michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
michael@0:  *
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: // Local Includes 
michael@0: #include "nsSHistory.h"
michael@0: #include <algorithm>
michael@0: 
michael@0: // Helper Classes
michael@0: #include "mozilla/Preferences.h"
michael@0: 
michael@0: // Interfaces Needed
michael@0: #include "nsILayoutHistoryState.h"
michael@0: #include "nsIDocShell.h"
michael@0: #include "nsIDocShellLoadInfo.h"
michael@0: #include "nsISHContainer.h"
michael@0: #include "nsIDocShellTreeItem.h"
michael@0: #include "nsIURI.h"
michael@0: #include "nsIContentViewer.h"
michael@0: #include "nsICacheService.h"
michael@0: #include "nsIObserverService.h"
michael@0: #include "prclist.h"
michael@0: #include "mozilla/Services.h"
michael@0: #include "nsTArray.h"
michael@0: #include "nsCOMArray.h"
michael@0: #include "nsDocShell.h"
michael@0: #include "mozilla/Attributes.h"
michael@0: #include "nsISHEntry.h"
michael@0: #include "nsISHTransaction.h"
michael@0: #include "nsISHistoryListener.h"
michael@0: #include "nsComponentManagerUtils.h"
michael@0: 
michael@0: // For calculating max history entries and max cachable contentviewers
michael@0: #include "prsystem.h"
michael@0: #include "mozilla/MathAlgorithms.h"
michael@0: 
michael@0: using namespace mozilla;
michael@0: 
michael@0: #define PREF_SHISTORY_SIZE "browser.sessionhistory.max_entries"
michael@0: #define PREF_SHISTORY_MAX_TOTAL_VIEWERS "browser.sessionhistory.max_total_viewers"
michael@0: 
michael@0: static const char* kObservedPrefs[] = {
michael@0:   PREF_SHISTORY_SIZE,
michael@0:   PREF_SHISTORY_MAX_TOTAL_VIEWERS,
michael@0:   nullptr
michael@0: };
michael@0: 
michael@0: static int32_t  gHistoryMaxSize = 50;
michael@0: // Max viewers allowed per SHistory objects
michael@0: static const int32_t  gHistoryMaxViewers = 3;
michael@0: // List of all SHistory objects, used for content viewer cache eviction
michael@0: static PRCList gSHistoryList;
michael@0: // Max viewers allowed total, across all SHistory objects - negative default
michael@0: // means we will calculate how many viewers to cache based on total memory
michael@0: int32_t nsSHistory::sHistoryMaxTotalViewers = -1;
michael@0: 
michael@0: // A counter that is used to be able to know the order in which
michael@0: // entries were touched, so that we can evict older entries first.
michael@0: static uint32_t gTouchCounter = 0;
michael@0: 
michael@0: #ifdef PR_LOGGING
michael@0: 
michael@0: static PRLogModuleInfo*
michael@0: GetSHistoryLog()
michael@0: {
michael@0:   static PRLogModuleInfo *sLog;
michael@0:   if (!sLog)
michael@0:     sLog = PR_NewLogModule("nsSHistory");
michael@0:   return sLog;
michael@0: }
michael@0: #define LOG(format) PR_LOG(GetSHistoryLog(), PR_LOG_DEBUG, format)
michael@0: 
michael@0: // This macro makes it easier to print a log message which includes a URI's
michael@0: // spec.  Example use:
michael@0: //
michael@0: //  nsIURI *uri = [...];
michael@0: //  LOG_SPEC(("The URI is %s.", _spec), uri);
michael@0: //
michael@0: #define LOG_SPEC(format, uri)                              \
michael@0:   PR_BEGIN_MACRO                                           \
michael@0:     if (PR_LOG_TEST(GetSHistoryLog(), PR_LOG_DEBUG)) {     \
michael@0:       nsAutoCString _specStr(NS_LITERAL_CSTRING("(null)"));\
michael@0:       if (uri) {                                           \
michael@0:         uri->GetSpec(_specStr);                            \
michael@0:       }                                                    \
michael@0:       const char* _spec = _specStr.get();                  \
michael@0:       LOG(format);                                         \
michael@0:     }                                                      \
michael@0:   PR_END_MACRO
michael@0: 
michael@0: // This macro makes it easy to log a message including an SHEntry's URI.
michael@0: // For example:
michael@0: //
michael@0: //  nsCOMPtr<nsISHEntry> shentry = [...];
michael@0: //  LOG_SHENTRY_SPEC(("shentry %p has uri %s.", shentry.get(), _spec), shentry);
michael@0: //
michael@0: #define LOG_SHENTRY_SPEC(format, shentry)                  \
michael@0:   PR_BEGIN_MACRO                                           \
michael@0:     if (PR_LOG_TEST(GetSHistoryLog(), PR_LOG_DEBUG)) {     \
michael@0:       nsCOMPtr<nsIURI> uri;                                \
michael@0:       shentry->GetURI(getter_AddRefs(uri));                \
michael@0:       LOG_SPEC(format, uri);                               \
michael@0:     }                                                      \
michael@0:   PR_END_MACRO
michael@0: 
michael@0: #else // !PR_LOGGING
michael@0: 
michael@0: #define LOG(format)
michael@0: #define LOG_SPEC(format, uri)
michael@0: #define LOG_SHENTRY_SPEC(format, shentry)
michael@0: 
michael@0: #endif // PR_LOGGING
michael@0: 
michael@0: // Iterates over all registered session history listeners.
michael@0: #define ITERATE_LISTENERS(body)                            \
michael@0:   PR_BEGIN_MACRO                                           \
michael@0:   {                                                        \
michael@0:     nsAutoTObserverArray<nsWeakPtr, 2>::EndLimitedIterator \
michael@0:       iter(mListeners);                                    \
michael@0:     while (iter.HasMore()) {                               \
michael@0:       nsCOMPtr<nsISHistoryListener> listener =             \
michael@0:         do_QueryReferent(iter.GetNext());                  \
michael@0:       if (listener) {                                      \
michael@0:         body                                               \
michael@0:       }                                                    \
michael@0:     }                                                      \
michael@0:   }                                                        \
michael@0:   PR_END_MACRO
michael@0: 
michael@0: // Calls a given method on all registered session history listeners.
michael@0: #define NOTIFY_LISTENERS(method, args)                     \
michael@0:   ITERATE_LISTENERS(                                       \
michael@0:     listener->method args;                                 \
michael@0:   );
michael@0: 
michael@0: // Calls a given method on all registered session history listeners.
michael@0: // Listeners may return 'false' to cancel an action so make sure that we
michael@0: // set the return value to 'false' if one of the listeners wants to cancel.
michael@0: #define NOTIFY_LISTENERS_CANCELABLE(method, retval, args)  \
michael@0:   PR_BEGIN_MACRO                                           \
michael@0:   {                                                        \
michael@0:     bool canceled = false;                                 \
michael@0:     retval = true;                                         \
michael@0:     ITERATE_LISTENERS(                                     \
michael@0:       listener->method args;                               \
michael@0:       if (!retval) {                                       \
michael@0:         canceled = true;                                   \
michael@0:       }                                                    \
michael@0:     );                                                     \
michael@0:     if (canceled) {                                        \
michael@0:       retval = false;                                      \
michael@0:     }                                                      \
michael@0:   }                                                        \
michael@0:   PR_END_MACRO
michael@0: 
michael@0: enum HistCmd{
michael@0:   HIST_CMD_BACK,
michael@0:   HIST_CMD_FORWARD,
michael@0:   HIST_CMD_GOTOINDEX,
michael@0:   HIST_CMD_RELOAD
michael@0: } ;
michael@0: 
michael@0: //*****************************************************************************
michael@0: //***      nsSHistoryObserver
michael@0: //*****************************************************************************
michael@0: 
michael@0: class nsSHistoryObserver MOZ_FINAL : public nsIObserver
michael@0: {
michael@0: 
michael@0: public:
michael@0:   NS_DECL_ISUPPORTS
michael@0:   NS_DECL_NSIOBSERVER
michael@0: 
michael@0:   nsSHistoryObserver() {}
michael@0: 
michael@0: protected:
michael@0:   ~nsSHistoryObserver() {}
michael@0: };
michael@0: 
michael@0: static nsSHistoryObserver* gObserver = nullptr;
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(nsSHistoryObserver, nsIObserver)
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistoryObserver::Observe(nsISupports *aSubject, const char *aTopic,
michael@0:                             const char16_t *aData)
michael@0: {
michael@0:   if (!strcmp(aTopic, NS_PREFBRANCH_PREFCHANGE_TOPIC_ID)) {
michael@0:     nsSHistory::UpdatePrefs();
michael@0:     nsSHistory::GloballyEvictContentViewers();
michael@0:   } else if (!strcmp(aTopic, NS_CACHESERVICE_EMPTYCACHE_TOPIC_ID) ||
michael@0:              !strcmp(aTopic, "memory-pressure")) {
michael@0:     nsSHistory::GloballyEvictAllContentViewers();
michael@0:   }
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: already_AddRefed<nsIContentViewer>
michael@0: GetContentViewerForTransaction(nsISHTransaction *aTrans)
michael@0: {
michael@0:   nsCOMPtr<nsISHEntry> entry;
michael@0:   aTrans->GetSHEntry(getter_AddRefs(entry));
michael@0:   if (!entry) {
michael@0:     return nullptr;
michael@0:   }
michael@0: 
michael@0:   nsCOMPtr<nsISHEntry> ownerEntry;
michael@0:   nsCOMPtr<nsIContentViewer> viewer;
michael@0:   entry->GetAnyContentViewer(getter_AddRefs(ownerEntry),
michael@0:                              getter_AddRefs(viewer));
michael@0:   return viewer.forget();
michael@0: }
michael@0: 
michael@0: void
michael@0: EvictContentViewerForTransaction(nsISHTransaction *aTrans)
michael@0: {
michael@0:   nsCOMPtr<nsISHEntry> entry;
michael@0:   aTrans->GetSHEntry(getter_AddRefs(entry));
michael@0:   nsCOMPtr<nsIContentViewer> viewer;
michael@0:   nsCOMPtr<nsISHEntry> ownerEntry;
michael@0:   entry->GetAnyContentViewer(getter_AddRefs(ownerEntry),
michael@0:                              getter_AddRefs(viewer));
michael@0:   if (viewer) {
michael@0:     NS_ASSERTION(ownerEntry,
michael@0:                  "Content viewer exists but its SHEntry is null");
michael@0: 
michael@0:     LOG_SHENTRY_SPEC(("Evicting content viewer 0x%p for "
michael@0:                       "owning SHEntry 0x%p at %s.",
michael@0:                       viewer.get(), ownerEntry.get(), _spec), ownerEntry);
michael@0: 
michael@0:     // Drop the presentation state before destroying the viewer, so that
michael@0:     // document teardown is able to correctly persist the state.
michael@0:     ownerEntry->SetContentViewer(nullptr);
michael@0:     ownerEntry->SyncPresentationState();
michael@0:     viewer->Destroy();
michael@0:   }
michael@0: }
michael@0: 
michael@0: } // anonymous namespace
michael@0: 
michael@0: //*****************************************************************************
michael@0: //***    nsSHistory: Object Management
michael@0: //*****************************************************************************
michael@0: 
michael@0: nsSHistory::nsSHistory() : mListRoot(nullptr), mIndex(-1), mLength(0), mRequestedIndex(-1)
michael@0: {
michael@0:   // Add this new SHistory object to the list
michael@0:   PR_APPEND_LINK(this, &gSHistoryList);
michael@0: }
michael@0: 
michael@0: 
michael@0: nsSHistory::~nsSHistory()
michael@0: {
michael@0:   // Remove this SHistory object from the list
michael@0:   PR_REMOVE_LINK(this);
michael@0: }
michael@0: 
michael@0: //*****************************************************************************
michael@0: //    nsSHistory: nsISupports
michael@0: //*****************************************************************************
michael@0: 
michael@0: NS_IMPL_ADDREF(nsSHistory)
michael@0: NS_IMPL_RELEASE(nsSHistory)
michael@0: 
michael@0: NS_INTERFACE_MAP_BEGIN(nsSHistory)
michael@0:    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsISHistory)
michael@0:    NS_INTERFACE_MAP_ENTRY(nsISHistory)
michael@0:    NS_INTERFACE_MAP_ENTRY(nsIWebNavigation)
michael@0:    NS_INTERFACE_MAP_ENTRY(nsISHistoryInternal)
michael@0: NS_INTERFACE_MAP_END
michael@0: 
michael@0: //*****************************************************************************
michael@0: //    nsSHistory: nsISHistory
michael@0: //*****************************************************************************
michael@0: 
michael@0: // static
michael@0: uint32_t
michael@0: nsSHistory::CalcMaxTotalViewers()
michael@0: {
michael@0:   // Calculate an estimate of how many ContentViewers we should cache based
michael@0:   // on RAM.  This assumes that the average ContentViewer is 4MB (conservative)
michael@0:   // and caps the max at 8 ContentViewers
michael@0:   //
michael@0:   // TODO: Should we split the cache memory betw. ContentViewer caching and
michael@0:   // nsCacheService?
michael@0:   //
michael@0:   // RAM      ContentViewers
michael@0:   // -----------------------
michael@0:   // 32   Mb       0
michael@0:   // 64   Mb       1
michael@0:   // 128  Mb       2
michael@0:   // 256  Mb       3
michael@0:   // 512  Mb       5
michael@0:   // 1024 Mb       8
michael@0:   // 2048 Mb       8
michael@0:   // 4096 Mb       8
michael@0:   uint64_t bytes = PR_GetPhysicalMemorySize();
michael@0: 
michael@0:   if (bytes == 0)
michael@0:     return 0;
michael@0: 
michael@0:   // Conversion from unsigned int64_t to double doesn't work on all platforms.
michael@0:   // We need to truncate the value at INT64_MAX to make sure we don't
michael@0:   // overflow.
michael@0:   if (bytes > INT64_MAX)
michael@0:     bytes = INT64_MAX;
michael@0: 
michael@0:   double kBytesD = (double)(bytes >> 10);
michael@0: 
michael@0:   // This is essentially the same calculation as for nsCacheService,
michael@0:   // except that we divide the final memory calculation by 4, since
michael@0:   // we assume each ContentViewer takes on average 4MB
michael@0:   uint32_t viewers = 0;
michael@0:   double x = std::log(kBytesD)/std::log(2.0) - 14;
michael@0:   if (x > 0) {
michael@0:     viewers    = (uint32_t)(x * x - x + 2.001); // add .001 for rounding
michael@0:     viewers   /= 4;
michael@0:   }
michael@0: 
michael@0:   // Cap it off at 8 max
michael@0:   if (viewers > 8) {
michael@0:     viewers = 8;
michael@0:   }
michael@0:   return viewers;
michael@0: }
michael@0: 
michael@0: // static
michael@0: void
michael@0: nsSHistory::UpdatePrefs()
michael@0: {
michael@0:   Preferences::GetInt(PREF_SHISTORY_SIZE, &gHistoryMaxSize);
michael@0:   Preferences::GetInt(PREF_SHISTORY_MAX_TOTAL_VIEWERS,
michael@0:                       &sHistoryMaxTotalViewers);
michael@0:   // If the pref is negative, that means we calculate how many viewers
michael@0:   // we think we should cache, based on total memory
michael@0:   if (sHistoryMaxTotalViewers < 0) {
michael@0:     sHistoryMaxTotalViewers = CalcMaxTotalViewers();
michael@0:   }
michael@0: }
michael@0: 
michael@0: // static
michael@0: nsresult
michael@0: nsSHistory::Startup()
michael@0: {
michael@0:   UpdatePrefs();
michael@0: 
michael@0:   // The goal of this is to unbreak users who have inadvertently set their
michael@0:   // session history size to less than the default value.
michael@0:   int32_t defaultHistoryMaxSize =
michael@0:     Preferences::GetDefaultInt(PREF_SHISTORY_SIZE, 50);
michael@0:   if (gHistoryMaxSize < defaultHistoryMaxSize) {
michael@0:     gHistoryMaxSize = defaultHistoryMaxSize;
michael@0:   }
michael@0:   
michael@0:   // Allow the user to override the max total number of cached viewers,
michael@0:   // but keep the per SHistory cached viewer limit constant
michael@0:   if (!gObserver) {
michael@0:     gObserver = new nsSHistoryObserver();
michael@0:     NS_ADDREF(gObserver);
michael@0:     Preferences::AddStrongObservers(gObserver, kObservedPrefs);
michael@0: 
michael@0:     nsCOMPtr<nsIObserverService> obsSvc =
michael@0:       mozilla::services::GetObserverService();
michael@0:     if (obsSvc) {
michael@0:       // Observe empty-cache notifications so tahat clearing the disk/memory
michael@0:       // cache will also evict all content viewers.
michael@0:       obsSvc->AddObserver(gObserver,
michael@0:                           NS_CACHESERVICE_EMPTYCACHE_TOPIC_ID, false);
michael@0: 
michael@0:       // Same for memory-pressure notifications
michael@0:       obsSvc->AddObserver(gObserver, "memory-pressure", false);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   // Initialize the global list of all SHistory objects
michael@0:   PR_INIT_CLIST(&gSHistoryList);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: // static
michael@0: void
michael@0: nsSHistory::Shutdown()
michael@0: {
michael@0:   if (gObserver) {
michael@0:     Preferences::RemoveObservers(gObserver, kObservedPrefs);
michael@0:     nsCOMPtr<nsIObserverService> obsSvc =
michael@0:       mozilla::services::GetObserverService();
michael@0:     if (obsSvc) {
michael@0:       obsSvc->RemoveObserver(gObserver, NS_CACHESERVICE_EMPTYCACHE_TOPIC_ID);
michael@0:       obsSvc->RemoveObserver(gObserver, "memory-pressure");
michael@0:     }
michael@0:     NS_RELEASE(gObserver);
michael@0:   }
michael@0: }
michael@0: 
michael@0: /* Add an entry to the History list at mIndex and 
michael@0:  * increment the index to point to the new entry
michael@0:  */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::AddEntry(nsISHEntry * aSHEntry, bool aPersist)
michael@0: {
michael@0:   NS_ENSURE_ARG(aSHEntry);
michael@0: 
michael@0:   nsCOMPtr<nsISHTransaction> currentTxn;
michael@0: 
michael@0:   if(mListRoot)
michael@0:     GetTransactionAtIndex(mIndex, getter_AddRefs(currentTxn));
michael@0: 
michael@0:   bool currentPersist = true;
michael@0:   if(currentTxn)
michael@0:     currentTxn->GetPersist(&currentPersist);
michael@0: 
michael@0:   int32_t currentIndex = mIndex;
michael@0: 
michael@0:   if(!currentPersist)
michael@0:   {
michael@0:     NOTIFY_LISTENERS(OnHistoryReplaceEntry, (currentIndex));
michael@0:     NS_ENSURE_SUCCESS(currentTxn->SetSHEntry(aSHEntry),NS_ERROR_FAILURE);
michael@0:     currentTxn->SetPersist(aPersist);
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   nsCOMPtr<nsISHTransaction> txn(do_CreateInstance(NS_SHTRANSACTION_CONTRACTID));
michael@0:   NS_ENSURE_TRUE(txn, NS_ERROR_FAILURE);
michael@0: 
michael@0:   nsCOMPtr<nsIURI> uri;
michael@0:   aSHEntry->GetURI(getter_AddRefs(uri));
michael@0:   NOTIFY_LISTENERS(OnHistoryNewEntry, (uri));
michael@0: 
michael@0:   // If a listener has changed mIndex, we need to get currentTxn again,
michael@0:   // otherwise we'll be left at an inconsistent state (see bug 320742)
michael@0:   if (currentIndex != mIndex) {
michael@0:     GetTransactionAtIndex(mIndex, getter_AddRefs(currentTxn));
michael@0:   }
michael@0: 
michael@0:   // Set the ShEntry and parent for the transaction. setting the 
michael@0:   // parent will properly set the parent child relationship
michael@0:   txn->SetPersist(aPersist);
michael@0:   NS_ENSURE_SUCCESS(txn->Create(aSHEntry, currentTxn), NS_ERROR_FAILURE);
michael@0:    
michael@0:   // A little tricky math here...  Basically when adding an object regardless of
michael@0:   // what the length was before, it should always be set back to the current and
michael@0:   // lop off the forward.
michael@0:   mLength = (++mIndex + 1);
michael@0: 
michael@0:   // If this is the very first transaction, initialize the list
michael@0:   if(!mListRoot)
michael@0:     mListRoot = txn;
michael@0: 
michael@0:   // Purge History list if it is too long
michael@0:   if ((gHistoryMaxSize >= 0) && (mLength > gHistoryMaxSize))
michael@0:     PurgeHistory(mLength-gHistoryMaxSize);
michael@0:   
michael@0:   RemoveDynEntries(mIndex - 1, mIndex);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: /* Get size of the history list */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetCount(int32_t * aResult)
michael@0: {
michael@0:   NS_ENSURE_ARG_POINTER(aResult);
michael@0:   *aResult = mLength;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: /* Get index of the history list */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetIndex(int32_t * aResult)
michael@0: {
michael@0:   NS_PRECONDITION(aResult, "null out param?");
michael@0:   *aResult = mIndex;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: /* Get the requestedIndex */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetRequestedIndex(int32_t * aResult)
michael@0: {
michael@0:   NS_PRECONDITION(aResult, "null out param?");
michael@0:   *aResult = mRequestedIndex;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: /* Get the entry at a given index */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetEntryAtIndex(int32_t aIndex, bool aModifyIndex, nsISHEntry** aResult)
michael@0: {
michael@0:   nsresult rv;
michael@0:   nsCOMPtr<nsISHTransaction> txn;
michael@0: 
michael@0:   /* GetTransactionAtIndex ensures aResult is valid and validates aIndex */
michael@0:   rv = GetTransactionAtIndex(aIndex, getter_AddRefs(txn));
michael@0:   if (NS_SUCCEEDED(rv) && txn) {
michael@0:     //Get the Entry from the transaction
michael@0:     rv = txn->GetSHEntry(aResult);
michael@0:     if (NS_SUCCEEDED(rv) && (*aResult)) {
michael@0:       // Set mIndex to the requested index, if asked to do so..
michael@0:       if (aModifyIndex) {
michael@0:         mIndex = aIndex;
michael@0:       }
michael@0:     } //entry
michael@0:   }  //Transaction
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: /* Get the transaction at a given index */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetTransactionAtIndex(int32_t aIndex, nsISHTransaction ** aResult)
michael@0: {
michael@0:   nsresult rv;
michael@0:   NS_ENSURE_ARG_POINTER(aResult);
michael@0: 
michael@0:   if ((mLength <= 0) || (aIndex < 0) || (aIndex >= mLength))
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   if (!mListRoot) 
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   if (aIndex == 0)
michael@0:   {
michael@0:     *aResult = mListRoot;
michael@0:     NS_ADDREF(*aResult);
michael@0:     return NS_OK;
michael@0:   } 
michael@0:   int32_t   cnt=0;
michael@0:   nsCOMPtr<nsISHTransaction>  tempPtr;
michael@0: 
michael@0:   rv = GetRootTransaction(getter_AddRefs(tempPtr));
michael@0:   if (NS_FAILED(rv) || !tempPtr)
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   while(1) {
michael@0:     nsCOMPtr<nsISHTransaction> ptr;
michael@0:     rv = tempPtr->GetNext(getter_AddRefs(ptr));
michael@0:     if (NS_SUCCEEDED(rv) && ptr) {
michael@0:       cnt++;
michael@0:       if (cnt == aIndex) {
michael@0:         *aResult = ptr;
michael@0:         NS_ADDREF(*aResult);
michael@0:         break;
michael@0:       }
michael@0:       else {
michael@0:         tempPtr = ptr;
michael@0:         continue;
michael@0:       }
michael@0:     }  //NS_SUCCEEDED
michael@0:     else 
michael@0:       return NS_ERROR_FAILURE;
michael@0:   }  // while 
michael@0:   
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: /* Get the index of a given entry */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetIndexOfEntry(nsISHEntry* aSHEntry, int32_t* aResult) {
michael@0:   NS_ENSURE_ARG(aSHEntry);
michael@0:   NS_ENSURE_ARG_POINTER(aResult);
michael@0:   *aResult = -1;
michael@0: 
michael@0:   if (mLength <= 0) {
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0: 
michael@0:   nsCOMPtr<nsISHTransaction> currentTxn;
michael@0:   int32_t cnt = 0;
michael@0: 
michael@0:   nsresult rv = GetRootTransaction(getter_AddRefs(currentTxn));
michael@0:   if (NS_FAILED(rv) || !currentTxn) {
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0: 
michael@0:   while (true) {
michael@0:     nsCOMPtr<nsISHEntry> entry;
michael@0:     rv = currentTxn->GetSHEntry(getter_AddRefs(entry));
michael@0:     if (NS_FAILED(rv) || !entry) {
michael@0:       return NS_ERROR_FAILURE;
michael@0:     }
michael@0: 
michael@0:     if (aSHEntry == entry) {
michael@0:       *aResult = cnt;
michael@0:       break;
michael@0:     }
michael@0: 
michael@0:     rv = currentTxn->GetNext(getter_AddRefs(currentTxn));
michael@0:     if (NS_FAILED(rv) || !currentTxn) {
michael@0:       return NS_ERROR_FAILURE;
michael@0:     }
michael@0: 
michael@0:     cnt++;
michael@0:   }
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: #ifdef DEBUG
michael@0: nsresult
michael@0: nsSHistory::PrintHistory()
michael@0: {
michael@0: 
michael@0:   nsCOMPtr<nsISHTransaction>   txn;
michael@0:   int32_t index = 0;
michael@0:   nsresult rv;
michael@0: 
michael@0:   if (!mListRoot) 
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   txn = mListRoot;
michael@0:     
michael@0:   while (1) {
michael@0:     if (!txn)
michael@0:       break;
michael@0:     nsCOMPtr<nsISHEntry>  entry;
michael@0:     rv = txn->GetSHEntry(getter_AddRefs(entry));
michael@0:     if (NS_FAILED(rv) && !entry)
michael@0:       return NS_ERROR_FAILURE;
michael@0: 
michael@0:     nsCOMPtr<nsILayoutHistoryState> layoutHistoryState;
michael@0:     nsCOMPtr<nsIURI>  uri;
michael@0:     nsXPIDLString title;
michael@0: 
michael@0:     entry->GetLayoutHistoryState(getter_AddRefs(layoutHistoryState));
michael@0:     entry->GetURI(getter_AddRefs(uri));
michael@0:     entry->GetTitle(getter_Copies(title));
michael@0: 
michael@0: #if 0
michael@0:     nsAutoCString url;
michael@0:     if (uri)
michael@0:      uri->GetSpec(url);
michael@0: 
michael@0:     printf("**** SH Transaction #%d, Entry = %x\n", index, entry.get());
michael@0:     printf("\t\t URL = %s\n", url.get());
michael@0: 
michael@0:     printf("\t\t Title = %s\n", NS_LossyConvertUTF16toASCII(title).get());
michael@0:     printf("\t\t layout History Data = %x\n", layoutHistoryState.get());
michael@0: #endif
michael@0: 
michael@0:     nsCOMPtr<nsISHTransaction> next;
michael@0:     rv = txn->GetNext(getter_AddRefs(next));
michael@0:     if (NS_SUCCEEDED(rv) && next) {
michael@0:       txn = next;
michael@0:       index++;
michael@0:       continue;
michael@0:     }
michael@0:     else
michael@0:       break;
michael@0:   }
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: #endif
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetRootTransaction(nsISHTransaction ** aResult)
michael@0: {
michael@0:   NS_ENSURE_ARG_POINTER(aResult);
michael@0:   *aResult=mListRoot;
michael@0:   NS_IF_ADDREF(*aResult);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: /* Get the max size of the history list */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetMaxLength(int32_t * aResult)
michael@0: {
michael@0:   NS_ENSURE_ARG_POINTER(aResult);
michael@0:   *aResult = gHistoryMaxSize;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: /* Set the max size of the history list */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::SetMaxLength(int32_t aMaxSize)
michael@0: {
michael@0:   if (aMaxSize < 0)
michael@0:     return NS_ERROR_ILLEGAL_VALUE;
michael@0: 
michael@0:   gHistoryMaxSize = aMaxSize;
michael@0:   if (mLength > aMaxSize)
michael@0:     PurgeHistory(mLength-aMaxSize);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::PurgeHistory(int32_t aEntries)
michael@0: {
michael@0:   if (mLength <= 0 || aEntries <= 0)
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   aEntries = std::min(aEntries, mLength);
michael@0:   
michael@0:   bool purgeHistory = true;
michael@0:   NOTIFY_LISTENERS_CANCELABLE(OnHistoryPurge, purgeHistory,
michael@0:                               (aEntries, &purgeHistory));
michael@0: 
michael@0:   if (!purgeHistory) {
michael@0:     // Listener asked us not to purge
michael@0:     return NS_SUCCESS_LOSS_OF_INSIGNIFICANT_DATA;
michael@0:   }
michael@0: 
michael@0:   int32_t cnt = 0;
michael@0:   while (cnt < aEntries) {
michael@0:     nsCOMPtr<nsISHTransaction> nextTxn;
michael@0:     if (mListRoot) {
michael@0:       mListRoot->GetNext(getter_AddRefs(nextTxn));
michael@0:       mListRoot->SetNext(nullptr);
michael@0:     }
michael@0:     mListRoot = nextTxn;
michael@0:     if (mListRoot) {
michael@0:       mListRoot->SetPrev(nullptr);
michael@0:     }
michael@0:     cnt++;        
michael@0:   }
michael@0:   mLength -= cnt;
michael@0:   mIndex -= cnt;
michael@0: 
michael@0:   // Now if we were not at the end of the history, mIndex could have
michael@0:   // become far too negative.  If so, just set it to -1.
michael@0:   if (mIndex < -1) {
michael@0:     mIndex = -1;
michael@0:   }
michael@0: 
michael@0:   if (mRootDocShell)
michael@0:     mRootDocShell->HistoryPurged(cnt);
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::AddSHistoryListener(nsISHistoryListener * aListener)
michael@0: {
michael@0:   NS_ENSURE_ARG_POINTER(aListener);
michael@0: 
michael@0:   // Check if the listener supports Weak Reference. This is a must.
michael@0:   // This listener functionality is used by embedders and we want to 
michael@0:   // have the right ownership with who ever listens to SHistory
michael@0:   nsWeakPtr listener = do_GetWeakReference(aListener);
michael@0:   if (!listener) return NS_ERROR_FAILURE;
michael@0: 
michael@0:   return mListeners.AppendElementUnlessExists(listener) ?
michael@0:     NS_OK : NS_ERROR_OUT_OF_MEMORY;
michael@0: }
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::RemoveSHistoryListener(nsISHistoryListener * aListener)
michael@0: {
michael@0:   // Make sure the listener that wants to be removed is the
michael@0:   // one we have in store. 
michael@0:   nsWeakPtr listener = do_GetWeakReference(aListener);
michael@0:   mListeners.RemoveElement(listener);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: /* Replace an entry in the History list at a particular index.
michael@0:  * Do not update index or count.
michael@0:  */
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::ReplaceEntry(int32_t aIndex, nsISHEntry * aReplaceEntry)
michael@0: {
michael@0:   NS_ENSURE_ARG(aReplaceEntry);
michael@0:   nsresult rv;
michael@0:   nsCOMPtr<nsISHTransaction> currentTxn;
michael@0: 
michael@0:   if (!mListRoot) // Session History is not initialised.
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   rv = GetTransactionAtIndex(aIndex, getter_AddRefs(currentTxn));
michael@0: 
michael@0:   if(currentTxn)
michael@0:   {
michael@0:     NOTIFY_LISTENERS(OnHistoryReplaceEntry, (aIndex));
michael@0: 
michael@0:     // Set the replacement entry in the transaction
michael@0:     rv = currentTxn->SetSHEntry(aReplaceEntry);
michael@0:     rv = currentTxn->SetPersist(true);
michael@0:   }
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::NotifyOnHistoryReload(nsIURI* aReloadURI, uint32_t aReloadFlags,
michael@0:                                   bool* aCanReload)
michael@0: {
michael@0:   NOTIFY_LISTENERS_CANCELABLE(OnHistoryReload, *aCanReload,
michael@0:                               (aReloadURI, aReloadFlags, aCanReload));
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::EvictOutOfRangeContentViewers(int32_t aIndex)
michael@0: {
michael@0:   // Check our per SHistory object limit in the currently navigated SHistory
michael@0:   EvictOutOfRangeWindowContentViewers(aIndex);
michael@0:   // Check our total limit across all SHistory objects
michael@0:   GloballyEvictContentViewers();
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::EvictAllContentViewers()
michael@0: {
michael@0:   // XXXbz we don't actually do a good job of evicting things as we should, so
michael@0:   // we might have viewers quite far from mIndex.  So just evict everything.
michael@0:   nsCOMPtr<nsISHTransaction> trans = mListRoot;
michael@0:   while (trans) {
michael@0:     EvictContentViewerForTransaction(trans);
michael@0: 
michael@0:     nsISHTransaction *temp = trans;
michael@0:     temp->GetNext(getter_AddRefs(trans));
michael@0:   }
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: 
michael@0: //*****************************************************************************
michael@0: //    nsSHistory: nsIWebNavigation
michael@0: //*****************************************************************************
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetCanGoBack(bool * aCanGoBack)
michael@0: {
michael@0:   NS_ENSURE_ARG_POINTER(aCanGoBack);
michael@0:   *aCanGoBack = false;
michael@0: 
michael@0:   int32_t index = -1;
michael@0:   NS_ENSURE_SUCCESS(GetIndex(&index), NS_ERROR_FAILURE);
michael@0:   if(index > 0)
michael@0:      *aCanGoBack = true;
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetCanGoForward(bool * aCanGoForward)
michael@0: {
michael@0:   NS_ENSURE_ARG_POINTER(aCanGoForward);
michael@0:   *aCanGoForward = false;
michael@0: 
michael@0:   int32_t index = -1;
michael@0:   int32_t count = -1;
michael@0: 
michael@0:   NS_ENSURE_SUCCESS(GetIndex(&index), NS_ERROR_FAILURE);
michael@0:   NS_ENSURE_SUCCESS(GetCount(&count), NS_ERROR_FAILURE);
michael@0: 
michael@0:   if((index >= 0) && (index < (count - 1)))
michael@0:     *aCanGoForward = true;
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GoBack()
michael@0: {
michael@0:   bool canGoBack = false;
michael@0: 
michael@0:   GetCanGoBack(&canGoBack);
michael@0:   if (!canGoBack)  // Can't go back
michael@0:     return NS_ERROR_UNEXPECTED;
michael@0:   return LoadEntry(mIndex-1, nsIDocShellLoadInfo::loadHistory, HIST_CMD_BACK);
michael@0: }
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GoForward()
michael@0: {
michael@0:   bool canGoForward = false;
michael@0: 
michael@0:   GetCanGoForward(&canGoForward);
michael@0:   if (!canGoForward)  // Can't go forward
michael@0:     return NS_ERROR_UNEXPECTED;
michael@0:   return LoadEntry(mIndex+1, nsIDocShellLoadInfo::loadHistory, HIST_CMD_FORWARD);
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::Reload(uint32_t aReloadFlags)
michael@0: {
michael@0:   nsDocShellInfoLoadType loadType;
michael@0:   if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_BYPASS_PROXY && 
michael@0:       aReloadFlags & nsIWebNavigation::LOAD_FLAGS_BYPASS_CACHE)
michael@0:   {
michael@0:     loadType = nsIDocShellLoadInfo::loadReloadBypassProxyAndCache;
michael@0:   }
michael@0:   else if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_BYPASS_PROXY)
michael@0:   {
michael@0:     loadType = nsIDocShellLoadInfo::loadReloadBypassProxy;
michael@0:   }
michael@0:   else if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_BYPASS_CACHE)
michael@0:   {
michael@0:     loadType = nsIDocShellLoadInfo::loadReloadBypassCache;
michael@0:   }
michael@0:   else if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_CHARSET_CHANGE)
michael@0:   {
michael@0:     loadType = nsIDocShellLoadInfo::loadReloadCharsetChange;
michael@0:   }
michael@0:   else if (aReloadFlags & nsIWebNavigation::LOAD_FLAGS_ALLOW_MIXED_CONTENT)
michael@0:   {
michael@0:     loadType = nsIDocShellLoadInfo::loadReloadMixedContent;
michael@0:   }
michael@0:   else
michael@0:   {
michael@0:     loadType = nsIDocShellLoadInfo::loadReloadNormal;
michael@0:   }
michael@0: 
michael@0:   // We are reloading. Send Reload notifications.
michael@0:   // nsDocShellLoadFlagType is not public, where as nsIWebNavigation
michael@0:   // is public. So send the reload notifications with the
michael@0:   // nsIWebNavigation flags.
michael@0:   bool canNavigate = true;
michael@0:   nsCOMPtr<nsIURI> currentURI;
michael@0:   GetCurrentURI(getter_AddRefs(currentURI));
michael@0:   NOTIFY_LISTENERS_CANCELABLE(OnHistoryReload, canNavigate,
michael@0:                               (currentURI, aReloadFlags, &canNavigate));
michael@0:   if (!canNavigate)
michael@0:     return NS_OK;
michael@0: 
michael@0:   return LoadEntry(mIndex, loadType, HIST_CMD_RELOAD);
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::ReloadCurrentEntry()
michael@0: {
michael@0:   // Notify listeners
michael@0:   bool canNavigate = true;
michael@0:   nsCOMPtr<nsIURI> currentURI;
michael@0:   GetCurrentURI(getter_AddRefs(currentURI));
michael@0:   NOTIFY_LISTENERS_CANCELABLE(OnHistoryGotoIndex, canNavigate,
michael@0:                               (mIndex, currentURI, &canNavigate));
michael@0:   if (!canNavigate)
michael@0:     return NS_OK;
michael@0: 
michael@0:   return LoadEntry(mIndex, nsIDocShellLoadInfo::loadHistory, HIST_CMD_RELOAD);
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSHistory::EvictOutOfRangeWindowContentViewers(int32_t aIndex)
michael@0: {
michael@0:   // XXX rename method to EvictContentViewersExceptAroundIndex, or something.
michael@0: 
michael@0:   // We need to release all content viewers that are no longer in the range
michael@0:   //
michael@0:   //  aIndex - gHistoryMaxViewers to aIndex + gHistoryMaxViewers
michael@0:   //
michael@0:   // to ensure that this SHistory object isn't responsible for more than
michael@0:   // gHistoryMaxViewers content viewers.  But our job is complicated by the
michael@0:   // fact that two transactions which are related by either hash navigations or
michael@0:   // history.pushState will have the same content viewer.
michael@0:   //
michael@0:   // To illustrate the issue, suppose gHistoryMaxViewers = 3 and we have four
michael@0:   // linked transactions in our history.  Suppose we then add a new content
michael@0:   // viewer and call into this function.  So the history looks like:
michael@0:   //
michael@0:   //   A A A A B
michael@0:   //     +     *
michael@0:   //
michael@0:   // where the letters are content viewers and + and * denote the beginning and
michael@0:   // end of the range aIndex +/- gHistoryMaxViewers.
michael@0:   //
michael@0:   // Although one copy of the content viewer A exists outside the range, we
michael@0:   // don't want to evict A, because it has other copies in range!
michael@0:   //
michael@0:   // We therefore adjust our eviction strategy to read:
michael@0:   //
michael@0:   //   Evict each content viewer outside the range aIndex -/+
michael@0:   //   gHistoryMaxViewers, unless that content viewer also appears within the
michael@0:   //   range.
michael@0:   //
michael@0:   // (Note that it's entirely legal to have two copies of one content viewer
michael@0:   // separated by a different content viewer -- call pushState twice, go back
michael@0:   // once, and refresh -- so we can't rely on identical viewers only appearing
michael@0:   // adjacent to one another.)
michael@0: 
michael@0:   if (aIndex < 0) {
michael@0:     return;
michael@0:   }
michael@0:   NS_ENSURE_TRUE_VOID(aIndex < mLength);
michael@0: 
michael@0:   // Calculate the range that's safe from eviction.
michael@0:   int32_t startSafeIndex = std::max(0, aIndex - gHistoryMaxViewers);
michael@0:   int32_t endSafeIndex = std::min(mLength, aIndex + gHistoryMaxViewers);
michael@0: 
michael@0:   LOG(("EvictOutOfRangeWindowContentViewers(index=%d), "
michael@0:        "mLength=%d. Safe range [%d, %d]",
michael@0:        aIndex, mLength, startSafeIndex, endSafeIndex)); 
michael@0: 
michael@0:   // The content viewers in range aIndex -/+ gHistoryMaxViewers will not be
michael@0:   // evicted.  Collect a set of them so we don't accidentally evict one of them
michael@0:   // if it appears outside this range.
michael@0:   nsCOMArray<nsIContentViewer> safeViewers;
michael@0:   nsCOMPtr<nsISHTransaction> trans;
michael@0:   GetTransactionAtIndex(startSafeIndex, getter_AddRefs(trans));
michael@0:   for (int32_t i = startSafeIndex; trans && i <= endSafeIndex; i++) {
michael@0:     nsCOMPtr<nsIContentViewer> viewer = GetContentViewerForTransaction(trans);
michael@0:     safeViewers.AppendObject(viewer);
michael@0:     nsISHTransaction *temp = trans;
michael@0:     temp->GetNext(getter_AddRefs(trans));
michael@0:   }
michael@0: 
michael@0:   // Walk the SHistory list and evict any content viewers that aren't safe.
michael@0:   GetTransactionAtIndex(0, getter_AddRefs(trans));
michael@0:   while (trans) {
michael@0:     nsCOMPtr<nsIContentViewer> viewer = GetContentViewerForTransaction(trans);
michael@0:     if (safeViewers.IndexOf(viewer) == -1) {
michael@0:       EvictContentViewerForTransaction(trans);
michael@0:     }
michael@0: 
michael@0:     nsISHTransaction *temp = trans;
michael@0:     temp->GetNext(getter_AddRefs(trans));
michael@0:   }
michael@0: }
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: class TransactionAndDistance
michael@0: {
michael@0: public:
michael@0:   TransactionAndDistance(nsISHTransaction *aTrans, uint32_t aDist)
michael@0:     : mTransaction(aTrans)
michael@0:     , mDistance(aDist)
michael@0:   {
michael@0:     mViewer = GetContentViewerForTransaction(aTrans);
michael@0:     NS_ASSERTION(mViewer, "Transaction should have a content viewer");
michael@0: 
michael@0:     nsCOMPtr<nsISHEntry> shentry;
michael@0:     mTransaction->GetSHEntry(getter_AddRefs(shentry));
michael@0: 
michael@0:     nsCOMPtr<nsISHEntryInternal> shentryInternal = do_QueryInterface(shentry);
michael@0:     if (shentryInternal) {
michael@0:       shentryInternal->GetLastTouched(&mLastTouched);
michael@0:     } else {
michael@0:       NS_WARNING("Can't cast to nsISHEntryInternal?");
michael@0:       mLastTouched = 0;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   bool operator<(const TransactionAndDistance &aOther) const
michael@0:   {
michael@0:     // Compare distances first, and fall back to last-accessed times.
michael@0:     if (aOther.mDistance != this->mDistance) {
michael@0:       return this->mDistance < aOther.mDistance;
michael@0:     }
michael@0: 
michael@0:     return this->mLastTouched < aOther.mLastTouched;
michael@0:   }
michael@0: 
michael@0:   bool operator==(const TransactionAndDistance &aOther) const
michael@0:   {
michael@0:     // This is a little silly; we need == so the default comaprator can be
michael@0:     // instantiated, but this function is never actually called when we sort
michael@0:     // the list of TransactionAndDistance objects.
michael@0:     return aOther.mDistance == this->mDistance &&
michael@0:            aOther.mLastTouched == this->mLastTouched;
michael@0:   }
michael@0: 
michael@0:   nsCOMPtr<nsISHTransaction> mTransaction;
michael@0:   nsCOMPtr<nsIContentViewer> mViewer;
michael@0:   uint32_t mLastTouched;
michael@0:   int32_t mDistance;
michael@0: };
michael@0: 
michael@0: } // anonymous namespace
michael@0: 
michael@0: //static
michael@0: void
michael@0: nsSHistory::GloballyEvictContentViewers()
michael@0: {
michael@0:   // First, collect from each SHistory object the transactions which have a
michael@0:   // cached content viewer.  Associate with each transaction its distance from
michael@0:   // its SHistory's current index.
michael@0: 
michael@0:   nsTArray<TransactionAndDistance> transactions;
michael@0: 
michael@0:   nsSHistory *shist = static_cast<nsSHistory*>(PR_LIST_HEAD(&gSHistoryList));
michael@0:   while (shist != &gSHistoryList) {
michael@0: 
michael@0:     // Maintain a list of the transactions which have viewers and belong to
michael@0:     // this particular shist object.  We'll add this list to the global list,
michael@0:     // |transactions|, eventually.
michael@0:     nsTArray<TransactionAndDistance> shTransactions;
michael@0: 
michael@0:     // Content viewers are likely to exist only within shist->mIndex -/+
michael@0:     // gHistoryMaxViewers, so only search within that range.
michael@0:     //
michael@0:     // A content viewer might exist outside that range due to either:
michael@0:     //
michael@0:     //   * history.pushState or hash navigations, in which case a copy of the
michael@0:     //     content viewer should exist within the range, or
michael@0:     //
michael@0:     //   * bugs which cause us not to call nsSHistory::EvictContentViewers()
michael@0:     //     often enough.  Once we do call EvictContentViewers() for the
michael@0:     //     SHistory object in question, we'll do a full search of its history
michael@0:     //     and evict the out-of-range content viewers, so we don't bother here.
michael@0:     //
michael@0:     int32_t startIndex = std::max(0, shist->mIndex - gHistoryMaxViewers);
michael@0:     int32_t endIndex = std::min(shist->mLength - 1,
michael@0:                               shist->mIndex + gHistoryMaxViewers);
michael@0:     nsCOMPtr<nsISHTransaction> trans;
michael@0:     shist->GetTransactionAtIndex(startIndex, getter_AddRefs(trans));
michael@0:     for (int32_t i = startIndex; trans && i <= endIndex; i++) {
michael@0:       nsCOMPtr<nsIContentViewer> contentViewer =
michael@0:         GetContentViewerForTransaction(trans);
michael@0: 
michael@0:       if (contentViewer) {
michael@0:         // Because one content viewer might belong to multiple SHEntries, we
michael@0:         // have to search through shTransactions to see if we already know
michael@0:         // about this content viewer.  If we find the viewer, update its
michael@0:         // distance from the SHistory's index and continue.
michael@0:         bool found = false;
michael@0:         for (uint32_t j = 0; j < shTransactions.Length(); j++) {
michael@0:           TransactionAndDistance &container = shTransactions[j];
michael@0:           if (container.mViewer == contentViewer) {
michael@0:             container.mDistance = std::min(container.mDistance, DeprecatedAbs(i - shist->mIndex));
michael@0:             found = true;
michael@0:             break;
michael@0:           }
michael@0:         }
michael@0: 
michael@0:         // If we didn't find a TransactionAndDistance for this content viewer, make a new
michael@0:         // one.
michael@0:         if (!found) {
michael@0:           TransactionAndDistance container(trans, DeprecatedAbs(i - shist->mIndex));
michael@0:           shTransactions.AppendElement(container);
michael@0:         }
michael@0:       }
michael@0: 
michael@0:       nsISHTransaction *temp = trans;
michael@0:       temp->GetNext(getter_AddRefs(trans));
michael@0:     }
michael@0: 
michael@0:     // We've found all the transactions belonging to shist which have viewers.
michael@0:     // Add those transactions to our global list and move on.
michael@0:     transactions.AppendElements(shTransactions);
michael@0:     shist = static_cast<nsSHistory*>(PR_NEXT_LINK(shist));
michael@0:   }
michael@0: 
michael@0:   // We now have collected all cached content viewers.  First check that we
michael@0:   // have enough that we actually need to evict some.
michael@0:   if ((int32_t)transactions.Length() <= sHistoryMaxTotalViewers) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   // If we need to evict, sort our list of transactions and evict the largest
michael@0:   // ones.  (We could of course get better algorithmic complexity here by using
michael@0:   // a heap or something more clever.  But sHistoryMaxTotalViewers isn't large,
michael@0:   // so let's not worry about it.)
michael@0:   transactions.Sort();
michael@0: 
michael@0:   for (int32_t i = transactions.Length() - 1;
michael@0:        i >= sHistoryMaxTotalViewers; --i) {
michael@0: 
michael@0:     EvictContentViewerForTransaction(transactions[i].mTransaction);
michael@0: 
michael@0:   }
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsSHistory::EvictExpiredContentViewerForEntry(nsIBFCacheEntry *aEntry)
michael@0: {
michael@0:   int32_t startIndex = std::max(0, mIndex - gHistoryMaxViewers);
michael@0:   int32_t endIndex = std::min(mLength - 1,
michael@0:                             mIndex + gHistoryMaxViewers);
michael@0:   nsCOMPtr<nsISHTransaction> trans;
michael@0:   GetTransactionAtIndex(startIndex, getter_AddRefs(trans));
michael@0: 
michael@0:   int32_t i;
michael@0:   for (i = startIndex; trans && i <= endIndex; ++i) {
michael@0:     nsCOMPtr<nsISHEntry> entry;
michael@0:     trans->GetSHEntry(getter_AddRefs(entry));
michael@0: 
michael@0:     // Does entry have the same BFCacheEntry as the argument to this method?
michael@0:     if (entry->HasBFCacheEntry(aEntry)) {
michael@0:       break;
michael@0:     }
michael@0: 
michael@0:     nsISHTransaction *temp = trans;
michael@0:     temp->GetNext(getter_AddRefs(trans));
michael@0:   }
michael@0:   if (i > endIndex)
michael@0:     return NS_OK;
michael@0:   
michael@0:   if (i == mIndex) {
michael@0:     NS_WARNING("How did the current SHEntry expire?");
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   EvictContentViewerForTransaction(trans);
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: // Evicts all content viewers in all history objects.  This is very
michael@0: // inefficient, because it requires a linear search through all SHistory
michael@0: // objects for each viewer to be evicted.  However, this method is called
michael@0: // infrequently -- only when the disk or memory cache is cleared.
michael@0: 
michael@0: //static
michael@0: void
michael@0: nsSHistory::GloballyEvictAllContentViewers()
michael@0: {
michael@0:   int32_t maxViewers = sHistoryMaxTotalViewers;
michael@0:   sHistoryMaxTotalViewers = 0;
michael@0:   GloballyEvictContentViewers();
michael@0:   sHistoryMaxTotalViewers = maxViewers;
michael@0: }
michael@0: 
michael@0: void GetDynamicChildren(nsISHContainer* aContainer,
michael@0:                         nsTArray<uint64_t>& aDocshellIDs,
michael@0:                         bool aOnlyTopLevelDynamic)
michael@0: {
michael@0:   int32_t count = 0;
michael@0:   aContainer->GetChildCount(&count);
michael@0:   for (int32_t i = 0; i < count; ++i) {
michael@0:     nsCOMPtr<nsISHEntry> child;
michael@0:     aContainer->GetChildAt(i, getter_AddRefs(child));
michael@0:     if (child) {
michael@0:       bool dynAdded = false;
michael@0:       child->IsDynamicallyAdded(&dynAdded);
michael@0:       if (dynAdded) {
michael@0:         uint64_t docshellID = 0;
michael@0:         child->GetDocshellID(&docshellID);
michael@0:         aDocshellIDs.AppendElement(docshellID);
michael@0:       }
michael@0:       if (!dynAdded || !aOnlyTopLevelDynamic) {
michael@0:         nsCOMPtr<nsISHContainer> childAsContainer = do_QueryInterface(child);
michael@0:         if (childAsContainer) {
michael@0:           GetDynamicChildren(childAsContainer, aDocshellIDs,
michael@0:                              aOnlyTopLevelDynamic);
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: bool
michael@0: RemoveFromSessionHistoryContainer(nsISHContainer* aContainer,
michael@0:                                   nsTArray<uint64_t>& aDocshellIDs)
michael@0: {
michael@0:   nsCOMPtr<nsISHEntry> root = do_QueryInterface(aContainer);
michael@0:   NS_ENSURE_TRUE(root, false);
michael@0: 
michael@0:   bool didRemove = false;
michael@0:   int32_t childCount = 0;
michael@0:   aContainer->GetChildCount(&childCount);
michael@0:   for (int32_t i = childCount - 1; i >= 0; --i) {
michael@0:     nsCOMPtr<nsISHEntry> child;
michael@0:     aContainer->GetChildAt(i, getter_AddRefs(child));
michael@0:     if (child) {
michael@0:       uint64_t docshelldID = 0;
michael@0:       child->GetDocshellID(&docshelldID);
michael@0:       if (aDocshellIDs.Contains(docshelldID)) {
michael@0:         didRemove = true;
michael@0:         aContainer->RemoveChild(child);
michael@0:       } else {
michael@0:         nsCOMPtr<nsISHContainer> container = do_QueryInterface(child);
michael@0:         if (container) {
michael@0:           bool childRemoved =
michael@0:             RemoveFromSessionHistoryContainer(container, aDocshellIDs);
michael@0:           if (childRemoved) {
michael@0:             didRemove = true;
michael@0:           }
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:   }
michael@0:   return didRemove;
michael@0: }
michael@0: 
michael@0: bool RemoveChildEntries(nsISHistory* aHistory, int32_t aIndex,
michael@0:                           nsTArray<uint64_t>& aEntryIDs)
michael@0: {
michael@0:   nsCOMPtr<nsISHEntry> rootHE;
michael@0:   aHistory->GetEntryAtIndex(aIndex, false, getter_AddRefs(rootHE));
michael@0:   nsCOMPtr<nsISHContainer> root = do_QueryInterface(rootHE);
michael@0:   return root ? RemoveFromSessionHistoryContainer(root, aEntryIDs) : false;
michael@0: }
michael@0: 
michael@0: bool IsSameTree(nsISHEntry* aEntry1, nsISHEntry* aEntry2)
michael@0: {
michael@0:   if (!aEntry1 && !aEntry2) {
michael@0:     return true;
michael@0:   }
michael@0:   if ((!aEntry1 && aEntry2) || (aEntry1 && !aEntry2)) {
michael@0:     return false;
michael@0:   }
michael@0:   uint32_t id1, id2;
michael@0:   aEntry1->GetID(&id1);
michael@0:   aEntry2->GetID(&id2);
michael@0:   if (id1 != id2) {
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   nsCOMPtr<nsISHContainer> container1 = do_QueryInterface(aEntry1);
michael@0:   nsCOMPtr<nsISHContainer> container2 = do_QueryInterface(aEntry2);
michael@0:   int32_t count1, count2;
michael@0:   container1->GetChildCount(&count1);
michael@0:   container2->GetChildCount(&count2);
michael@0:   // We allow null entries in the end of the child list.
michael@0:   int32_t count = std::max(count1, count2);
michael@0:   for (int32_t i = 0; i < count; ++i) {
michael@0:     nsCOMPtr<nsISHEntry> child1, child2;
michael@0:     container1->GetChildAt(i, getter_AddRefs(child1));
michael@0:     container2->GetChildAt(i, getter_AddRefs(child2));
michael@0:     if (!IsSameTree(child1, child2)) {
michael@0:       return false;
michael@0:     }
michael@0:   }
michael@0:   
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: bool
michael@0: nsSHistory::RemoveDuplicate(int32_t aIndex, bool aKeepNext)
michael@0: {
michael@0:   NS_ASSERTION(aIndex >= 0, "aIndex must be >= 0!");
michael@0:   NS_ASSERTION(aIndex != 0 || aKeepNext,
michael@0:                "If we're removing index 0 we must be keeping the next");
michael@0:   NS_ASSERTION(aIndex != mIndex, "Shouldn't remove mIndex!");
michael@0:   int32_t compareIndex = aKeepNext ? aIndex + 1 : aIndex - 1;
michael@0:   nsCOMPtr<nsISHEntry> root1, root2;
michael@0:   GetEntryAtIndex(aIndex, false, getter_AddRefs(root1));
michael@0:   GetEntryAtIndex(compareIndex, false, getter_AddRefs(root2));
michael@0:   if (IsSameTree(root1, root2)) {
michael@0:     nsCOMPtr<nsISHTransaction> txToRemove, txToKeep, txNext, txPrev;
michael@0:     GetTransactionAtIndex(aIndex, getter_AddRefs(txToRemove));
michael@0:     GetTransactionAtIndex(compareIndex, getter_AddRefs(txToKeep));
michael@0:     NS_ENSURE_TRUE(txToRemove, false);
michael@0:     NS_ENSURE_TRUE(txToKeep, false);
michael@0:     txToRemove->GetNext(getter_AddRefs(txNext));
michael@0:     txToRemove->GetPrev(getter_AddRefs(txPrev));
michael@0:     txToRemove->SetNext(nullptr);
michael@0:     txToRemove->SetPrev(nullptr);
michael@0:     if (aKeepNext) {
michael@0:       if (txPrev) {
michael@0:         txPrev->SetNext(txToKeep);
michael@0:       } else {
michael@0:         txToKeep->SetPrev(nullptr);
michael@0:       }
michael@0:     } else {
michael@0:       txToKeep->SetNext(txNext);
michael@0:     }
michael@0: 
michael@0:     if (aIndex == 0 && aKeepNext) {
michael@0:       NS_ASSERTION(txToRemove == mListRoot,
michael@0:                    "Transaction at index 0 should be mListRoot!");
michael@0:       // We're removing the very first session history transaction!
michael@0:       mListRoot = txToKeep;
michael@0:     }
michael@0:     if (mRootDocShell) {
michael@0:       static_cast<nsDocShell*>(mRootDocShell)->HistoryTransactionRemoved(aIndex);
michael@0:     }
michael@0: 
michael@0:     // Adjust our indices to reflect the removed transaction
michael@0:     if (mIndex > aIndex) {
michael@0:       mIndex = mIndex - 1;
michael@0:     }
michael@0: 
michael@0:     // NB: If the transaction we are removing is the transaction currently
michael@0:     // being navigated to (mRequestedIndex) then we adjust the index
michael@0:     // only if we're not keeping the next entry (because if we are keeping
michael@0:     // the next entry (because the current is a duplicate of the next), then
michael@0:     // that entry slides into the spot that we're currently pointing to.
michael@0:     // We don't do this adjustment for mIndex because mIndex cannot equal
michael@0:     // aIndex.
michael@0: 
michael@0:     // NB: We don't need to guard on mRequestedIndex being nonzero here,
michael@0:     // because either they're strictly greater than aIndex which is at least
michael@0:     // zero, or they are equal to aIndex in which case aKeepNext must be true
michael@0:     // if aIndex is zero.
michael@0:     if (mRequestedIndex > aIndex || (mRequestedIndex == aIndex && !aKeepNext)) {
michael@0:       mRequestedIndex = mRequestedIndex - 1;
michael@0:     }
michael@0:     --mLength;
michael@0:     return true;
michael@0:   }
michael@0:   return false;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP_(void)
michael@0: nsSHistory::RemoveEntries(nsTArray<uint64_t>& aIDs, int32_t aStartIndex)
michael@0: {
michael@0:   int32_t index = aStartIndex;
michael@0:   while(index >= 0 && RemoveChildEntries(this, --index, aIDs));
michael@0:   int32_t minIndex = index;
michael@0:   index = aStartIndex;
michael@0:   while(index >= 0 && RemoveChildEntries(this, index++, aIDs));
michael@0:   
michael@0:   // We need to remove duplicate nsSHEntry trees.
michael@0:   bool didRemove = false;
michael@0:   while (index > minIndex) {
michael@0:     if (index != mIndex) {
michael@0:       didRemove = RemoveDuplicate(index, index < mIndex) || didRemove;
michael@0:     }
michael@0:     --index;
michael@0:   }
michael@0:   if (didRemove && mRootDocShell) {
michael@0:     nsRefPtr<nsIRunnable> ev =
michael@0:       NS_NewRunnableMethod(static_cast<nsDocShell*>(mRootDocShell),
michael@0:                            &nsDocShell::FireDummyOnLocationChange);
michael@0:     NS_DispatchToCurrentThread(ev);
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: nsSHistory::RemoveDynEntries(int32_t aOldIndex, int32_t aNewIndex)
michael@0: {
michael@0:   // Search for the entries which are in the current index,
michael@0:   // but not in the new one.
michael@0:   nsCOMPtr<nsISHEntry> originalSH;
michael@0:   GetEntryAtIndex(aOldIndex, false, getter_AddRefs(originalSH));
michael@0:   nsCOMPtr<nsISHContainer> originalContainer = do_QueryInterface(originalSH);
michael@0:   nsAutoTArray<uint64_t, 16> toBeRemovedEntries;
michael@0:   if (originalContainer) {
michael@0:     nsTArray<uint64_t> originalDynDocShellIDs;
michael@0:     GetDynamicChildren(originalContainer, originalDynDocShellIDs, true);
michael@0:     if (originalDynDocShellIDs.Length()) {
michael@0:       nsCOMPtr<nsISHEntry> currentSH;
michael@0:       GetEntryAtIndex(aNewIndex, false, getter_AddRefs(currentSH));
michael@0:       nsCOMPtr<nsISHContainer> newContainer = do_QueryInterface(currentSH);
michael@0:       if (newContainer) {
michael@0:         nsTArray<uint64_t> newDynDocShellIDs;
michael@0:         GetDynamicChildren(newContainer, newDynDocShellIDs, false);
michael@0:         for (uint32_t i = 0; i < originalDynDocShellIDs.Length(); ++i) {
michael@0:           if (!newDynDocShellIDs.Contains(originalDynDocShellIDs[i])) {
michael@0:             toBeRemovedEntries.AppendElement(originalDynDocShellIDs[i]);
michael@0:           }
michael@0:         }
michael@0:       }
michael@0:     }
michael@0:   }
michael@0:   if (toBeRemovedEntries.Length()) {
michael@0:     RemoveEntries(toBeRemovedEntries, aOldIndex);
michael@0:   }
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::UpdateIndex()
michael@0: {
michael@0:   // Update the actual index with the right value. 
michael@0:   if (mIndex != mRequestedIndex && mRequestedIndex != -1) {
michael@0:     RemoveDynEntries(mIndex, mRequestedIndex);
michael@0:     mIndex = mRequestedIndex;
michael@0:   }
michael@0: 
michael@0:   mRequestedIndex = -1;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::Stop(uint32_t aStopFlags)
michael@0: {
michael@0:   //Not implemented
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetDocument(nsIDOMDocument** aDocument)
michael@0: {
michael@0:   // Not implemented
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetCurrentURI(nsIURI** aResultURI)
michael@0: {
michael@0:   NS_ENSURE_ARG_POINTER(aResultURI);
michael@0:   nsresult rv;
michael@0: 
michael@0:   nsCOMPtr<nsISHEntry> currentEntry;
michael@0:   rv = GetEntryAtIndex(mIndex, false, getter_AddRefs(currentEntry));
michael@0:   if (NS_FAILED(rv) && !currentEntry) return rv;
michael@0:   rv = currentEntry->GetURI(aResultURI);
michael@0:   return rv;
michael@0: }
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetReferringURI(nsIURI** aURI)
michael@0: {
michael@0:   *aURI = nullptr;
michael@0:   // Not implemented
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::SetSessionHistory(nsISHistory* aSessionHistory)
michael@0: {
michael@0:   // Not implemented
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 	
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetSessionHistory(nsISHistory** aSessionHistory)
michael@0: {
michael@0:   // Not implemented
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::LoadURIWithBase(const char16_t* aURI,
michael@0:                             uint32_t aLoadFlags,
michael@0:                             nsIURI* aReferringURI,
michael@0:                             nsIInputStream* aPostStream,
michael@0:                             nsIInputStream* aExtraHeaderStream,
michael@0:                             nsIURI* aBaseURI)
michael@0: {
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::LoadURI(const char16_t* aURI,
michael@0:                     uint32_t aLoadFlags,
michael@0:                     nsIURI* aReferringURI,
michael@0:                     nsIInputStream* aPostStream,
michael@0:                     nsIInputStream* aExtraHeaderStream)
michael@0: {
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GotoIndex(int32_t aIndex)
michael@0: {
michael@0:   return LoadEntry(aIndex, nsIDocShellLoadInfo::loadHistory, HIST_CMD_GOTOINDEX);
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsSHistory::LoadNextPossibleEntry(int32_t aNewIndex, long aLoadType, uint32_t aHistCmd)
michael@0: {
michael@0:   mRequestedIndex = -1;
michael@0:   if (aNewIndex < mIndex) {
michael@0:     return LoadEntry(aNewIndex - 1, aLoadType, aHistCmd);
michael@0:   }
michael@0:   if (aNewIndex > mIndex) {
michael@0:     return LoadEntry(aNewIndex + 1, aLoadType, aHistCmd);
michael@0:   }
michael@0:   return NS_ERROR_FAILURE;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::LoadEntry(int32_t aIndex, long aLoadType, uint32_t aHistCmd)
michael@0: {
michael@0:   nsCOMPtr<nsIDocShell> docShell;
michael@0:   // Keep note of requested history index in mRequestedIndex.
michael@0:   mRequestedIndex = aIndex;
michael@0: 
michael@0:   nsCOMPtr<nsISHEntry> prevEntry;
michael@0:   GetEntryAtIndex(mIndex, false, getter_AddRefs(prevEntry));
michael@0: 
michael@0:   nsCOMPtr<nsISHEntry> nextEntry;
michael@0:   GetEntryAtIndex(mRequestedIndex, false, getter_AddRefs(nextEntry));
michael@0:   if (!nextEntry || !prevEntry) {
michael@0:     mRequestedIndex = -1;
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0: 
michael@0:   // Remember that this entry is getting loaded at this point in the sequence
michael@0:   nsCOMPtr<nsISHEntryInternal> entryInternal = do_QueryInterface(nextEntry);
michael@0: 
michael@0:   if (entryInternal) {
michael@0:     entryInternal->SetLastTouched(++gTouchCounter);
michael@0:   }
michael@0: 
michael@0:   // Send appropriate listener notifications
michael@0:   bool canNavigate = true;
michael@0:   // Get the uri for the entry we are about to visit
michael@0:   nsCOMPtr<nsIURI> nextURI;
michael@0:   nextEntry->GetURI(getter_AddRefs(nextURI));
michael@0: 
michael@0:   if (aHistCmd == HIST_CMD_BACK) {
michael@0:     // We are going back one entry. Send GoBack notifications
michael@0:     NOTIFY_LISTENERS_CANCELABLE(OnHistoryGoBack, canNavigate,
michael@0:                                 (nextURI, &canNavigate));
michael@0:   } else if (aHistCmd == HIST_CMD_FORWARD) {
michael@0:     // We are going forward. Send GoForward notification
michael@0:     NOTIFY_LISTENERS_CANCELABLE(OnHistoryGoForward, canNavigate,
michael@0:                                 (nextURI, &canNavigate));
michael@0:   } else if (aHistCmd == HIST_CMD_GOTOINDEX) {
michael@0:     // We are going somewhere else. This is not reload either
michael@0:     NOTIFY_LISTENERS_CANCELABLE(OnHistoryGotoIndex, canNavigate,
michael@0:                                 (aIndex, nextURI, &canNavigate));
michael@0:   }
michael@0: 
michael@0:   if (!canNavigate) {
michael@0:     // If the listener asked us not to proceed with 
michael@0:     // the operation, simply return.    
michael@0:     mRequestedIndex = -1;
michael@0:     return NS_OK;  // XXX Maybe I can return some other error code?
michael@0:   }
michael@0: 
michael@0:   nsCOMPtr<nsIURI> nexturi;
michael@0:   int32_t pCount=0, nCount=0;
michael@0:   nsCOMPtr<nsISHContainer> prevAsContainer(do_QueryInterface(prevEntry));
michael@0:   nsCOMPtr<nsISHContainer> nextAsContainer(do_QueryInterface(nextEntry));
michael@0:   if (prevAsContainer && nextAsContainer) {
michael@0:     prevAsContainer->GetChildCount(&pCount);
michael@0:     nextAsContainer->GetChildCount(&nCount);
michael@0:   }
michael@0:   
michael@0:   nsCOMPtr<nsIDocShellLoadInfo> loadInfo;
michael@0:   if (mRequestedIndex == mIndex) {
michael@0:     // Possibly a reload case 
michael@0:     docShell = mRootDocShell;
michael@0:   }
michael@0:   else {
michael@0:     // Going back or forward.
michael@0:     if ((pCount > 0) && (nCount > 0)) {
michael@0:       /* THis is a subframe navigation. Go find 
michael@0:        * the docshell in which load should happen
michael@0:        */
michael@0:       bool frameFound = false;
michael@0:       nsresult rv = CompareFrames(prevEntry, nextEntry, mRootDocShell, aLoadType, &frameFound);
michael@0:       if (!frameFound) {
michael@0:         // We did not successfully find the subframe in which
michael@0:         // the new url was to be loaded. Go further in the history.
michael@0:         return LoadNextPossibleEntry(aIndex, aLoadType, aHistCmd);
michael@0:       }
michael@0:       return rv;
michael@0:     }   // (pCount >0)
michael@0:     else {
michael@0:       // Loading top level page.
michael@0:       uint32_t prevID = 0;
michael@0:       uint32_t nextID = 0;
michael@0:       prevEntry->GetID(&prevID);
michael@0:       nextEntry->GetID(&nextID);
michael@0:       if (prevID == nextID) {
michael@0:         // Try harder to find something new to load.
michael@0:         // This may happen for example if some page removed iframes dynamically.
michael@0:         return LoadNextPossibleEntry(aIndex, aLoadType, aHistCmd);
michael@0:       }
michael@0:       docShell = mRootDocShell;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   if (!docShell) {
michael@0:     // we did not successfully go to the proper index.
michael@0:     // return error.
michael@0:     mRequestedIndex = -1;
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0: 
michael@0:   // Start the load on the appropriate docshell
michael@0:   return InitiateLoad(nextEntry, docShell, aLoadType);
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsSHistory::CompareFrames(nsISHEntry * aPrevEntry, nsISHEntry * aNextEntry, nsIDocShell * aParent, long aLoadType, bool * aIsFrameFound)
michael@0: {
michael@0:   if (!aPrevEntry || !aNextEntry || !aParent)
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   // We should be comparing only entries which were created for the
michael@0:   // same docshell. This is here to just prevent anything strange happening.
michael@0:   // This check could be possibly an assertion.
michael@0:   uint64_t prevdID, nextdID;
michael@0:   aPrevEntry->GetDocshellID(&prevdID);
michael@0:   aNextEntry->GetDocshellID(&nextdID);
michael@0:   NS_ENSURE_STATE(prevdID == nextdID);
michael@0: 
michael@0:   nsresult result = NS_OK;
michael@0:   uint32_t prevID, nextID;
michael@0: 
michael@0:   aPrevEntry->GetID(&prevID);
michael@0:   aNextEntry->GetID(&nextID);
michael@0:  
michael@0:   // Check the IDs to verify if the pages are different.
michael@0:   if (prevID != nextID) {
michael@0:     if (aIsFrameFound)
michael@0:       *aIsFrameFound = true;
michael@0:     // Set the Subframe flag of the entry to indicate that
michael@0:     // it is subframe navigation        
michael@0:     aNextEntry->SetIsSubFrame(true);
michael@0:     InitiateLoad(aNextEntry, aParent, aLoadType);
michael@0:     return NS_OK;
michael@0:   }
michael@0: 
michael@0:   /* The root entries are the same, so compare any child frames */
michael@0:   int32_t pcnt=0, ncnt=0, dsCount=0;
michael@0:   nsCOMPtr<nsISHContainer>  prevContainer(do_QueryInterface(aPrevEntry));
michael@0:   nsCOMPtr<nsISHContainer>  nextContainer(do_QueryInterface(aNextEntry));
michael@0: 
michael@0:   if (!aParent)
michael@0:     return NS_ERROR_FAILURE;
michael@0:   if (!prevContainer || !nextContainer)
michael@0:     return NS_ERROR_FAILURE;
michael@0: 
michael@0:   prevContainer->GetChildCount(&pcnt);
michael@0:   nextContainer->GetChildCount(&ncnt);
michael@0:   aParent->GetChildCount(&dsCount);
michael@0: 
michael@0:   // Create an array for child docshells.
michael@0:   nsCOMArray<nsIDocShell> docshells;
michael@0:   for (int32_t i = 0; i < dsCount; ++i) {
michael@0:     nsCOMPtr<nsIDocShellTreeItem> treeItem;
michael@0:     aParent->GetChildAt(i, getter_AddRefs(treeItem));
michael@0:     nsCOMPtr<nsIDocShell> shell = do_QueryInterface(treeItem);
michael@0:     if (shell) {
michael@0:       docshells.AppendObject(shell);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   // Search for something to load next.
michael@0:   for (int32_t i = 0; i < ncnt; ++i) {
michael@0:     // First get an entry which may cause a new page to be loaded.
michael@0:     nsCOMPtr<nsISHEntry> nChild;
michael@0:     nextContainer->GetChildAt(i, getter_AddRefs(nChild));
michael@0:     if (!nChild) {
michael@0:       continue;
michael@0:     }
michael@0:     uint64_t docshellID = 0;
michael@0:     nChild->GetDocshellID(&docshellID);
michael@0: 
michael@0:     // Then find the associated docshell.
michael@0:     nsIDocShell* dsChild = nullptr;
michael@0:     int32_t count = docshells.Count();
michael@0:     for (int32_t j = 0; j < count; ++j) {
michael@0:       uint64_t shellID = 0;
michael@0:       nsIDocShell* shell = docshells[j];
michael@0:       shell->GetHistoryID(&shellID);
michael@0:       if (shellID == docshellID) {
michael@0:         dsChild = shell;
michael@0:         break;
michael@0:       }
michael@0:     }
michael@0:     if (!dsChild) {
michael@0:       continue;
michael@0:     }
michael@0: 
michael@0:     // Then look at the previous entries to see if there was
michael@0:     // an entry for the docshell.
michael@0:     nsCOMPtr<nsISHEntry> pChild;
michael@0:     for (int32_t k = 0; k < pcnt; ++k) {
michael@0:       nsCOMPtr<nsISHEntry> child;
michael@0:       prevContainer->GetChildAt(k, getter_AddRefs(child));
michael@0:       if (child) {
michael@0:         uint64_t dID = 0;
michael@0:         child->GetDocshellID(&dID);
michael@0:         if (dID == docshellID) {
michael@0:           pChild = child;
michael@0:           break;
michael@0:         }
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     // Finally recursively call this method.
michael@0:     // This will either load a new page to shell or some subshell or
michael@0:     // do nothing.
michael@0:     CompareFrames(pChild, nChild, dsChild, aLoadType, aIsFrameFound);
michael@0:   }     
michael@0:   return result;
michael@0: }
michael@0: 
michael@0: 
michael@0: nsresult 
michael@0: nsSHistory::InitiateLoad(nsISHEntry * aFrameEntry, nsIDocShell * aFrameDS, long aLoadType)
michael@0: {
michael@0:   NS_ENSURE_STATE(aFrameDS && aFrameEntry);
michael@0: 
michael@0:   nsCOMPtr<nsIDocShellLoadInfo> loadInfo;
michael@0: 
michael@0:   /* Set the loadType in the SHEntry too to  what was passed on.
michael@0:    * This will be passed on to child subframes later in nsDocShell,
michael@0:    * so that proper loadType is maintained through out a frameset
michael@0:    */
michael@0:   aFrameEntry->SetLoadType(aLoadType);    
michael@0:   aFrameDS->CreateLoadInfo (getter_AddRefs(loadInfo));
michael@0: 
michael@0:   loadInfo->SetLoadType(aLoadType);
michael@0:   loadInfo->SetSHEntry(aFrameEntry);
michael@0: 
michael@0:   nsCOMPtr<nsIURI> nextURI;
michael@0:   aFrameEntry->GetURI(getter_AddRefs(nextURI));
michael@0:   // Time   to initiate a document load
michael@0:   return aFrameDS->LoadURI(nextURI, loadInfo, nsIWebNavigation::LOAD_FLAGS_NONE, false);
michael@0: 
michael@0: }
michael@0: 
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::SetRootDocShell(nsIDocShell * aDocShell)
michael@0: {
michael@0:   mRootDocShell = aDocShell;
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetRootDocShell(nsIDocShell ** aDocShell)
michael@0: {
michael@0:   NS_ENSURE_ARG_POINTER(aDocShell);
michael@0: 
michael@0:   *aDocShell = mRootDocShell;
michael@0:   //Not refcounted. May this method should not be available for public
michael@0:   // NS_IF_ADDREF(*aDocShell);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHistory::GetSHistoryEnumerator(nsISimpleEnumerator** aEnumerator)
michael@0: {
michael@0:   nsresult status = NS_OK;
michael@0: 
michael@0:   NS_ENSURE_ARG_POINTER(aEnumerator);
michael@0:   nsSHEnumerator * iterator = new nsSHEnumerator(this);
michael@0:   if (iterator && NS_FAILED(status = CallQueryInterface(iterator, aEnumerator)))
michael@0:     delete iterator;
michael@0:   return status;
michael@0: }
michael@0: 
michael@0: 
michael@0: //*****************************************************************************
michael@0: //***    nsSHEnumerator: Object Management
michael@0: //*****************************************************************************
michael@0: 
michael@0: nsSHEnumerator::nsSHEnumerator(nsSHistory * aSHistory):mIndex(-1)
michael@0: {
michael@0:   mSHistory = aSHistory;
michael@0: }
michael@0: 
michael@0: nsSHEnumerator::~nsSHEnumerator()
michael@0: {
michael@0:   mSHistory = nullptr;
michael@0: }
michael@0: 
michael@0: NS_IMPL_ISUPPORTS(nsSHEnumerator, nsISimpleEnumerator)
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsSHEnumerator::HasMoreElements(bool * aReturn)
michael@0: {
michael@0:   int32_t cnt;
michael@0:   *aReturn = false;
michael@0:   mSHistory->GetCount(&cnt);
michael@0:   if (mIndex >= -1 && mIndex < (cnt-1) ) { 
michael@0:     *aReturn = true;
michael@0:   }
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: 
michael@0: NS_IMETHODIMP 
michael@0: nsSHEnumerator::GetNext(nsISupports **aItem)
michael@0: {
michael@0:   NS_ENSURE_ARG_POINTER(aItem);
michael@0:   int32_t cnt= 0;
michael@0: 
michael@0:   nsresult  result = NS_ERROR_FAILURE;
michael@0:   mSHistory->GetCount(&cnt);
michael@0:   if (mIndex < (cnt-1)) {
michael@0:     mIndex++;
michael@0:     nsCOMPtr<nsISHEntry> hEntry;
michael@0:     result = mSHistory->GetEntryAtIndex(mIndex, false, getter_AddRefs(hEntry));
michael@0:     if (hEntry)
michael@0:       result = CallQueryInterface(hEntry, aItem);
michael@0:   }
michael@0:   return result;
michael@0: }