docshell/base/BaseHistory.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "BaseHistory.h"
   8 #include "nsThreadUtils.h"
   9 #include "mozilla/dom/ContentParent.h"
  10 #include "mozilla/dom/Document.h"
  11 #include "mozilla/dom/Link.h"
  12 #include "mozilla/dom/Element.h"
  13 #include "mozilla/StaticPrefs_browser.h"
  14 #include "mozilla/StaticPrefs_layout.h"
  15
  16 namespace mozilla {
  17
  18 using mozilla::dom::ContentParent;
  19 using mozilla::dom::Link;
  20
  21 BaseHistory::BaseHistory() : mTrackedURIs(kTrackedUrisInitialSize) {}
  22
  23 BaseHistory::~BaseHistory() = default;
  24
  25 static constexpr nsLiteralCString kDisallowedSchemes[] = {
  26     "about"_ns,         "blob"_ns,           "cached-favicon"_ns,
  27     "chrome"_ns,        "data"_ns,           "imap"_ns,
  28     "javascript"_ns,    "mailbox"_ns,        "news"_ns,
  29     "page-icon"_ns,     "resource"_ns,       "view-source"_ns,
  30     "moz-extension"_ns, "moz-page-thumb"_ns,
  31 };
  32
  33 bool BaseHistory::CanStore(nsIURI* aURI) {
  34   nsAutoCString scheme;
  35   if (NS_WARN_IF(NS_FAILED(aURI->GetScheme(scheme)))) {
  36     return false;
  37   }
  38
  39   if (!scheme.EqualsLiteral("http") && !scheme.EqualsLiteral("https")) {
  40     for (const nsLiteralCString& disallowed : kDisallowedSchemes) {
  41       if (scheme.Equals(disallowed)) {
  42         return false;
  43       }
  44     }
  45   }
  46
  47   nsAutoCString spec;
  48   aURI->GetSpec(spec);
  49   return spec.Length() <= StaticPrefs::browser_history_maxUrlLength();
  50 }
  51
  52 void BaseHistory::ScheduleVisitedQuery(nsIURI* aURI,
  53                                        dom::ContentParent* aForProcess) {
  54   mPendingQueries.WithEntryHandle(aURI, [&](auto&& entry) {
  55     auto& set = entry.OrInsertWith([] { return ContentParentSet(); });
  56     if (aForProcess) {
  57       set.Insert(aForProcess);
  58     }
  59   });
  60   if (mStartPendingVisitedQueriesScheduled) {
  61     return;
  62   }
  63   mStartPendingVisitedQueriesScheduled =
  64       NS_SUCCEEDED(NS_DispatchToMainThreadQueue(
  65           NS_NewRunnableFunction(
  66               "BaseHistory::StartPendingVisitedQueries",
  67               [self = RefPtr<BaseHistory>(this)] {
  68                 self->mStartPendingVisitedQueriesScheduled = false;
  69                 auto queries = std::move(self->mPendingQueries);
  70                 self->StartPendingVisitedQueries(std::move(queries));
  71                 MOZ_DIAGNOSTIC_ASSERT(self->mPendingQueries.IsEmpty());
  72               }),
  73           EventQueuePriority::Idle));
  74 }
  75
  76 void BaseHistory::CancelVisitedQueryIfPossible(nsIURI* aURI) {
  77   mPendingQueries.Remove(aURI);
  78   // TODO(bug 1591393): It could be worth to make this virtual and allow places
  79   // to stop the existing database query? Needs some measurement.
  80 }
  81
  82 void BaseHistory::RegisterVisitedCallback(nsIURI* aURI, Link* aLink) {
  83   MOZ_ASSERT(NS_IsMainThread());
  84   MOZ_ASSERT(aURI, "Must pass a non-null URI!");
  85   MOZ_ASSERT(aLink, "Must pass a non-null Link!");
  86
  87   if (!CanStore(aURI)) {
  88     aLink->VisitedQueryFinished(/* visited = */ false);
  89     return;
  90   }
  91
  92   // Obtain our array of observers for this URI.
  93   auto* const links =
  94       mTrackedURIs.WithEntryHandle(aURI, [&](auto&& entry) -> ObservingLinks* {
  95         MOZ_DIAGNOSTIC_ASSERT(!entry || !entry->mLinks.IsEmpty(),
  96                               "An empty key was kept around in our hashtable!");
  97         if (!entry) {
  98           ScheduleVisitedQuery(aURI, nullptr);
  99         }
 100
 101         return &entry.OrInsertWith([] { return ObservingLinks{}; });
 102       });
 103
 104   if (!links) {
 105     return;
 106   }
 107
 108   // Sanity check that Links are not registered more than once for a given URI.
 109   // This will not catch a case where it is registered for two different URIs.
 110   MOZ_DIAGNOSTIC_ASSERT(!links->mLinks.Contains(aLink),
 111                         "Already tracking this Link object!");
 112
 113   links->mLinks.AppendElement(aLink);
 114
 115   // If this link has already been queried and we should notify, do so now.
 116   switch (links->mStatus) {
 117     case VisitedStatus::Unknown:
 118       break;
 119     case VisitedStatus::Unvisited:
 120       [[fallthrough]];
 121     case VisitedStatus::Visited:
 122       aLink->VisitedQueryFinished(links->mStatus == VisitedStatus::Visited);
 123       break;
 124   }
 125 }
 126
 127 void BaseHistory::UnregisterVisitedCallback(nsIURI* aURI, Link* aLink) {
 128   MOZ_ASSERT(NS_IsMainThread());
 129   MOZ_ASSERT(aURI, "Must pass a non-null URI!");
 130   MOZ_ASSERT(aLink, "Must pass a non-null Link object!");
 131
 132   // Get the array, and remove the item from it.
 133   auto entry = mTrackedURIs.Lookup(aURI);
 134   if (!entry) {
 135     MOZ_ASSERT(!CanStore(aURI),
 136                "Trying to unregister URI that wasn't registered, "
 137                "and that could be visited!");
 138     return;
 139   }
 140
 141   ObserverArray& observers = entry->mLinks;
 142   if (!observers.RemoveElement(aLink)) {
 143     MOZ_ASSERT_UNREACHABLE("Trying to unregister node that wasn't registered!");
 144     return;
 145   }
 146
 147   // If the array is now empty, we should remove it from the hashtable.
 148   if (observers.IsEmpty()) {
 149     entry.Remove();
 150     CancelVisitedQueryIfPossible(aURI);
 151   }
 152 }
 153
 154 void BaseHistory::NotifyVisited(
 155     nsIURI* aURI, VisitedStatus aStatus,
 156     const ContentParentSet* aListOfProcessesToNotify) {
 157   MOZ_ASSERT(NS_IsMainThread());
 158   MOZ_ASSERT(aStatus != VisitedStatus::Unknown);
 159
 160   NotifyVisitedInThisProcess(aURI, aStatus);
 161   if (XRE_IsParentProcess()) {
 162     NotifyVisitedFromParent(aURI, aStatus, aListOfProcessesToNotify);
 163   }
 164 }
 165
 166 void BaseHistory::NotifyVisitedInThisProcess(nsIURI* aURI,
 167                                              VisitedStatus aStatus) {
 168   if (NS_WARN_IF(!aURI)) {
 169     return;
 170   }
 171
 172   auto entry = mTrackedURIs.Lookup(aURI);
 173   if (!entry) {
 174     // If we have no observers for this URI, we have nothing to notify about.
 175     return;
 176   }
 177
 178   ObservingLinks& links = entry.Data();
 179   links.mStatus = aStatus;
 180
 181   // If we have a key, it should have at least one observer.
 182   MOZ_ASSERT(!links.mLinks.IsEmpty());
 183
 184   // Dispatch an event to each document which has a Link observing this URL.
 185   // These will fire asynchronously in the correct DocGroup.
 186
 187   const bool visited = aStatus == VisitedStatus::Visited;
 188   for (Link* link : links.mLinks.BackwardRange()) {
 189     link->VisitedQueryFinished(visited);
 190   }
 191 }
 192
 193 void BaseHistory::SendPendingVisitedResultsToChildProcesses() {
 194   MOZ_ASSERT(!mPendingResults.IsEmpty());
 195
 196   mStartPendingResultsScheduled = false;
 197
 198   auto results = std::move(mPendingResults);
 199   MOZ_ASSERT(mPendingResults.IsEmpty());
 200
 201   nsTArray<ContentParent*> cplist;
 202   nsTArray<dom::VisitedQueryResult> resultsForProcess;
 203   ContentParent::GetAll(cplist);
 204   for (ContentParent* cp : cplist) {
 205     resultsForProcess.ClearAndRetainStorage();
 206     for (auto& result : results) {
 207       if (result.mProcessesToNotify.IsEmpty() ||
 208           result.mProcessesToNotify.Contains(cp)) {
 209         resultsForProcess.AppendElement(result.mResult);
 210       }
 211     }
 212     if (!resultsForProcess.IsEmpty()) {
 213       Unused << NS_WARN_IF(!cp->SendNotifyVisited(resultsForProcess));
 214     }
 215   }
 216 }
 217
 218 void BaseHistory::NotifyVisitedFromParent(
 219     nsIURI* aURI, VisitedStatus aStatus,
 220     const ContentParentSet* aListOfProcessesToNotify) {
 221   MOZ_ASSERT(XRE_IsParentProcess());
 222
 223   if (aListOfProcessesToNotify && aListOfProcessesToNotify->IsEmpty()) {
 224     return;
 225   }
 226
 227   auto& result = *mPendingResults.AppendElement();
 228   result.mResult.visited() = aStatus == VisitedStatus::Visited;
 229   result.mResult.uri() = aURI;
 230   if (aListOfProcessesToNotify) {
 231     for (auto* entry : *aListOfProcessesToNotify) {
 232       result.mProcessesToNotify.Insert(entry);
 233     }
 234   }
 235
 236   if (mStartPendingResultsScheduled) {
 237     return;
 238   }
 239
 240   mStartPendingResultsScheduled = NS_SUCCEEDED(NS_DispatchToMainThreadQueue(
 241       NewRunnableMethod(
 242           "BaseHistory::SendPendingVisitedResultsToChildProcesses", this,
 243           &BaseHistory::SendPendingVisitedResultsToChildProcesses),
 244       EventQueuePriority::Idle));
 245 }
 246
 247 }  // namespace mozilla