The Tor Browser: modules/libpref/src/nsPrefBranch.cpp@129ffea94266 (annotated)

modules/libpref/src/nsPrefBranch.cpp@129ffea94266 (annotated)

modules/libpref/src/nsPrefBranch.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* 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 "mozilla/dom/ContentChild.h"
 #include "nsXULAppAPI.h"
 #include "nsPrefBranch.h"
 #include "nsILocalFile.h" // nsILocalFile used for backwards compatibility
 #include "nsIObserverService.h"
 #include "nsXPCOM.h"
 #include "nsISupportsPrimitives.h"
 #include "nsIDirectoryService.h"
 #include "nsString.h"
 #include "nsReadableUtils.h"
 #include "nsXPIDLString.h"
 #include "nsPrintfCString.h"
 #include "nsIStringBundle.h"
 #include "prefapi.h"
 #include "pldhash.h"
 #include "nsCRT.h"
 #include "mozilla/Services.h"
 #include "prefapi_private_data.h"
 #ifdef MOZ_CRASHREPORTER
 #include "nsICrashReporter.h"
 #endif
 #include "nsIConsoleService.h"
 #ifdef DEBUG
 #define ENSURE_MAIN_PROCESS(message, pref) do {                                \
   if (GetContentChild()) {                                                     \
     nsPrintfCString msg("ENSURE_MAIN_PROCESS failed. %s %s", message, pref);   \
     NS_ERROR(msg.get());                                                       \
     return NS_ERROR_NOT_AVAILABLE;                                             \
   }                                                                            \
 } while (0);
 #else
 #define ENSURE_MAIN_PROCESS(message, pref)                                     \
   if (GetContentChild()) {                                                     \
     return NS_ERROR_NOT_AVAILABLE;                                             \
   }
 #endif
 // Definitions
 struct EnumerateData {
   const char  *parent;
   nsTArray<nsCString> *pref_list;
 };
 // Prototypes
 static PLDHashOperator
   pref_enumChild(PLDHashTable *table, PLDHashEntryHdr *heh,
                  uint32_t i, void *arg);
 using mozilla::dom::ContentChild;
 static ContentChild*
 GetContentChild()
 {
   if (XRE_GetProcessType() == GeckoProcessType_Content) {
     ContentChild* cpc = ContentChild::GetSingleton();
     if (!cpc) {
       NS_RUNTIMEABORT("Content Protocol is NULL!  We're going to crash!");
     }
     return cpc;
   }
   return nullptr;
 }
 /*
  * Constructor/Destructor
  */
 nsPrefBranch::nsPrefBranch(const char *aPrefRoot, bool aDefaultBranch)
 {
   mPrefRoot = aPrefRoot;
   mPrefRootLength = mPrefRoot.Length();
   mIsDefault = aDefaultBranch;
   mFreeingObserverList = false;
   nsCOMPtr<nsIObserverService> observerService =
     mozilla::services::GetObserverService();
   if (observerService) {
     ++mRefCnt;    // Our refcnt must be > 0 when we call this, or we'll get deleted!
     // add weak so we don't have to clean up at shutdown
     observerService->AddObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID, true);
     --mRefCnt;
   }
 }
 nsPrefBranch::~nsPrefBranch()
 {
   freeObserverList();
   nsCOMPtr<nsIObserverService> observerService =
     mozilla::services::GetObserverService();
   if (observerService)
     observerService->RemoveObserver(this, NS_XPCOM_SHUTDOWN_OBSERVER_ID);
 }
 /*
  * nsISupports Implementation
  */
 NS_IMPL_ADDREF(nsPrefBranch)
 NS_IMPL_RELEASE(nsPrefBranch)
 NS_INTERFACE_MAP_BEGIN(nsPrefBranch)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIPrefBranch)
   NS_INTERFACE_MAP_ENTRY(nsIPrefBranch)
   NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIPrefBranch2, !mIsDefault)
   NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIPrefBranchInternal, !mIsDefault)
   NS_INTERFACE_MAP_ENTRY(nsIObserver)
   NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
 NS_INTERFACE_MAP_END
 /*
  * nsIPrefBranch Implementation
  */
 NS_IMETHODIMP nsPrefBranch::GetRoot(char **aRoot)
 {
   NS_ENSURE_ARG_POINTER(aRoot);
   mPrefRoot.Truncate(mPrefRootLength);
   *aRoot = ToNewCString(mPrefRoot);
   return NS_OK;
 }
 NS_IMETHODIMP nsPrefBranch::GetPrefType(const char *aPrefName, int32_t *_retval)
 {
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   *_retval = PREF_GetPrefType(pref);
   return NS_OK;
 }
 NS_IMETHODIMP nsPrefBranch::GetBoolPref(const char *aPrefName, bool *_retval)
 {
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   return PREF_GetBoolPref(pref, _retval, mIsDefault);
 }
 NS_IMETHODIMP nsPrefBranch::SetBoolPref(const char *aPrefName, bool aValue)
 {
   ENSURE_MAIN_PROCESS("Cannot SetBoolPref from content process:", aPrefName);
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   return PREF_SetBoolPref(pref, aValue, mIsDefault);
 }
 NS_IMETHODIMP nsPrefBranch::GetFloatPref(const char *aPrefName, float *_retval)
 {
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   nsAutoCString stringVal;
   nsresult rv = GetCharPref(pref, getter_Copies(stringVal));
   if (NS_SUCCEEDED(rv)) {
     *_retval = stringVal.ToFloat(&rv);
   }
   return rv;
 }
 NS_IMETHODIMP nsPrefBranch::GetCharPref(const char *aPrefName, char **_retval)
 {
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   return PREF_CopyCharPref(pref, _retval, mIsDefault);
 }
 NS_IMETHODIMP nsPrefBranch::SetCharPref(const char *aPrefName, const char *aValue)
 {
   nsresult rv = CheckSanityOfStringLength(aPrefName, aValue);
   if (NS_FAILED(rv)) {
     return rv;
   }
   return SetCharPrefInternal(aPrefName, aValue);
 }
 nsresult nsPrefBranch::SetCharPrefInternal(const char *aPrefName, const char *aValue)
 {
   ENSURE_MAIN_PROCESS("Cannot SetCharPref from content process:", aPrefName);
   NS_ENSURE_ARG(aPrefName);
   NS_ENSURE_ARG(aValue);
   const char *pref = getPrefName(aPrefName);
   return PREF_SetCharPref(pref, aValue, mIsDefault);
 }
 NS_IMETHODIMP nsPrefBranch::GetIntPref(const char *aPrefName, int32_t *_retval)
 {
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   return PREF_GetIntPref(pref, _retval, mIsDefault);
 }
 NS_IMETHODIMP nsPrefBranch::SetIntPref(const char *aPrefName, int32_t aValue)
 {
   ENSURE_MAIN_PROCESS("Cannot SetIntPref from content process:", aPrefName);
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   return PREF_SetIntPref(pref, aValue, mIsDefault);
 }
 NS_IMETHODIMP nsPrefBranch::GetComplexValue(const char *aPrefName, const nsIID & aType, void **_retval)
 {
   NS_ENSURE_ARG(aPrefName);
   nsresult       rv;
   nsXPIDLCString utf8String;
   // we have to do this one first because it's different than all the rest
   if (aType.Equals(NS_GET_IID(nsIPrefLocalizedString))) {
     nsCOMPtr<nsIPrefLocalizedString> theString(do_CreateInstance(NS_PREFLOCALIZEDSTRING_CONTRACTID, &rv));
     if (NS_FAILED(rv)) return rv;
     const char *pref = getPrefName(aPrefName);
     bool    bNeedDefault = false;
     if (mIsDefault) {
       bNeedDefault = true;
     } else {
       // if there is no user (or locked) value
       if (!PREF_HasUserPref(pref) && !PREF_PrefIsLocked(pref)) {
         bNeedDefault = true;
       }
     }
     // if we need to fetch the default value, do that instead, otherwise use the
     // value we pulled in at the top of this function
     if (bNeedDefault) {
       nsXPIDLString utf16String;
       rv = GetDefaultFromPropertiesFile(pref, getter_Copies(utf16String));
       if (NS_SUCCEEDED(rv)) {
         theString->SetData(utf16String.get());
       }
     } else {
       rv = GetCharPref(aPrefName, getter_Copies(utf8String));
       if (NS_SUCCEEDED(rv)) {
         theString->SetData(NS_ConvertUTF8toUTF16(utf8String).get());
       }
     }
     if (NS_SUCCEEDED(rv)) {
       theString.forget(reinterpret_cast<nsIPrefLocalizedString**>(_retval));
     }
     return rv;
   }
   // if we can't get the pref, there's no point in being here
   rv = GetCharPref(aPrefName, getter_Copies(utf8String));
   if (NS_FAILED(rv)) {
     return rv;
   }
   // also check nsILocalFile, for backwards compatibility
   if (aType.Equals(NS_GET_IID(nsIFile)) || aType.Equals(NS_GET_IID(nsILocalFile))) {
     if (GetContentChild()) {
       NS_ERROR("cannot get nsIFile pref from content process");
       return NS_ERROR_NOT_AVAILABLE;
     }
     nsCOMPtr<nsIFile> file(do_CreateInstance(NS_LOCAL_FILE_CONTRACTID, &rv));
     if (NS_SUCCEEDED(rv)) {
       rv = file->SetPersistentDescriptor(utf8String);
       if (NS_SUCCEEDED(rv)) {
         file.forget(reinterpret_cast<nsIFile**>(_retval));
         return NS_OK;
       }
     }
     return rv;
   }
   if (aType.Equals(NS_GET_IID(nsIRelativeFilePref))) {
     if (GetContentChild()) {
       NS_ERROR("cannot get nsIRelativeFilePref from content process");
       return NS_ERROR_NOT_AVAILABLE;
     }
     nsACString::const_iterator keyBegin, strEnd;
     utf8String.BeginReading(keyBegin);
     utf8String.EndReading(strEnd);
     // The pref has the format: [fromKey]a/b/c
     if (*keyBegin++ != '[')
       return NS_ERROR_FAILURE;
     nsACString::const_iterator keyEnd(keyBegin);
     if (!FindCharInReadable(']', keyEnd, strEnd))
       return NS_ERROR_FAILURE;
     nsAutoCString key(Substring(keyBegin, keyEnd));
     nsCOMPtr<nsIFile> fromFile;
     nsCOMPtr<nsIProperties> directoryService(do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv));
     if (NS_FAILED(rv))
       return rv;
     rv = directoryService->Get(key.get(), NS_GET_IID(nsIFile), getter_AddRefs(fromFile));
     if (NS_FAILED(rv))
       return rv;
     nsCOMPtr<nsIFile> theFile;
     rv = NS_NewNativeLocalFile(EmptyCString(), true, getter_AddRefs(theFile));
     if (NS_FAILED(rv))
       return rv;
     rv = theFile->SetRelativeDescriptor(fromFile, Substring(++keyEnd, strEnd));
     if (NS_FAILED(rv))
       return rv;
     nsCOMPtr<nsIRelativeFilePref> relativePref;
     rv = NS_NewRelativeFilePref(theFile, key, getter_AddRefs(relativePref));
     if (NS_FAILED(rv))
       return rv;
     relativePref.forget(reinterpret_cast<nsIRelativeFilePref**>(_retval));
     return NS_OK;
   }
   if (aType.Equals(NS_GET_IID(nsISupportsString))) {
     nsCOMPtr<nsISupportsString> theString(do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID, &rv));
     if (NS_SUCCEEDED(rv)) {
       // Debugging to see why we end up with very long strings here with
       // some addons, see bug 836263.
       nsAutoString wdata;
       if (!AppendUTF8toUTF16(utf8String, wdata, mozilla::fallible_t())) {
 #ifdef MOZ_CRASHREPORTER
         nsCOMPtr<nsICrashReporter> cr =
           do_GetService("@mozilla.org/toolkit/crash-reporter;1");
         if (cr) {
           cr->AnnotateCrashReport(NS_LITERAL_CSTRING("bug836263-size"),
                                   nsPrintfCString("%x", utf8String.Length()));
           cr->RegisterAppMemory(uint64_t(utf8String.BeginReading()),
                                 std::min(0x1000U, utf8String.Length()));
         }
 #endif
         NS_RUNTIMEABORT("bug836263");
       }
       theString->SetData(wdata);
       theString.forget(reinterpret_cast<nsISupportsString**>(_retval));
     }
     return rv;
   }
   NS_WARNING("nsPrefBranch::GetComplexValue - Unsupported interface type");
   return NS_NOINTERFACE;
 }
 nsresult nsPrefBranch::CheckSanityOfStringLength(const char* aPrefName, const char* aValue) {
   if (!aValue) {
     return NS_OK;
   }
   return CheckSanityOfStringLength(aPrefName, strlen(aValue));
 }
 nsresult nsPrefBranch::CheckSanityOfStringLength(const char* aPrefName, const nsAString& aValue) {
   return CheckSanityOfStringLength(aPrefName, aValue.Length());
 }
 nsresult nsPrefBranch::CheckSanityOfStringLength(const char* aPrefName, const uint32_t aLength) {
   if (aLength > MAX_PREF_LENGTH) {
     return NS_ERROR_ILLEGAL_VALUE;
   }
   if (aLength <= MAX_ADVISABLE_PREF_LENGTH) {
     return NS_OK;
   }
   nsresult rv;
   nsCOMPtr<nsIConsoleService> console = do_GetService("@mozilla.org/consoleservice;1", &rv);
   if (NS_FAILED(rv)) {
     return rv;
   }
   nsAutoCString message(nsPrintfCString("Warning: attempting to write %d bytes to preference %s. This is bad for general performance and memory usage. Such an amount of data should rather be written to an external file.",
                                         aLength,
                                         aPrefName));
   rv = console->LogStringMessage(NS_ConvertUTF8toUTF16(message).get());
   if (NS_FAILED(rv)) {
     return rv;
   }
   return NS_OK;
 }
 NS_IMETHODIMP nsPrefBranch::SetComplexValue(const char *aPrefName, const nsIID & aType, nsISupports *aValue)
 {
   ENSURE_MAIN_PROCESS("Cannot SetComplexValue from content process:", aPrefName);
   NS_ENSURE_ARG(aPrefName);
   nsresult   rv = NS_NOINTERFACE;
   // also check nsILocalFile, for backwards compatibility
   if (aType.Equals(NS_GET_IID(nsIFile)) || aType.Equals(NS_GET_IID(nsILocalFile))) {
     nsCOMPtr<nsIFile> file = do_QueryInterface(aValue);
     if (!file)
       return NS_NOINTERFACE;
     nsAutoCString descriptorString;
     rv = file->GetPersistentDescriptor(descriptorString);
     if (NS_SUCCEEDED(rv)) {
       rv = SetCharPrefInternal(aPrefName, descriptorString.get());
     }
     return rv;
   }
   if (aType.Equals(NS_GET_IID(nsIRelativeFilePref))) {
     nsCOMPtr<nsIRelativeFilePref> relFilePref = do_QueryInterface(aValue);
     if (!relFilePref)
       return NS_NOINTERFACE;
     nsCOMPtr<nsIFile> file;
     relFilePref->GetFile(getter_AddRefs(file));
     if (!file)
       return NS_NOINTERFACE;
     nsAutoCString relativeToKey;
     (void) relFilePref->GetRelativeToKey(relativeToKey);
     nsCOMPtr<nsIFile> relativeToFile;
     nsCOMPtr<nsIProperties> directoryService(do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID, &rv));
     if (NS_FAILED(rv))
       return rv;
     rv = directoryService->Get(relativeToKey.get(), NS_GET_IID(nsIFile), getter_AddRefs(relativeToFile));
     if (NS_FAILED(rv))
       return rv;
     nsAutoCString relDescriptor;
     rv = file->GetRelativeDescriptor(relativeToFile, relDescriptor);
     if (NS_FAILED(rv))
       return rv;
     nsAutoCString descriptorString;
     descriptorString.Append('[');
     descriptorString.Append(relativeToKey);
     descriptorString.Append(']');
     descriptorString.Append(relDescriptor);
     return SetCharPrefInternal(aPrefName, descriptorString.get());
   }
   if (aType.Equals(NS_GET_IID(nsISupportsString))) {
     nsCOMPtr<nsISupportsString> theString = do_QueryInterface(aValue);
     if (theString) {
       nsString wideString;
       rv = theString->GetData(wideString);
       if (NS_SUCCEEDED(rv)) {
         // Check sanity of string length before any lengthy conversion
         rv = CheckSanityOfStringLength(aPrefName, wideString);
         if (NS_FAILED(rv)) {
           return rv;
         }
         rv = SetCharPrefInternal(aPrefName, NS_ConvertUTF16toUTF8(wideString).get());
       }
     }
     return rv;
   }
   if (aType.Equals(NS_GET_IID(nsIPrefLocalizedString))) {
     nsCOMPtr<nsIPrefLocalizedString> theString = do_QueryInterface(aValue);
     if (theString) {
       nsXPIDLString wideString;
       rv = theString->GetData(getter_Copies(wideString));
       if (NS_SUCCEEDED(rv)) {
         // Check sanity of string length before any lengthy conversion
         rv = CheckSanityOfStringLength(aPrefName, wideString);
         if (NS_FAILED(rv)) {
           return rv;
         }
         rv = SetCharPrefInternal(aPrefName, NS_ConvertUTF16toUTF8(wideString).get());
       }
     }
     return rv;
   }
   NS_WARNING("nsPrefBranch::SetComplexValue - Unsupported interface type");
   return NS_NOINTERFACE;
 }
 NS_IMETHODIMP nsPrefBranch::ClearUserPref(const char *aPrefName)
 {
   ENSURE_MAIN_PROCESS("Cannot ClearUserPref from content process:", aPrefName);
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   return PREF_ClearUserPref(pref);
 }
 NS_IMETHODIMP nsPrefBranch::PrefHasUserValue(const char *aPrefName, bool *_retval)
 {
   NS_ENSURE_ARG_POINTER(_retval);
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   *_retval = PREF_HasUserPref(pref);
   return NS_OK;
 }
 NS_IMETHODIMP nsPrefBranch::LockPref(const char *aPrefName)
 {
   ENSURE_MAIN_PROCESS("Cannot LockPref from content process:", aPrefName);
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   return PREF_LockPref(pref, true);
 }
 NS_IMETHODIMP nsPrefBranch::PrefIsLocked(const char *aPrefName, bool *_retval)
 {
   ENSURE_MAIN_PROCESS("Cannot check PrefIsLocked from content process:", aPrefName);
   NS_ENSURE_ARG_POINTER(_retval);
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   *_retval = PREF_PrefIsLocked(pref);
   return NS_OK;
 }
 NS_IMETHODIMP nsPrefBranch::UnlockPref(const char *aPrefName)
 {
   ENSURE_MAIN_PROCESS("Cannot UnlockPref from content process:", aPrefName);
   NS_ENSURE_ARG(aPrefName);
   const char *pref = getPrefName(aPrefName);
   return PREF_LockPref(pref, false);
 }
 /* void resetBranch (in string startingAt); */
 NS_IMETHODIMP nsPrefBranch::ResetBranch(const char *aStartingAt)
 {
   return NS_ERROR_NOT_IMPLEMENTED;
 }
 NS_IMETHODIMP nsPrefBranch::DeleteBranch(const char *aStartingAt)
 {
   ENSURE_MAIN_PROCESS("Cannot DeleteBranch from content process:", aStartingAt);
   NS_ENSURE_ARG(aStartingAt);
   const char *pref = getPrefName(aStartingAt);
   return PREF_DeleteBranch(pref);
 }
 NS_IMETHODIMP nsPrefBranch::GetChildList(const char *aStartingAt, uint32_t *aCount, char ***aChildArray)
 {
   char            **outArray;
   int32_t         numPrefs;
   int32_t         dwIndex;
   EnumerateData   ed;
   nsAutoTArray<nsCString, 32> prefArray;
   NS_ENSURE_ARG(aStartingAt);
   NS_ENSURE_ARG_POINTER(aCount);
   NS_ENSURE_ARG_POINTER(aChildArray);
   *aChildArray = nullptr;
   *aCount = 0;
   if (!gHashTable.ops)
     return NS_ERROR_NOT_INITIALIZED;
   // this will contain a list of all the pref name strings
   // allocate on the stack for speed
   ed.parent = getPrefName(aStartingAt);
   ed.pref_list = &prefArray;
   PL_DHashTableEnumerate(&gHashTable, pref_enumChild, &ed);
   // now that we've built up the list, run the callback on
   // all the matching elements
   numPrefs = prefArray.Length();
   if (numPrefs) {
     outArray = (char **)nsMemory::Alloc(numPrefs * sizeof(char *));
     if (!outArray)
       return NS_ERROR_OUT_OF_MEMORY;
     for (dwIndex = 0; dwIndex < numPrefs; ++dwIndex) {
       // we need to lop off mPrefRoot in case the user is planning to pass this
       // back to us because if they do we are going to add mPrefRoot again.
       const nsCString& element = prefArray[dwIndex];
       outArray[dwIndex] = (char *)nsMemory::Clone(
         element.get() + mPrefRootLength, element.Length() - mPrefRootLength + 1);
       if (!outArray[dwIndex]) {
         // we ran out of memory... this is annoying
         NS_FREE_XPCOM_ALLOCATED_POINTER_ARRAY(dwIndex, outArray);
         return NS_ERROR_OUT_OF_MEMORY;
       }
     }
     *aChildArray = outArray;
   }
   *aCount = numPrefs;
   return NS_OK;
 }
 NS_IMETHODIMP nsPrefBranch::AddObserver(const char *aDomain, nsIObserver *aObserver, bool aHoldWeak)
 {
   PrefCallback *pCallback;
   const char *pref;
   NS_ENSURE_ARG(aDomain);
   NS_ENSURE_ARG(aObserver);
   // hold a weak reference to the observer if so requested
   if (aHoldWeak) {
     nsCOMPtr<nsISupportsWeakReference> weakRefFactory = do_QueryInterface(aObserver);
     if (!weakRefFactory) {
       // the caller didn't give us a object that supports weak reference... tell them
       return NS_ERROR_INVALID_ARG;
     }
     // Construct a PrefCallback with a weak reference to the observer.
     pCallback = new PrefCallback(aDomain, weakRefFactory, this);
   } else {
     // Construct a PrefCallback with a strong reference to the observer.
     pCallback = new PrefCallback(aDomain, aObserver, this);
   }
   if (mObservers.Get(pCallback)) {
     NS_WARNING("Ignoring duplicate observer.");
     delete pCallback;
     return NS_OK;
   }
   mObservers.Put(pCallback, pCallback);
   // We must pass a fully qualified preference name to the callback
   // aDomain == nullptr is the only possible failure, and we trapped it with
   // NS_ENSURE_ARG above.
   pref = getPrefName(aDomain);
   PREF_RegisterCallback(pref, NotifyObserver, pCallback);
   return NS_OK;
 }
 NS_IMETHODIMP nsPrefBranch::RemoveObserver(const char *aDomain, nsIObserver *aObserver)
 {
   NS_ENSURE_ARG(aDomain);
   NS_ENSURE_ARG(aObserver);
   nsresult rv = NS_OK;
   // If we're in the middle of a call to freeObserverList, don't process this
   // RemoveObserver call -- the observer in question will be removed soon, if
   // it hasn't been already.
   //
   // It's important that we don't touch mObservers in any way -- even a Get()
   // which retuns null might cause the hashtable to resize itself, which will
   // break the Enumerator in freeObserverList.
   if (mFreeingObserverList)
     return NS_OK;
   // Remove the relevant PrefCallback from mObservers and get an owning
   // pointer to it.  Unregister the callback first, and then let the owning
   // pointer go out of scope and destroy the callback.
   PrefCallback key(aDomain, aObserver, this);
   nsAutoPtr<PrefCallback> pCallback;
   mObservers.RemoveAndForget(&key, pCallback);
   if (pCallback) {
     // aDomain == nullptr is the only possible failure, trapped above
     const char *pref = getPrefName(aDomain);
     rv = PREF_UnregisterCallback(pref, NotifyObserver, pCallback);
   }
   return rv;
 }
 NS_IMETHODIMP nsPrefBranch::Observe(nsISupports *aSubject, const char *aTopic, const char16_t *someData)
 {
   // watch for xpcom shutdown and free our observers to eliminate any cyclic references
   if (!nsCRT::strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
     freeObserverList();
   }
   return NS_OK;
 }
 /* static */
 void nsPrefBranch::NotifyObserver(const char *newpref, void *data)
 {
   PrefCallback *pCallback = (PrefCallback *)data;
   nsCOMPtr<nsIObserver> observer = pCallback->GetObserver();
   if (!observer) {
     // The observer has expired.  Let's remove this callback.
     pCallback->GetPrefBranch()->RemoveExpiredCallback(pCallback);
     return;
   }
   // remove any root this string may contain so as to not confuse the observer
   // by passing them something other than what they passed us as a topic
   uint32_t len = pCallback->GetPrefBranch()->GetRootLength();
   nsAutoCString suffix(newpref + len);
   observer->Observe(static_cast<nsIPrefBranch *>(pCallback->GetPrefBranch()),
                     NS_PREFBRANCH_PREFCHANGE_TOPIC_ID,
                     NS_ConvertASCIItoUTF16(suffix).get());
 }
 PLDHashOperator
 FreeObserverFunc(PrefCallback *aKey,
                  nsAutoPtr<PrefCallback> &aCallback,
                  void *aArgs)
 {
   // Calling NS_RELEASE below might trigger a call to
   // nsPrefBranch::RemoveObserver, since some classes remove themselves from
   // the pref branch on destruction.  We don't need to worry about this causing
   // double-frees, however, because freeObserverList sets mFreeingObserverList
   // to true, which prevents RemoveObserver calls from doing anything.
   nsPrefBranch *prefBranch = aCallback->GetPrefBranch();
   const char *pref = prefBranch->getPrefName(aCallback->GetDomain().get());
   PREF_UnregisterCallback(pref, nsPrefBranch::NotifyObserver, aCallback);
   return PL_DHASH_REMOVE;
 }
 void nsPrefBranch::freeObserverList(void)
 {
   // We need to prevent anyone from modifying mObservers while we're
   // enumerating over it.  In particular, some clients will call
   // RemoveObserver() when they're destructed; we need to keep those calls from
   // touching mObservers.
   mFreeingObserverList = true;
   mObservers.Enumerate(&FreeObserverFunc, nullptr);
   mFreeingObserverList = false;
 }
 void
 nsPrefBranch::RemoveExpiredCallback(PrefCallback *aCallback)
 {
   NS_PRECONDITION(aCallback->IsExpired(), "Callback should be expired.");
   mObservers.Remove(aCallback);
 }
 nsresult nsPrefBranch::GetDefaultFromPropertiesFile(const char *aPrefName, char16_t **return_buf)
 {
   nsresult rv;
   // the default value contains a URL to a .properties file
   nsXPIDLCString propertyFileURL;
   rv = PREF_CopyCharPref(aPrefName, getter_Copies(propertyFileURL), true);
   if (NS_FAILED(rv))
     return rv;
   nsCOMPtr<nsIStringBundleService> bundleService =
     mozilla::services::GetStringBundleService();
   if (!bundleService)
     return NS_ERROR_FAILURE;
   nsCOMPtr<nsIStringBundle> bundle;
   rv = bundleService->CreateBundle(propertyFileURL,
                                    getter_AddRefs(bundle));
   if (NS_FAILED(rv))
     return rv;
   // string names are in unicode
   nsAutoString stringId;
   stringId.AssignASCII(aPrefName);
   return bundle->GetStringFromName(stringId.get(), return_buf);
 }
 const char *nsPrefBranch::getPrefName(const char *aPrefName)
 {
   NS_ASSERTION(aPrefName, "null pref name!");
   // for speed, avoid strcpy if we can:
   if (mPrefRoot.IsEmpty())
     return aPrefName;
   // isn't there a better way to do this? this is really kind of gross.
   mPrefRoot.Truncate(mPrefRootLength);
   mPrefRoot.Append(aPrefName);
   return mPrefRoot.get();
 }
 static PLDHashOperator
 pref_enumChild(PLDHashTable *table, PLDHashEntryHdr *heh,
                uint32_t i, void *arg)
 {
   PrefHashEntry *he = static_cast<PrefHashEntry*>(heh);
   EnumerateData *d = reinterpret_cast<EnumerateData *>(arg);
   if (strncmp(he->key, d->parent, strlen(d->parent)) == 0) {
     d->pref_list->AppendElement(he->key);
   }
   return PL_DHASH_NEXT;
 }
 //----------------------------------------------------------------------------
 // nsPrefLocalizedString
 //----------------------------------------------------------------------------
 nsPrefLocalizedString::nsPrefLocalizedString()
 {
 }
 nsPrefLocalizedString::~nsPrefLocalizedString()
 {
 }
 /*
  * nsISupports Implementation
  */
 NS_IMPL_ADDREF(nsPrefLocalizedString)
 NS_IMPL_RELEASE(nsPrefLocalizedString)
 NS_INTERFACE_MAP_BEGIN(nsPrefLocalizedString)
     NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIPrefLocalizedString)
     NS_INTERFACE_MAP_ENTRY(nsIPrefLocalizedString)
     NS_INTERFACE_MAP_ENTRY(nsISupportsString)
 NS_INTERFACE_MAP_END
 nsresult nsPrefLocalizedString::Init()
 {
   nsresult rv;
   mUnicodeString = do_CreateInstance(NS_SUPPORTS_STRING_CONTRACTID, &rv);
   return rv;
 }
 NS_IMETHODIMP
 nsPrefLocalizedString::GetData(char16_t **_retval)
 {
   nsAutoString data;
   nsresult rv = GetData(data);
   if (NS_FAILED(rv))
     return rv;
   *_retval = ToNewUnicode(data);
   if (!*_retval)
     return NS_ERROR_OUT_OF_MEMORY;
   return NS_OK;
 }
 NS_IMETHODIMP
 nsPrefLocalizedString::SetData(const char16_t *aData)
 {
   if (!aData)
     return SetData(EmptyString());
   return SetData(nsDependentString(aData));
 }
 NS_IMETHODIMP
 nsPrefLocalizedString::SetDataWithLength(uint32_t aLength,
                                          const char16_t *aData)
 {
   if (!aData)
     return SetData(EmptyString());
   return SetData(Substring(aData, aLength));
 }
 //----------------------------------------------------------------------------
 // nsRelativeFilePref
 //----------------------------------------------------------------------------
 NS_IMPL_ISUPPORTS(nsRelativeFilePref, nsIRelativeFilePref)
 nsRelativeFilePref::nsRelativeFilePref()
 {
 }
 nsRelativeFilePref::~nsRelativeFilePref()
 {
 }
 NS_IMETHODIMP nsRelativeFilePref::GetFile(nsIFile **aFile)
 {
   NS_ENSURE_ARG_POINTER(aFile);
   *aFile = mFile;
   NS_IF_ADDREF(*aFile);
   return NS_OK;
 }
 NS_IMETHODIMP nsRelativeFilePref::SetFile(nsIFile *aFile)
 {
   mFile = aFile;
   return NS_OK;
 }
 NS_IMETHODIMP nsRelativeFilePref::GetRelativeToKey(nsACString& aRelativeToKey)
 {
   aRelativeToKey.Assign(mRelativeToKey);
   return NS_OK;
 }
 NS_IMETHODIMP nsRelativeFilePref::SetRelativeToKey(const nsACString& aRelativeToKey)
 {
   mRelativeToKey.Assign(aRelativeToKey);
   return NS_OK;
 }
 #undef ENSURE_MAIN_PROCESS

The Tor Browser / annotate

modules/libpref/src/nsPrefBranch.cpp@129ffea94266 (annotated)

modules/libpref/src/nsPrefBranch.cpp