michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
michael@0:  * vim: sw=2 ts=2 et :
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 dom_plugins_PluginIdentifierChild_h
michael@0: #define dom_plugins_PluginIdentifierChild_h
michael@0: 
michael@0: #include "mozilla/plugins/PPluginIdentifierChild.h"
michael@0: #include "npapi.h"
michael@0: #include "npruntime.h"
michael@0: 
michael@0: #include "nsString.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace plugins {
michael@0: 
michael@0: class PluginModuleChild;
michael@0: 
michael@0: /**
michael@0:  * Plugin identifiers may be "temporary", see the comment on the
michael@0:  * PPluginIdentifier constructor for details. This means that any IPDL method
michael@0:  * which receives a PPluginIdentifierChild* parameter must use StackIdentifier
michael@0:  * to track it.
michael@0:  */
michael@0: class PluginIdentifierChild : public PPluginIdentifierChild
michael@0: {
michael@0:   friend class PluginModuleChild;
michael@0: public:
michael@0:   bool IsString()
michael@0:   {
michael@0:     return mIsString;
michael@0:   }
michael@0: 
michael@0:   NPIdentifier ToNPIdentifier()
michael@0:   {
michael@0:     if (mCanonicalIdentifier) {
michael@0:       return mCanonicalIdentifier;
michael@0:     }
michael@0: 
michael@0:     NS_ASSERTION(mHashed, "Handing out an unhashed identifier?");
michael@0:     return this;
michael@0:   }
michael@0: 
michael@0:   void MakePermanent();
michael@0: 
michael@0:   class MOZ_STACK_CLASS StackIdentifier
michael@0:   {
michael@0:   public:
michael@0:     StackIdentifier(PPluginIdentifierChild* actor)
michael@0:       : mIdentifier(static_cast<PluginIdentifierChild*>(actor))
michael@0:     {
michael@0:       if (mIdentifier)
michael@0:         mIdentifier->StartTemporary();
michael@0:     }
michael@0: 
michael@0:     ~StackIdentifier() {
michael@0:       if (mIdentifier)
michael@0:         mIdentifier->FinishTemporary();
michael@0:     }
michael@0: 
michael@0:     PluginIdentifierChild* operator->() { return mIdentifier; }
michael@0: 
michael@0:   private:
michael@0:     PluginIdentifierChild* mIdentifier;
michael@0:   };
michael@0: 
michael@0: protected:
michael@0:   PluginIdentifierChild(bool aIsString)
michael@0:     : mCanonicalIdentifier(nullptr)
michael@0:     , mHashed(false)
michael@0:     , mTemporaryRefs(0)
michael@0:     , mIsString(aIsString)
michael@0:   {
michael@0:     MOZ_COUNT_CTOR(PluginIdentifierChild);
michael@0:   }
michael@0: 
michael@0:   virtual ~PluginIdentifierChild()
michael@0:   {
michael@0:     MOZ_COUNT_DTOR(PluginIdentifierChild);
michael@0:   }
michael@0: 
michael@0:   // The following functions are implemented by the subclasses for their
michael@0:   // identifier maps.
michael@0:   virtual PluginIdentifierChild* GetCanonical() = 0;
michael@0:   virtual void Hash() = 0;
michael@0:   virtual void Unhash() = 0;
michael@0: 
michael@0: private:
michael@0:   void StartTemporary();
michael@0:   void FinishTemporary();
michael@0: 
michael@0:   // There's a possibility that we already have an actor that wraps the same
michael@0:   // string or int because we do all this identifier construction
michael@0:   // asynchronously. In this case we need to hand out the canonical version
michael@0:   // created by the child side.
michael@0:   //
michael@0:   // In order to deal with temporary identifiers which appear on the stack,
michael@0:   // identifiers use the following state invariants:
michael@0:   //
michael@0:   // * mCanonicalIdentifier is non-nullptr: this is a duplicate identifier, no
michael@0:   //   further information is necessary.
michael@0:   // * mHashed is false: this identifier is a newborn, non-permanent identifier
michael@0:   // * mHashed is true, mTemporaryRefs is 0: this identifier is permanent
michael@0:   // * mHashed is true, mTemporaryRefs is non-0: this identifier is temporary;
michael@0:   //   if NPN_GetFooIdentifier is called for it, we need to retain it. If
michael@0:   //   all stack references are lost, unhash it because it will soon be 
michael@0:   //   deleted.
michael@0: 
michael@0:   PluginIdentifierChild* mCanonicalIdentifier;
michael@0:   bool mHashed;
michael@0:   unsigned int mTemporaryRefs;
michael@0:   bool mIsString;
michael@0: };
michael@0: 
michael@0: class PluginIdentifierChildString : public PluginIdentifierChild
michael@0: {
michael@0:   friend class PluginModuleChild;
michael@0: public:
michael@0:   NPUTF8* ToString()
michael@0:   {
michael@0:     return ToNewCString(mString);
michael@0:   }
michael@0: 
michael@0: protected:
michael@0:   PluginIdentifierChildString(const nsCString& aString)
michael@0:     : PluginIdentifierChild(true),
michael@0:       mString(aString)
michael@0:   { }
michael@0: 
michael@0:   virtual PluginIdentifierChild* GetCanonical();
michael@0:   virtual void Hash();
michael@0:   virtual void Unhash();
michael@0: 
michael@0:   nsCString mString;
michael@0: };
michael@0: 
michael@0: class PluginIdentifierChildInt : public PluginIdentifierChild
michael@0: {
michael@0:   friend class PluginModuleChild;
michael@0: public:
michael@0:   int32_t ToInt()
michael@0:   {
michael@0:     return mInt;
michael@0:   }
michael@0: 
michael@0: protected:
michael@0:   PluginIdentifierChildInt(int32_t aInt)
michael@0:     : PluginIdentifierChild(false),
michael@0:       mInt(aInt)
michael@0:   { }
michael@0: 
michael@0:   virtual PluginIdentifierChild* GetCanonical();
michael@0:   virtual void Hash();
michael@0:   virtual void Unhash();
michael@0: 
michael@0:   int32_t mInt;
michael@0: };
michael@0: 
michael@0: } // namespace plugins
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // dom_plugins_PluginIdentifierChild_h