gecko-dev/dom/html/nsHTMLDNSPrefetch.cpp
Ralph Giles 0aa89fc17e Bug 1269475 - Fix uninitialized variable warning. r=jdm
Initialize rv at declaration to handle the !hrefURI case.

MozReview-Commit-ID: 65tEvO4hNEA
2016-05-02 16:47:36 -07:00

479 lines
14 KiB
C++

/* -*- 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 "base/basictypes.h"
#include "mozilla/net/NeckoCommon.h"
#include "mozilla/net/NeckoChild.h"
#include "nsURLHelper.h"
#include "nsHTMLDNSPrefetch.h"
#include "nsCOMPtr.h"
#include "nsString.h"
#include "nsNetUtil.h"
#include "nsNetCID.h"
#include "nsIProtocolHandler.h"
#include "nsIDNSListener.h"
#include "nsIWebProgressListener.h"
#include "nsIWebProgress.h"
#include "nsCURILoader.h"
#include "nsIDNSRecord.h"
#include "nsIDNSService.h"
#include "nsICancelable.h"
#include "nsGkAtoms.h"
#include "nsIDocument.h"
#include "nsThreadUtils.h"
#include "nsITimer.h"
#include "nsIObserverService.h"
#include "mozilla/dom/Link.h"
#include "mozilla/Preferences.h"
using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::net;
static NS_DEFINE_CID(kDNSServiceCID, NS_DNSSERVICE_CID);
bool sDisablePrefetchHTTPSPref;
static bool sInitialized = false;
static nsIDNSService *sDNSService = nullptr;
static nsHTMLDNSPrefetch::nsDeferrals *sPrefetches = nullptr;
static nsHTMLDNSPrefetch::nsListener *sDNSListener = nullptr;
nsresult
nsHTMLDNSPrefetch::Initialize()
{
if (sInitialized) {
NS_WARNING("Initialize() called twice");
return NS_OK;
}
sPrefetches = new nsHTMLDNSPrefetch::nsDeferrals();
NS_ADDREF(sPrefetches);
sDNSListener = new nsHTMLDNSPrefetch::nsListener();
NS_ADDREF(sDNSListener);
sPrefetches->Activate();
Preferences::AddBoolVarCache(&sDisablePrefetchHTTPSPref,
"network.dns.disablePrefetchFromHTTPS");
// Default is false, so we need an explicit call to prime the cache.
sDisablePrefetchHTTPSPref =
Preferences::GetBool("network.dns.disablePrefetchFromHTTPS", true);
NS_IF_RELEASE(sDNSService);
nsresult rv;
rv = CallGetService(kDNSServiceCID, &sDNSService);
if (NS_FAILED(rv)) return rv;
if (IsNeckoChild())
NeckoChild::InitNeckoChild();
sInitialized = true;
return NS_OK;
}
nsresult
nsHTMLDNSPrefetch::Shutdown()
{
if (!sInitialized) {
NS_WARNING("Not Initialized");
return NS_OK;
}
sInitialized = false;
NS_IF_RELEASE(sDNSService);
NS_IF_RELEASE(sPrefetches);
NS_IF_RELEASE(sDNSListener);
return NS_OK;
}
bool
nsHTMLDNSPrefetch::IsAllowed (nsIDocument *aDocument)
{
if (NS_IsAppOffline(aDocument->NodePrincipal())) {
return false;
}
// There is no need to do prefetch on non UI scenarios such as XMLHttpRequest.
return aDocument->IsDNSPrefetchAllowed() && aDocument->GetWindow();
}
nsresult
nsHTMLDNSPrefetch::Prefetch(Link *aElement, uint16_t flags)
{
if (!(sInitialized && sPrefetches && sDNSService && sDNSListener))
return NS_ERROR_NOT_AVAILABLE;
return sPrefetches->Add(flags, aElement);
}
nsresult
nsHTMLDNSPrefetch::PrefetchLow(Link *aElement)
{
return Prefetch(aElement, nsIDNSService::RESOLVE_PRIORITY_LOW);
}
nsresult
nsHTMLDNSPrefetch::PrefetchMedium(Link *aElement)
{
return Prefetch(aElement, nsIDNSService::RESOLVE_PRIORITY_MEDIUM);
}
nsresult
nsHTMLDNSPrefetch::PrefetchHigh(Link *aElement)
{
return Prefetch(aElement, 0);
}
nsresult
nsHTMLDNSPrefetch::Prefetch(const nsAString &hostname, uint16_t flags)
{
if (IsNeckoChild()) {
// We need to check IsEmpty() because net_IsValidHostName()
// considers empty strings to be valid hostnames
if (!hostname.IsEmpty() &&
net_IsValidHostName(NS_ConvertUTF16toUTF8(hostname))) {
// during shutdown gNeckoChild might be null
if (gNeckoChild) {
gNeckoChild->SendHTMLDNSPrefetch(nsAutoString(hostname), flags);
}
}
return NS_OK;
}
if (!(sInitialized && sDNSService && sPrefetches && sDNSListener))
return NS_ERROR_NOT_AVAILABLE;
nsCOMPtr<nsICancelable> tmpOutstanding;
return sDNSService->AsyncResolve(NS_ConvertUTF16toUTF8(hostname),
flags | nsIDNSService::RESOLVE_SPECULATE,
sDNSListener, nullptr,
getter_AddRefs(tmpOutstanding));
}
nsresult
nsHTMLDNSPrefetch::PrefetchLow(const nsAString &hostname)
{
return Prefetch(hostname, nsIDNSService::RESOLVE_PRIORITY_LOW);
}
nsresult
nsHTMLDNSPrefetch::PrefetchMedium(const nsAString &hostname)
{
return Prefetch(hostname, nsIDNSService::RESOLVE_PRIORITY_MEDIUM);
}
nsresult
nsHTMLDNSPrefetch::PrefetchHigh(const nsAString &hostname)
{
return Prefetch(hostname, 0);
}
nsresult
nsHTMLDNSPrefetch::CancelPrefetch(Link *aElement,
uint16_t flags,
nsresult aReason)
{
if (!(sInitialized && sPrefetches && sDNSService && sDNSListener))
return NS_ERROR_NOT_AVAILABLE;
nsAutoString hostname;
aElement->GetHostname(hostname);
return CancelPrefetch(hostname, flags, aReason);
}
nsresult
nsHTMLDNSPrefetch::CancelPrefetch(const nsAString &hostname,
uint16_t flags,
nsresult aReason)
{
// Forward this request to Necko Parent if we're a child process
if (IsNeckoChild()) {
// We need to check IsEmpty() because net_IsValidHostName()
// considers empty strings to be valid hostnames
if (!hostname.IsEmpty() &&
net_IsValidHostName(NS_ConvertUTF16toUTF8(hostname))) {
// during shutdown gNeckoChild might be null
if (gNeckoChild) {
gNeckoChild->SendCancelHTMLDNSPrefetch(nsString(hostname), flags,
aReason);
}
}
return NS_OK;
}
if (!(sInitialized && sDNSService && sPrefetches && sDNSListener))
return NS_ERROR_NOT_AVAILABLE;
// Forward cancellation to DNS service
return sDNSService->CancelAsyncResolve(NS_ConvertUTF16toUTF8(hostname),
flags
| nsIDNSService::RESOLVE_SPECULATE,
sDNSListener, aReason);
}
nsresult
nsHTMLDNSPrefetch::CancelPrefetchLow(Link *aElement, nsresult aReason)
{
return CancelPrefetch(aElement, nsIDNSService::RESOLVE_PRIORITY_LOW,
aReason);
}
nsresult
nsHTMLDNSPrefetch::CancelPrefetchLow(const nsAString &hostname, nsresult aReason)
{
return CancelPrefetch(hostname, nsIDNSService::RESOLVE_PRIORITY_LOW,
aReason);
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////
NS_IMPL_ISUPPORTS(nsHTMLDNSPrefetch::nsListener,
nsIDNSListener)
NS_IMETHODIMP
nsHTMLDNSPrefetch::nsListener::OnLookupComplete(nsICancelable *request,
nsIDNSRecord *rec,
nsresult status)
{
return NS_OK;
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////
nsHTMLDNSPrefetch::nsDeferrals::nsDeferrals()
: mHead(0),
mTail(0),
mActiveLoaderCount(0),
mTimerArmed(false)
{
mTimer = do_CreateInstance("@mozilla.org/timer;1");
}
nsHTMLDNSPrefetch::nsDeferrals::~nsDeferrals()
{
if (mTimerArmed) {
mTimerArmed = false;
mTimer->Cancel();
}
Flush();
}
NS_IMPL_ISUPPORTS(nsHTMLDNSPrefetch::nsDeferrals,
nsIWebProgressListener,
nsISupportsWeakReference,
nsIObserver)
void
nsHTMLDNSPrefetch::nsDeferrals::Flush()
{
while (mHead != mTail) {
mEntries[mTail].mElement = nullptr;
mTail = (mTail + 1) & sMaxDeferredMask;
}
}
nsresult
nsHTMLDNSPrefetch::nsDeferrals::Add(uint16_t flags, Link *aElement)
{
// The FIFO has no lock, so it can only be accessed on main thread
NS_ASSERTION(NS_IsMainThread(), "nsDeferrals::Add must be on main thread");
aElement->OnDNSPrefetchDeferred();
if (((mHead + 1) & sMaxDeferredMask) == mTail)
return NS_ERROR_DNS_LOOKUP_QUEUE_FULL;
mEntries[mHead].mFlags = flags;
mEntries[mHead].mElement = do_GetWeakReference(aElement);
mHead = (mHead + 1) & sMaxDeferredMask;
if (!mActiveLoaderCount && !mTimerArmed && mTimer) {
mTimerArmed = true;
mTimer->InitWithFuncCallback(Tick, this, 2000, nsITimer::TYPE_ONE_SHOT);
}
return NS_OK;
}
void
nsHTMLDNSPrefetch::nsDeferrals::SubmitQueue()
{
NS_ASSERTION(NS_IsMainThread(), "nsDeferrals::SubmitQueue must be on main thread");
nsCString hostName;
if (!sDNSService) return;
while (mHead != mTail) {
nsCOMPtr<nsIContent> content = do_QueryReferent(mEntries[mTail].mElement);
if (content) {
nsCOMPtr<Link> link = do_QueryInterface(content);
// Only prefetch here if request was deferred and deferral not cancelled
if (link && link->HasDeferredDNSPrefetchRequest()) {
nsCOMPtr<nsIURI> hrefURI(link ? link->GetURI() : nullptr);
bool isLocalResource = false;
nsresult rv = NS_OK;
hostName.Truncate();
if (hrefURI) {
hrefURI->GetAsciiHost(hostName);
rv = NS_URIChainHasFlags(hrefURI,
nsIProtocolHandler::URI_IS_LOCAL_RESOURCE,
&isLocalResource);
}
if (!hostName.IsEmpty() && NS_SUCCEEDED(rv) && !isLocalResource) {
if (IsNeckoChild()) {
// during shutdown gNeckoChild might be null
if (gNeckoChild) {
gNeckoChild->SendHTMLDNSPrefetch(NS_ConvertUTF8toUTF16(hostName),
mEntries[mTail].mFlags);
}
} else {
nsCOMPtr<nsICancelable> tmpOutstanding;
rv = sDNSService->AsyncResolve(hostName,
mEntries[mTail].mFlags
| nsIDNSService::RESOLVE_SPECULATE,
sDNSListener, nullptr,
getter_AddRefs(tmpOutstanding));
// Tell link that deferred prefetch was requested
if (NS_SUCCEEDED(rv))
link->OnDNSPrefetchRequested();
}
}
}
}
mEntries[mTail].mElement = nullptr;
mTail = (mTail + 1) & sMaxDeferredMask;
}
if (mTimerArmed) {
mTimerArmed = false;
mTimer->Cancel();
}
}
void
nsHTMLDNSPrefetch::nsDeferrals::Activate()
{
// Register as an observer for the document loader
nsCOMPtr<nsIWebProgress> progress =
do_GetService(NS_DOCUMENTLOADER_SERVICE_CONTRACTID);
if (progress)
progress->AddProgressListener(this, nsIWebProgress::NOTIFY_STATE_DOCUMENT);
// Register as an observer for xpcom shutdown events so we can drop any element refs
nsCOMPtr<nsIObserverService> observerService =
mozilla::services::GetObserverService();
if (observerService)
observerService->AddObserver(this, "xpcom-shutdown", true);
}
// nsITimer related method
void
nsHTMLDNSPrefetch::nsDeferrals::Tick(nsITimer *aTimer, void *aClosure)
{
nsHTMLDNSPrefetch::nsDeferrals *self = (nsHTMLDNSPrefetch::nsDeferrals *) aClosure;
NS_ASSERTION(NS_IsMainThread(), "nsDeferrals::Tick must be on main thread");
NS_ASSERTION(self->mTimerArmed, "Timer is not armed");
self->mTimerArmed = false;
// If the queue is not submitted here because there are outstanding pages being loaded,
// there is no need to rearm the timer as the queue will be submtited when those
// loads complete.
if (!self->mActiveLoaderCount)
self->SubmitQueue();
}
//////////// nsIWebProgressListener methods
NS_IMETHODIMP
nsHTMLDNSPrefetch::nsDeferrals::OnStateChange(nsIWebProgress* aWebProgress,
nsIRequest *aRequest,
uint32_t progressStateFlags,
nsresult aStatus)
{
// The FIFO has no lock, so it can only be accessed on main thread
NS_ASSERTION(NS_IsMainThread(), "nsDeferrals::OnStateChange must be on main thread");
if (progressStateFlags & STATE_IS_DOCUMENT) {
if (progressStateFlags & STATE_STOP) {
// Initialization may have missed a STATE_START notification, so do
// not go negative
if (mActiveLoaderCount)
mActiveLoaderCount--;
if (!mActiveLoaderCount)
SubmitQueue();
}
else if (progressStateFlags & STATE_START)
mActiveLoaderCount++;
}
return NS_OK;
}
NS_IMETHODIMP
nsHTMLDNSPrefetch::nsDeferrals::OnProgressChange(nsIWebProgress *aProgress,
nsIRequest *aRequest,
int32_t curSelfProgress,
int32_t maxSelfProgress,
int32_t curTotalProgress,
int32_t maxTotalProgress)
{
return NS_OK;
}
NS_IMETHODIMP
nsHTMLDNSPrefetch::nsDeferrals::OnLocationChange(nsIWebProgress* aWebProgress,
nsIRequest* aRequest,
nsIURI *location,
uint32_t aFlags)
{
return NS_OK;
}
NS_IMETHODIMP
nsHTMLDNSPrefetch::nsDeferrals::OnStatusChange(nsIWebProgress* aWebProgress,
nsIRequest* aRequest,
nsresult aStatus,
const char16_t* aMessage)
{
return NS_OK;
}
NS_IMETHODIMP
nsHTMLDNSPrefetch::nsDeferrals::OnSecurityChange(nsIWebProgress *aWebProgress,
nsIRequest *aRequest,
uint32_t state)
{
return NS_OK;
}
//////////// nsIObserver method
NS_IMETHODIMP
nsHTMLDNSPrefetch::nsDeferrals::Observe(nsISupports *subject,
const char *topic,
const char16_t *data)
{
if (!strcmp(topic, "xpcom-shutdown"))
Flush();
return NS_OK;
}