Source code

Revision control

Other Tools

/* -*- 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 "BaseHistory.h"
#include "nsThreadUtils.h"
#include "mozilla/dom/ContentParent.h"
#include "mozilla/dom/Document.h"
#include "mozilla/dom/Link.h"
#include "mozilla/dom/Element.h"
#include "mozilla/StaticPrefs_layout.h"
namespace mozilla {
using mozilla::dom::ContentParent;
using mozilla::dom::Document;
using mozilla::dom::Element;
using mozilla::dom::Link;
BaseHistory::BaseHistory() : mTrackedURIs(kTrackedUrisInitialSize) {}
BaseHistory::~BaseHistory() = default;
void BaseHistory::ScheduleVisitedQuery(nsIURI* aURI) {
mPendingQueries.PutEntry(aURI);
if (mStartPendingVisitedQueriesScheduled) {
return;
}
mStartPendingVisitedQueriesScheduled =
NS_SUCCEEDED(NS_DispatchToMainThreadQueue(
NS_NewRunnableFunction(
"BaseHistory::StartPendingVisitedQueries",
[self = RefPtr<BaseHistory>(this)] {
self->mStartPendingVisitedQueriesScheduled = false;
auto queries = std::move(self->mPendingQueries);
self->StartPendingVisitedQueries(queries);
MOZ_DIAGNOSTIC_ASSERT(self->mPendingQueries.IsEmpty());
}),
EventQueuePriority::Idle));
}
void BaseHistory::CancelVisitedQueryIfPossible(nsIURI* aURI) {
mPendingQueries.RemoveEntry(aURI);
// TODO(bug 1591393): It could be worth to make this virtual and allow places
// to stop the existing database query? Needs some measurement.
}
void BaseHistory::RegisterVisitedCallback(nsIURI* aURI, Link* aLink) {
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(aURI, "Must pass a non-null URI!");
if (XRE_IsContentProcess()) {
MOZ_ASSERT(aLink, "Must pass a non-null Link!");
}
// Obtain our array of observers for this URI.
auto entry = mTrackedURIs.LookupForAdd(aURI);
MOZ_DIAGNOSTIC_ASSERT(!entry || !entry.Data().mLinks.IsEmpty(),
"An empty key was kept around in our hashtable!");
if (!entry) {
ScheduleVisitedQuery(aURI);
}
if (!aLink) {
// In IPC builds, we are passed a nullptr Link from
// ContentParent::RecvStartVisitedQuery. All of our code after this point
// assumes aLink is non-nullptr, so we have to return now.
MOZ_DIAGNOSTIC_ASSERT(XRE_IsParentProcess(),
"We should only ever get a null Link "
"in the parent process!");
// We don't want to remove if we're tracking other links.
if (!entry) {
entry.OrRemove();
}
return;
}
ObservingLinks& links = entry.OrInsert([] { return ObservingLinks{}; });
// Sanity check that Links are not registered more than once for a given URI.
// This will not catch a case where it is registered for two different URIs.
MOZ_DIAGNOSTIC_ASSERT(!links.mLinks.Contains(aLink),
"Already tracking this Link object!");
// FIXME(emilio): We should consider changing this (see the entry.Remove()
// call in NotifyVisitedInThisProcess).
MOZ_DIAGNOSTIC_ASSERT(links.mStatus != VisitedStatus::Visited,
"We don't keep tracking known-visited links");
links.mLinks.AppendElement(aLink);
// If this link has already been queried and we should notify, do so now.
switch (links.mStatus) {
case VisitedStatus::Unknown:
break;
case VisitedStatus::Unvisited:
if (!StaticPrefs::layout_css_notify_of_unvisited()) {
break;
}
[[fallthrough]];
case VisitedStatus::Visited:
aLink->VisitedQueryFinished(links.mStatus == VisitedStatus::Visited);
break;
}
}
void BaseHistory::UnregisterVisitedCallback(nsIURI* aURI, Link* aLink) {
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(aURI, "Must pass a non-null URI!");
MOZ_ASSERT(aLink, "Must pass a non-null Link object!");
// Get the array, and remove the item from it.
auto entry = mTrackedURIs.Lookup(aURI);
if (!entry) {
MOZ_ASSERT_UNREACHABLE("Trying to unregister URI that wasn't registered!");
return;
}
ObserverArray& observers = entry.Data().mLinks;
if (!observers.RemoveElement(aLink)) {
MOZ_ASSERT_UNREACHABLE("Trying to unregister node that wasn't registered!");
return;
}
// If the array is now empty, we should remove it from the hashtable.
if (observers.IsEmpty()) {
entry.Remove();
CancelVisitedQueryIfPossible(aURI);
}
}
void BaseHistory::NotifyVisited(nsIURI* aURI, VisitedStatus aStatus) {
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(aStatus != VisitedStatus::Unknown);
if (aStatus == VisitedStatus::Unvisited &&
!StaticPrefs::layout_css_notify_of_unvisited()) {
return;
}
NotifyVisitedInThisProcess(aURI, aStatus);
if (XRE_IsParentProcess()) {
NotifyVisitedFromParent(aURI, aStatus);
}
}
void BaseHistory::NotifyVisitedInThisProcess(nsIURI* aURI,
VisitedStatus aStatus) {
if (NS_WARN_IF(!aURI)) {
return;
}
auto entry = mTrackedURIs.Lookup(aURI);
if (!entry) {
// If we have no observers for this URI, we have nothing to notify about.
return;
}
ObservingLinks& links = entry.Data();
links.mStatus = aStatus;
// If we have a key, it should have at least one observer.
MOZ_ASSERT(!links.mLinks.IsEmpty());
// Dispatch an event to each document which has a Link observing this URL.
// These will fire asynchronously in the correct DocGroup.
const bool visited = aStatus == VisitedStatus::Visited;
for (Link* link : links.mLinks.BackwardRange()) {
link->VisitedQueryFinished(visited);
}
// We never go from visited -> unvisited.
//
// FIXME(emilio): It seems unfortunate to remove a link to a visited uri and
// then re-add it to the document to trigger a new visited query. It shouldn't
// if we keep track of mStatus.
if (visited) {
entry.Remove();
}
}
void BaseHistory::SendPendingVisitedResultsToChildProcesses() {
MOZ_ASSERT(!mPendingResults.IsEmpty());
mStartPendingResultsScheduled = false;
auto results = std::move(mPendingResults);
MOZ_ASSERT(mPendingResults.IsEmpty());
nsTArray<ContentParent*> cplist;
ContentParent::GetAll(cplist);
for (ContentParent* cp : cplist) {
Unused << NS_WARN_IF(!cp->SendNotifyVisited(results));
}
}
void BaseHistory::NotifyVisitedFromParent(nsIURI* aURI, VisitedStatus aStatus) {
MOZ_ASSERT(XRE_IsParentProcess());
auto& result = *mPendingResults.AppendElement();
result.visited() = aStatus == VisitedStatus::Visited;
result.uri() = aURI;
if (mStartPendingResultsScheduled) {
return;
}
mStartPendingResultsScheduled = NS_SUCCEEDED(NS_DispatchToMainThreadQueue(
NewRunnableMethod(
"BaseHistory::SendPendingVisitedResultsToChildProcesses", this,
&BaseHistory::SendPendingVisitedResultsToChildProcesses),
EventQueuePriority::Idle));
}
} // namespace mozilla