWindow(SW_SHOW);
dlgPrintStatus.UpdateWindow();
// start document printing process
if (!printInfo.m_bDocObject)
{
printInfo.m_nJobNumber = dcPrint.StartDoc(&docInfo);
if (printInfo.m_nJobNumber == SP_ERROR)
{
// enable main window before proceeding
hwndTemp->EnableWindow(TRUE);
// cleanup and show error message
OnEndPrinting(&dcPrint, &printInfo);
dlgPrintStatus.DestroyWindow();
dcPrint.Detach(); // will be cleaned up by CPrintInfo destructor
AfxMessageBox(AFX_IDP_FAILED_TO_START_PRINT);
return;
}
}
// Guarantee values are in the valid range
UINT nEndPage = printInfo.GetToPage();
UINT nStartPage = printInfo.GetFromPage();
if (nEndPage < printInfo.GetMinPage())
nEndPage = printInfo.GetMinPage();
if (nEndPage > printInfo.GetMaxPage())
nEndPage = printInfo.GetMaxPage();
if (nStartPage < printInfo.GetMinPage())
nStartPage = printInfo.GetMinPage();
if (nStartPage > printInfo.GetMaxPage())
nStartPage = printInfo.GetMaxPage();
int nStep = (nEndPage >= nStartPage) ? 1 : -1;
nEndPage = (nEndPage == 0xffff) ? 0xffff : nEndPage + nStep;
VERIFY(strTemp.LoadString(AFX_IDS_PRINTPAGENUM));
// If it's a doc object, we don't loop page-by-page
// because doc objects don't support that kind of levity.
BOOL bError = FALSE;
if (printInfo.m_bDocObject)
{
OnPrepareDC(&dcPrint, &printInfo);
OnPrint(&dcPrint, &printInfo);
}
else
{
// begin page printing loop
for (printInfo.m_nCurPage = nStartPage;
printInfo.m_nCurPage != nEndPage; printInfo.m_nCurPage += nStep)
{
OnPrepareDC(&dcPrint, &printInfo);
// check for end of print
if (!printInfo.m_bContinuePrinting)
break;
// write current page
TCHAR szBuf[80];
ATL_CRT_ERRORCHECK_SPRINTF(_sntprintf_s(szBuf, _countof(szBuf), _countof(szBuf) - 1, strTemp, printInfo.m_nCurPage));
dlgPrintStatus.SetDlgItemText(AFX_IDC_PRINT_PAGENUM, szBuf);
// set up drawing rect to entire page (in logical coordinates)
printInfo.m_rectDraw.SetRect(0, 0,
dcPrint.GetDeviceCaps(HORZRES),
dcPrint.GetDeviceCaps(VERTRES));
dcPrint.DPtoLP(&printInfo.m_rectDraw);
// attempt to start the current page
if (dcPrint.StartPage() < 0)
{
bError = TRUE;
break;
}
// must call OnPrepareDC on newer versions of Windows because
// StartPage now resets the device attributes.
OnPrepareDC(&dcPrint, &printInfo);
ASSERT(printInfo.m_bContinuePrinting);
// page successfully started, so now render the page
OnPrint(&dcPrint, &printInfo);
if ((nStep > 0) && // pages are printed in ascending order
(nEndPage > printInfo.GetMaxPage() + nStep)) // out off pages
{
// OnPrint may have set the last page
// because the end of the document was reached.
// The loop must not continue with the next iteration.
nEndPage = printInfo.GetMaxPage() + nStep;
}
// If the user restarts the job when it's spooling, all
// subsequent calls to EndPage returns < 0. The first time
// GetLastError returns ERROR_PRINT_CANCELLED
if (dcPrint.EndPage() < 0 && (GetLastError()!= ERROR_SUCCESS))
{
HANDLE hPrinter;
if (!OpenPrinter(LPTSTR(printInfo.m_pPD->GetDeviceName().GetBuffer()), &hPrinter, NULL))
{
bError = TRUE;
break;
}
DWORD cBytesNeeded;
if(!GetJob(hPrinter,printInfo.m_nJobNumber,1,NULL,0,&cBytesNeeded))
{
if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
{
bError = TRUE;
break;
}
}
JOB_INFO_1 *pJobInfo;
if((pJobInfo = (JOB_INFO_1 *)malloc(cBytesNeeded))== NULL)
{
bError = TRUE;
break;
}
DWORD cBytesUsed;
BOOL bRet = GetJob(hPrinter,printInfo.m_nJobNumber,1,LPBYTE(pJobInfo),cBytesNeeded,&cBytesUsed);
DWORD dwJobStatus = pJobInfo->Status;
free(pJobInfo);
pJobInfo = NULL;
// if job status is restart, just continue
if(!bRet || !(dwJobStatus & JOB_STATUS_RESTART) )
{
bError = TRUE;
break;
}
}
if(!_AfxAbortProc(dcPrint.m_hDC, 0))
{
bError = TRUE;
break;
}
}
}
// cleanup document printing process
if (!printInfo.m_bDocObject)
{
if (!bError)
dcPrint.EndDoc();
else
dcPrint.AbortDoc();
}
hwndTemp->EnableWindow(); // enable main window
OnEndPrinting(&dcPrint, &printInfo); // clean up after printing
dlgPrintStatus.DestroyWindow();
dcPrint.Detach(); // will be cleaned up by CPrintInfo destructor
}
}
I've tried to search for instance caching and singletons on Google and StackOverflow without success, seeing only posts about module.exports, if you know a post that answers this question, feel free to reference it. Thank you!
I have an application that needs to work on a set of objects that rarely change, and hence need to be cached for performance optimisation.
Here is a toy example where a single property is set directly.
When I call the application, I export an object that will contain the set of cached objects in assets_cached.js:
const Assets = {};
module.exports.Assets = Assets;
In another module of the application I have an ES6 class:
const _ = require('lodash')
const { Assets } = require('./assets_cached')
class Asset {
constructor(id, some_property) {
if (id in Assets) {
// Update instance data with cached properties
_.assign(this, Assets_cached[id]);
} else {
// If it's not cached, create a new object
this.id = id;
this.some_property = some_property;
// Cache this object
Assets_cached[id] = this;
}
}
getProperty() {
return this.some_property;
}
setProperty(value) {
this.some_property = value;
// Is there a way of avoiding having to do this double assignment?
Assets_cached[id].some_property = value;
}
}
module.exports = Asset;
How may I avoid having to set the some_property twice (in the current instance and the cache, while ensuring that other instances are updated in parallel)?
Ideally I'd like to do something like:
if (id in Assets) {
this = Assets.cached[id]
}
inside the constructor, but this is not possible.
What's the most elegant and correct way of making this work?
Ideally I'd like to do something like this = Assets.cached[id] inside the constructor
The magic keyword here is return. You can just return an arbitrary object from the constructor and it will be used instead of this.
constructor(id, some_property) {
if (id in Assets) {
// use cached instance instead of creating a new one
return Assets_cached[id];
} else {
this.id = id;
this.some_property = some_property;
// Cache this object
Assets_cached[id] = this;
}
}
Here is the approach to the comment that was made some half an hour ago ...
const { Assets_cached } = require('./assets_cached');
// const { AssetStore } = require('./assetstore');
class Asset {
constructor(id, some_property) { // clean/lean constructor.
this.id = id;
this.some_property = some_property;
}
getProperty() {
return this.some_property;
}
setProperty(value) {
this.some_property = value;
}
}
function isAsset(type) {
// poor man's approach ... change to something more feasible.
return (type instanceof Asset);
}
function createAsset(id, some_property) { // factory that also handles caching.
var
asset = Assets_cached[id];
// asset = AssetStore.get(id);
if (!(asset && isAsset(asset))) {
asset = Assets_cached[id] = (new Asset(id, some_property));
// AssetStore.put(id, (asset = new Asset(id, some_property)));
}
return asset;
}
module.exports = {
create : createAsset,
isAsset : isAsset
};
Note
One also should consider providing a minimal API to Assets_cached, something like put/set, get and delete instead of Assets_cached being an entirely exposed, plain key-value store.
I try to put a file into a richtext but it crashes !
In my first code, I try to use directly "getFirstItem", in first time it was ok but now i try to use it again and it crashed.
In second time i pass with an object and it find my obj doesn't an richtextItem (instanceof) ???
I don't understand.
I have the message : "lotus.domino.local.Item cannot be cast to lotus.domino.RichTextItem" ?
Could you help me ?
public void copieFichierDansRichText(String idDocument, String nomRti, File file,
String nameFichier, String chemin) throws NotesException {
lotus.domino.Session session = Utils.getSession();
lotus.domino.Database db = session.getCurrentDatabase();
lotus.domino.Document monDoc = db.getDocumentByUNID(idDocument);
lotus.domino.RichTextItem rtiNew = null;
try {
try {
if (monDoc != null) {
// if (monDoc.getFirstItem(nomRti) != null) {
// rtiNew = (lotus.domino.RichTextItem)
// monDoc.getFirstItem(nomRti);
// } else {
// rtiNew = (lotus.domino.RichTextItem)
// monDoc.createRichTextItem(nomRti);
// }
Object obj = null;
if (monDoc.getFirstItem(nomRti) != null) {
obj = monDoc.getFirstItem(nomRti);
if (obj instanceof lotus.domino.RichTextItem) {
rtiNew = (lotus.domino.RichTextItem) obj;
}
} else {
obj = monDoc.createRichTextItem(nomRti);
if (obj instanceof lotus.domino.RichTextItem) {
rtiNew = (lotus.domino.RichTextItem) obj;
}
}
PieceJointe pieceJointe = new PieceJointe();
pieceJointe = buildPieceJointe(file, nameFichier, chemin);
rtiNew.embedObject(EmbeddedObject.EMBED_ATTACHMENT, "", pieceJointe.getChemin()
+ pieceJointe.getNomPiece(), pieceJointe.getNomPiece());
monDoc.computeWithForm(true, false);
monDoc.save(true);
}
} finally {
rtiNew.recycle();
monDoc.recycle();
db.recycle();
session.recycle();
}
} catch (Exception e) {
e.printStackTrace();
}
}
EDIT : I try to modify my code with yours advices but the items never considerate as richtextitem. It is my problem. I don't understand why, because in my field it is a richtext ! For it, the item can't do :
rtiNew = (lotus.domino.RichTextItem) item1;
because item1 not be a richtext !!!
I was trying to take all the fields and pass in the item one by one, and it never go to the obj instance of lotus.domini.RichTextItem....
Vector items = doc.getItems();
for (int i=0; i<items.size(); i++) {
// get next element from the Vector (returns java.lang.Object)
Object obj = items.elementAt(i);
// is the item a RichTextItem?
if (obj instanceof RichTextItem) {
// yes it is - cast it as such // it never go here !!
rt = (RichTextItem)obj;
} else {
// nope - cast it as an Item
item = (Item)obj;
}
}
A couple of things. First of all I would set up a util class method to handle the object recycling in a neater way:
public enum DominoUtil {
;
public static void recycle(Base... bases) {
for (Base base : bases) {
if (base != null) {
try {
base.recycle();
} catch (Exception e) {
// Do nothing
}
}
}
}
}
Secondly I would remove the reduntants try/catch blocks and simplify it like this:
private void copieFichierDansRichText(String idDocument, String nomRti, File file,
String nameFichier, String chemin) {
Session session = DominoUtils.getCurrentSession();
Database db = session.getCurrentDatabase();
Document monDoc = null;
try {
monDoc = db.getDocumentByUNID(idDocument);
Item item = monDoc.getFirstItem(nomRti);
if (item == null) {
item = monDoc.createRichTextItem(nomRti);
} else if (item.getType() != Item.RICHTEXT) {
// The item is not a rich text item
// What are you going to do now?
}
RichTextItem rtItem = (RichTextItem) item;
PieceJointe pieceJointe = new PieceJointe();
pieceJointe = buildPieceJointe(file, nameFichier, chemin);
rtItem.embedObject(EmbeddedObject.EMBED_ATTACHMENT, "", pieceJointe.getChemin()
+ pieceJointe.getNomPiece(), pieceJointe.getNomPiece());
monDoc.computeWithForm(true, false);
monDoc.save(true);
} catch (NotesException e) {
throw new FacesException(e);
} finally {
DominoUtil.recycle(monDoc);
}
}
Finally, apart from the monDoc, you need not recycle anything else. Actually Session would be automatically recycled and anything beneath with it (so no need to recycle db, let alone the session!, good rule is don't recycle what you didn't instantiate), but it's not bad to keep the habit of keeping an eye on what you instantiate. If it were a loop with many documents you definitively want to do that. If you also worked with many items you would want to recycle them as early as possible. Anyway, considered the scope of the code it's sufficient like this. Obviously you would call DominoUtil.recycle directly from the try block. If you have multiple objects you can recycle them at once possibly by listing them in the reverse order you set them (eg. DominoUtil.recycle(item, doc, view)).
Also, what I think you miss is the check on the item in case it's not a RichTextItem - and therefore can't be cast. I put a comment where I think you should decide what to do before proceeding. If you let it like that and let the code proceed you will have the code throw an error. Always better to catch the lower level exception and re-throw a higher one (you don't want the end user to know more than it is necessary to know). In this case I went for the simplest thing: wrapped NotesException in a FacesException.
I have a huge web app that is having issues with memory leak in IE 6.
Fixing a memory leak in a 5 line code sample that demonstrates the problem is easy.
But if I have a very huge application, where should a start from?
Check out Drip. That usually takes the guesswork out of IE memory leaks.
If for some reason Drip doesn't find it, take a close look at any JavaScript code that works with events. That is almost always the source of any significant memory leak in a browser.
Destroying a DOM element with handlers attached to it, without removing those handlers first, will prevent the memory associated with those handlers from being recovered.
Does the application use a lot of JavaScript?
If it does, then one thing I've found that helps for avoiding memory leaks is to make sure you're using a JavaScript framework such as Prototype or jQuery because they have tried and tested event-handling code that doesn't leak memory.
IE6 can also leak memory if you have circular references to DOM objects
Also try this JavaScript Memory Leak Detector and see if you can diagnose where the problem is
Here is how I solved the memory leak problem in IE7. The idea is to dispose/set to null all expando-properties on all DOM nodes at unloading the page. This worked for me. You may find it useful.
<!--[if lt IE 8]>
<script type="text/javascript">
function disposeAll() {
if (window.document.all) {
for (var index = 0; index < window.document.all.length; index++) {
try { dispose(window.document.all[index], []); } catch (e) { debugger; }
}
}
dispose(window.document.body, []);
dispose(window.document, []);
dispose(window, []);
window.disposeAll = null;
window.dispose = null;
window.onunload = null;
}
function dispose(something, map) {
if (something == null) return;
if (something.dispose && typeof (something.dispose) == 'function') {
try { something.dispose(); } catch (e) { debugger; }
}
map.push(something);
for (var key in something) {
var value = null;
try { value = something[key]; } catch (e) { };
if (value == null || value == dispose || value == disposeAll) continue;
var processed = null;
for (var index = 0; index < map.length; index++) {
if (map[index] === value) {
processed = value;
break;
}
}
if (processed != null) continue;
var constructor = value.constructor;
if (constructor == Object || constructor == Array) {
try { dispose(value, map); } catch (e) { debugger; }
}
if (constructor == Object || constructor == Array || constructor == Function) {
try { something[key] = null; } catch (e) { debugger; }
}
}
map.pop();
}
(function() {
var previousUnloadHandler = window.onunload;
if (previousUnloadHandler == null) {
window.onunload = disposeAll;
} else {
window.onunload = function() {
previousUnloadHandler.apply(this, arguments); // <== HERE YOU MAY WANT TO HAVE AN "IF" TO MAKE SURE THE ORIGINAL UNLOAD EVENT WASN'T CANCELLED
disposeAll();
previousUnloadHandler = null;
};
}
}());
</script>
<![endif]-->
You may want to remove all "debugger;" statements if you don't feel like dealing with some occasional exceptions.