Class RBuf8

class RBuf8 : public TDes8;

Description

8 bit resizable buffer descriptor.

The class provides a buffer that contains, accesses and manipulates TUint8 data. The buffer itself is on the heap, and is managed by the class.

Internally, RBuf8 behaves in one of two ways:

• as a TPtr8 descriptor type, where the buffer just contains data

• as a pointer to a heap descriptor, an HBufC8* type, where the buffer contains both descriptor information and the data.

Note that the handling of the distinction is hidden from view.

An RBuf8 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 RBuf8 object is responsible for freeing memory when the object itself is closed.

The class is intended for instantiation.

The class is derived from TDes8, 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 RBuf8 object can be passed to any function that is prototyped to take a TDes8 or a TDesC8 type.

Derivation

• TDesC8 - Abstract base class for 8-bit non-modifiable descriptors

• TDes8 - Abstract base class for 8-bit modifiable descriptors

• RBuf8 - 8 bit resizable buffer descriptor

Members

Defined in RBuf8:
Assign(), Assign(), Assign(), Assign(), CleanupClosePushL(), Close(), Create(), Create(), Create(), CreateL(), CreateL(), CreateL(), CreateL(), CreateMax(), CreateMaxL(), RBuf8(), RBuf8(), RBuf8(), ReAlloc(), ReAllocL(), Swap(), __DECLARE_TEST, iEBufCPtrType, iEPtrType, operator=(), operator=(), operator=()

Inherited from TDes8:
Append(), AppendFill(), AppendFormat(), AppendFormatList(), AppendJustify(), AppendNum(), AppendNumFixedWidth(), AppendNumFixedWidthUC(), AppendNumUC(), Capitalize(), Collapse(), Collate(), Copy(), CopyC(), CopyCP(), CopyF(), CopyLC(), CopyUC(), Delete(), Expand(), Fill(), FillZ(), Fold(), Format(), FormatList(), Insert(), Justify(), LeftTPtr(), LowerCase(), MaxLength(), MaxSize(), MidTPtr(), Num(), NumFixedWidth(), NumFixedWidthUC(), NumUC(), PtrZ(), Repeat(), Replace(), RightTPtr(), SetLength(), SetMax(), Trim(), TrimAll(), TrimLeft(), TrimRight(), UpperCase(), WPtr(), Zero(), ZeroTerminate(), iMaxLength, operator+=(), operator[]()

Inherited from TDesC8:
Alloc(), AllocL(), AllocLC(), AtC(), Compare(), CompareC(), CompareF(), DoSetLength(), Find(), FindC(), FindF(), Left(), Length(), Locate(), LocateF(), LocateReverse(), LocateReverseF(), Match(), MatchC(), MatchF(), Mid(), Ptr(), Right(), Size(), Type(), operator!=(), operator>(), operator>=(), operator<(), operator<=(), operator==()

See also:

• TBuf8
• TPtr8
• HBufC8
• TDesC8
• TDes8

IMPORT_C RBuf8();

Description

Default constructor.

Constructs a zero-length 8-bit resizable buffer descriptor.

Note that the object owns no allocated memory.

IMPORT_C RBuf8(HBufC8 *aHBuf);

Description

Constructor.

Constructs an 8-bit resizable buffer descriptor, transferring ownership of the specified heap descriptor to this object.

Parameters

HBufC8 *aHBuf The heap descriptor to be transferred to this object. This pointer can be NULL, which means that a zero length 8-bit resizable buffer descriptor is constructed, and the object will not own any allocated memory.

protected: IMPORT_C RBuf8(TInt aType, TInt aLength, TInt aMaxLength);

Description

Protected constructor.

Parameters

TInt aType TInt aLength TInt aMaxLength

inline RBuf8 &operator=(const TUint8 *aString);

Description

Copies data into this descriptor replacing any existing data.

The length of this descriptor is set to reflect the new data.

Parameters

const TUint8 *aString A pointer to a zero-terminated string.

Return value

RBuf8 & A reference to this, the target descriptor.

Panic codes

USER 11, if the length of the string, excluding the zero terminator, is greater than the maximum length of this (target) descriptor.

inline RBuf8 &operator=(const TDesC8 &aDes);

Description

Copies data into this descriptor replacing any existing data.

The length of this descriptor is set to reflect the new data.

Parameters

const TDesC8 &aDes An 8-bit non-modifiable descriptor.

Return value

RBuf8 & A reference to this, the target descriptor.

Panic codes

USER 11, if the length of the descriptor aDes is greater than the maximum length of this (target) descriptor.

inline RBuf8 &operator=(const RBuf8 &aDes);

Description

Copies data into this descriptor replacing any existing data.

The length of this descriptor is set to reflect the new data.

Parameters

const RBuf8 &aDes A 8-bit buffer descriptor.

Return value

RBuf8 & A reference to this, the target descriptor.

Panic codes

USER 11, if the length of the descriptor aDes is greater than the maximum length of this (target) descriptor.

IMPORT_C void Assign(const RBuf8 &aRBuf);

Description

Transfers ownership of the specified 8-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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

const RBuf8 &aRBuf The source 8-bit resizable buffer. The ownership of this object's buffer is to be transferred.

See also:

• RBuf8::Close()

IMPORT_C void Assign(TUint8 *aHeapCell, TInt aMaxLength);

Description

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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

TUint8 *aHeapCell The allocated memory to be assigned to this object. This pointer can be NULL, which means that a zero length 8-bit resizable buffer descriptor is created. TInt aMaxLength The maximum length of the descriptor.

Panic codes

USER 20 If the specified maximum length is greater then the size of the allocated heap cell, or the specified maximum length is NOT zero when the pointer to the heap cell is NULL.

See also:

• TDesC8::Length()
• TDes8::MaxLength()
• RBuf8::Close()

IMPORT_C void Assign(TUint8 *aHeapCell, TInt aLength, TInt aMaxLength);

Description

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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

TUint8 *aHeapCell The allocated memory to be assigned to this object. TInt aLength The length of the descriptor. TInt aMaxLength The maximum length of the descriptor.

Panic codes

USER 20 If the specified maximum length is greater then the size of the allocated heap cell, or the specified length is greater then the specified maximum length, or the specified maximum length is NOT zero when the pointer to the heap cell is NULL.

See also:

• TDesC8::Length()
• TDes8::MaxLength()
• RBuf8::Close()

IMPORT_C void Assign(HBufC8 *aHBuf);

Description

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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

HBufC8 *aHBuf The heap descriptor to be transferred to this object. This pointer can be NULL, which means that a zero length 8-bit resizable buffer descriptor is created.

See also:

• RBuf8::Close()

IMPORT_C void Swap(RBuf8 &aRBuf);

Description

Swaps the content of two 8-bit resizable buffer descriptors.

Parameters

RBuf8 &aRBuf The 8-bit resizable buffer descriptor whose contents are to be swapped with this one.

IMPORT_C TInt Create(TInt aMaxLength);

Description

Creates an 8-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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

TInt aMaxLength The maximum length of the descriptor.

Return value

TInt KErrNone, if successful; KErrNoMemory, if there is insufficient memory.

See also:

• TDesC8::Length()
• TDes8::MaxLength()
• RBuf8::Close()

IMPORT_C void CreateL(TInt aMaxLength);

Description

Creates an 8-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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

TInt aMaxLength The length and the maximum length of the descriptor.

Leave codes

KErrNoMemory If there is insufficient memory.

See also:

• TDesC8::Length()
• TDes8::MaxLength()
• RBuf8::Close()

IMPORT_C TInt CreateMax(TInt aMaxLength);

Description

Creates an 8-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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

TInt aMaxLength The length and the maximum length of the descriptor.

Return value

TInt KErrNone, if successful; KErrNoMemory, if there is insufficient memory.

See also:

• RBuf8::Close()

IMPORT_C void CreateMaxL(TInt aMaxLength);

Description

Creates an 8-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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

TInt aMaxLength The length and the maximum length of the descriptor.

Leave codes

KErrNoMemory If there is insufficient memory.

See also:

• TDesC8::Length()
• TDes8::MaxLength()
• RBuf8::Close()

inline void CreateL(RReadStream &aStream, TInt aMaxLength);

Description

Creates an 8-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 HBufC8::NewL(RReadStream&,TInt) variant and then assigning the resulting heap descriptor using the RBuf8::Assign(HBufC8*) variant. The comments that describe the HBufC8::NewL() variant also apply to this RBuf8::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.

Parameters

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 TInt Create(const TDesC8 &aDes);

Description

Creates a 8-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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

const TDesC8 &aDes Source descriptor to be copied into this object.

Return value

TInt KErrNone, if successful; KErrNoMemory, if there is insufficient memory.

See also:

• TDesC8::Length()
• TDes8::MaxLength()
• TDes8::Copy()
• RBuf8::Close()

IMPORT_C void CreateL(const TDesC8 &aDes);

Description

Creates an 8-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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

const TDesC8 &aDes Source descriptor to be copied into this object.

Leave codes

KErrNoMemory If there is insufficient memory.

See also:

• TDesC8::Length()
• TDes8::MaxLength()
• TDes8::Copy()
• RBuf8::Close()

IMPORT_C TInt Create(const TDesC8 &aDes, TInt aMaxLength);

Description

Creates an 8-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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

const TDesC8 &aDes Source descriptor to be copied into this object. TInt aMaxLength The maximum length of this descriptor.

Return value

TInt KErrNone, if successful; KErrNoMemory, if there is insufficient memory.

See also:

• TDesC8::Length()
• TDes8::MaxLength()
• TDes8::Copy()
• RBuf8::Close()

IMPORT_C void CreateL(const TDesC8 &aDes, TInt aMaxLength);

Description

Creates an 8-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, RBuf8::Close() should be invoked on this descriptor before this function is invoked.

Parameters

const TDesC8 &aDes Source descriptor to be copied into this object. TInt aMaxLength The maximum length of this descriptor.

Leave codes

KErrNoMemory If there is insufficient memory.

See also:

• TDesC8::Length()
• TDes8::MaxLength()
• TDes8::Copy()
• RBuf8::Close()

IMPORT_C TInt ReAlloc(TInt aMaxLength);

Description

Resizes this 8-bit resizable buffer descriptor.

The length and contents of the descriptor are unchanged.

Parameters

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.

Return value

TInt KErrNone, if successful; KErrNoMemory, if there is insufficient memory.

Panic codes

USER 26 If the new maximum length is less then the current descriptor length.

IMPORT_C void ReAllocL(TInt aMaxLength);

Description

Resizes this 8-bit resizable buffer descriptor, leaving on failure.

The length and contents of the descriptor are unchanged.

Parameters

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.

Panic codes

USER 26 If the new maximum length is less then the current descriptor length.

IMPORT_C void Close();

Description

Deallocates memory assigned to this object, and re-initializes the object as a zero-length descriptor.

IMPORT_C void CleanupClosePushL();

Description

Pushes a cleanup item for this object onto the cleanup stack.

The effect of this is to cause Close() to be called on this 8-bit resizable buffer descriptor, when CleanupStack::PopAndDestroy() is called at some later time.

...
RBuf8 x;
....
x.CleanupClosePushL();
...
CleanupStack::PopAndDestroy();
...

See also:

• RBuf8::Close()

protected: TUint8 * iEPtrType;

Description

protected: HBufC8 * iEBufCPtrType;

Description

protected: __DECLARE_TEST;

Description