gecko-dev/accessible/ipc/win/HandlerProvider.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 mozilla_a11y_HandlerProvider_h
#define mozilla_a11y_HandlerProvider_h

#include "mozilla/a11y/AccessibleHandler.h"
#include "mozilla/a11y/HandlerDataCleanup.h"
#include "mozilla/AlreadyAddRefed.h"
#include "mozilla/Atomics.h"
#include "mozilla/mscom/IHandlerProvider.h"
#include "mozilla/mscom/Ptr.h"
#include "mozilla/mscom/StructStream.h"
#include "mozilla/Mutex.h"
#include "mozilla/UniquePtr.h"
#include "HandlerData.h"

struct NEWEST_IA2_INTERFACE;

namespace mozilla {

namespace mscom {

class StructToStream;

}  // namespace mscom

namespace a11y {

class HandlerProvider final : public IGeckoBackChannel,
                              public mscom::IHandlerProvider {
 public:
  HandlerProvider(REFIID aIid, mscom::InterceptorTargetPtr<IUnknown> aTarget);

  // IUnknown
  STDMETHODIMP QueryInterface(REFIID riid, void** ppv) override;
  STDMETHODIMP_(ULONG) AddRef() override;
  STDMETHODIMP_(ULONG) Release() override;

  // IHandlerProvider
  STDMETHODIMP GetHandler(NotNull<CLSID*> aHandlerClsid) override;
  STDMETHODIMP GetHandlerPayloadSize(NotNull<mscom::IInterceptor*> aInterceptor,
                                     NotNull<DWORD*> aOutPayloadSize) override;
  STDMETHODIMP WriteHandlerPayload(NotNull<mscom::IInterceptor*> aInterceptor,
                                   NotNull<IStream*> aStream) override;
  STDMETHODIMP_(REFIID) MarshalAs(REFIID aIid) override;
  STDMETHODIMP DisconnectHandlerRemotes() override;
  STDMETHODIMP IsInterfaceMaybeSupported(REFIID aIid) override;
  STDMETHODIMP_(REFIID)
  GetEffectiveOutParamIid(REFIID aCallIid, ULONG aCallMethod) override;
  STDMETHODIMP NewInstance(
      REFIID aIid, mscom::InterceptorTargetPtr<IUnknown> aTarget,
      NotNull<mscom::IHandlerProvider**> aOutNewPayload) override;

  // IGeckoBackChannel
  STDMETHODIMP put_HandlerControl(long aPid, IHandlerControl* aCtrl) override;
  STDMETHODIMP Refresh(DynamicIA2Data* aOutData) override;
  STDMETHODIMP get_AllTextInfo(BSTR* aText, IAccessibleHyperlink*** aHyperlinks,
                               long* aNHyperlinks, IA2TextSegment** aAttribRuns,
                               long* aNAttribRuns) override;
  STDMETHODIMP get_RelationsInfo(IARelationData** aRelations,
                                 long* aNRelations) override;
  STDMETHODIMP get_AllChildren(AccChildData** aChildren,
                               ULONG* aNChildren) override;

 private:
  ~HandlerProvider() = default;

  void SetHandlerControlOnMainThread(
      DWORD aPid, mscom::ProxyUniquePtr<IHandlerControl> aCtrl);
  void GetAndSerializePayload(const MutexAutoLock&,
                              NotNull<mscom::IInterceptor*> aInterceptor);
  void BuildStaticIA2Data(NotNull<mscom::IInterceptor*> aInterceptor,
                          StaticIA2Data* aOutData);
  /**
   * Pass true for aMarshaledByCom if this struct is being directly marshaled as
   * an out parameter of a COM method, currently only
   * IGeckoBackChannel::Refresh.
   * When aMarshaledByCom is false, this means the struct is being marshaled
   * by RPC encoding functions. This means we must allocate memory differently,
   * even though we're using this as part of a COM handler payload.
   */
  void BuildDynamicIA2Data(DynamicIA2Data* aOutIA2Data,
                           bool aMarshaledByCom = false);
  void BuildInitialIA2Data(NotNull<mscom::IInterceptor*> aInterceptor,
                           StaticIA2Data* aOutStaticData,
                           DynamicIA2Data* aOutDynamicData);
  bool IsTargetInterfaceCacheable();

  /**
   * Build the payload for later marshaling.
   * This is intended to be used during a bulk fetch operation and must only be
   * called from the main thread.
   */
  void PrebuildPayload(NotNull<mscom::IInterceptor*> aInterceptor);

  // Replace a raw object from the main thread with a wrapped, intercepted
  // object suitable for calling from the MTA.
  // The reference to the original object is adopted; i.e. you should not
  // separately release it.
  // This is intended for objects returned from method calls on the main thread.
  template <typename Interface>
  HRESULT ToWrappedObject(Interface** aObj);
  void GetAllTextInfoMainThread(BSTR* aText,
                                IAccessibleHyperlink*** aHyperlinks,
                                long* aNHyperlinks,
                                IA2TextSegment** aAttribRuns,
                                long* aNAttribRuns, HRESULT* result);
  void GetRelationsInfoMainThread(IARelationData** aRelations,
                                  long* aNRelations, HRESULT* result);
  void GetAllChildrenMainThread(AccChildData** aChildren, ULONG* aNChildren,
                                HRESULT* result);

  Atomic<uint32_t> mRefCnt;
  Mutex mMutex;  // Protects mSerializer
  const IID mTargetUnkIid;
  mscom::InterceptorTargetPtr<IUnknown>
      mTargetUnk;  // Constant, main thread only
  UniquePtr<mscom::StructToStream> mSerializer;
  RefPtr<IUnknown> mFastMarshalUnk;

  struct IA2PayloadDeleter {
    void operator()(IA2Payload* aPayload) {
      // When CoMarshalInterface writes interfaces out to a stream, it AddRefs.
      // Therefore, we must release our references after this.
      ReleaseStaticIA2DataInterfaces(aPayload->mStaticData);
      CleanupDynamicIA2Data(aPayload->mDynamicData);
      delete aPayload;
    }
  };
  using IA2PayloadPtr = UniquePtr<IA2Payload, IA2PayloadDeleter>;

  // Used when the payload is built prior to marshaling the object by a bulk
  // fetch operation. See prebuildPayload().
  IA2PayloadPtr mPayload;
  Mutex mPayloadMutex;  // Protects mPayload
};

}  // namespace a11y
}  // namespace mozilla

#endif  // mozilla_a11y_HandlerProvider_h