class RBuf16 : public TDes16 |
16 bit resizable buffer descriptor.
The class provides a buffer that contains, accesses and manipulates TUint16 data. The buffer itself is on the heap, and is managed by the class.
Internally, RBuf16 behaves in one of two ways:
as a TPtr16 descriptor type, where the buffer just contains data
as a pointer to a heap descriptor, an HBufC16* type, where the buffer contains both descriptor information and the data.
Note that the handling of the distinction is hidden from view.
An RBuf16 object can allocate its own buffer. Alternatively, it can take ownership of a pre-existing section of allocated memory, or it can take ownership of a pre-existing heap descriptor. It can also reallocate the buffer to resize it. Regardless of the way in which the buffer has been allocated, the RBuf16 object is responsible for freeing memory when the object itself is closed.
The class is intended for instantiation.
The class is derived from TDes16 , which means that data can be both accessed and modified. The base classes provide the functions through which the data is accessed. In addition, an RBuf16 object can be passed to any function that is prototyped to take a TDes16 or a TDesC16 type.
Public Member Functions | |
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RBuf16 () | |
RBuf16 ( HBufC16 *) | |
IMPORT_C void | Assign (const RBuf16 &) |
IMPORT_C void | Assign ( TUint16 *, TInt ) |
IMPORT_C void | Assign ( TUint16 *, TInt , TInt ) |
IMPORT_C void | Assign ( HBufC16 *) |
IMPORT_C void | CleanupClosePushL () |
IMPORT_C void | Close () |
IMPORT_C TInt | Create ( TInt ) |
IMPORT_C TInt | Create (const TDesC16 &) |
IMPORT_C TInt | Create (const TDesC16 &, TInt ) |
IMPORT_C void | CreateL ( TInt ) |
void | CreateL (RReadStream &, TInt ) |
IMPORT_C void | CreateL (const TDesC16 &) |
IMPORT_C void | CreateL (const TDesC16 &, TInt ) |
IMPORT_C TInt | CreateMax ( TInt ) |
IMPORT_C void | CreateMaxL ( TInt ) |
IMPORT_C TInt | ReAlloc ( TInt ) |
IMPORT_C void | ReAllocL ( TInt ) |
IMPORT_C void | Swap ( RBuf16 &) |
RBuf16 & | operator= (const TUint16 *) |
RBuf16 & | operator= (const TDesC16 &) |
RBuf16 & | operator= (const RBuf16 &) |
Protected Member Functions | |
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RBuf16 ( TInt , TInt , TInt ) | |
RBuf16 (const RBuf16 &) |
Inherited Enumerations | |
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TDesC16:TPrefix |
Public Attributes | |
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HBufC16 * | iEBufCPtrType |
TUint16 * | iEPtrType |
Protected Attributes | |
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union RBuf16::@6 | @7 |
__DECLARE_TEST |
Inherited Attributes | |
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TDes16::iMaxLength |
IMPORT_C | RBuf16 | ( | ) |
Default constructor.
Constructs a zero-length 16-bit resizable buffer descriptor.
Note that the object owns no allocated memory.
IMPORT_C | RBuf16 | ( | HBufC16 * | aHBuf | ) | [explicit] |
Constructor.
Constructs a 16-bit resizable buffer descriptor, transferring ownership of the specified heap descriptor to this object.
HBufC16 * aHBuf | The heap descriptor to be transferred to this object. This pointer can be NULL, which means that a zero length 16-bit resizable buffer descriptor is constructed, and the object will not own any allocated memory. |
IMPORT_C | RBuf16 | ( | TInt | aType, |
TInt | aLength, | |||
TInt | aMaxLength | |||
) | [protected] |
Protected constructor.
IMPORT_C void | Assign | ( | const RBuf16 & | aRBuf | ) |
Transfers ownership of the specified 16-bit resizable buffer descriptor's buffer to this object.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
const RBuf16 & aRBuf | The source 16-bit resizable buffer. The ownership of this object's buffer is to be transferred. |
IMPORT_C void | Assign | ( | TUint16 * | aHeapCell, |
TInt | aMaxLength | |||
) |
Assigns ownership of the specified allocated memory to this object.
The allocated memory forms the buffer for this descriptor. The current length of the descriptor is set to zero.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
IMPORT_C void | Assign | ( | TUint16 * | aHeapCell, |
TInt | aLength, | |||
TInt | aMaxLength | |||
) |
Assigns ownership of the specified allocated memory to this object.
The allocated memory forms the buffer for this descriptor. The current length of the descriptor is set to the value of the second parameter.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
IMPORT_C void | Assign | ( | HBufC16 * | aHBuf | ) |
Transfers ownership of the specified heap descriptor to this object.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
HBufC16 * aHBuf | The heap descriptor to be transferred to this object. This pointer can be NULL, which means that a zero length 16-bit resizable buffer descriptor is created. |
IMPORT_C void | CleanupClosePushL | ( | ) |
Pushes a cleanup item for this object onto the cleanup stack.
The effect of this is to cause Close() to be called on this 16-bit resizable buffer descriptor, when CleanupStack::PopAndDestroy() is called at some later time.
... RBuf16 x; .... x.CleanupClosePushL(); ... CleanupStack::PopAndDestroy(); ...
IMPORT_C void | Close | ( | ) |
Deallocates memory assigned to this object, and re-initializes the object as a zero-length descriptor.
IMPORT_C TInt | Create | ( | TInt | aMaxLength | ) |
Creates a 16-bit resizable buffer descriptor.
The function allocates sufficient memory to contain descriptor data up to the specified maximum length.
The current length of the descriptor is set to zero. The maximum length of the descriptor is set to the specified value.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
TInt aMaxLength | The maximum length of the descriptor. |
IMPORT_C TInt | Create | ( | const TDesC16 & | aDes | ) |
Creates a 16-bit resizable buffer descriptor to contain a copy of the specified (source) descriptor.
The function allocates sufficient memory so that this descriptor's maximum length is the same as the length of the source descriptor. Both the current length and the maximum length of this descriptor are set to the length of the source descriptor.
The data contained in the source descriptor is copied into this descriptor.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
TDesC16::Length() TDes16::MaxLength() TDes16::Copy() RBuf16::Close()
const TDesC16 & aDes | Source descriptor to be copied into this object. |
IMPORT_C TInt | Create | ( | const TDesC16 & | aDes, |
TInt | aMaxLength | |||
) |
Creates a 16-bit resizable buffer descriptor to contain a copy of the specified (source) descriptor.
The function allocates sufficient memory so that this descriptor's maximum length is the same as the value of the aMaxLength parameter.
The data contained in the source descriptor is copied into this descriptor. The length of data copied is either
the length of the source descriptor aDes
or
the value of the aMaxLength parameter
whichever is the smaller value. The current length of this descriptor is also set to the smaller value.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
TDesC16::Length() TDes16::MaxLength() TDes16::Copy() RBuf16::Close()
IMPORT_C void | CreateL | ( | TInt | aMaxLength | ) |
Creates 16-bit resizable buffer descriptor, and leaves on failure.
The function allocates sufficient memory to contain descriptor data up to the specified maximum length.
The current length of the descriptor is set to zero. The maximum length of the descriptor is set to the specified value.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
TInt aMaxLength | The maximum length of the descriptor. |
void | CreateL | ( | RReadStream & | aStream, |
TInt | aMaxLength | |||
) | [inline] |
Creates a 16-bit resizable buffer descriptor that has been initialised with data from the specified read stream; leaves on failure.
Data is assigned to the new descriptor from the specified stream. This variant assumes that the stream contains the length of the data followed by the data itself.
The function is implemented by calling the HBufC16::NewL (RReadStream&,TInt) variant and then assigning the resulting heap descriptor using the RBuf16::Assign(HBufC16*) variant. The comments that describe the HBufC16::NewL() variant also apply to this RBuf16::CreateL() function.
The function may leave with one of the system-wide error codes, specifically KErrOverflow, if the length of the data as read from the stream is greater than the upper limit as specified by the aMaxLength parameter.
RReadStream & aStream | The stream from which the data length and the data to be assigned to the new descriptor, are taken. |
TInt aMaxLength | The upper limit on the length of data that the descriptor is to represent. The value of this parameter must be non-negative otherwise the underlying function will panic. |
IMPORT_C void | CreateL | ( | const TDesC16 & | aDes | ) |
Creates a 16-bit resizable buffer descriptor to contain a copy of the specified (source) descriptor, and leaves on failure.
The function allocates sufficient memory so that this descriptor's maximum length is the same as the length of the source descriptor.Both the current length and the maximum length of this descriptor are set to the length of the source descriptor.
The data contained in the source descriptor is copied into this descriptor.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
const TDesC16 & aDes | Source descriptor to be copied into this object. |
IMPORT_C void | CreateL | ( | const TDesC16 & | aDes, |
TInt | aMaxLength | |||
) |
Creates a 16-bit resizable buffer descriptor to contain a copy of the specified (source) descriptor, and leaves on failure.
The function allocates sufficient memory so that this descriptor's maximum length is the same as the value of the aMaxLength parameter.
The data contained in the source descriptor is copied into this descriptor. The length of data copied is either
the length of the source descriptor aDes
or
the value of the aMaxLength parameter
whichever is the smaller value. The current length of this descriptor is also set to the smaller value.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
IMPORT_C TInt | CreateMax | ( | TInt | aMaxLength | ) |
Creates a 16-bit resizable buffer descriptor.
The function allocates sufficient memory to contain descriptor data up to the specified maximum length.
Both the current length and the maximum length of the descriptor are set to the specified value.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
TInt aMaxLength | The length and the maximum length of the descriptor. |
IMPORT_C void | CreateMaxL | ( | TInt | aMaxLength | ) |
Creates a 16-bit resizable buffer descriptor, and leaves on failure.
The function allocates sufficient memory to contain descriptor data up to the specified maximum length.
Both the current length and the maximum length of the descriptor are set to the specified value.
Note that the function assumes that this descriptor does not already own any allocated memory. It does not check, nor does it free any pre-existing owned allocated memory. If this descriptor does already own allocated memory, RBuf16::Close() should be invoked on this descriptor before this function is invoked.
TInt aMaxLength | The length and the maximum length of the descriptor. |
IMPORT_C TInt | ReAlloc | ( | TInt | aMaxLength | ) |
Resizes this 16-bit resizable buffer descriptor.
The length and contents of the descriptor are unchanged.
If the buffer descriptor was created from a zero-length heap descriptor HBufC, this method might leak memory (the heap descriptor is not freed). It is possible to avoid this by calling the Close() method prior to ReAlloc() , but this should be done only in this situation (otherwise the buffer contents will be lost).
if (desc.MaxLength() == 0) desc.Close();before the call to ReAlloc() .
TInt aMaxLength | The new maximum length of the descriptor. This can be zero, which results in a descriptor with zero maximum length and no allocated memory. |
IMPORT_C void | ReAllocL | ( | TInt | aMaxLength | ) |
Resizes this 16-bit resizable buffer descriptor, leaving on failure.
The length and contents of the descriptor are unchanged.
If the buffer descriptor was created from a zero-length heap descriptor HBufC, this method might leak memory (the heap descriptor is not freed). It is possible to avoid this by calling the Close() method prior to ReAllocL() , but this should be done only in this situation (otherwise the buffer contents will be lost).
if (desc.MaxLength() == 0) desc.Close();before the call to ReAlloc() .
TInt aMaxLength | The new maximum length of the descriptor. This can be zero, which results in a descriptor with zero maximum length and no allocated memory. |
IMPORT_C void | Swap | ( | RBuf16 & | aRBuf | ) |
Swaps the content of two 16-bit resizable buffer descriptors.
RBuf16 & aRBuf | The 16-bit resizable buffer descriptor whose contents are to be swapped with this one. |
RBuf16 & | operator= | ( | const TUint16 * | aString | ) | [inline] |
Copies data into this descriptor replacing any existing data.
The length of this descriptor is set to reflect the new data.
const TUint16 * aString | A pointer to a zero-terminated string. |
RBuf16 & | operator= | ( | const TDesC16 & | aDes | ) | [inline] |
Copies data into this descriptor replacing any existing data.
The length of this descriptor is set to reflect the new data.
const TDesC16 & aDes | A 16-bit non-modifiable descriptor. |
RBuf16 & | operator= | ( | const RBuf16 & | aDes | ) | [inline] |
Copies data into this descriptor replacing any existing data.
The length of this descriptor is set to reflect the new data.
const RBuf16 & aDes | A 16-bit buffer descriptor. |
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All rights
reserved. Unless otherwise stated, these materials are provided under the terms of the Eclipse Public License
v1.0.