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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "mozilla/SimpleEnumerator.h"
#include "nsICategoryManager.h"
#include "nsISupportsPrimitives.h"
#include "nsXPCOMCID.h"
#include "nsCategoryCache.h"
using mozilla::SimpleEnumerator;
nsCategoryObserver::nsCategoryObserver(const nsACString& aCategory)
: mCategory(aCategory),
mCallback(nullptr),
mClosure(nullptr),
mObserversRemoved(false) {
MOZ_ASSERT(NS_IsMainThread());
// 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;
}
for (auto& categoryEntry : SimpleEnumerator<nsICategoryEntry>(enumerator)) {
nsAutoCString entryValue;
categoryEntry->GetValue(entryValue);
if (nsCOMPtr<nsISupports> service = do_GetService(entryValue.get())) {
nsAutoCString entryName;
categoryEntry->GetEntry(entryName);
mHash.InsertOrUpdate(entryName, service);
}
}
// 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);
}
}
nsCategoryObserver::~nsCategoryObserver() = default;
NS_IMPL_ISUPPORTS(nsCategoryObserver, nsIObserver)
void nsCategoryObserver::ListenerDied() {
MOZ_ASSERT(NS_IsMainThread());
RemoveObservers();
mCallback = nullptr;
mClosure = nullptr;
}
void nsCategoryObserver::SetListener(void(aCallback)(void*), void* aClosure) {
MOZ_ASSERT(NS_IsMainThread());
mCallback = aCallback;
mClosure = aClosure;
}
void nsCategoryObserver::RemoveObservers() {
MOZ_ASSERT(NS_IsMainThread());
if (mObserversRemoved) {
return;
}
if (mCallback) {
mCallback(mClosure);
}
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 char16_t* aData) {
MOZ_ASSERT(NS_IsMainThread());
if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
mHash.Clear();
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.GetWeak(str)) {
return NS_OK;
}
nsCOMPtr<nsICategoryManager> catMan =
do_GetService(NS_CATEGORYMANAGER_CONTRACTID);
if (!catMan) {
return NS_OK;
}
nsCString entryValue;
catMan->GetCategoryEntry(mCategory, str, entryValue);
nsCOMPtr<nsISupports> service = do_GetService(entryValue.get());
if (service) {
mHash.InsertOrUpdate(str, service);
}
if (mCallback) {
mCallback(mClosure);
}
} else if (strcmp(aTopic, NS_XPCOM_CATEGORY_ENTRY_REMOVED_OBSERVER_ID) == 0) {
mHash.Remove(str);
if (mCallback) {
mCallback(mClosure);
}
} else if (strcmp(aTopic, NS_XPCOM_CATEGORY_CLEARED_OBSERVER_ID) == 0) {
mHash.Clear();
if (mCallback) {
mCallback(mClosure);
}
}
return NS_OK;
}