????????? ????? ??? ?????? (http://ce.aut.ac.ir/islab)

1
?????? ??? Component ?? ?? COM ?? ???? Interface

• ????? ??? ?????? ????? ??? ????
• ????? ??????
• ???? ?????? ????

2
Component Object Model

• ????? ?? ?????? ????????? ???? ???????? ?????
• ????? ?? ???? ?????? ?????
• ????? ?? ??? ??? ??? ????? (Microsoft Windows,
  Microsoft Windows NT, Apple, Mac, Unix)
• ????? ??????? ??? ????? Component-based

3
?????? ??? Component ??

• Component ?? ?? ???? Interface ?? ?? ??????
  ?????? ?????
• ????? ?? ?? ?? Component ?? ???? ????? ?? ?? ??
  Interface ?? ????
• ????? ?????? ?? ???? ??? Object ???? ????? (??
  ???? Object ?? ?? C)

4
????? ?? Interface

• interface ILookup public IUnknown
• public
• virtual HRESULT __stdcall LookupByName( LPTSTR
  lpName,TCHAR lplpNumber) 0
• virtual HRESULT __stdcall LookupByNumber(LPTSTR
  lpNumber, TCHAR lplpName) 0

5
????? ??? Interface

• Interface ?? ???? ?????? ???
• Interface ????? ?? Component ?? ??? ?? ?? ??
  ???????? ?? ???
• Client ?? ??? ? ??? ?? ???? Interface ?? ??
  Component ?? ?? ?????? ?????
• ?? ?? ?? Component ?? ?? ????? ??? ?? ??
  Interface ????? ????
• ?? Interface ????? ?? GUID ?? ???? ?? ?????? ??
  ?? ?? ???? ???? ID ?? ????
• Interface ?? ????? Version ??? ????? ??? ?????

6
???? Interface
?? Component ?? ????? ??? ?? ?? Interface ?????
????
A
Object
B
C
7
???? Interface
Client Application
Object
Interface Pointer
8
???? Interface
Application
Object
Object
Application
9
Global Unique Identifiers

• 128 ??? ?? ???? ? ???? ???
• ???? ????? ?? Interface ?? ? Component ?? ?? ???
  ?? ???
• ????? Human-Readable ???? ?? ????? ????? ?? ?????
  ??? ? ???? ????? ??????? ??? ???
• ???? ?? ???? ?? Component ?? ?? Component ???
  ?????? ???? ??????
• ?????
• Microsoft UUIDgen
• CoCreateGUID

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IUnknown Interface

• ???? ????? ???? ???? ????????? ????? Interface ??
  ??? ?? ???
• ???? Interface ?? ?? ?? ??? ?? ???? ? Component
  ?? ???? ?? ?? ????? ???? ??????
• ????? ?? ??? ???? ???
• QueryInterface
• AddRef
• Release

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IUnknown Interface

• interface IUnknown
• virtual HRESULT QueryInterface(IID iid,
  void ppvObj) 0
• virtual ULONG AddRef() 0
• virtual ULONG Release() 0

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QueryInterface

• ?? ??? ???? ? ?? ???? ???? ???? ?? ????? ?? ??
  Interface ??? ???? Component ???? ??? ????? ??
  ???? ?? ???
• ???? ??????? ?? ?????? ??? ?? ?? Component ??
  ????? QueryInterface ????? ?? ?? Component ??
  Call ??????
• Succeed
• Fail

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• LPLOOKUP pLookup
• TCHAR szNumber64
• HRESULT hRes
• //Call QueryInterface on the component object
  PhoneBook, asking for a pointer
• //to the Ilookup interface identified by a unique
  interface ID.
• hRes pPhoneBook-gtQueryInterface( IID_ILOOKUP,
  pLookup)
• if( SUCCEEDED( hRes ) )
• // use Ilookup interface pointer
• pLookup-gtLookupByName(Hamid", szNumber)
• pLookup-gtRelease() // finished using the
  IPhoneBook interface pointer
• else
• // Failed to acquire Ilookup interface pointer.

14
Component Object Library

• ??????? ???? ???? ?????? ??? Component ?? ?? ????
  Interface ?? ?? ????? ?? ???
• ????? ????
• ???? ???? ID ????? ?? Component ?? registry
  database
• exe CoRegisterClassFactory
• DLL DllGetClassFactory
• ????? ?? ?? Interface ???? ??? ?????????? ?? ???

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Client Process
In-Process Component Object
In-Process Server
Client Application
Local Object Proxy
COM
Remote Object Proxy
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Inter-Process Communication
LRPC
LRPC
Cross-Process With Lightweight RPC
RPC
RPC
Cross-network With true RPC
17
Local Server Process
Local Object
Stub Object
COM
Local Server
Remote Server Process
Remote Component Object
Stub Object
COM
Remote Server