michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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: #ifndef nsPrefBranch_h
michael@0: #define nsPrefBranch_h
michael@0: 
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsIObserver.h"
michael@0: #include "nsIPrefBranch.h"
michael@0: #include "nsIPrefBranchInternal.h"
michael@0: #include "nsIPrefLocalizedString.h"
michael@0: #include "nsXPCOM.h"
michael@0: #include "nsISupportsPrimitives.h"
michael@0: #include "nsIRelativeFilePref.h"
michael@0: #include "nsIFile.h"
michael@0: #include "nsString.h"
michael@0: #include "nsTArray.h"
michael@0: #include "nsWeakReference.h"
michael@0: #include "nsClassHashtable.h"
michael@0: #include "nsCRT.h"
michael@0: #include "nsISupportsImpl.h"
michael@0: #include "mozilla/HashFunctions.h"
michael@0: #include "mozilla/MemoryReporting.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: class PreferenceServiceReporter;
michael@0: } // namespace mozilla;
michael@0: 
michael@0: class nsPrefBranch;
michael@0: 
michael@0: class PrefCallback : public PLDHashEntryHdr {
michael@0:   friend class mozilla::PreferenceServiceReporter;
michael@0: 
michael@0:   public:
michael@0:     typedef PrefCallback* KeyType;
michael@0:     typedef const PrefCallback* KeyTypePointer;
michael@0: 
michael@0:     static const PrefCallback* KeyToPointer(PrefCallback *aKey)
michael@0:     {
michael@0:       return aKey;
michael@0:     }
michael@0: 
michael@0:     static PLDHashNumber HashKey(const PrefCallback *aKey)
michael@0:     {
michael@0:       uint32_t hash = mozilla::HashString(aKey->mDomain);
michael@0:       return mozilla::AddToHash(hash, aKey->mCanonical);
michael@0:     }
michael@0: 
michael@0: 
michael@0:   public:
michael@0:     // Create a PrefCallback with a strong reference to its observer.
michael@0:     PrefCallback(const char *aDomain, nsIObserver *aObserver,
michael@0:                  nsPrefBranch *aBranch)
michael@0:       : mDomain(aDomain),
michael@0:         mBranch(aBranch),
michael@0:         mWeakRef(nullptr),
michael@0:         mStrongRef(aObserver)
michael@0:     {
michael@0:       MOZ_COUNT_CTOR(PrefCallback);
michael@0:       nsCOMPtr<nsISupports> canonical = do_QueryInterface(aObserver);
michael@0:       mCanonical = canonical;
michael@0:     }
michael@0: 
michael@0:     // Create a PrefCallback with a weak reference to its observer.
michael@0:     PrefCallback(const char *aDomain,
michael@0:                  nsISupportsWeakReference *aObserver,
michael@0:                  nsPrefBranch *aBranch)
michael@0:       : mDomain(aDomain),
michael@0:         mBranch(aBranch),
michael@0:         mWeakRef(do_GetWeakReference(aObserver)),
michael@0:         mStrongRef(nullptr)
michael@0:     {
michael@0:       MOZ_COUNT_CTOR(PrefCallback);
michael@0:       nsCOMPtr<nsISupports> canonical = do_QueryInterface(aObserver);
michael@0:       mCanonical = canonical;
michael@0:     }
michael@0: 
michael@0:     // Copy constructor needs to be explicit or the linker complains.
michael@0:     PrefCallback(const PrefCallback *&aCopy)
michael@0:       : mDomain(aCopy->mDomain),
michael@0:         mBranch(aCopy->mBranch),
michael@0:         mWeakRef(aCopy->mWeakRef),
michael@0:         mStrongRef(aCopy->mStrongRef),
michael@0:         mCanonical(aCopy->mCanonical)
michael@0:     {
michael@0:       MOZ_COUNT_CTOR(PrefCallback);
michael@0:     }
michael@0: 
michael@0:     ~PrefCallback()
michael@0:     {
michael@0:       MOZ_COUNT_DTOR(PrefCallback);
michael@0:     }
michael@0: 
michael@0:     bool KeyEquals(const PrefCallback *aKey) const
michael@0:     {
michael@0:       // We want to be able to look up a weakly-referencing PrefCallback after
michael@0:       // its observer has died so we can remove it from the table.  Once the
michael@0:       // callback's observer dies, its canonical pointer is stale -- in
michael@0:       // particular, we may have allocated a new observer in the same spot in
michael@0:       // memory!  So we can't just compare canonical pointers to determine
michael@0:       // whether aKey refers to the same observer as this.
michael@0:       //
michael@0:       // Our workaround is based on the way we use this hashtable: When we ask
michael@0:       // the hashtable to remove a PrefCallback whose weak reference has
michael@0:       // expired, we use as the key for removal the same object as was inserted
michael@0:       // into the hashtable.  Thus we can say that if one of the keys' weak
michael@0:       // references has expired, the two keys are equal iff they're the same
michael@0:       // object.
michael@0: 
michael@0:       if (IsExpired() || aKey->IsExpired())
michael@0:         return this == aKey;
michael@0: 
michael@0:       if (mCanonical != aKey->mCanonical)
michael@0:         return false;
michael@0: 
michael@0:       return mDomain.Equals(aKey->mDomain);
michael@0:     }
michael@0: 
michael@0:     PrefCallback *GetKey() const
michael@0:     {
michael@0:       return const_cast<PrefCallback*>(this);
michael@0:     }
michael@0: 
michael@0:     // Get a reference to the callback's observer, or null if the observer was
michael@0:     // weakly referenced and has been destroyed.
michael@0:     already_AddRefed<nsIObserver> GetObserver() const
michael@0:     {
michael@0:       if (!IsWeak()) {
michael@0:         nsCOMPtr<nsIObserver> copy = mStrongRef;
michael@0:         return copy.forget();
michael@0:       }
michael@0: 
michael@0:       nsCOMPtr<nsIObserver> observer = do_QueryReferent(mWeakRef);
michael@0:       return observer.forget();
michael@0:     }
michael@0: 
michael@0:     const nsCString& GetDomain() const
michael@0:     {
michael@0:       return mDomain;
michael@0:     }
michael@0: 
michael@0:     nsPrefBranch* GetPrefBranch() const
michael@0:     {
michael@0:       return mBranch;
michael@0:     }
michael@0: 
michael@0:     // Has this callback's weak reference died?
michael@0:     bool IsExpired() const
michael@0:     {
michael@0:       if (!IsWeak())
michael@0:         return false;
michael@0: 
michael@0:       nsCOMPtr<nsIObserver> observer(do_QueryReferent(mWeakRef));
michael@0:       return !observer;
michael@0:     }
michael@0: 
michael@0:     enum { ALLOW_MEMMOVE = true };
michael@0: 
michael@0:   private:
michael@0:     nsCString             mDomain;
michael@0:     nsPrefBranch         *mBranch;
michael@0: 
michael@0:     // Exactly one of mWeakRef and mStrongRef should be non-null.
michael@0:     nsWeakPtr             mWeakRef;
michael@0:     nsCOMPtr<nsIObserver> mStrongRef;
michael@0: 
michael@0:     // We need a canonical nsISupports pointer, per bug 578392.
michael@0:     nsISupports          *mCanonical;
michael@0: 
michael@0:     bool IsWeak() const
michael@0:     {
michael@0:       return !!mWeakRef;
michael@0:     }
michael@0: };
michael@0: 
michael@0: class nsPrefBranch : public nsIPrefBranchInternal,
michael@0:                      public nsIObserver,
michael@0:                      public nsSupportsWeakReference
michael@0: {
michael@0:   friend class mozilla::PreferenceServiceReporter;
michael@0: public:
michael@0:   NS_DECL_ISUPPORTS
michael@0:   NS_DECL_NSIPREFBRANCH
michael@0:   NS_DECL_NSIPREFBRANCH2
michael@0:   NS_DECL_NSIOBSERVER
michael@0: 
michael@0:   nsPrefBranch(const char *aPrefRoot, bool aDefaultBranch);
michael@0:   virtual ~nsPrefBranch();
michael@0: 
michael@0:   int32_t GetRootLength() { return mPrefRootLength; }
michael@0: 
michael@0:   nsresult RemoveObserverFromMap(const char *aDomain, nsISupports *aObserver);
michael@0: 
michael@0:   static void NotifyObserver(const char *newpref, void *data);
michael@0: 
michael@0:   size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
michael@0: 
michael@0: protected:
michael@0:   nsPrefBranch()    /* disallow use of this constructer */
michael@0:     { }
michael@0: 
michael@0:   nsresult   GetDefaultFromPropertiesFile(const char *aPrefName, char16_t **return_buf);
michael@0:   // As SetCharPref, but without any check on the length of |aValue|
michael@0:   nsresult   SetCharPrefInternal(const char *aPrefName, const char *aValue);
michael@0:   // Reject strings that are more than 1Mb, warn if strings are more than 16kb
michael@0:   nsresult   CheckSanityOfStringLength(const char* aPrefName, const nsAString& aValue);
michael@0:   nsresult   CheckSanityOfStringLength(const char* aPrefName, const char* aValue);
michael@0:   nsresult   CheckSanityOfStringLength(const char* aPrefName, const uint32_t aLength);
michael@0:   void RemoveExpiredCallback(PrefCallback *aCallback);
michael@0:   const char *getPrefName(const char *aPrefName);
michael@0:   void       freeObserverList(void);
michael@0: 
michael@0:   friend PLDHashOperator
michael@0:     FreeObserverFunc(PrefCallback *aKey,
michael@0:                      nsAutoPtr<PrefCallback> &aCallback,
michael@0:                      void *aArgs);
michael@0: 
michael@0: private:
michael@0:   int32_t               mPrefRootLength;
michael@0:   nsCString             mPrefRoot;
michael@0:   bool                  mIsDefault;
michael@0: 
michael@0:   bool                  mFreeingObserverList;
michael@0:   nsClassHashtable<PrefCallback, PrefCallback> mObservers;
michael@0: };
michael@0: 
michael@0: 
michael@0: class nsPrefLocalizedString : public nsIPrefLocalizedString,
michael@0:                               public nsISupportsString
michael@0: {
michael@0: public:
michael@0:   nsPrefLocalizedString();
michael@0:   virtual ~nsPrefLocalizedString();
michael@0: 
michael@0:   NS_DECL_ISUPPORTS
michael@0:   NS_FORWARD_NSISUPPORTSSTRING(mUnicodeString->)
michael@0:   NS_FORWARD_NSISUPPORTSPRIMITIVE(mUnicodeString->)
michael@0: 
michael@0:   nsresult Init();
michael@0: 
michael@0: private:
michael@0:   NS_IMETHOD GetData(char16_t**);
michael@0:   NS_IMETHOD SetData(const char16_t* aData);
michael@0:   NS_IMETHOD SetDataWithLength(uint32_t aLength, const char16_t *aData);
michael@0: 
michael@0:   nsCOMPtr<nsISupportsString> mUnicodeString;
michael@0: };
michael@0: 
michael@0: 
michael@0: class nsRelativeFilePref : public nsIRelativeFilePref
michael@0: {
michael@0: public:
michael@0:   NS_DECL_ISUPPORTS
michael@0:   NS_DECL_NSIRELATIVEFILEPREF
michael@0:   
michael@0:                 nsRelativeFilePref();
michael@0:   virtual       ~nsRelativeFilePref();
michael@0:   
michael@0: private:
michael@0:   nsCOMPtr<nsIFile> mFile;
michael@0:   nsCString mRelativeToKey;
michael@0: };
michael@0: 
michael@0: #endif