The Tor Browser: modules/libpref/src/nsPrefBranch.h@6474c204b198 (annotated)

modules/libpref/src/nsPrefBranch.h@6474c204b198 (annotated)

modules/libpref/src/nsPrefBranch.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* -*- 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/. */
 #ifndef nsPrefBranch_h
 #define nsPrefBranch_h
 #include "nsCOMPtr.h"
 #include "nsIObserver.h"
 #include "nsIPrefBranch.h"
 #include "nsIPrefBranchInternal.h"
 #include "nsIPrefLocalizedString.h"
 #include "nsXPCOM.h"
 #include "nsISupportsPrimitives.h"
 #include "nsIRelativeFilePref.h"
 #include "nsIFile.h"
 #include "nsString.h"
 #include "nsTArray.h"
 #include "nsWeakReference.h"
 #include "nsClassHashtable.h"
 #include "nsCRT.h"
 #include "nsISupportsImpl.h"
 #include "mozilla/HashFunctions.h"
 #include "mozilla/MemoryReporting.h"
 namespace mozilla {
 class PreferenceServiceReporter;
 } // namespace mozilla;
 class nsPrefBranch;
 class PrefCallback : public PLDHashEntryHdr {
   friend class mozilla::PreferenceServiceReporter;
   public:
     typedef PrefCallback* KeyType;
     typedef const PrefCallback* KeyTypePointer;
     static const PrefCallback* KeyToPointer(PrefCallback *aKey)
     {
       return aKey;
     }
     static PLDHashNumber HashKey(const PrefCallback *aKey)
     {
       uint32_t hash = mozilla::HashString(aKey->mDomain);
       return mozilla::AddToHash(hash, aKey->mCanonical);
     }
   public:
     // Create a PrefCallback with a strong reference to its observer.
     PrefCallback(const char *aDomain, nsIObserver *aObserver,
                  nsPrefBranch *aBranch)
       : mDomain(aDomain),
         mBranch(aBranch),
         mWeakRef(nullptr),
         mStrongRef(aObserver)
     {
       MOZ_COUNT_CTOR(PrefCallback);
       nsCOMPtr<nsISupports> canonical = do_QueryInterface(aObserver);
       mCanonical = canonical;
     }
     // Create a PrefCallback with a weak reference to its observer.
     PrefCallback(const char *aDomain,
                  nsISupportsWeakReference *aObserver,
                  nsPrefBranch *aBranch)
       : mDomain(aDomain),
         mBranch(aBranch),
         mWeakRef(do_GetWeakReference(aObserver)),
         mStrongRef(nullptr)
     {
       MOZ_COUNT_CTOR(PrefCallback);
       nsCOMPtr<nsISupports> canonical = do_QueryInterface(aObserver);
       mCanonical = canonical;
     }
     // Copy constructor needs to be explicit or the linker complains.
     PrefCallback(const PrefCallback *&aCopy)
       : mDomain(aCopy->mDomain),
         mBranch(aCopy->mBranch),
         mWeakRef(aCopy->mWeakRef),
         mStrongRef(aCopy->mStrongRef),
         mCanonical(aCopy->mCanonical)
     {
       MOZ_COUNT_CTOR(PrefCallback);
     }
     ~PrefCallback()
     {
       MOZ_COUNT_DTOR(PrefCallback);
     }
     bool KeyEquals(const PrefCallback *aKey) const
     {
       // We want to be able to look up a weakly-referencing PrefCallback after
       // its observer has died so we can remove it from the table.  Once the
       // callback's observer dies, its canonical pointer is stale -- in
       // particular, we may have allocated a new observer in the same spot in
       // memory!  So we can't just compare canonical pointers to determine
       // whether aKey refers to the same observer as this.
       //
       // Our workaround is based on the way we use this hashtable: When we ask
       // the hashtable to remove a PrefCallback whose weak reference has
       // expired, we use as the key for removal the same object as was inserted
       // into the hashtable.  Thus we can say that if one of the keys' weak
       // references has expired, the two keys are equal iff they're the same
       // object.
       if (IsExpired() || aKey->IsExpired())
         return this == aKey;
       if (mCanonical != aKey->mCanonical)
         return false;
       return mDomain.Equals(aKey->mDomain);
     }
     PrefCallback *GetKey() const
     {
       return const_cast<PrefCallback*>(this);
     }
     // Get a reference to the callback's observer, or null if the observer was
     // weakly referenced and has been destroyed.
     already_AddRefed<nsIObserver> GetObserver() const
     {
       if (!IsWeak()) {
         nsCOMPtr<nsIObserver> copy = mStrongRef;
         return copy.forget();
       }
       nsCOMPtr<nsIObserver> observer = do_QueryReferent(mWeakRef);
       return observer.forget();
     }
     const nsCString& GetDomain() const
     {
       return mDomain;
     }
     nsPrefBranch* GetPrefBranch() const
     {
       return mBranch;
     }
     // Has this callback's weak reference died?
     bool IsExpired() const
     {
       if (!IsWeak())
         return false;
       nsCOMPtr<nsIObserver> observer(do_QueryReferent(mWeakRef));
       return !observer;
     }
     enum { ALLOW_MEMMOVE = true };
   private:
     nsCString             mDomain;
     nsPrefBranch         *mBranch;
     // Exactly one of mWeakRef and mStrongRef should be non-null.
     nsWeakPtr             mWeakRef;
     nsCOMPtr<nsIObserver> mStrongRef;
     // We need a canonical nsISupports pointer, per bug 578392.
     nsISupports          *mCanonical;
     bool IsWeak() const
     {
       return !!mWeakRef;
     }
 };
 class nsPrefBranch : public nsIPrefBranchInternal,
                      public nsIObserver,
                      public nsSupportsWeakReference
 {
   friend class mozilla::PreferenceServiceReporter;
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSIPREFBRANCH
   NS_DECL_NSIPREFBRANCH2
   NS_DECL_NSIOBSERVER
   nsPrefBranch(const char *aPrefRoot, bool aDefaultBranch);
   virtual ~nsPrefBranch();
   int32_t GetRootLength() { return mPrefRootLength; }
   nsresult RemoveObserverFromMap(const char *aDomain, nsISupports *aObserver);
   static void NotifyObserver(const char *newpref, void *data);
   size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
 protected:
   nsPrefBranch()    /* disallow use of this constructer */
     { }
   nsresult   GetDefaultFromPropertiesFile(const char *aPrefName, char16_t **return_buf);
   // As SetCharPref, but without any check on the length of |aValue|
   nsresult   SetCharPrefInternal(const char *aPrefName, const char *aValue);
   // Reject strings that are more than 1Mb, warn if strings are more than 16kb
   nsresult   CheckSanityOfStringLength(const char* aPrefName, const nsAString& aValue);
   nsresult   CheckSanityOfStringLength(const char* aPrefName, const char* aValue);
   nsresult   CheckSanityOfStringLength(const char* aPrefName, const uint32_t aLength);
   void RemoveExpiredCallback(PrefCallback *aCallback);
   const char *getPrefName(const char *aPrefName);
   void       freeObserverList(void);
   friend PLDHashOperator
     FreeObserverFunc(PrefCallback *aKey,
                      nsAutoPtr<PrefCallback> &aCallback,
                      void *aArgs);
 private:
   int32_t               mPrefRootLength;
   nsCString             mPrefRoot;
   bool                  mIsDefault;
   bool                  mFreeingObserverList;
   nsClassHashtable<PrefCallback, PrefCallback> mObservers;
 };
 class nsPrefLocalizedString : public nsIPrefLocalizedString,
                               public nsISupportsString
 {
 public:
   nsPrefLocalizedString();
   virtual ~nsPrefLocalizedString();
   NS_DECL_ISUPPORTS
   NS_FORWARD_NSISUPPORTSSTRING(mUnicodeString->)
   NS_FORWARD_NSISUPPORTSPRIMITIVE(mUnicodeString->)
   nsresult Init();
 private:
   NS_IMETHOD GetData(char16_t**);
   NS_IMETHOD SetData(const char16_t* aData);
   NS_IMETHOD SetDataWithLength(uint32_t aLength, const char16_t *aData);
   nsCOMPtr<nsISupportsString> mUnicodeString;
 };
 class nsRelativeFilePref : public nsIRelativeFilePref
 {
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_NSIRELATIVEFILEPREF
                 nsRelativeFilePref();
   virtual       ~nsRelativeFilePref();
 private:
   nsCOMPtr<nsIFile> mFile;
   nsCString mRelativeToKey;
 };
 #endif

The Tor Browser / annotate

modules/libpref/src/nsPrefBranch.h@6474c204b198 (annotated)

modules/libpref/src/nsPrefBranch.h