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Diffstat (limited to 'docshell/shistory/nsSHistory.cpp')
| -rw-r--r-- | docshell/shistory/nsSHistory.cpp | 1977 |
1 files changed, 1977 insertions, 0 deletions
diff --git a/docshell/shistory/nsSHistory.cpp b/docshell/shistory/nsSHistory.cpp new file mode 100644 index 0000000000..1581cd55c2 --- /dev/null +++ b/docshell/shistory/nsSHistory.cpp @@ -0,0 +1,1977 @@ +/* -*- 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 "nsSHistory.h" + +#include <algorithm> + +#include "nsContentUtils.h" +#include "nsCOMArray.h" +#include "nsComponentManagerUtils.h" +#include "nsDocShell.h" +#include "nsIContentViewer.h" +#include "nsIDocShell.h" +#include "nsDocShellLoadState.h" +#include "nsIDocShellTreeItem.h" +#include "nsILayoutHistoryState.h" +#include "nsIObserverService.h" +#include "nsISHEntry.h" +#include "nsISHistoryListener.h" +#include "nsIURI.h" +#include "nsIXULRuntime.h" +#include "nsNetUtil.h" +#include "nsSHEntry.h" +#include "SessionHistoryEntry.h" +#include "nsTArray.h" +#include "prsystem.h" + +#include "mozilla/Attributes.h" +#include "mozilla/dom/CanonicalBrowsingContext.h" +#include "mozilla/dom/ContentParent.h" +#include "mozilla/LinkedList.h" +#include "mozilla/MathAlgorithms.h" +#include "mozilla/Preferences.h" +#include "mozilla/Services.h" +#include "mozilla/StaticPtr.h" +#include "mozilla/dom/CanonicalBrowsingContext.h" +#include "nsIWebNavigation.h" +#include "nsDocShellLoadTypes.h" +#include "base/process.h" + +using namespace mozilla; +using namespace mozilla::dom; + +#define PREF_SHISTORY_SIZE "browser.sessionhistory.max_entries" +#define PREF_SHISTORY_MAX_TOTAL_VIEWERS \ + "browser.sessionhistory.max_total_viewers" +#define CONTENT_VIEWER_TIMEOUT_SECONDS \ + "browser.sessionhistory.contentViewerTimeout" + +// Default this to time out unused content viewers after 30 minutes +#define CONTENT_VIEWER_TIMEOUT_SECONDS_DEFAULT (30 * 60) + +static const char* kObservedPrefs[] = { + PREF_SHISTORY_SIZE, PREF_SHISTORY_MAX_TOTAL_VIEWERS, nullptr}; + +static int32_t gHistoryMaxSize = 50; +// List of all SHistory objects, used for content viewer cache eviction +static LinkedList<nsSHistory> gSHistoryList; +// Max viewers allowed total, across all SHistory objects - negative default +// means we will calculate how many viewers to cache based on total memory +int32_t nsSHistory::sHistoryMaxTotalViewers = -1; + +// A counter that is used to be able to know the order in which +// entries were touched, so that we can evict older entries first. +static uint32_t gTouchCounter = 0; + +extern mozilla::LazyLogModule gSHLog; + +LazyLogModule gSHistoryLog("nsSHistory"); + +#define LOG(format) MOZ_LOG(gSHistoryLog, mozilla::LogLevel::Debug, format) + +extern mozilla::LazyLogModule gPageCacheLog; + +// This macro makes it easier to print a log message which includes a URI's +// spec. Example use: +// +// nsIURI *uri = [...]; +// LOG_SPEC(("The URI is %s.", _spec), uri); +// +#define LOG_SPEC(format, uri) \ + PR_BEGIN_MACRO \ + if (MOZ_LOG_TEST(gSHistoryLog, LogLevel::Debug)) { \ + nsAutoCString _specStr("(null)"_ns); \ + if (uri) { \ + _specStr = uri->GetSpecOrDefault(); \ + } \ + const char* _spec = _specStr.get(); \ + LOG(format); \ + } \ + PR_END_MACRO + +// This macro makes it easy to log a message including an SHEntry's URI. +// For example: +// +// nsCOMPtr<nsISHEntry> shentry = [...]; +// LOG_SHENTRY_SPEC(("shentry %p has uri %s.", shentry.get(), _spec), shentry); +// +#define LOG_SHENTRY_SPEC(format, shentry) \ + PR_BEGIN_MACRO \ + if (MOZ_LOG_TEST(gSHistoryLog, LogLevel::Debug)) { \ + nsCOMPtr<nsIURI> uri = shentry->GetURI(); \ + LOG_SPEC(format, uri); \ + } \ + PR_END_MACRO + +// Iterates over all registered session history listeners. +#define ITERATE_LISTENERS(body) \ + PR_BEGIN_MACRO { \ + for (const nsWeakPtr& weakPtr : mListeners.EndLimitedRange()) { \ + nsCOMPtr<nsISHistoryListener> listener = do_QueryReferent(weakPtr); \ + if (listener) { \ + body \ + } \ + } \ + } \ + PR_END_MACRO + +// Calls a given method on all registered session history listeners. +#define NOTIFY_LISTENERS(method, args) \ + ITERATE_LISTENERS(listener->method args;); + +// Calls a given method on all registered session history listeners. +// Listeners may return 'false' to cancel an action so make sure that we +// set the return value to 'false' if one of the listeners wants to cancel. +#define NOTIFY_LISTENERS_CANCELABLE(method, retval, args) \ + PR_BEGIN_MACRO { \ + bool canceled = false; \ + retval = true; \ + ITERATE_LISTENERS(listener->method args; \ + if (!retval) { canceled = true; }); \ + if (canceled) { \ + retval = false; \ + } \ + } \ + PR_END_MACRO + +class MOZ_STACK_CLASS SHistoryChangeNotifier { + public: + explicit SHistoryChangeNotifier(nsSHistory* aHistory) { + // If we're already in an update, the outermost change notifier will + // update browsing context in the destructor. + if (!aHistory->HasOngoingUpdate()) { + aHistory->SetHasOngoingUpdate(true); + mSHistory = aHistory; + mInitialIndex = aHistory->Index(); + mInitialLength = aHistory->Length(); + } + } + + ~SHistoryChangeNotifier() { + if (mSHistory) { + MOZ_ASSERT(mSHistory->HasOngoingUpdate()); + mSHistory->SetHasOngoingUpdate(false); + if (mSHistory->GetBrowsingContext()) { + mSHistory->GetBrowsingContext()->SessionHistoryChanged( + mSHistory->Index() - mInitialIndex, + mSHistory->Length() - mInitialLength); + } + + if (mozilla::SessionHistoryInParent() && + mSHistory->GetBrowsingContext()) { + mSHistory->GetBrowsingContext() + ->Canonical() + ->HistoryCommitIndexAndLength(); + } + } + } + + RefPtr<nsSHistory> mSHistory; + int32_t mInitialIndex; + int32_t mInitialLength; +}; + +enum HistCmd { HIST_CMD_GOTOINDEX, HIST_CMD_RELOAD }; + +class nsSHistoryObserver final : public nsIObserver { + public: + NS_DECL_ISUPPORTS + NS_DECL_NSIOBSERVER + + nsSHistoryObserver() {} + + static void PrefChanged(const char* aPref, void* aSelf); + void PrefChanged(const char* aPref); + + protected: + ~nsSHistoryObserver() {} +}; + +StaticRefPtr<nsSHistoryObserver> gObserver; + +NS_IMPL_ISUPPORTS(nsSHistoryObserver, nsIObserver) + +// static +void nsSHistoryObserver::PrefChanged(const char* aPref, void* aSelf) { + static_cast<nsSHistoryObserver*>(aSelf)->PrefChanged(aPref); +} + +void nsSHistoryObserver::PrefChanged(const char* aPref) { + nsSHistory::UpdatePrefs(); + nsSHistory::GloballyEvictContentViewers(); +} + +NS_IMETHODIMP +nsSHistoryObserver::Observe(nsISupports* aSubject, const char* aTopic, + const char16_t* aData) { + if (!strcmp(aTopic, "cacheservice:empty-cache") || + !strcmp(aTopic, "memory-pressure")) { + nsSHistory::GloballyEvictAllContentViewers(); + } + + return NS_OK; +} + +void nsSHistory::EvictContentViewerForEntry(nsISHEntry* aEntry) { + nsCOMPtr<nsIContentViewer> viewer = aEntry->GetContentViewer(); + if (viewer) { + LOG_SHENTRY_SPEC(("Evicting content viewer 0x%p for " + "owning SHEntry 0x%p at %s.", + viewer.get(), aEntry, _spec), + aEntry); + + // Drop the presentation state before destroying the viewer, so that + // document teardown is able to correctly persist the state. + NotifyListenersContentViewerEvicted(1); + aEntry->SetContentViewer(nullptr); + aEntry->SyncPresentationState(); + viewer->Destroy(); + } + + // When dropping bfcache, we have to remove associated dynamic entries as + // well. + int32_t index = GetIndexOfEntry(aEntry); + if (index != -1) { + RemoveDynEntries(index, aEntry); + } +} + +nsSHistory::nsSHistory(BrowsingContext* aRootBC) + : mRootBC(aRootBC), + mHasOngoingUpdate(false), + mIsRemote(false), + mIndex(-1), + mRequestedIndex(-1), + mRootDocShellID(aRootBC->GetHistoryID()) { + static bool sCalledStartup = false; + if (!sCalledStartup) { + Startup(); + sCalledStartup = true; + } + + // Add this new SHistory object to the list + gSHistoryList.insertBack(this); + + // Init mHistoryTracker on setting mRootBC so we can bind its event + // target to the tabGroup. + nsPIDOMWindowOuter* win; + if (mRootBC && (win = mRootBC->GetDOMWindow())) { + nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(win); + mHistoryTracker = mozilla::MakeUnique<HistoryTracker>( + this, + mozilla::Preferences::GetUint(CONTENT_VIEWER_TIMEOUT_SECONDS, + CONTENT_VIEWER_TIMEOUT_SECONDS_DEFAULT), + global->EventTargetFor(mozilla::TaskCategory::Other)); + } +} + +nsSHistory::~nsSHistory() {} + +NS_IMPL_ADDREF(nsSHistory) +NS_IMPL_RELEASE(nsSHistory) + +NS_INTERFACE_MAP_BEGIN(nsSHistory) + NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsISHistory) + NS_INTERFACE_MAP_ENTRY(nsISHistory) + NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference) +NS_INTERFACE_MAP_END + +// static +uint32_t nsSHistory::CalcMaxTotalViewers() { +// This value allows tweaking how fast the allowed amount of content viewers +// grows with increasing amounts of memory. Larger values mean slower growth. +#ifdef ANDROID +# define MAX_TOTAL_VIEWERS_BIAS 15.9 +#else +# define MAX_TOTAL_VIEWERS_BIAS 14 +#endif + + // Calculate an estimate of how many ContentViewers we should cache based + // on RAM. This assumes that the average ContentViewer is 4MB (conservative) + // and caps the max at 8 ContentViewers + // + // TODO: Should we split the cache memory betw. ContentViewer caching and + // nsCacheService? + // + // RAM | ContentViewers | on Android + // ------------------------------------- + // 32 Mb 0 0 + // 64 Mb 1 0 + // 128 Mb 2 0 + // 256 Mb 3 1 + // 512 Mb 5 2 + // 768 Mb 6 2 + // 1024 Mb 8 3 + // 2048 Mb 8 5 + // 3072 Mb 8 7 + // 4096 Mb 8 8 + uint64_t bytes = PR_GetPhysicalMemorySize(); + + if (bytes == 0) { + return 0; + } + + // Conversion from unsigned int64_t to double doesn't work on all platforms. + // We need to truncate the value at INT64_MAX to make sure we don't + // overflow. + if (bytes > INT64_MAX) { + bytes = INT64_MAX; + } + + double kBytesD = (double)(bytes >> 10); + + // This is essentially the same calculation as for nsCacheService, + // except that we divide the final memory calculation by 4, since + // we assume each ContentViewer takes on average 4MB + uint32_t viewers = 0; + double x = std::log(kBytesD) / std::log(2.0) - MAX_TOTAL_VIEWERS_BIAS; + if (x > 0) { + viewers = (uint32_t)(x * x - x + 2.001); // add .001 for rounding + viewers /= 4; + } + + // Cap it off at 8 max + if (viewers > 8) { + viewers = 8; + } + return viewers; +} + +// static +void nsSHistory::UpdatePrefs() { + Preferences::GetInt(PREF_SHISTORY_SIZE, &gHistoryMaxSize); + if (mozilla::SessionHistoryInParent()) { + sHistoryMaxTotalViewers = 0; + return; + } + + Preferences::GetInt(PREF_SHISTORY_MAX_TOTAL_VIEWERS, + &sHistoryMaxTotalViewers); + // If the pref is negative, that means we calculate how many viewers + // we think we should cache, based on total memory + if (sHistoryMaxTotalViewers < 0) { + sHistoryMaxTotalViewers = CalcMaxTotalViewers(); + } +} + +// static +nsresult nsSHistory::Startup() { + UpdatePrefs(); + + // The goal of this is to unbreak users who have inadvertently set their + // session history size to less than the default value. + int32_t defaultHistoryMaxSize = + Preferences::GetInt(PREF_SHISTORY_SIZE, 50, PrefValueKind::Default); + if (gHistoryMaxSize < defaultHistoryMaxSize) { + gHistoryMaxSize = defaultHistoryMaxSize; + } + + // Allow the user to override the max total number of cached viewers, + // but keep the per SHistory cached viewer limit constant + if (!gObserver) { + gObserver = new nsSHistoryObserver(); + Preferences::RegisterCallbacks(nsSHistoryObserver::PrefChanged, + kObservedPrefs, gObserver.get()); + + nsCOMPtr<nsIObserverService> obsSvc = + mozilla::services::GetObserverService(); + if (obsSvc) { + // Observe empty-cache notifications so tahat clearing the disk/memory + // cache will also evict all content viewers. + obsSvc->AddObserver(gObserver, "cacheservice:empty-cache", false); + + // Same for memory-pressure notifications + obsSvc->AddObserver(gObserver, "memory-pressure", false); + } + } + + return NS_OK; +} + +// static +void nsSHistory::Shutdown() { + if (gObserver) { + Preferences::UnregisterCallbacks(nsSHistoryObserver::PrefChanged, + kObservedPrefs, gObserver.get()); + + nsCOMPtr<nsIObserverService> obsSvc = + mozilla::services::GetObserverService(); + if (obsSvc) { + obsSvc->RemoveObserver(gObserver, "cacheservice:empty-cache"); + obsSvc->RemoveObserver(gObserver, "memory-pressure"); + } + gObserver = nullptr; + } +} + +// static +already_AddRefed<nsISHEntry> nsSHistory::GetRootSHEntry(nsISHEntry* aEntry) { + nsCOMPtr<nsISHEntry> rootEntry = aEntry; + nsCOMPtr<nsISHEntry> result = nullptr; + while (rootEntry) { + result = rootEntry; + rootEntry = result->GetParent(); + } + + return result.forget(); +} + +// static +nsresult nsSHistory::WalkHistoryEntries(nsISHEntry* aRootEntry, + BrowsingContext* aBC, + WalkHistoryEntriesFunc aCallback, + void* aData) { + NS_ENSURE_TRUE(aRootEntry, NS_ERROR_FAILURE); + + int32_t childCount = aRootEntry->GetChildCount(); + for (int32_t i = 0; i < childCount; i++) { + nsCOMPtr<nsISHEntry> childEntry; + aRootEntry->GetChildAt(i, getter_AddRefs(childEntry)); + if (!childEntry) { + // childEntry can be null for valid reasons, for example if the + // docshell at index i never loaded anything useful. + // Remember to clone also nulls in the child array (bug 464064). + aCallback(nullptr, nullptr, i, aData); + continue; + } + + BrowsingContext* childBC = nullptr; + if (aBC) { + for (BrowsingContext* child : aBC->Children()) { + // If the SH pref is on and we are in the parent process, update + // canonical BC directly + bool foundChild = false; + if (mozilla::SessionHistoryInParent() && XRE_IsParentProcess()) { + if (child->Canonical()->HasHistoryEntry(childEntry)) { + childBC = child; + foundChild = true; + } + } + + nsDocShell* docshell = static_cast<nsDocShell*>(child->GetDocShell()); + if (docshell && docshell->HasHistoryEntry(childEntry)) { + childBC = docshell->GetBrowsingContext(); + foundChild = true; + } + + // XXX Simplify this once the old and new session history + // implementations don't run at the same time. + if (foundChild) { + break; + } + } + } + + nsresult rv = aCallback(childEntry, childBC, i, aData); + NS_ENSURE_SUCCESS(rv, rv); + } + + return NS_OK; +} + +// callback data for WalkHistoryEntries +struct MOZ_STACK_CLASS CloneAndReplaceData { + CloneAndReplaceData(uint32_t aCloneID, nsISHEntry* aReplaceEntry, + bool aCloneChildren, nsISHEntry* aDestTreeParent) + : cloneID(aCloneID), + cloneChildren(aCloneChildren), + replaceEntry(aReplaceEntry), + destTreeParent(aDestTreeParent) {} + + uint32_t cloneID; + bool cloneChildren; + nsISHEntry* replaceEntry; + nsISHEntry* destTreeParent; + nsCOMPtr<nsISHEntry> resultEntry; +}; + +nsresult nsSHistory::CloneAndReplaceChild(nsISHEntry* aEntry, + BrowsingContext* aOwnerBC, + int32_t aChildIndex, void* aData) { + nsCOMPtr<nsISHEntry> dest; + + CloneAndReplaceData* data = static_cast<CloneAndReplaceData*>(aData); + uint32_t cloneID = data->cloneID; + nsISHEntry* replaceEntry = data->replaceEntry; + + if (!aEntry) { + if (data->destTreeParent) { + data->destTreeParent->AddChild(nullptr, aChildIndex); + } + return NS_OK; + } + + uint32_t srcID = aEntry->GetID(); + + nsresult rv = NS_OK; + if (srcID == cloneID) { + // Replace the entry + dest = replaceEntry; + } else { + // Clone the SHEntry... + rv = aEntry->Clone(getter_AddRefs(dest)); + NS_ENSURE_SUCCESS(rv, rv); + } + dest->SetIsSubFrame(true); + + if (srcID != cloneID || data->cloneChildren) { + // Walk the children + CloneAndReplaceData childData(cloneID, replaceEntry, data->cloneChildren, + dest); + rv = nsSHistory::WalkHistoryEntries(aEntry, aOwnerBC, CloneAndReplaceChild, + &childData); + NS_ENSURE_SUCCESS(rv, rv); + } + + if (srcID != cloneID && aOwnerBC) { + nsSHistory::HandleEntriesToSwapInDocShell(aOwnerBC, aEntry, dest); + } + + if (data->destTreeParent) { + data->destTreeParent->AddChild(dest, aChildIndex); + } + data->resultEntry = dest; + return rv; +} + +// static +nsresult nsSHistory::CloneAndReplace( + nsISHEntry* aSrcEntry, BrowsingContext* aOwnerBC, uint32_t aCloneID, + nsISHEntry* aReplaceEntry, bool aCloneChildren, nsISHEntry** aDestEntry) { + NS_ENSURE_ARG_POINTER(aDestEntry); + NS_ENSURE_TRUE(aReplaceEntry, NS_ERROR_FAILURE); + CloneAndReplaceData data(aCloneID, aReplaceEntry, aCloneChildren, nullptr); + nsresult rv = CloneAndReplaceChild(aSrcEntry, aOwnerBC, 0, &data); + data.resultEntry.swap(*aDestEntry); + return rv; +} + +// static +void nsSHistory::WalkContiguousEntries( + nsISHEntry* aEntry, const std::function<void(nsISHEntry*)>& aCallback) { + MOZ_ASSERT(aEntry); + + nsCOMPtr<nsISHistory> shistory = aEntry->GetShistory(); + if (!shistory) { + // If there is no session history in the entry, it means this is not a root + // entry. So, we can return from here. + return; + } + + int32_t index = shistory->GetIndexOfEntry(aEntry); + int32_t count = shistory->GetCount(); + + nsCOMPtr<nsIURI> targetURI = aEntry->GetURI(); + + // First, call the callback on the input entry. + aCallback(aEntry); + + // Walk backward to find the entries that have the same origin as the + // input entry. + for (int32_t i = index - 1; i >= 0; i--) { + RefPtr<nsISHEntry> entry; + shistory->GetEntryAtIndex(i, getter_AddRefs(entry)); + if (entry) { + nsCOMPtr<nsIURI> uri = entry->GetURI(); + if (NS_FAILED(nsContentUtils::GetSecurityManager()->CheckSameOriginURI( + targetURI, uri, false, false))) { + break; + } + + aCallback(entry); + } + } + + // Then, Walk forward. + for (int32_t i = index + 1; i < count; i++) { + RefPtr<nsISHEntry> entry; + shistory->GetEntryAtIndex(i, getter_AddRefs(entry)); + if (entry) { + nsCOMPtr<nsIURI> uri = entry->GetURI(); + if (NS_FAILED(nsContentUtils::GetSecurityManager()->CheckSameOriginURI( + targetURI, uri, false, false))) { + break; + } + + aCallback(entry); + } + } +} + +NS_IMETHODIMP +nsSHistory::AddChildSHEntryHelper(nsISHEntry* aCloneRef, nsISHEntry* aNewEntry, + BrowsingContext* aRootBC, + bool aCloneChildren) { + MOZ_ASSERT(aRootBC->IsTop()); + + /* You are currently in the rootDocShell. + * You will get here when a subframe has a new url + * to load and you have walked up the tree all the + * way to the top to clone the current SHEntry hierarchy + * and replace the subframe where a new url was loaded with + * a new entry. + */ + nsCOMPtr<nsISHEntry> child; + nsCOMPtr<nsISHEntry> currentHE; + int32_t index = mIndex; + if (index < 0) { + return NS_ERROR_FAILURE; + } + + GetEntryAtIndex(index, getter_AddRefs(currentHE)); + NS_ENSURE_TRUE(currentHE, NS_ERROR_FAILURE); + + nsresult rv = NS_OK; + uint32_t cloneID = aCloneRef->GetID(); + rv = nsSHistory::CloneAndReplace(currentHE, aRootBC, cloneID, aNewEntry, + aCloneChildren, getter_AddRefs(child)); + + if (NS_SUCCEEDED(rv)) { + rv = AddEntry(child, true); + if (NS_SUCCEEDED(rv)) { + child->SetDocshellID(aRootBC->GetHistoryID()); + } + } + + return rv; +} + +nsresult nsSHistory::SetChildHistoryEntry(nsISHEntry* aEntry, + BrowsingContext* aBC, + int32_t aEntryIndex, void* aData) { + SwapEntriesData* data = static_cast<SwapEntriesData*>(aData); + if (!aBC || aBC == data->ignoreBC) { + return NS_OK; + } + + nsISHEntry* destTreeRoot = data->destTreeRoot; + + nsCOMPtr<nsISHEntry> destEntry; + + if (data->destTreeParent) { + // aEntry is a clone of some child of destTreeParent, but since the + // trees aren't necessarily in sync, we'll have to locate it. + // Note that we could set aShell's entry to null if we don't find a + // corresponding entry under destTreeParent. + + uint32_t targetID = aEntry->GetID(); + + // First look at the given index, since this is the common case. + nsCOMPtr<nsISHEntry> entry; + data->destTreeParent->GetChildAt(aEntryIndex, getter_AddRefs(entry)); + if (entry && entry->GetID() == targetID) { + destEntry.swap(entry); + } else { + int32_t childCount; + data->destTreeParent->GetChildCount(&childCount); + for (int32_t i = 0; i < childCount; ++i) { + data->destTreeParent->GetChildAt(i, getter_AddRefs(entry)); + if (!entry) { + continue; + } + + if (entry->GetID() == targetID) { + destEntry.swap(entry); + break; + } + } + } + } else { + destEntry = destTreeRoot; + } + + nsSHistory::HandleEntriesToSwapInDocShell(aBC, aEntry, destEntry); + // Now handle the children of aEntry. + SwapEntriesData childData = {data->ignoreBC, destTreeRoot, destEntry}; + return nsSHistory::WalkHistoryEntries(aEntry, aBC, SetChildHistoryEntry, + &childData); +} + +// static +void nsSHistory::HandleEntriesToSwapInDocShell( + mozilla::dom::BrowsingContext* aBC, nsISHEntry* aOldEntry, + nsISHEntry* aNewEntry) { + bool shPref = mozilla::SessionHistoryInParent(); + if (aBC->IsInProcess() || !shPref) { + nsDocShell* docshell = static_cast<nsDocShell*>(aBC->GetDocShell()); + if (docshell) { + docshell->SwapHistoryEntries(aOldEntry, aNewEntry); + } + } else { + // FIXME Bug 1633988: Need to update entries? + } + + // XXX Simplify this once the old and new session history implementations + // don't run at the same time. + if (shPref && XRE_IsParentProcess()) { + aBC->Canonical()->SwapHistoryEntries(aOldEntry, aNewEntry); + } +} + +void nsSHistory::UpdateRootBrowsingContextState() { + if (mRootBC) { + bool sameDocument = IsEmptyOrHasEntriesForSingleTopLevelPage(); + if (sameDocument != mRootBC->GetIsSingleToplevelInHistory()) { + // If the browsing context is discarded then its session history is + // invalid and will go away. + Unused << mRootBC->SetIsSingleToplevelInHistory(sameDocument); + } + } +} + +NS_IMETHODIMP +nsSHistory::AddToRootSessionHistory(bool aCloneChildren, nsISHEntry* aOSHE, + BrowsingContext* aRootBC, + nsISHEntry* aEntry, uint32_t aLoadType, + bool aShouldPersist, + Maybe<int32_t>* aPreviousEntryIndex, + Maybe<int32_t>* aLoadedEntryIndex) { + MOZ_ASSERT(aRootBC->IsTop()); + + nsresult rv = NS_OK; + + // If we need to clone our children onto the new session + // history entry, do so now. + if (aCloneChildren && aOSHE) { + uint32_t cloneID = aOSHE->GetID(); + nsCOMPtr<nsISHEntry> newEntry; + nsSHistory::CloneAndReplace(aOSHE, aRootBC, cloneID, aEntry, true, + getter_AddRefs(newEntry)); + NS_ASSERTION(aEntry == newEntry, + "The new session history should be in the new entry"); + } + // This is the root docshell + bool addToSHistory = !LOAD_TYPE_HAS_FLAGS( + aLoadType, nsIWebNavigation::LOAD_FLAGS_REPLACE_HISTORY); + if (!addToSHistory) { + // Replace current entry in session history; If the requested index is + // valid, it indicates the loading was triggered by a history load, and + // we should replace the entry at requested index instead. + int32_t index = GetIndexForReplace(); + + // Replace the current entry with the new entry + if (index >= 0) { + rv = ReplaceEntry(index, aEntry); + } else { + // If we're trying to replace an inexistant shistory entry, append. + addToSHistory = true; + } + } + if (addToSHistory) { + // Add to session history + *aPreviousEntryIndex = Some(mIndex); + rv = AddEntry(aEntry, aShouldPersist); + *aLoadedEntryIndex = Some(mIndex); + MOZ_LOG(gPageCacheLog, LogLevel::Verbose, + ("Previous index: %d, Loaded index: %d", + aPreviousEntryIndex->value(), aLoadedEntryIndex->value())); + } + if (NS_SUCCEEDED(rv)) { + aEntry->SetDocshellID(aRootBC->GetHistoryID()); + } + return rv; +} + +/* Add an entry to the History list at mIndex and + * increment the index to point to the new entry + */ +NS_IMETHODIMP +nsSHistory::AddEntry(nsISHEntry* aSHEntry, bool aPersist) { + NS_ENSURE_ARG(aSHEntry); + + nsCOMPtr<nsISHistory> shistoryOfEntry = aSHEntry->GetShistory(); + if (shistoryOfEntry && shistoryOfEntry != this) { + NS_WARNING( + "The entry has been associated to another nsISHistory instance. " + "Try nsISHEntry.clone() and nsISHEntry.abandonBFCacheEntry() " + "first if you're copying an entry from another nsISHistory."); + return NS_ERROR_FAILURE; + } + + aSHEntry->SetShistory(this); + + // If we have a root docshell, update the docshell id of the root shentry to + // match the id of that docshell + if (mRootBC) { + aSHEntry->SetDocshellID(mRootDocShellID); + } + + if (mIndex >= 0) { + MOZ_ASSERT(mIndex < Length(), "Index out of range!"); + if (mIndex >= Length()) { + return NS_ERROR_FAILURE; + } + + if (mEntries[mIndex] && !mEntries[mIndex]->GetPersist()) { + NOTIFY_LISTENERS(OnHistoryReplaceEntry, ()); + aSHEntry->SetPersist(aPersist); + mEntries[mIndex] = aSHEntry; + UpdateRootBrowsingContextState(); + return NS_OK; + } + } + SHistoryChangeNotifier change(this); + + nsCOMPtr<nsIURI> uri = aSHEntry->GetURI(); + NOTIFY_LISTENERS(OnHistoryNewEntry, (uri, mIndex)); + + // Remove all entries after the current one, add the new one, and set the + // new one as the current one. + MOZ_ASSERT(mIndex >= -1); + aSHEntry->SetPersist(aPersist); + mEntries.TruncateLength(mIndex + 1); + mEntries.AppendElement(aSHEntry); + mIndex++; + + // Purge History list if it is too long + if (gHistoryMaxSize >= 0 && Length() > gHistoryMaxSize) { + PurgeHistory(Length() - gHistoryMaxSize); + } + + UpdateRootBrowsingContextState(); + + return NS_OK; +} + +void nsSHistory::NotifyOnHistoryReplaceEntry() { + NOTIFY_LISTENERS(OnHistoryReplaceEntry, ()); +} + +/* Get size of the history list */ +NS_IMETHODIMP +nsSHistory::GetCount(int32_t* aResult) { + MOZ_ASSERT(aResult, "null out param?"); + *aResult = Length(); + return NS_OK; +} + +NS_IMETHODIMP +nsSHistory::GetIndex(int32_t* aResult) { + MOZ_ASSERT(aResult, "null out param?"); + *aResult = mIndex; + return NS_OK; +} + +NS_IMETHODIMP +nsSHistory::SetIndex(int32_t aIndex) { + if (aIndex < 0 || aIndex >= Length()) { + return NS_ERROR_FAILURE; + } + + mIndex = aIndex; + return NS_OK; +} + +/* Get the requestedIndex */ +NS_IMETHODIMP +nsSHistory::GetRequestedIndex(int32_t* aResult) { + MOZ_ASSERT(aResult, "null out param?"); + *aResult = mRequestedIndex; + return NS_OK; +} + +NS_IMETHODIMP_(void) +nsSHistory::InternalSetRequestedIndex(int32_t aRequestedIndex) { + MOZ_ASSERT(aRequestedIndex >= -1 && aRequestedIndex < Length()); + mRequestedIndex = aRequestedIndex; +} + +NS_IMETHODIMP +nsSHistory::GetEntryAtIndex(int32_t aIndex, nsISHEntry** aResult) { + NS_ENSURE_ARG_POINTER(aResult); + + if (aIndex < 0 || aIndex >= Length()) { + return NS_ERROR_FAILURE; + } + + *aResult = mEntries[aIndex]; + NS_ADDREF(*aResult); + return NS_OK; +} + +NS_IMETHODIMP_(int32_t) +nsSHistory::GetIndexOfEntry(nsISHEntry* aSHEntry) { + for (int32_t i = 0; i < Length(); i++) { + if (aSHEntry == mEntries[i]) { + return i; + } + } + + return -1; +} + +static void LogEntry(nsISHEntry* aEntry, int32_t aIndex, int32_t aTotal, + const nsCString& aPrefix, bool aIsCurrent) { + if (!aEntry) { + MOZ_LOG(gSHLog, LogLevel::Debug, + (" %s+- %i SH Entry null\n", aPrefix.get(), aIndex)); + return; + } + + nsCOMPtr<nsIURI> uri = aEntry->GetURI(); + nsAutoString title; + aEntry->GetTitle(title); + + SHEntrySharedParentState* shared; + if (mozilla::SessionHistoryInParent()) { + shared = static_cast<SessionHistoryEntry*>(aEntry)->SharedInfo(); + } else { + shared = static_cast<nsSHEntry*>(aEntry)->GetState(); + } + + nsID docShellId; + aEntry->GetDocshellID(docShellId); + + int32_t childCount = aEntry->GetChildCount(); + + MOZ_LOG(gSHLog, LogLevel::Debug, + ("%s%s+- %i SH Entry %p %" PRIu64 " %s\n", aIsCurrent ? ">" : " ", + aPrefix.get(), aIndex, aEntry, shared->GetId(), + nsIDToCString(docShellId).get())); + + nsCString prefix(aPrefix); + if (aIndex < aTotal - 1) { + prefix.AppendLiteral("| "); + } else { + prefix.AppendLiteral(" "); + } + + MOZ_LOG(gSHLog, LogLevel::Debug, + (" %s%s URL = %s\n", prefix.get(), childCount > 0 ? "|" : " ", + uri->GetSpecOrDefault().get())); + MOZ_LOG(gSHLog, LogLevel::Debug, + (" %s%s Title = %s\n", prefix.get(), childCount > 0 ? "|" : " ", + NS_LossyConvertUTF16toASCII(title).get())); + + nsCOMPtr<nsISHEntry> prevChild; + for (int32_t i = 0; i < childCount; ++i) { + nsCOMPtr<nsISHEntry> child; + aEntry->GetChildAt(i, getter_AddRefs(child)); + LogEntry(child, i, childCount, prefix, false); + child.swap(prevChild); + } +} + +void nsSHistory::LogHistory() { + if (!MOZ_LOG_TEST(gSHLog, LogLevel::Debug)) { + return; + } + + MOZ_LOG(gSHLog, LogLevel::Debug, ("nsSHistory %p\n", this)); + int32_t length = Length(); + for (int32_t i = 0; i < length; i++) { + LogEntry(mEntries[i], i, length, EmptyCString(), i == mIndex); + } +} + +void nsSHistory::WindowIndices(int32_t aIndex, int32_t* aOutStartIndex, + int32_t* aOutEndIndex) { + *aOutStartIndex = std::max(0, aIndex - nsSHistory::VIEWER_WINDOW); + *aOutEndIndex = std::min(Length() - 1, aIndex + nsSHistory::VIEWER_WINDOW); +} + +NS_IMETHODIMP +nsSHistory::PurgeHistory(int32_t aNumEntries) { + if (Length() <= 0 || aNumEntries <= 0) { + return NS_ERROR_FAILURE; + } + + SHistoryChangeNotifier change(this); + + aNumEntries = std::min(aNumEntries, Length()); + + NOTIFY_LISTENERS(OnHistoryPurge, ()); + + // Remove the first `aNumEntries` entries. + mEntries.RemoveElementsAt(0, aNumEntries); + + // Adjust the indices, but don't let them go below -1. + mIndex -= aNumEntries; + mIndex = std::max(mIndex, -1); + mRequestedIndex -= aNumEntries; + mRequestedIndex = std::max(mRequestedIndex, -1); + + if (mRootBC && mRootBC->GetDocShell()) { + mRootBC->GetDocShell()->HistoryPurged(aNumEntries); + } + + UpdateRootBrowsingContextState(); + + return NS_OK; +} + +NS_IMETHODIMP +nsSHistory::AddSHistoryListener(nsISHistoryListener* aListener) { + NS_ENSURE_ARG_POINTER(aListener); + + // Check if the listener supports Weak Reference. This is a must. + // This listener functionality is used by embedders and we want to + // have the right ownership with who ever listens to SHistory + nsWeakPtr listener = do_GetWeakReference(aListener); + if (!listener) { + return NS_ERROR_FAILURE; + } + + mListeners.AppendElementUnlessExists(listener); + return NS_OK; +} + +void nsSHistory::NotifyListenersContentViewerEvicted(uint32_t aNumEvicted) { + NOTIFY_LISTENERS(OnContentViewerEvicted, (aNumEvicted)); +} + +NS_IMETHODIMP +nsSHistory::RemoveSHistoryListener(nsISHistoryListener* aListener) { + // Make sure the listener that wants to be removed is the + // one we have in store. + nsWeakPtr listener = do_GetWeakReference(aListener); + mListeners.RemoveElement(listener); + return NS_OK; +} + +/* Replace an entry in the History list at a particular index. + * Do not update index or count. + */ +NS_IMETHODIMP +nsSHistory::ReplaceEntry(int32_t aIndex, nsISHEntry* aReplaceEntry) { + NS_ENSURE_ARG(aReplaceEntry); + + if (aIndex < 0 || aIndex >= Length()) { + return NS_ERROR_FAILURE; + } + + nsCOMPtr<nsISHistory> shistoryOfEntry = aReplaceEntry->GetShistory(); + if (shistoryOfEntry && shistoryOfEntry != this) { + NS_WARNING( + "The entry has been associated to another nsISHistory instance. " + "Try nsISHEntry.clone() and nsISHEntry.abandonBFCacheEntry() " + "first if you're copying an entry from another nsISHistory."); + return NS_ERROR_FAILURE; + } + + aReplaceEntry->SetShistory(this); + + NOTIFY_LISTENERS(OnHistoryReplaceEntry, ()); + + aReplaceEntry->SetPersist(true); + mEntries[aIndex] = aReplaceEntry; + + UpdateRootBrowsingContextState(); + + return NS_OK; +} + +NS_IMETHODIMP +nsSHistory::NotifyOnHistoryReload(bool* aCanReload) { + NOTIFY_LISTENERS_CANCELABLE(OnHistoryReload, *aCanReload, (aCanReload)); + return NS_OK; +} + +NS_IMETHODIMP +nsSHistory::EvictOutOfRangeContentViewers(int32_t aIndex) { + // Check our per SHistory object limit in the currently navigated SHistory + EvictOutOfRangeWindowContentViewers(aIndex); + // Check our total limit across all SHistory objects + GloballyEvictContentViewers(); + return NS_OK; +} + +NS_IMETHODIMP_(void) +nsSHistory::EvictContentViewersOrReplaceEntry(nsISHEntry* aNewSHEntry, + bool aReplace) { + if (!aReplace) { + int32_t curIndex; + GetIndex(&curIndex); + if (curIndex > -1) { + EvictOutOfRangeContentViewers(curIndex); + } + } else { + nsCOMPtr<nsISHEntry> rootSHEntry = nsSHistory::GetRootSHEntry(aNewSHEntry); + + int32_t index = GetIndexOfEntry(rootSHEntry); + if (index > -1) { + ReplaceEntry(index, rootSHEntry); + } + } +} + +NS_IMETHODIMP +nsSHistory::EvictAllContentViewers() { + // XXXbz we don't actually do a good job of evicting things as we should, so + // we might have viewers quite far from mIndex. So just evict everything. + for (int32_t i = 0; i < Length(); i++) { + EvictContentViewerForEntry(mEntries[i]); + } + + return NS_OK; +} + +/* static */ +void nsSHistory::LoadURIs(nsTArray<LoadEntryResult>& aLoadResults) { + for (LoadEntryResult& loadEntry : aLoadResults) { + loadEntry.mBrowsingContext->LoadURI(loadEntry.mLoadState, false); + } +} + +NS_IMETHODIMP +nsSHistory::Reload(uint32_t aReloadFlags) { + nsTArray<LoadEntryResult> loadResults; + nsresult rv = Reload(aReloadFlags, loadResults); + NS_ENSURE_SUCCESS(rv, rv); + + if (loadResults.IsEmpty()) { + return NS_OK; + } + + LoadURIs(loadResults); + return NS_OK; +} + +nsresult nsSHistory::Reload(uint32_t aReloadFlags, + nsTArray<LoadEntryResult>& aLoadResults) { + MOZ_ASSERT(aLoadResults.IsEmpty()); + + uint32_t loadType; + if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_BYPASS_PROXY && + aReloadFlags & nsIWebNavigation::LOAD_FLAGS_BYPASS_CACHE) { + loadType = LOAD_RELOAD_BYPASS_PROXY_AND_CACHE; + } else if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_BYPASS_PROXY) { + loadType = LOAD_RELOAD_BYPASS_PROXY; + } else if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_BYPASS_CACHE) { + loadType = LOAD_RELOAD_BYPASS_CACHE; + } else if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_CHARSET_CHANGE) { + loadType = LOAD_RELOAD_CHARSET_CHANGE; + } else if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_ALLOW_MIXED_CONTENT) { + loadType = LOAD_RELOAD_ALLOW_MIXED_CONTENT; + } else { + loadType = LOAD_RELOAD_NORMAL; + } + + // We are reloading. Send Reload notifications. + // nsDocShellLoadFlagType is not public, where as nsIWebNavigation + // is public. So send the reload notifications with the + // nsIWebNavigation flags. + bool canNavigate = true; + NOTIFY_LISTENERS_CANCELABLE(OnHistoryReload, canNavigate, (&canNavigate)); + if (!canNavigate) { + return NS_OK; + } + + nsresult rv = LoadEntry(mIndex, loadType, HIST_CMD_RELOAD, aLoadResults); + if (NS_FAILED(rv)) { + aLoadResults.Clear(); + return rv; + } + + return NS_OK; +} + +NS_IMETHODIMP +nsSHistory::ReloadCurrentEntry() { + nsTArray<LoadEntryResult> loadResults; + nsresult rv = ReloadCurrentEntry(loadResults); + NS_ENSURE_SUCCESS(rv, rv); + + LoadURIs(loadResults); + return NS_OK; +} + +nsresult nsSHistory::ReloadCurrentEntry( + nsTArray<LoadEntryResult>& aLoadResults) { + // Notify listeners + NOTIFY_LISTENERS(OnHistoryGotoIndex, ()); + + return LoadEntry(mIndex, LOAD_HISTORY, HIST_CMD_RELOAD, aLoadResults); +} + +void nsSHistory::EvictOutOfRangeWindowContentViewers(int32_t aIndex) { + // XXX rename method to EvictContentViewersExceptAroundIndex, or something. + + // We need to release all content viewers that are no longer in the range + // + // aIndex - VIEWER_WINDOW to aIndex + VIEWER_WINDOW + // + // to ensure that this SHistory object isn't responsible for more than + // VIEWER_WINDOW content viewers. But our job is complicated by the + // fact that two entries which are related by either hash navigations or + // history.pushState will have the same content viewer. + // + // To illustrate the issue, suppose VIEWER_WINDOW = 3 and we have four + // linked entries in our history. Suppose we then add a new content + // viewer and call into this function. So the history looks like: + // + // A A A A B + // + * + // + // where the letters are content viewers and + and * denote the beginning and + // end of the range aIndex +/- VIEWER_WINDOW. + // + // Although one copy of the content viewer A exists outside the range, we + // don't want to evict A, because it has other copies in range! + // + // We therefore adjust our eviction strategy to read: + // + // Evict each content viewer outside the range aIndex -/+ + // VIEWER_WINDOW, unless that content viewer also appears within the + // range. + // + // (Note that it's entirely legal to have two copies of one content viewer + // separated by a different content viewer -- call pushState twice, go back + // once, and refresh -- so we can't rely on identical viewers only appearing + // adjacent to one another.) + + if (aIndex < 0) { + return; + } + NS_ENSURE_TRUE_VOID(aIndex < Length()); + + // Calculate the range that's safe from eviction. + int32_t startSafeIndex, endSafeIndex; + WindowIndices(aIndex, &startSafeIndex, &endSafeIndex); + + LOG( + ("EvictOutOfRangeWindowContentViewers(index=%d), " + "Length()=%d. Safe range [%d, %d]", + aIndex, Length(), startSafeIndex, endSafeIndex)); + + // The content viewers in range aIndex -/+ VIEWER_WINDOW will not be + // evicted. Collect a set of them so we don't accidentally evict one of them + // if it appears outside this range. + nsCOMArray<nsIContentViewer> safeViewers; + for (int32_t i = startSafeIndex; i <= endSafeIndex; i++) { + nsCOMPtr<nsIContentViewer> viewer = mEntries[i]->GetContentViewer(); + safeViewers.AppendObject(viewer); + } + + // Walk the SHistory list and evict any content viewers that aren't safe. + // (It's important that the condition checks Length(), rather than a cached + // copy of Length(), because the length might change between iterations.) + for (int32_t i = 0; i < Length(); i++) { + nsCOMPtr<nsISHEntry> entry = mEntries[i]; + nsCOMPtr<nsIContentViewer> viewer = entry->GetContentViewer(); + if (safeViewers.IndexOf(viewer) == -1) { + EvictContentViewerForEntry(entry); + } + } +} + +namespace { + +class EntryAndDistance { + public: + EntryAndDistance(nsSHistory* aSHistory, nsISHEntry* aEntry, uint32_t aDist) + : mSHistory(aSHistory), + mEntry(aEntry), + mViewer(aEntry->GetContentViewer()), + mLastTouched(mEntry->GetLastTouched()), + mDistance(aDist) { + NS_ASSERTION(mViewer, "Entry should have a content viewer"); + } + + bool operator<(const EntryAndDistance& aOther) const { + // Compare distances first, and fall back to last-accessed times. + if (aOther.mDistance != this->mDistance) { + return this->mDistance < aOther.mDistance; + } + + return this->mLastTouched < aOther.mLastTouched; + } + + bool operator==(const EntryAndDistance& aOther) const { + // This is a little silly; we need == so the default comaprator can be + // instantiated, but this function is never actually called when we sort + // the list of EntryAndDistance objects. + return aOther.mDistance == this->mDistance && + aOther.mLastTouched == this->mLastTouched; + } + + RefPtr<nsSHistory> mSHistory; + nsCOMPtr<nsISHEntry> mEntry; + nsCOMPtr<nsIContentViewer> mViewer; + uint32_t mLastTouched; + int32_t mDistance; +}; + +} // namespace + +// static +void nsSHistory::GloballyEvictContentViewers() { + // First, collect from each SHistory object the entries which have a cached + // content viewer. Associate with each entry its distance from its SHistory's + // current index. + + nsTArray<EntryAndDistance> entries; + + for (auto shist : gSHistoryList) { + // FIXME Bug 1546348: Make global eviction work for session history in the + // parent and remove mIsRemote. + if (shist->mIsRemote) { + continue; + } + + // Maintain a list of the entries which have viewers and belong to + // this particular shist object. We'll add this list to the global list, + // |entries|, eventually. + nsTArray<EntryAndDistance> shEntries; + + // Content viewers are likely to exist only within shist->mIndex -/+ + // VIEWER_WINDOW, so only search within that range. + // + // A content viewer might exist outside that range due to either: + // + // * history.pushState or hash navigations, in which case a copy of the + // content viewer should exist within the range, or + // + // * bugs which cause us not to call nsSHistory::EvictContentViewers() + // often enough. Once we do call EvictContentViewers() for the + // SHistory object in question, we'll do a full search of its history + // and evict the out-of-range content viewers, so we don't bother here. + // + int32_t startIndex, endIndex; + shist->WindowIndices(shist->mIndex, &startIndex, &endIndex); + for (int32_t i = startIndex; i <= endIndex; i++) { + nsCOMPtr<nsISHEntry> entry = shist->mEntries[i]; + nsCOMPtr<nsIContentViewer> contentViewer = entry->GetContentViewer(); + + if (contentViewer) { + // Because one content viewer might belong to multiple SHEntries, we + // have to search through shEntries to see if we already know + // about this content viewer. If we find the viewer, update its + // distance from the SHistory's index and continue. + bool found = false; + for (uint32_t j = 0; j < shEntries.Length(); j++) { + EntryAndDistance& container = shEntries[j]; + if (container.mViewer == contentViewer) { + container.mDistance = + std::min(container.mDistance, DeprecatedAbs(i - shist->mIndex)); + found = true; + break; + } + } + + // If we didn't find a EntryAndDistance for this content viewer, make a + // new one. + if (!found) { + EntryAndDistance container(shist, entry, + DeprecatedAbs(i - shist->mIndex)); + shEntries.AppendElement(container); + } + } + } + + // We've found all the entries belonging to shist which have viewers. + // Add those entries to our global list and move on. + entries.AppendElements(shEntries); + } + + // We now have collected all cached content viewers. First check that we + // have enough that we actually need to evict some. + if ((int32_t)entries.Length() <= sHistoryMaxTotalViewers) { + return; + } + + // If we need to evict, sort our list of entries and evict the largest + // ones. (We could of course get better algorithmic complexity here by using + // a heap or something more clever. But sHistoryMaxTotalViewers isn't large, + // so let's not worry about it.) + entries.Sort(); + + for (int32_t i = entries.Length() - 1; i >= sHistoryMaxTotalViewers; --i) { + (entries[i].mSHistory)->EvictContentViewerForEntry(entries[i].mEntry); + } +} + +nsresult nsSHistory::FindEntryForBFCache(nsIBFCacheEntry* aBFEntry, + nsISHEntry** aResult, + int32_t* aResultIndex) { + *aResult = nullptr; + *aResultIndex = -1; + + int32_t startIndex, endIndex; + WindowIndices(mIndex, &startIndex, &endIndex); + + for (int32_t i = startIndex; i <= endIndex; ++i) { + nsCOMPtr<nsISHEntry> shEntry = mEntries[i]; + + // Does shEntry have the same BFCacheEntry as the argument to this method? + if (shEntry->HasBFCacheEntry(aBFEntry)) { + shEntry.forget(aResult); + *aResultIndex = i; + return NS_OK; + } + } + return NS_ERROR_FAILURE; +} + +nsresult nsSHistory::EvictExpiredContentViewerForEntry( + nsIBFCacheEntry* aBFEntry) { + int32_t index; + nsCOMPtr<nsISHEntry> shEntry; + FindEntryForBFCache(aBFEntry, getter_AddRefs(shEntry), &index); + + if (index == mIndex) { + NS_WARNING("How did the current SHEntry expire?"); + return NS_OK; + } + + if (shEntry) { + EvictContentViewerForEntry(shEntry); + } + + return NS_OK; +} + +NS_IMETHODIMP_(void) +nsSHistory::AddToExpirationTracker(nsIBFCacheEntry* aBFEntry) { + RefPtr<nsSHEntryShared> entry = static_cast<nsSHEntryShared*>(aBFEntry); + if (!mHistoryTracker || !entry) { + return; + } + + mHistoryTracker->AddObject(entry); + return; +} + +NS_IMETHODIMP_(void) +nsSHistory::RemoveFromExpirationTracker(nsIBFCacheEntry* aBFEntry) { + RefPtr<nsSHEntryShared> entry = static_cast<nsSHEntryShared*>(aBFEntry); + MOZ_ASSERT(mHistoryTracker && !mHistoryTracker->IsEmpty()); + if (!mHistoryTracker || !entry) { + return; + } + + mHistoryTracker->RemoveObject(entry); +} + +// Evicts all content viewers in all history objects. This is very +// inefficient, because it requires a linear search through all SHistory +// objects for each viewer to be evicted. However, this method is called +// infrequently -- only when the disk or memory cache is cleared. + +// static +void nsSHistory::GloballyEvictAllContentViewers() { + int32_t maxViewers = sHistoryMaxTotalViewers; + sHistoryMaxTotalViewers = 0; + GloballyEvictContentViewers(); + sHistoryMaxTotalViewers = maxViewers; +} + +void GetDynamicChildren(nsISHEntry* aEntry, nsTArray<nsID>& aDocshellIDs) { + int32_t count = aEntry->GetChildCount(); + for (int32_t i = 0; i < count; ++i) { + nsCOMPtr<nsISHEntry> child; + aEntry->GetChildAt(i, getter_AddRefs(child)); + if (child) { + if (child->IsDynamicallyAdded()) { + child->GetDocshellID(*aDocshellIDs.AppendElement()); + } else { + GetDynamicChildren(child, aDocshellIDs); + } + } + } +} + +bool RemoveFromSessionHistoryEntry(nsISHEntry* aRoot, + nsTArray<nsID>& aDocshellIDs) { + bool didRemove = false; + int32_t childCount = aRoot->GetChildCount(); + for (int32_t i = childCount - 1; i >= 0; --i) { + nsCOMPtr<nsISHEntry> child; + aRoot->GetChildAt(i, getter_AddRefs(child)); + if (child) { + nsID docshelldID; + child->GetDocshellID(docshelldID); + if (aDocshellIDs.Contains(docshelldID)) { + didRemove = true; + aRoot->RemoveChild(child); + } else if (RemoveFromSessionHistoryEntry(child, aDocshellIDs)) { + didRemove = true; + } + } + } + return didRemove; +} + +bool RemoveChildEntries(nsISHistory* aHistory, int32_t aIndex, + nsTArray<nsID>& aEntryIDs) { + nsCOMPtr<nsISHEntry> root; + aHistory->GetEntryAtIndex(aIndex, getter_AddRefs(root)); + return root ? RemoveFromSessionHistoryEntry(root, aEntryIDs) : false; +} + +bool IsSameTree(nsISHEntry* aEntry1, nsISHEntry* aEntry2) { + if (!aEntry1 && !aEntry2) { + return true; + } + if ((!aEntry1 && aEntry2) || (aEntry1 && !aEntry2)) { + return false; + } + uint32_t id1 = aEntry1->GetID(); + uint32_t id2 = aEntry2->GetID(); + if (id1 != id2) { + return false; + } + + int32_t count1 = aEntry1->GetChildCount(); + int32_t count2 = aEntry2->GetChildCount(); + // We allow null entries in the end of the child list. + int32_t count = std::max(count1, count2); + for (int32_t i = 0; i < count; ++i) { + nsCOMPtr<nsISHEntry> child1, child2; + aEntry1->GetChildAt(i, getter_AddRefs(child1)); + aEntry2->GetChildAt(i, getter_AddRefs(child2)); + if (!IsSameTree(child1, child2)) { + return false; + } + } + + return true; +} + +bool nsSHistory::RemoveDuplicate(int32_t aIndex, bool aKeepNext) { + NS_ASSERTION(aIndex >= 0, "aIndex must be >= 0!"); + NS_ASSERTION(aIndex != 0 || aKeepNext, + "If we're removing index 0 we must be keeping the next"); + NS_ASSERTION(aIndex != mIndex, "Shouldn't remove mIndex!"); + + int32_t compareIndex = aKeepNext ? aIndex + 1 : aIndex - 1; + + nsresult rv; + nsCOMPtr<nsISHEntry> root1, root2; + rv = GetEntryAtIndex(aIndex, getter_AddRefs(root1)); + if (NS_FAILED(rv)) { + return false; + } + rv = GetEntryAtIndex(compareIndex, getter_AddRefs(root2)); + if (NS_FAILED(rv)) { + return false; + } + + SHistoryChangeNotifier change(this); + + if (IsSameTree(root1, root2)) { + mEntries.RemoveElementAt(aIndex); + + // FIXME Bug 1546350: Reimplement history listeners. + // if (mRootBC && mRootBC->GetDocShell()) { + // static_cast<nsDocShell*>(mRootBC->GetDocShell()) + // ->HistoryEntryRemoved(aIndex); + //} + + // Adjust our indices to reflect the removed entry. + if (mIndex > aIndex) { + mIndex = mIndex - 1; + } + + // NB: If the entry we are removing is the entry currently + // being navigated to (mRequestedIndex) then we adjust the index + // only if we're not keeping the next entry (because if we are keeping + // the next entry (because the current is a duplicate of the next), then + // that entry slides into the spot that we're currently pointing to. + // We don't do this adjustment for mIndex because mIndex cannot equal + // aIndex. + + // NB: We don't need to guard on mRequestedIndex being nonzero here, + // because either they're strictly greater than aIndex which is at least + // zero, or they are equal to aIndex in which case aKeepNext must be true + // if aIndex is zero. + if (mRequestedIndex > aIndex || (mRequestedIndex == aIndex && !aKeepNext)) { + mRequestedIndex = mRequestedIndex - 1; + } + + return true; + } + return false; +} + +NS_IMETHODIMP_(void) +nsSHistory::RemoveEntries(nsTArray<nsID>& aIDs, int32_t aStartIndex) { + bool didRemove; + RemoveEntries(aIDs, aStartIndex, &didRemove); + if (didRemove && mRootBC && mRootBC->GetDocShell()) { + mRootBC->GetDocShell()->DispatchLocationChangeEvent(); + } +} + +void nsSHistory::RemoveEntries(nsTArray<nsID>& aIDs, int32_t aStartIndex, + bool* aDidRemove) { + SHistoryChangeNotifier change(this); + + int32_t index = aStartIndex; + while (index >= 0 && RemoveChildEntries(this, --index, aIDs)) { + } + int32_t minIndex = index; + index = aStartIndex; + while (index >= 0 && RemoveChildEntries(this, index++, aIDs)) { + } + + // We need to remove duplicate nsSHEntry trees. + *aDidRemove = false; + while (index > minIndex) { + if (index != mIndex && RemoveDuplicate(index, index < mIndex)) { + *aDidRemove = true; + } + --index; + } + + UpdateRootBrowsingContextState(); +} + +void nsSHistory::RemoveFrameEntries(nsISHEntry* aEntry) { + int32_t count = aEntry->GetChildCount(); + AutoTArray<nsID, 16> ids; + for (int32_t i = 0; i < count; ++i) { + nsCOMPtr<nsISHEntry> child; + aEntry->GetChildAt(i, getter_AddRefs(child)); + if (child) { + child->GetDocshellID(*ids.AppendElement()); + } + } + RemoveEntries(ids, mIndex); +} + +void nsSHistory::RemoveDynEntries(int32_t aIndex, nsISHEntry* aEntry) { + // Remove dynamic entries which are at the index and belongs to the container. + nsCOMPtr<nsISHEntry> entry(aEntry); + if (!entry) { + GetEntryAtIndex(aIndex, getter_AddRefs(entry)); + } + + if (entry) { + AutoTArray<nsID, 16> toBeRemovedEntries; + GetDynamicChildren(entry, toBeRemovedEntries); + if (toBeRemovedEntries.Length()) { + RemoveEntries(toBeRemovedEntries, aIndex); + } + } +} + +void nsSHistory::RemoveDynEntriesForBFCacheEntry(nsIBFCacheEntry* aBFEntry) { + int32_t index; + nsCOMPtr<nsISHEntry> shEntry; + FindEntryForBFCache(aBFEntry, getter_AddRefs(shEntry), &index); + if (shEntry) { + RemoveDynEntries(index, shEntry); + } +} + +NS_IMETHODIMP +nsSHistory::UpdateIndex() { + SHistoryChangeNotifier change(this); + + // Update the actual index with the right value. + if (mIndex != mRequestedIndex && mRequestedIndex != -1) { + mIndex = mRequestedIndex; + } + + mRequestedIndex = -1; + return NS_OK; +} + +NS_IMETHODIMP +nsSHistory::GotoIndex(int32_t aIndex) { + nsTArray<LoadEntryResult> loadResults; + nsresult rv = GotoIndex(aIndex, loadResults); + NS_ENSURE_SUCCESS(rv, rv); + + LoadURIs(loadResults); + return NS_OK; +} + +NS_IMETHODIMP_(void) +nsSHistory::EnsureCorrectEntryAtCurrIndex(nsISHEntry* aEntry) { + int index = mRequestedIndex == -1 ? mIndex : mRequestedIndex; + if (index > -1 && (mEntries[index] != aEntry)) { + ReplaceEntry(index, aEntry); + } +} + +nsresult nsSHistory::GotoIndex(int32_t aIndex, + nsTArray<LoadEntryResult>& aLoadResults, + bool aSameEpoch) { + return LoadEntry(aIndex, LOAD_HISTORY, HIST_CMD_GOTOINDEX, aLoadResults, + aSameEpoch); +} + +NS_IMETHODIMP_(bool) +nsSHistory::HasUserInteractionAtIndex(int32_t aIndex) { + nsCOMPtr<nsISHEntry> entry; + GetEntryAtIndex(aIndex, getter_AddRefs(entry)); + if (!entry) { + return false; + } + return entry->GetHasUserInteraction(); +} + +nsresult nsSHistory::LoadNextPossibleEntry( + int32_t aNewIndex, long aLoadType, uint32_t aHistCmd, + nsTArray<LoadEntryResult>& aLoadResults) { + mRequestedIndex = -1; + if (aNewIndex < mIndex) { + return LoadEntry(aNewIndex - 1, aLoadType, aHistCmd, aLoadResults); + } + if (aNewIndex > mIndex) { + return LoadEntry(aNewIndex + 1, aLoadType, aHistCmd, aLoadResults); + } + return NS_ERROR_FAILURE; +} + +nsresult nsSHistory::LoadEntry(int32_t aIndex, long aLoadType, + uint32_t aHistCmd, + nsTArray<LoadEntryResult>& aLoadResults, + bool aSameEpoch) { + MOZ_LOG(gSHistoryLog, LogLevel::Debug, + ("LoadEntry(%d, 0x%lx, %u)", aIndex, aLoadType, aHistCmd)); + if (!mRootBC) { + return NS_ERROR_FAILURE; + } + + if (aIndex < 0 || aIndex >= Length()) { + MOZ_LOG(gSHistoryLog, LogLevel::Debug, ("Index out of range")); + // The index is out of range + return NS_ERROR_FAILURE; + } + + // This is a normal local history navigation. + + nsCOMPtr<nsISHEntry> prevEntry; + nsCOMPtr<nsISHEntry> nextEntry; + GetEntryAtIndex(mIndex, getter_AddRefs(prevEntry)); + GetEntryAtIndex(aIndex, getter_AddRefs(nextEntry)); + if (!nextEntry || !prevEntry) { + mRequestedIndex = -1; + return NS_ERROR_FAILURE; + } + + if (mozilla::SessionHistoryInParent()) { + if (aHistCmd == HIST_CMD_GOTOINDEX) { + // https://html.spec.whatwg.org/#history-traversal: + // To traverse the history + // "If entry has a different Document object than the current entry, then + // run the following substeps: Remove any tasks queued by the history + // traversal task source..." + // + // aSameEpoch is true only if the navigations would have been + // generated in the same spin of the event loop (i.e. history.go(-2); + // history.go(-1)) and from the same content process. + if (aSameEpoch) { + bool same_doc = false; + prevEntry->SharesDocumentWith(nextEntry, &same_doc); + if (!same_doc) { + MOZ_LOG( + gSHistoryLog, LogLevel::Debug, + ("Aborting GotoIndex %d - same epoch and not same doc", aIndex)); + // Ignore this load. Before SessionHistoryInParent, this would + // have been dropped in InternalLoad after we filter out SameDoc + // loads. + return NS_ERROR_FAILURE; + } + } + } + } + // Keep note of requested history index in mRequestedIndex; after all bailouts + mRequestedIndex = aIndex; + + // Remember that this entry is getting loaded at this point in the sequence + + nextEntry->SetLastTouched(++gTouchCounter); + + // Get the uri for the entry we are about to visit + nsCOMPtr<nsIURI> nextURI = nextEntry->GetURI(); + + MOZ_ASSERT(nextURI, "nextURI can't be null"); + + // Send appropriate listener notifications. + if (aHistCmd == HIST_CMD_GOTOINDEX) { + // We are going somewhere else. This is not reload either + NOTIFY_LISTENERS(OnHistoryGotoIndex, ()); + } + + if (mRequestedIndex == mIndex) { + // Possibly a reload case + InitiateLoad(nextEntry, mRootBC, aLoadType, aLoadResults); + return NS_OK; + } + + // Going back or forward. + bool differenceFound = LoadDifferingEntries(prevEntry, nextEntry, mRootBC, + aLoadType, aLoadResults); + if (!differenceFound) { + // We did not find any differences. Go further in the history. + return LoadNextPossibleEntry(aIndex, aLoadType, aHistCmd, aLoadResults); + } + + return NS_OK; +} + +bool nsSHistory::LoadDifferingEntries(nsISHEntry* aPrevEntry, + nsISHEntry* aNextEntry, + BrowsingContext* aParent, long aLoadType, + nsTArray<LoadEntryResult>& aLoadResults) { + MOZ_ASSERT(aPrevEntry && aNextEntry && aParent); + + uint32_t prevID = aPrevEntry->GetID(); + uint32_t nextID = aNextEntry->GetID(); + + // Check the IDs to verify if the pages are different. + if (prevID != nextID) { + // Set the Subframe flag if not navigating the root docshell. + aNextEntry->SetIsSubFrame(aParent != mRootBC); + InitiateLoad(aNextEntry, aParent, aLoadType, aLoadResults); + return true; + } + + // The entries are the same, so compare any child frames + int32_t pcnt = aPrevEntry->GetChildCount(); + int32_t ncnt = aNextEntry->GetChildCount(); + + // Create an array for child browsing contexts. + nsTArray<RefPtr<BrowsingContext>> browsingContexts; + aParent->GetChildren(browsingContexts); + + // Search for something to load next. + bool differenceFound = false; + for (int32_t i = 0; i < ncnt; ++i) { + // First get an entry which may cause a new page to be loaded. + nsCOMPtr<nsISHEntry> nChild; + aNextEntry->GetChildAt(i, getter_AddRefs(nChild)); + if (!nChild) { + continue; + } + nsID docshellID; + nChild->GetDocshellID(docshellID); + + // Then find the associated docshell. + RefPtr<BrowsingContext> bcChild; + for (const RefPtr<BrowsingContext>& bc : browsingContexts) { + if (bc->GetHistoryID() == docshellID) { + bcChild = bc; + break; + } + } + if (!bcChild) { + continue; + } + + // Then look at the previous entries to see if there was + // an entry for the docshell. + nsCOMPtr<nsISHEntry> pChild; + for (int32_t k = 0; k < pcnt; ++k) { + nsCOMPtr<nsISHEntry> child; + aPrevEntry->GetChildAt(k, getter_AddRefs(child)); + if (child) { + nsID dID; + child->GetDocshellID(dID); + if (dID == docshellID) { + pChild = child; + break; + } + } + } + if (!pChild) { + continue; + } + + // Finally recursively call this method. + // This will either load a new page to shell or some subshell or + // do nothing. + if (LoadDifferingEntries(pChild, nChild, bcChild, aLoadType, + aLoadResults)) { + differenceFound = true; + } + } + return differenceFound; +} + +void nsSHistory::InitiateLoad(nsISHEntry* aFrameEntry, + BrowsingContext* aFrameBC, long aLoadType, + nsTArray<LoadEntryResult>& aLoadResults) { + MOZ_ASSERT(aFrameBC && aFrameEntry); + + LoadEntryResult* loadResult = aLoadResults.AppendElement(); + loadResult->mBrowsingContext = aFrameBC; + + nsCOMPtr<nsIURI> newURI = aFrameEntry->GetURI(); + RefPtr<nsDocShellLoadState> loadState = new nsDocShellLoadState(newURI); + + /* Set the loadType in the SHEntry too to what was passed on. + * This will be passed on to child subframes later in nsDocShell, + * so that proper loadType is maintained through out a frameset + */ + aFrameEntry->SetLoadType(aLoadType); + + loadState->SetLoadType(aLoadType); + + loadState->SetSHEntry(aFrameEntry); + + // If we're loading from the current active entry we want to treat it as not + // a same-document navigation (see nsDocShell::IsSameDocumentNavigation), so + // record that here in the LoadingSessionHistoryEntry. + bool loadingFromActiveEntry; + if (mozilla::SessionHistoryInParent()) { + loadingFromActiveEntry = + aFrameBC->Canonical()->GetActiveSessionHistoryEntry() == aFrameEntry; + } else { + loadingFromActiveEntry = + aFrameBC->GetDocShell() && + nsDocShell::Cast(aFrameBC->GetDocShell())->IsOSHE(aFrameEntry); + } + loadState->SetLoadIsFromSessionHistory(mRequestedIndex, Length(), + loadingFromActiveEntry); + + if (mozilla::SessionHistoryInParent()) { + nsCOMPtr<SessionHistoryEntry> she = do_QueryInterface(aFrameEntry); + aFrameBC->Canonical()->AddLoadingSessionHistoryEntry( + loadState->GetLoadingSessionHistoryInfo()->mLoadId, she); + } + + nsCOMPtr<nsIURI> originalURI = aFrameEntry->GetOriginalURI(); + loadState->SetOriginalURI(originalURI); + + loadState->SetLoadReplace(aFrameEntry->GetLoadReplace()); + + loadState->SetLoadFlags(nsIWebNavigation::LOAD_FLAGS_NONE); + nsCOMPtr<nsIPrincipal> triggeringPrincipal = + aFrameEntry->GetTriggeringPrincipal(); + loadState->SetTriggeringPrincipal(triggeringPrincipal); + loadState->SetFirstParty(false); + nsCOMPtr<nsIContentSecurityPolicy> csp = aFrameEntry->GetCsp(); + loadState->SetCsp(csp); + + loadResult->mLoadState = std::move(loadState); +} + +NS_IMETHODIMP +nsSHistory::CreateEntry(nsISHEntry** aEntry) { + nsCOMPtr<nsISHEntry> entry; + if (XRE_IsParentProcess() && mozilla::SessionHistoryInParent()) { + entry = new SessionHistoryEntry(); + } else { + entry = new nsSHEntry(); + } + entry.forget(aEntry); + return NS_OK; +} + +NS_IMETHODIMP_(bool) +nsSHistory::IsEmptyOrHasEntriesForSingleTopLevelPage() { + if (mEntries.IsEmpty()) { + return true; + } + + nsISHEntry* entry = mEntries[0]; + size_t length = mEntries.Length(); + for (size_t i = 1; i < length; ++i) { + bool sharesDocument = false; + mEntries[i]->SharesDocumentWith(entry, &sharesDocument); + if (!sharesDocument) { + return false; + } + } + + return true; +} |