array.h revision 7cef16c9d90088abef7e4c82a9a5603f7c56611a
/** @file
* MS COM / XPCOM Abstraction Layer:
* Safe array helper class declaration
*/
/*
* Copyright (C) 2006-2007 Sun Microsystems, Inc.
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*
* The contents of this file may alternatively be used under the terms
* of the Common Development and Distribution License Version 1.0
* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
* VirtualBox OSE distribution, in which case the provisions of the
* CDDL are applicable instead of those of the GPL.
*
* You may elect to license modified versions of this file under the
* terms and conditions of either the GPL or the CDDL or both.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 USA or visit http://www.sun.com if you need
* additional information or have any questions.
*/
#ifndef ___VBox_com_array_h
#define ___VBox_com_array_h
/** @defgroup grp_COM_arrays COM/XPCOM Arrays
* @{
*
* The COM/XPCOM array support layer provides a cross-platform way to pass
* arrays to and from COM interface methods and consists of the com::SafeArray
* template and a set of ComSafeArray* macros part of which is defined in
* VBox/com/defs.h.
*
* This layer works with interface attributes and method parameters that have
* the 'safearray="yes"' attribute in the XIDL definition:
* @code
<interface name="ISomething" ...>
<method name="testArrays">
<param name="inArr" type="long" dir="in" safearray="yes"/>
<param name="outArr" type="long" dir="out" safearray="yes"/>
<param name="retArr" type="long" dir="return" safearray="yes"/>
</method>
</interface>
* @endcode
*
* Methods generated from this and similar definitions are implemented in
* component classes using the following declarations:
* @code
STDMETHOD(TestArrays) (ComSafeArrayIn (LONG, aIn),
ComSafeArrayOut (LONG, aOut),
ComSafeArrayOut (LONG, aRet));
* @endcode
*
* And the following function bodies:
* @code
STDMETHODIMP Component::TestArrays (ComSafeArrayIn (LONG, aIn),
ComSafeArrayOut (LONG, aOut),
ComSafeArrayOut (LONG, aRet))
{
if (ComSafeArrayInIsNull (aIn))
return E_INVALIDARG;
if (ComSafeArrayOutIsNull (aOut))
return E_POINTER;
if (ComSafeArrayOutIsNull (aRet))
return E_POINTER;
// Use SafeArray to access the input array parameter
com::SafeArray <LONG> in (ComSafeArrayInArg (aIn));
for (size_t i = 0; i < in.size(); ++ i)
LogFlow (("*** in[%u]=%d\n", i, in [i]));
// Use SafeArray to create the return array (the same technique is used
// for output array paramters)
SafeArray <LONG> ret (in.size() * 2);
for (size_t i = 0; i < in.size(); ++ i)
{
ret [i] = in [i];
ret [i + in.size()] = in [i] * 10;
}
ret.detachTo (ComSafeArrayOutArg (aRet));
return S_OK;
}
* @endcode
*
* Such methods can be called from the client code using the following pattern:
* @code
ComPtr <ISomething> component;
// ...
com::SafeArray <LONG> in (3);
in [0] = -1;
in [1] = -2;
in [2] = -3;
com::SafeArray <LONG> out;
com::SafeArray <LONG> ret;
HRESULT rc = component->TestArrays (ComSafeArrayAsInParam (in),
ComSafeArrayAsOutParam (out),
ComSafeArrayAsOutParam (ret));
if (SUCCEEDED (rc))
for (size_t i = 0; i < ret.size(); ++ i)
printf ("*** ret[%u]=%d\n", i, ret [i]);
* @endcode
*
* For interoperability with standard C++ containers, there is a template
* constructor that takes such a container as argument and performs a deep copy
* of its contents. This can be used in method implementations like this:
* @code
STDMETHODIMP Component::COMGETTER(Values) (ComSafeArrayOut (int, aValues))
{
// ... assume there is a |std::list <int> mValues| data member
com::SafeArray <int> values (mValues);
values.detachTo (ComSafeArrayOutArg (aValues));
return S_OK;
}
* @endcode
*
* The current implementation of the SafeArray layer supports all types normally
* allowed in XIDL as array element types (including 'wstring' and 'uuid').
* However, 'pointer-to-...' types (e.g. 'long *', 'wstring *') are not
* supported and therefore cannot be used as element types.
*
* Note that for GUID arrays you should use SafeGUIDArray and
* SafeConstGUIDArray, customized SafeArray<> specializations.
*
* Also note that in order to pass input BSTR array parameters declared
* using the ComSafeArrayIn (IN_BSTR, aParam) macro to the SafeArray<>
* constructor using the ComSafeArrayInArg() macro, you should use IN_BSTR
* as the SafeArray<> template argument, not just BSTR.
*
* Arrays of interface pointers are also supported but they require to use a
* special SafeArray implementation, com::SafeIfacePointer, which takes the
* interface class name as a template argument (e.g. com::SafeIfacePointer
* <IUnknown>). This implementation functions identically to com::SafeArray.
*/
#if defined (VBOX_WITH_XPCOM)
# include <nsMemory.h>
#endif
#include "VBox/com/defs.h"
#include "VBox/com/ptr.h"
#include "VBox/com/assert.h"
#include "iprt/cpp/utils.h"
#if defined (VBOX_WITH_XPCOM)
/**
* Wraps the given com::SafeArray instance to generate an expression that is
* suitable for passing it to functions that take input safearray parameters
* declared using the ComSafeArrayIn macro.
*
* @param aArray com::SafeArray instance to pass as an input parameter.
*/
#define ComSafeArrayAsInParam(aArray) \
(aArray).size(), (aArray).__asInParam_Arr ((aArray).raw())
/**
* Wraps the given com::SafeArray instance to generate an expression that is
* suitable for passing it to functions that take output safearray parameters
* declared using the ComSafeArrayOut macro.
*
* @param aArray com::SafeArray instance to pass as an output parameter.
*/
#define ComSafeArrayAsOutParam(aArray) \
(aArray).__asOutParam_Size(), (aArray).__asOutParam_Arr()
#else /* defined (VBOX_WITH_XPCOM) */
#define ComSafeArrayAsInParam(aArray) (aArray).__asInParam()
#define ComSafeArrayAsOutParam(aArray) (aArray).__asOutParam()
#endif /* defined (VBOX_WITH_XPCOM) */
/**
*
*/
namespace com
{
#if defined (VBOX_WITH_XPCOM)
////////////////////////////////////////////////////////////////////////////////
/**
* Provides various helpers for SafeArray.
*
* @param T Type of array elements.
*/
template <typename T>
struct SafeArrayTraits
{
protected:
/** Initializes memory for aElem. */
static void Init (T &aElem) { aElem = 0; }
/** Initializes memory occupied by aElem. */
static void Uninit (T &aElem) { aElem = 0; }
/** Creates a deep copy of aFrom and stores it in aTo. */
static void Copy (const T &aFrom, T &aTo) { aTo = aFrom; }
public:
/* Magic to workaround strict rules of par. 4.4.4 of the C++ standard (that
* in particular forbid casts of 'char **' to 'const char **'). Then initial
* reason for this magic is that XPIDL declares input strings
* (char/PRUnichar pointers) as const but doesn't do so for pointers to
* arrays. */
static T *__asInParam_Arr (T *aArr) { return aArr; }
static T *__asInParam_Arr (const T *aArr) { return const_cast <T *> (aArr); }
};
template <typename T>
struct SafeArrayTraits <T *>
{
// Arbitrary pointers are not supported
};
template<>
struct SafeArrayTraits <PRUnichar *>
{
protected:
static void Init (PRUnichar * &aElem) { aElem = NULL; }
static void Uninit (PRUnichar * &aElem)
{
if (aElem)
{
::SysFreeString (aElem);
aElem = NULL;
}
}
static void Copy (const PRUnichar * aFrom, PRUnichar * &aTo)
{
AssertCompile (sizeof (PRUnichar) == sizeof (OLECHAR));
aTo = aFrom ? ::SysAllocString ((const OLECHAR *) aFrom) : NULL;
}
public:
/* Magic to workaround strict rules of par. 4.4.4 of the C++ standard */
static const PRUnichar **__asInParam_Arr (PRUnichar **aArr)
{
return const_cast <const PRUnichar **> (aArr);
}
static const PRUnichar **__asInParam_Arr (const PRUnichar **aArr) { return aArr; }
};
template<>
struct SafeArrayTraits <const PRUnichar *>
{
protected:
static void Init (const PRUnichar * &aElem) { aElem = NULL; }
static void Uninit (const PRUnichar * &aElem)
{
if (aElem)
{
::SysFreeString (const_cast <PRUnichar *> (aElem));
aElem = NULL;
}
}
static void Copy (const PRUnichar * aFrom, const PRUnichar * &aTo)
{
AssertCompile (sizeof (PRUnichar) == sizeof (OLECHAR));
aTo = aFrom ? ::SysAllocString ((const OLECHAR *) aFrom) : NULL;
}
public:
/* Magic to workaround strict rules of par. 4.4.4 of the C++ standard */
static const PRUnichar **__asInParam_Arr (const PRUnichar **aArr) { return aArr; }
};
template<>
struct SafeArrayTraits <nsID *>
{
protected:
static void Init (nsID * &aElem) { aElem = NULL; }
static void Uninit (nsID * &aElem)
{
if (aElem)
{
::nsMemory::Free (aElem);
aElem = NULL;
}
}
static void Copy (const nsID * aFrom, nsID * &aTo)
{
if (aFrom)
{
aTo = (nsID *) ::nsMemory::Alloc (sizeof (nsID));
if (aTo)
*aTo = *aFrom;
}
else
aTo = NULL;
}
/* This specification is also reused for SafeConstGUIDArray, so provide a
* no-op Init() and Uninit() which are necessary for SafeArray<> but should
* be never called in context of SafeConstGUIDArray. */
static void Init (const nsID * &aElem) { NOREF (aElem); AssertFailed(); }
static void Uninit (const nsID * &aElem) { NOREF (aElem); AssertFailed(); }
public:
/** Magic to workaround strict rules of par. 4.4.4 of the C++ standard. */
static const nsID **__asInParam_Arr (nsID **aArr)
{
return const_cast <const nsID **> (aArr);
}
static const nsID **__asInParam_Arr (const nsID **aArr) { return aArr; }
};
#else /* defined (VBOX_WITH_XPCOM) */
////////////////////////////////////////////////////////////////////////////////
struct SafeArrayTraitsBase
{
protected:
static SAFEARRAY *CreateSafeArray (VARTYPE aVarType, SAFEARRAYBOUND *aBound)
{ return SafeArrayCreate (aVarType, 1, aBound); }
};
/**
* Provides various helpers for SafeArray.
*
* @param T Type of array elements.
*
* Specializations of this template must provide the following methods:
*
// Returns the VARTYPE of COM SafeArray elements to be used for T
static VARTYPE VarType();
// Returns the number of VarType() elements necessary for aSize
// elements of T
static ULONG VarCount (size_t aSize);
// Returns the number of elements of T that fit into the given number of
// VarType() elements (opposite to VarCount (size_t aSize)).
static size_t Size (ULONG aVarCount);
// Creates a deep copy of aFrom and stores it in aTo
static void Copy (ULONG aFrom, ULONG &aTo);
*/
template <typename T>
struct SafeArrayTraits : public SafeArrayTraitsBase
{
protected:
// Arbitrary types are treated as passed by value and each value is
// represented by a number of VT_Ix type elements where VT_Ix has the
// biggest possible bitness necessary to represent T w/o a gap. COM enums
// fall into this category.
static VARTYPE VarType()
{
if (sizeof (T) % 8 == 0) return VT_I8;
if (sizeof (T) % 4 == 0) return VT_I4;
if (sizeof (T) % 2 == 0) return VT_I2;
return VT_I1;
}
static ULONG VarCount (size_t aSize)
{
if (sizeof (T) % 8 == 0) return (ULONG) ((sizeof (T) / 8) * aSize);
if (sizeof (T) % 4 == 0) return (ULONG) ((sizeof (T) / 4) * aSize);
if (sizeof (T) % 2 == 0) return (ULONG) ((sizeof (T) / 2) * aSize);
return (ULONG) (sizeof (T) * aSize);
}
static size_t Size (ULONG aVarCount)
{
if (sizeof (T) % 8 == 0) return (size_t) (aVarCount * 8) / sizeof (T);
if (sizeof (T) % 4 == 0) return (size_t) (aVarCount * 4) / sizeof (T);
if (sizeof (T) % 2 == 0) return (size_t) (aVarCount * 2) / sizeof (T);
return (size_t) aVarCount / sizeof (T);
}
static void Copy (T aFrom, T &aTo) { aTo = aFrom; }
};
template <typename T>
struct SafeArrayTraits <T *>
{
// Arbitrary pointer types are not supported
};
/* Although the generic SafeArrayTraits template would work for all integers,
* we specialize it for some of them in order to use the correct VT_ type */
template<>
struct SafeArrayTraits <LONG> : public SafeArrayTraitsBase
{
protected:
static VARTYPE VarType() { return VT_I4; }
static ULONG VarCount (size_t aSize) { return (ULONG) aSize; }
static size_t Size (ULONG aVarCount) { return (size_t) aVarCount; }
static void Copy (LONG aFrom, LONG &aTo) { aTo = aFrom; }
};
template<>
struct SafeArrayTraits <ULONG> : public SafeArrayTraitsBase
{
protected:
static VARTYPE VarType() { return VT_UI4; }
static ULONG VarCount (size_t aSize) { return (ULONG) aSize; }
static size_t Size (ULONG aVarCount) { return (size_t) aVarCount; }
static void Copy (ULONG aFrom, ULONG &aTo) { aTo = aFrom; }
};
template<>
struct SafeArrayTraits <LONG64> : public SafeArrayTraitsBase
{
protected:
static VARTYPE VarType() { return VT_I8; }
static ULONG VarCount (size_t aSize) { return (ULONG) aSize; }
static size_t Size (ULONG aVarCount) { return (size_t) aVarCount; }
static void Copy (LONG64 aFrom, LONG64 &aTo) { aTo = aFrom; }
};
template<>
struct SafeArrayTraits <ULONG64> : public SafeArrayTraitsBase
{
protected:
static VARTYPE VarType() { return VT_UI8; }
static ULONG VarCount (size_t aSize) { return (ULONG) aSize; }
static size_t Size (ULONG aVarCount) { return (size_t) aVarCount; }
static void Copy (ULONG64 aFrom, ULONG64 &aTo) { aTo = aFrom; }
};
template<>
struct SafeArrayTraits <BSTR> : public SafeArrayTraitsBase
{
protected:
static VARTYPE VarType() { return VT_BSTR; }
static ULONG VarCount (size_t aSize) { return (ULONG) aSize; }
static size_t Size (ULONG aVarCount) { return (size_t) aVarCount; }
static void Copy (BSTR aFrom, BSTR &aTo)
{
aTo = aFrom ? ::SysAllocString ((const OLECHAR *) aFrom) : NULL;
}
};
template<>
struct SafeArrayTraits <GUID> : public SafeArrayTraitsBase
{
protected:
/* Use the 64-bit unsigned integer type for GUID */
static VARTYPE VarType() { return VT_UI8; }
/* GUID is 128 bit, so we need two VT_UI8 */
static ULONG VarCount (size_t aSize)
{
AssertCompileSize (GUID, 16);
return (ULONG) (aSize * 2);
}
static size_t Size (ULONG aVarCount) { return (size_t) aVarCount / 2; }
static void Copy (GUID aFrom, GUID &aTo) { aTo = aFrom; }
};
/**
* Helper for SafeArray::__asOutParam() that automatically updates m.raw after a
* non-NULL m.arr assignment.
*/
class OutSafeArrayDipper
{
OutSafeArrayDipper (SAFEARRAY **aArr, void **aRaw)
: arr (aArr), raw (aRaw) { Assert (*aArr == NULL && *aRaw == NULL); }
SAFEARRAY **arr;
void **raw;
template <class, class> friend class SafeArray;
public:
~OutSafeArrayDipper()
{
if (*arr != NULL)
{
HRESULT rc = SafeArrayAccessData (*arr, raw);
AssertComRC (rc);
}
}
operator SAFEARRAY **() { return arr; }
};
#endif /* defined (VBOX_WITH_XPCOM) */
////////////////////////////////////////////////////////////////////////////////
/**
* The SafeArray class represents the safe array type used in COM to pass arrays
* to/from interface methods.
*
* This helper class hides all MSCOM/XPCOM specific implementation details and,
* together with ComSafeArrayIn, ComSafeArrayOut and ComSafeArrayRet macros,
* provides a platform-neutral way to handle safe arrays in the method
* implementation.
*
* When an instance of this class is destroyed, it automatically frees all
* resources occupied by individual elements of the array as well as by the
* array itself. However, when the value of an element is manually changed
* using #operator[] or by accessing array data through the #raw() pointer, it is
* the caller's responsibility to free resources occupied by the previous
* element's value.
*
* Also, objects of this class do not support copy and assignment operations and
* therefore cannot be returned from functions by value. In other words, this
* class is just a temporary storage for handling interface method calls and not
* intended to be used to store arrays as data members and such -- you should
* use normal list/vector classes for that.
*
* @note The current implementation supports only one-dimensional arrays.
*
* @note This class is not thread-safe.
*/
template <typename T, class Traits = SafeArrayTraits <T> >
class SafeArray : public Traits
{
public:
/**
* Creates a null array.
*/
SafeArray() {}
/**
* Creates a new array of the given size. All elements of the newly created
* array initialized with null values.
*
* @param aSize Initial number of elements in the array.
*
* @note If this object remains null after construction it means that there
* was not enough memory for creating an array of the requested size.
* The constructor will also assert in this case.
*/
SafeArray (size_t aSize) { resize (aSize); }
/**
* Weakly attaches this instance to the existing array passed in a method
* parameter declared using the ComSafeArrayIn macro. When using this call,
* always wrap the parameter name in the ComSafeArrayInArg macro call like
* this:
* <pre>
* SafeArray safeArray (ComSafeArrayInArg (aArg));
* </pre>
*
* Note that this constructor doesn't take the ownership of the array. In
* particular, it means that operations that operate on the ownership (e.g.
* #detachTo()) are forbidden and will assert.
*
* @param aArg Input method parameter to attach to.
*/
SafeArray (ComSafeArrayIn (T, aArg))
{
#if defined (VBOX_WITH_XPCOM)
AssertReturnVoid (aArg != NULL);
m.size = aArgSize;
m.arr = aArg;
m.isWeak = true;
#else /* defined (VBOX_WITH_XPCOM) */
AssertReturnVoid (aArg != NULL);
SAFEARRAY *arg = *aArg;
if (arg)
{
AssertReturnVoid (arg->cDims == 1);
VARTYPE vt;
HRESULT rc = SafeArrayGetVartype (arg, &vt);
AssertComRCReturnVoid (rc);
AssertMsgReturnVoid (vt == VarType(),
("Expected vartype %d, got %d.\n",
VarType(), vt));
rc = SafeArrayAccessData (arg, (void HUGEP **) &m.raw);
AssertComRCReturnVoid (rc);
}
m.arr = arg;
m.isWeak = true;
#endif /* defined (VBOX_WITH_XPCOM) */
}
/**
* Creates a deep copy of the given standard C++ container that stores
* T objects.
*
* @param aCntr Container object to copy.
*
* @param C Standard C++ container template class (normally deduced from
* @c aCntr).
*/
template <template <typename, typename> class C, class A>
SafeArray (const C <T, A> & aCntr)
{
resize (aCntr.size());
AssertReturnVoid (!isNull());
size_t i = 0;
for (typename C <T, A>::const_iterator it = aCntr.begin();
it != aCntr.end(); ++ it, ++ i)
#if defined (VBOX_WITH_XPCOM)
Copy (*it, m.arr [i]);
#else
Copy (*it, m.raw [i]);
#endif
}
/**
* Creates a deep copy of the given standard C++ map that stores T objects
* as values.
*
* @param aMap Map object to copy.
*
* @param C Standard C++ map template class (normally deduced from
* @c aCntr).
* @param L Standard C++ compare class (deduced from @c aCntr).
* @param A Standard C++ allocator class (deduced from @c aCntr).
* @param K Map key class (deduced from @c aCntr).
*/
template <template <typename, typename, typename, typename>
class C, class L, class A, class K>
SafeArray (const C <K, T, L, A> & aMap)
{
typedef C <K, T, L, A> Map;
resize (aMap.size());
AssertReturnVoid (!isNull());
int i = 0;
for (typename Map::const_iterator it = aMap.begin();
it != aMap.end(); ++ it, ++ i)
#if defined (VBOX_WITH_XPCOM)
Copy (it->second, m.arr [i]);
#else
Copy (it->second, m.raw [i]);
#endif
}
/**
* Destroys this instance after calling #setNull() to release allocated
* resources. See #setNull() for more details.
*/
virtual ~SafeArray() { setNull(); }
/**
* Returns @c true if this instance represents a null array.
*/
bool isNull() const { return m.arr == NULL; }
/**
* Resets this instance to null and, if this instance is not a weak one,
* releases any resources occupied by the array data.
*
* @note This method destroys (cleans up) all elements of the array using
* the corresponding cleanup routine for the element type before the
* array itself is destroyed.
*/
virtual void setNull() { m.uninit(); }
/**
* Returns @c true if this instance is weak. A weak instance doesn't own the
* array data and therefore operations manipulating the ownership (e.g.
* #detachTo()) are forbidden and will assert.
*/
bool isWeak() const { return m.isWeak; }
/** Number of elements in the array. */
size_t size() const
{
#if defined (VBOX_WITH_XPCOM)
if (m.arr)
return m.size;
return 0;
#else
if (m.arr)
return Size (m.arr->rgsabound [0].cElements);
return 0;
#endif
}
/**
* Appends a copy of the given element at the end of the array.
*
* The array size is increased by one by this method and the additional
* space is allocated as needed.
*
* This method is handy in cases where you want to assign a copy of the
* existing value to the array element, for example:
* <tt>Bstr string; array.push_back (string);</tt>. If you create a string
* just to put it in the array, you may find #appendedRaw() more useful.
*
* @param aElement Element to append.
*
* @return @c true on success and @c false if there is not enough
* memory for resizing.
*/
bool push_back (const T &aElement)
{
if (!ensureCapacity (size() + 1))
return false;
#if defined (VBOX_WITH_XPCOM)
Copy (aElement, m.arr [m.size]);
++ m.size;
#else
Copy (aElement, m.raw [size() - 1]);
#endif
return true;
}
/**
* Appends an empty element at the end of the array and returns a raw
* pointer to it suitable for assigning a raw value (w/o constructing a
* copy).
*
* The array size is increased by one by this method and the additional
* space is allocated as needed.
*
* Note that in case of raw assignment, value ownership (for types with
* dynamically allocated data and for interface pointers) is transferred to
* the safe array object.
*
* This method is handy for operations like
* <tt>Bstr ("foo").detachTo (array.appendedRaw());</tt>. Don't use it as
* an l-value (<tt>array.appendedRaw() = SysAllocString (L"tralala");</tt>)
* since this doesn't check for a NULL condition; use #resize() and
* #setRawAt() instead. If you need to assign a copy of the existing value
* instead of transferring the ownership, look at #push_back().
*
* @return Raw pointer to the added element or NULL if no memory.
*/
T *appendedRaw()
{
if (!ensureCapacity (size() + 1))
return NULL;
#if defined (VBOX_WITH_XPCOM)
Init (m.arr [m.size]);
++ m.size;
return &m.arr [m.size - 1];
#else
/* nothing to do here, SafeArrayCreate() has performed element
* initialization */
return &m.raw [size() - 1];
#endif
}
/**
* Resizes the array preserving its contents when possible. If the new size
* is larger than the old size, new elements are initialized with null
* values. If the new size is less than the old size, the contents of the
* array beyond the new size is lost.
*
* @param aNewSize New number of elements in the array.
* @return @c true on success and @c false if there is not enough
* memory for resizing.
*/
bool resize (size_t aNewSize)
{
if (!ensureCapacity (aNewSize))
return false;
#if defined (VBOX_WITH_XPCOM)
if (m.size < aNewSize)
{
/* initialize the new elements */
for (size_t i = m.size; i < aNewSize; ++ i)
Init (m.arr [i]);
}
m.size = aNewSize;
#else
/* nothing to do here, SafeArrayCreate() has performed element
* initialization */
#endif
return true;
}
/**
* Reinitializes this instance by preallocating space for the given number
* of elements. The previous array contents is lost.
*
* @param aNewSize New number of elements in the array.
* @return @c true on success and @c false if there is not enough
* memory for resizing.
*/
bool reset (size_t aNewSize)
{
m.uninit();
return resize (aNewSize);
}
/**
* Returns a pointer to the raw array data. Use this raw pointer with care
* as no type or bound checking is done for you in this case.
*
* @note This method returns @c NULL when this instance is null.
* @see #operator[]
*/
T *raw()
{
#if defined (VBOX_WITH_XPCOM)
return m.arr;
#else
return m.raw;
#endif
}
/**
* Const version of #raw().
*/
const T *raw() const
{
#if defined (VBOX_WITH_XPCOM)
return m.arr;
#else
return m.raw;
#endif
}
/**
* Array access operator that returns an array element by reference. A bit
* safer than #raw(): asserts and returns an invalid reference if this
* instance is null or if the index is out of bounds.
*
* @note For weak instances, this call will succeed but the behavior of
* changing the contents of an element of the weak array instance is
* undefined and may lead to a program crash on some platforms.
*/
T &operator[] (size_t aIdx)
{
AssertReturn (m.arr != NULL, *((T *) NULL));
AssertReturn (aIdx < size(), *((T *) NULL));
#if defined (VBOX_WITH_XPCOM)
return m.arr [aIdx];
#else
AssertReturn (m.raw != NULL, *((T *) NULL));
return m.raw [aIdx];
#endif
}
/**
* Const version of #operator[] that returns an array element by value.
*/
const T operator[] (size_t aIdx) const
{
AssertReturn (m.arr != NULL, *((T *) NULL));
AssertReturn (aIdx < size(), *((T *) NULL));
#if defined (VBOX_WITH_XPCOM)
return m.arr [aIdx];
#else
AssertReturn (m.raw != NULL, *((T *) NULL));
return m.raw [aIdx];
#endif
}
/**
* Creates a copy of this array and stores it in a method parameter declared
* using the ComSafeArrayOut macro. When using this call, always wrap the
* parameter name in the ComSafeArrayOutArg macro call like this:
* <pre>
* safeArray.cloneTo (ComSafeArrayOutArg (aArg));
* </pre>
*
* @note It is assumed that the ownership of the returned copy is
* transferred to the caller of the method and he is responsible to free the
* array data when it is no longer needed.
*
* @param aArg Output method parameter to clone to.
*/
virtual const SafeArray &cloneTo (ComSafeArrayOut (T, aArg)) const
{
/// @todo Implement me!
#if defined (VBOX_WITH_XPCOM)
NOREF (aArgSize);
NOREF (aArg);
#else
NOREF (aArg);
#endif
AssertFailedReturn (*this);
}
/**
* Transfers the ownership of this array's data to the specified location
* declared using the ComSafeArrayOut macro and makes this array a null
* array. When using this call, always wrap the parameter name in the
* ComSafeArrayOutArg macro call like this:
* <pre>
* safeArray.detachTo (ComSafeArrayOutArg (aArg));
* </pre>
*
* Detaching the null array is also possible in which case the location will
* receive NULL.
*
* @note Since the ownership of the array data is transferred to the
* caller of the method, he is responsible to free the array data when it is
* no longer needed.
*
* @param aArg Location to detach to.
*/
virtual SafeArray &detachTo (ComSafeArrayOut (T, aArg))
{
AssertReturn (m.isWeak == false, *this);
#if defined (VBOX_WITH_XPCOM)
AssertReturn (aArgSize != NULL, *this);
AssertReturn (aArg != NULL, *this);
*aArgSize = m.size;
*aArg = m.arr;
m.isWeak = false;
m.size = 0;
m.arr = NULL;
#else /* defined (VBOX_WITH_XPCOM) */
AssertReturn (aArg != NULL, *this);
*aArg = m.arr;
if (m.raw)
{
HRESULT rc = SafeArrayUnaccessData (m.arr);
AssertComRCReturn (rc, *this);
m.raw = NULL;
}
m.isWeak = false;
m.arr = NULL;
#endif /* defined (VBOX_WITH_XPCOM) */
return *this;
}
// Public methods for internal purposes only.
#if defined (VBOX_WITH_XPCOM)
/** Internal function. Never call it directly. */
PRUint32 *__asOutParam_Size() { setNull(); return &m.size; }
/** Internal function Never call it directly. */
T **__asOutParam_Arr() { Assert (isNull()); return &m.arr; }
#else /* defined (VBOX_WITH_XPCOM) */
/** Internal function Never call it directly. */
SAFEARRAY ** __asInParam() { return &m.arr; }
/** Internal function Never call it directly. */
OutSafeArrayDipper __asOutParam()
{ setNull(); return OutSafeArrayDipper (&m.arr, (void **) &m.raw); }
#endif /* defined (VBOX_WITH_XPCOM) */
static const SafeArray Null;
protected:
DECLARE_CLS_COPY_CTOR_ASSIGN_NOOP(SafeArray)
/**
* Ensures that the array is big enough to contain aNewSize elements.
*
* If the new size is greater than the current capacity, a new array is
* allocated and elements from the old array are copied over. The size of
* the array doesn't change, only the capacity increases (which is always
* greater than the size). Note that the additionally allocated elements are
* left uninitialized by this method.
*
* If the new size is less than the current size, the existing array is
* truncated to the specified size and the elements outside the new array
* boundary are freed.
*
* If the new size is the same as the current size, nothing happens.
*
* @param aNewSize New size of the array.
*
* @return @c true on success and @c false if not enough memory.
*/
bool ensureCapacity (size_t aNewSize)
{
AssertReturn (!m.isWeak, false);
#if defined (VBOX_WITH_XPCOM)
/* Note: we distinguish between a null array and an empty (zero
* elements) array. Therefore we never use zero in malloc (even if
* aNewSize is zero) to make sure we get a non-null pointer. */
if (m.size == aNewSize && m.arr != NULL)
return true;
/* Allocate in 16-byte pieces. */
size_t newCapacity = RT_MAX ((aNewSize + 15) / 16 * 16, 16);
if (m.capacity != newCapacity)
{
T *newArr = (T *) nsMemory::Alloc (RT_MAX (newCapacity, 1) * sizeof (T));
AssertReturn (newArr != NULL, false);
if (m.arr != NULL)
{
if (m.size > aNewSize)
{
/* Truncation takes place, uninit exceeding elements and
* shrink the size. */
for (size_t i = aNewSize; i < m.size; ++ i)
Uninit (m.arr [i]);
m.size = aNewSize;
}
/* Copy the old contents. */
memcpy (newArr, m.arr, m.size * sizeof (T));
nsMemory::Free ((void *) m.arr);
}
m.arr = newArr;
}
else
{
if (m.size > aNewSize)
{
/* Truncation takes place, uninit exceeding elements and
* shrink the size. */
for (size_t i = aNewSize; i < m.size; ++ i)
Uninit (m.arr [i]);
m.size = aNewSize;
}
}
m.capacity = newCapacity;
#else
SAFEARRAYBOUND bound = { VarCount (aNewSize), 0 };
HRESULT rc;
if (m.arr == NULL)
{
m.arr = CreateSafeArray (VarType(), &bound);
AssertReturn (m.arr != NULL, false);
}
else
{
SafeArrayUnaccessData (m.arr);
rc = SafeArrayRedim (m.arr, &bound);
AssertComRCReturn (rc == S_OK, false);
}
rc = SafeArrayAccessData (m.arr, (void HUGEP **) &m.raw);
AssertComRCReturn (rc, false);
#endif
return true;
}
struct Data
{
Data()
: isWeak (false)
#if defined (VBOX_WITH_XPCOM)
, capacity (0), size (0), arr (NULL)
#else
, arr (NULL), raw (NULL)
#endif
{}
~Data() { uninit(); }
void uninit()
{
#if defined (VBOX_WITH_XPCOM)
if (arr)
{
if (!isWeak)
{
for (size_t i = 0; i < size; ++ i)
Uninit (arr [i]);
nsMemory::Free ((void *) arr);
}
else
isWeak = false;
arr = NULL;
}
size = capacity = 0;
#else /* defined (VBOX_WITH_XPCOM) */
if (arr)
{
if (raw)
{
SafeArrayUnaccessData (arr);
raw = NULL;
}
if (!isWeak)
{
HRESULT rc = SafeArrayDestroy (arr);
AssertComRCReturnVoid (rc);
}
else
isWeak = false;
arr = NULL;
}
#endif /* defined (VBOX_WITH_XPCOM) */
}
bool isWeak : 1;
#if defined (VBOX_WITH_XPCOM)
PRUint32 capacity;
PRUint32 size;
T *arr;
#else
SAFEARRAY *arr;
T *raw;
#endif
};
Data m;
};
////////////////////////////////////////////////////////////////////////////////
#if defined (VBOX_WITH_XPCOM)
/**
* Version of com::SafeArray for arrays of GUID.
*
* In MS COM, GUID arrays store GUIDs by value and therefore input arrays are
* represented using |GUID *| and out arrays -- using |GUID **|. In XPCOM,
* GUID arrays store pointers to nsID so that input arrays are |const nsID **|
* and out arrays are |nsID ***|. Due to this difference, it is impossible to
* work with arrays of GUID on both platforms by simply using com::SafeArray
* <GUID>. This class is intended to provide some level of cross-platform
* behavior.
*
* The basic usage pattern is basically similar to com::SafeArray<> except that
* you use ComSafeGUIDArrayIn* and ComSafeGUIDArrayOut* macros instead of
* ComSafeArrayIn* and ComSafeArrayOut*. Another important nuance is that the
* raw() array type is different (nsID **, or GUID ** on XPCOM and GUID * on MS
* COM) so it is recommended to use operator[] instead which always returns a
* GUID by value.
*
* Note that due to const modifiers, you cannot use SafeGUIDArray for input GUID
* arrays. Please use SafeConstGUIDArray for this instead.
*
* Other than mentioned above, the functionality of this class is equivalent to
* com::SafeArray<>. See the description of that template and its methods for
* more information.
*
* Output GUID arrays are handled by a separate class, SafeGUIDArrayOut, since
* this class cannot handle them because of const modifiers.
*/
class SafeGUIDArray : public SafeArray <nsID *>
{
public:
typedef SafeArray <nsID *> Base;
class nsIDRef
{
public:
nsIDRef (nsID * &aVal) : mVal (aVal) {}
operator const nsID &() const { return mVal ? *mVal : *Empty; }
operator nsID() const { return mVal ? *mVal : *Empty; }
const nsID *operator&() const { return mVal ? mVal : Empty; }
nsIDRef &operator= (const nsID &aThat)
{
if (mVal == NULL)
Copy (&aThat, mVal);
else
*mVal = aThat;
return *this;
}
private:
nsID * &mVal;
static const nsID *Empty;
friend class SafeGUIDArray;
};
/** See SafeArray<>::SafeArray(). */
SafeGUIDArray() {}
/** See SafeArray<>::SafeArray (size_t). */
SafeGUIDArray (size_t aSize) : Base (aSize) {}
/**
* Array access operator that returns an array element by reference. As a
* special case, the return value of this operator on XPCOM is an nsID (GUID)
* reference, instead of an nsID pointer (the actual SafeArray template
* argument), for compatibility with the MS COM version.
*
* The rest is equivalent to SafeArray<>::operator[].
*/
nsIDRef operator[] (size_t aIdx)
{
Assert (m.arr != NULL);
Assert (aIdx < size());
return nsIDRef (m.arr [aIdx]);
}
/**
* Const version of #operator[] that returns an array element by value.
*/
const nsID &operator[] (size_t aIdx) const
{
Assert (m.arr != NULL);
Assert (aIdx < size());
return m.arr [aIdx] ? *m.arr [aIdx] : *nsIDRef::Empty;
}
};
/**
* Version of com::SafeArray for const arrays of GUID.
*
* This class is used to work with input GUID array parameters in method
* implementations. See SafeGUIDArray for more details.
*/
class SafeConstGUIDArray : public SafeArray <const nsID *,
SafeArrayTraits <nsID *> >
{
public:
typedef SafeArray <const nsID *, SafeArrayTraits <nsID *> > Base;
/** See SafeArray<>::SafeArray(). */
SafeConstGUIDArray() {}
/* See SafeArray<>::SafeArray (ComSafeArrayIn (T, aArg)). */
SafeConstGUIDArray (ComSafeGUIDArrayIn (aArg))
: Base (ComSafeGUIDArrayInArg (aArg)) {}
/**
* Array access operator that returns an array element by reference. As a
* special case, the return value of this operator on XPCOM is nsID (GUID)
* instead of nsID *, for compatibility with the MS COM version.
*
* The rest is equivalent to SafeArray<>::operator[].
*/
const nsID &operator[] (size_t aIdx) const
{
AssertReturn (m.arr != NULL, **((const nsID * *) NULL));
AssertReturn (aIdx < size(), **((const nsID * *) NULL));
return *m.arr [aIdx];
}
private:
/* These are disabled because of const. */
bool reset (size_t aNewSize) { NOREF (aNewSize); return false; }
};
#else /* defined (VBOX_WITH_XPCOM) */
typedef SafeArray <GUID> SafeGUIDArray;
typedef SafeArray <const GUID, SafeArrayTraits <GUID> > SafeConstGUIDArray;
#endif /* defined (VBOX_WITH_XPCOM) */
////////////////////////////////////////////////////////////////////////////////
#if defined (VBOX_WITH_XPCOM)
template <class I>
struct SafeIfaceArrayTraits
{
protected:
static void Init (I * &aElem) { aElem = NULL; }
static void Uninit (I * &aElem)
{
if (aElem)
{
aElem->Release();
aElem = NULL;
}
}
static void Copy (I * aFrom, I * &aTo)
{
if (aFrom != NULL)
{
aTo = aFrom;
aTo->AddRef();
}
else
aTo = NULL;
}
public:
/* Magic to workaround strict rules of par. 4.4.4 of the C++ standard. */
static I **__asInParam_Arr (I **aArr) { return aArr; }
static I **__asInParam_Arr (const I **aArr) { return const_cast <I **> (aArr); }
};
#else /* defined (VBOX_WITH_XPCOM) */
template <class I>
struct SafeIfaceArrayTraits
{
protected:
static VARTYPE VarType() { return VT_DISPATCH; }
static ULONG VarCount (size_t aSize) { return (ULONG) aSize; }
static size_t Size (ULONG aVarCount) { return (size_t) aVarCount; }
static void Copy (I * aFrom, I * &aTo)
{
if (aFrom != NULL)
{
aTo = aFrom;
aTo->AddRef();
}
else
aTo = NULL;
}
static SAFEARRAY *CreateSafeArray (VARTYPE aVarType, SAFEARRAYBOUND *aBound)
{
NOREF (aVarType);
return SafeArrayCreateEx (VT_DISPATCH, 1, aBound, (PVOID) &_ATL_IIDOF (I));
}
};
#endif /* defined (VBOX_WITH_XPCOM) */
////////////////////////////////////////////////////////////////////////////////
/**
* Version of com::SafeArray for arrays of interface pointers.
*
* Except that it manages arrays of interface pointers, the usage of this class
* is identical to com::SafeArray.
*
* @param I Interface class (no asterisk).
*/
template <class I>
class SafeIfaceArray : public SafeArray <I *, SafeIfaceArrayTraits <I> >
{
public:
typedef SafeArray <I *, SafeIfaceArrayTraits <I> > Base;
/**
* Creates a null array.
*/
SafeIfaceArray() {}
/**
* Creates a new array of the given size. All elements of the newly created
* array initialized with null values.
*
* @param aSize Initial number of elements in the array. Must be greater
* than 0.
*
* @note If this object remains null after construction it means that there
* was not enough memory for creating an array of the requested size.
* The constructor will also assert in this case.
*/
SafeIfaceArray (size_t aSize) { Base::resize (aSize); }
/**
* Weakly attaches this instance to the existing array passed in a method
* parameter declared using the ComSafeArrayIn macro. When using this call,
* always wrap the parameter name in the ComSafeArrayOutArg macro call like
* this:
* <pre>
* SafeArray safeArray (ComSafeArrayInArg (aArg));
* </pre>
*
* Note that this constructor doesn't take the ownership of the array. In
* particular, this means that operations that operate on the ownership
* (e.g. #detachTo()) are forbidden and will assert.
*
* @param aArg Input method parameter to attach to.
*/
SafeIfaceArray (ComSafeArrayIn (I *, aArg))
{
#if defined (VBOX_WITH_XPCOM)
AssertReturnVoid (aArg != NULL);
Base::m.size = aArgSize;
Base::m.arr = aArg;
Base::m.isWeak = true;
#else /* defined (VBOX_WITH_XPCOM) */
AssertReturnVoid (aArg != NULL);
SAFEARRAY *arg = *aArg;
if (arg)
{
AssertReturnVoid (arg->cDims == 1);
VARTYPE vt;
HRESULT rc = SafeArrayGetVartype (arg, &vt);
AssertComRCReturnVoid (rc);
AssertMsgReturnVoid (vt == VT_UNKNOWN || vt == VT_DISPATCH,
("Expected vartype VT_UNKNOWN, got %d.\n",
VarType(), vt));
GUID guid;
rc = SafeArrayGetIID (arg, &guid);
AssertComRCReturnVoid (rc);
AssertMsgReturnVoid (InlineIsEqualGUID (_ATL_IIDOF (I), guid),
("Expected IID {%Vuuid}, got {%Vuuid}.\n",
&_ATL_IIDOF (I), &guid));
rc = SafeArrayAccessData (arg, (void HUGEP **) &m.raw);
AssertComRCReturnVoid (rc);
}
m.arr = arg;
m.isWeak = true;
#endif /* defined (VBOX_WITH_XPCOM) */
}
/**
* Creates a deep copy of the given standard C++ container that stores
* interface pointers as objects of the ComPtr <I> class.
*
* @param aCntr Container object to copy.
*
* @param C Standard C++ container template class (normally deduced from
* @c aCntr).
* @param A Standard C++ allocator class (deduced from @c aCntr).
* @param OI Argument to the ComPtr template (deduced from @c aCntr).
*/
template <template <typename, typename> class C, class A, class OI>
SafeIfaceArray (const C <ComPtr <OI>, A> & aCntr)
{
typedef C <ComPtr <OI>, A> List;
Base::resize (aCntr.size());
AssertReturnVoid (!Base::isNull());
int i = 0;
for (typename List::const_iterator it = aCntr.begin();
it != aCntr.end(); ++ it, ++ i)
#if defined (VBOX_WITH_XPCOM)
Copy (*it, Base::m.arr [i]);
#else
Copy (*it, Base::m.raw [i]);
#endif
}
/**
* Creates a deep copy of the given standard C++ container that stores
* interface pointers as objects of the ComObjPtr <I> class.
*
* @param aCntr Container object to copy.
*
* @param C Standard C++ container template class (normally deduced from
* @c aCntr).
* @param A Standard C++ allocator class (deduced from @c aCntr).
* @param OI Argument to the ComObjPtr template (deduced from @c aCntr).
*/
template <template <typename, typename> class C, class A, class OI>
SafeIfaceArray (const C <ComObjPtr <OI>, A> & aCntr)
{
typedef C <ComObjPtr <OI>, A> List;
Base::resize (aCntr.size());
AssertReturnVoid (!Base::isNull());
int i = 0;
for (typename List::const_iterator it = aCntr.begin();
it != aCntr.end(); ++ it, ++ i)
#if defined (VBOX_WITH_XPCOM)
Copy (*it, Base::m.arr [i]);
#else
Copy (*it, Base::m.raw [i]);
#endif
}
/**
* Creates a deep copy of the given standard C++ map whose values are
* interface pointers stored as objects of the ComPtr <I> class.
*
* @param aMap Map object to copy.
*
* @param C Standard C++ map template class (normally deduced from
* @c aCntr).
* @param L Standard C++ compare class (deduced from @c aCntr).
* @param A Standard C++ allocator class (deduced from @c aCntr).
* @param K Map key class (deduced from @c aCntr).
* @param OI Argument to the ComPtr template (deduced from @c aCntr).
*/
template <template <typename, typename, typename, typename>
class C, class L, class A, class K, class OI>
SafeIfaceArray (const C <K, ComPtr <OI>, L, A> & aMap)
{
typedef C <K, ComPtr <OI>, L, A> Map;
Base::resize (aMap.size());
AssertReturnVoid (!Base::isNull());
int i = 0;
for (typename Map::const_iterator it = aMap.begin();
it != aMap.end(); ++ it, ++ i)
#if defined (VBOX_WITH_XPCOM)
Copy (it->second, Base::m.arr [i]);
#else
Copy (it->second, Base::m.raw [i]);
#endif
}
/**
* Creates a deep copy of the given standard C++ map whose values are
* interface pointers stored as objects of the ComObjPtr <I> class.
*
* @param aMap Map object to copy.
*
* @param C Standard C++ map template class (normally deduced from
* @c aCntr).
* @param L Standard C++ compare class (deduced from @c aCntr).
* @param A Standard C++ allocator class (deduced from @c aCntr).
* @param K Map key class (deduced from @c aCntr).
* @param OI Argument to the ComObjPtr template (deduced from @c aCntr).
*/
template <template <typename, typename, typename, typename>
class C, class L, class A, class K, class OI>
SafeIfaceArray (const C <K, ComObjPtr <OI>, L, A> & aMap)
{
typedef C <K, ComObjPtr <OI>, L, A> Map;
Base::resize (aMap.size());
AssertReturnVoid (!Base::isNull());
int i = 0;
for (typename Map::const_iterator it = aMap.begin();
it != aMap.end(); ++ it, ++ i)
#if defined (VBOX_WITH_XPCOM)
Copy (it->second, Base::m.arr [i]);
#else
Copy (it->second, Base::m.raw [i]);
#endif
}
};
} /* namespace com */
/** @} */
#endif /* ___VBox_com_array_h */