gecko-dev/dom/plugins/ipc/PluginIdentifierChild.h
2012-05-21 12:12:37 +01:00

165 lines
4.1 KiB
C++

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