gecko-dev/xpcom/glue/nsCategoryCache.cpp

151 lines
4.6 KiB
C++

/* vim:set st=2 sts=2 ts=2 et cin: */
/* 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/. */
#include "nsIObserverService.h"
#include "mozilla/Services.h"
#include "nsISupportsPrimitives.h"
#include "nsXPCOMCID.h"
#include "nsCategoryCache.h"
nsCategoryObserver::nsCategoryObserver(const char* aCategory,
nsCategoryListener* aListener)
: mListener(nullptr), mCategory(aCategory), mObserversRemoved(false)
{
mHash.Init();
mListener = aListener;
// First, enumerate the currently existing entries
nsCOMPtr<nsICategoryManager> catMan =
do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
if (!catMan)
return;
nsCOMPtr<nsISimpleEnumerator> enumerator;
nsresult rv = catMan->EnumerateCategory(aCategory,
getter_AddRefs(enumerator));
if (NS_FAILED(rv))
return;
nsTArray<nsCString> entries;
nsCOMPtr<nsISupports> entry;
while (NS_SUCCEEDED(enumerator->GetNext(getter_AddRefs(entry)))) {
nsCOMPtr<nsISupportsCString> entryName = do_QueryInterface(entry, &rv);
if (NS_SUCCEEDED(rv)) {
nsAutoCString categoryEntry;
rv = entryName->GetData(categoryEntry);
nsCString entryValue;
catMan->GetCategoryEntry(aCategory,
categoryEntry.get(),
getter_Copies(entryValue));
if (NS_SUCCEEDED(rv)) {
mHash.Put(categoryEntry, entryValue);
entries.AppendElement(entryValue);
}
}
}
// Now, listen for changes
nsCOMPtr<nsIObserverService> serv =
mozilla::services::GetObserverService();
if (serv) {
serv->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
serv->AddObserver(this, NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID, false);
serv->AddObserver(this, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID, false);
serv->AddObserver(this, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID, false);
}
for (int32_t i = entries.Length() - 1; i >= 0; --i)
mListener->EntryAdded(entries[i]);
}
nsCategoryObserver::~nsCategoryObserver() {
}
NS_IMPL_ISUPPORTS1(nsCategoryObserver, nsIObserver)
void
nsCategoryObserver::ListenerDied() {
mListener = nullptr;
RemoveObservers();
}
NS_HIDDEN_(void)
nsCategoryObserver::RemoveObservers() {
if (mObserversRemoved)
return;
mObserversRemoved = true;
nsCOMPtr<nsIObserverService> obsSvc =
mozilla::services::GetObserverService();
if (obsSvc) {
obsSvc->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
obsSvc->RemoveObserver(this, NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID);
obsSvc->RemoveObserver(this, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID);
obsSvc->RemoveObserver(this, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID);
}
}
NS_IMETHODIMP
nsCategoryObserver::Observe(nsISupports* aSubject, const char* aTopic,
const PRUnichar* aData) {
if (!mListener)
return NS_OK;
if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
mHash.Clear();
mListener->CategoryCleared();
RemoveObservers();
return NS_OK;
}
if (!aData ||
!nsDependentString(aData).Equals(NS_ConvertASCIItoUTF16(mCategory)))
return NS_OK;
nsAutoCString str;
nsCOMPtr<nsISupportsCString> strWrapper(do_QueryInterface(aSubject));
if (strWrapper)
strWrapper->GetData(str);
if (strcmp(aTopic, NS_XPCOM_CATEGORY_ENTRY_ADDED_OBSERVER_ID) == 0) {
// We may get an add notification even when we already have an entry. This
// is due to the notification happening asynchronously, so if the entry gets
// added and an nsCategoryObserver gets instantiated before events get
// processed, we'd get the notification for an existing entry.
// Do nothing in that case.
if (mHash.Get(str, nullptr))
return NS_OK;
nsCOMPtr<nsICategoryManager> catMan =
do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
if (!catMan)
return NS_OK;
nsCString entryValue;
catMan->GetCategoryEntry(mCategory.get(),
str.get(),
getter_Copies(entryValue));
mHash.Put(str, entryValue);
mListener->EntryAdded(entryValue);
} else if (strcmp(aTopic, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID) == 0) {
nsAutoCString val;
if (mHash.Get(str, &val)) {
mHash.Remove(str);
mListener->EntryRemoved(val);
}
} else if (strcmp(aTopic, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID) == 0) {
mHash.Clear();
mListener->CategoryCleared();
}
return NS_OK;
}