Mem Class Reference

#include <e32std.h>

class Mem

Public Member Functions
IMPORT_C const TCollationMethod *	CollationMethodById(TUint)
IMPORT_C const TCollationMethod *	CollationMethodByIndex(TInt)
IMPORT_C TUint	CollationMethodId(TInt)
IMPORT_C TInt	CollationMethods()
IMPORT_C TInt	Compare(const TUint8 , TInt, const TUint8 , TInt)
IMPORT_C TInt	Compare(const TUint16 , TInt, const TUint16 , TInt)
IMPORT_C TInt	CompareC(const TUint8 , TInt, const TUint8 , TInt)
IMPORT_C TInt	CompareC(const TUint16 , TInt, const TUint16 , TInt)
IMPORT_C TInt	CompareC(const TUint16 , TInt, const TUint16 , TInt, TInt, const TCollationMethod *)
IMPORT_C TInt	CompareF(const TUint8 , TInt, const TUint8 , TInt)
IMPORT_C TInt	CompareF(const TUint16 , TInt, const TUint16 , TInt)
TUint8 *	Copy(TAny , const TAny , TInt)
IMPORT_C void	Crc(TUint16 &, const TAny *, TInt)
IMPORT_C void	Crc32(TUint32 &, const TAny *, TInt)
void	Fill(TAny *, TInt, TChar)
void	FillZ(TAny *, TInt)
IMPORT_C const TCollationMethod *	GetDefaultMatchingTable()
TUint8 *	Move(TAny , const TAny , TInt)
IMPORT_C void	Swap(TAny , TAny , TInt)

Detailed Description

Contains a set of static functions which perform manipulation of data in memory.

The arguments passed to the functions of this class are pointers to memory locations and length values. These functions are, therefore, not normally used in open code but are suitable for implementing data manipulation for other classes. Typically the interface provided by such classes is typesafe and hides this direct memory to memory manipulation.

Member Function Documentation

CollationMethodById ( TUint )

IMPORT_C const TCollationMethod *

CollationMethodById

(

TUint

aId

)

[static]

Gets the collation method identified by the specified Uid.

This function is only defined for 16 bit (Unicode) build variants. This means that the function is not defined for 8 bit build variants, even when an explicit 16 bit descriptor is used.

Parameters
aId	The Uid of a collation method in the set of collation methods in this locale.

Return Value: A pointer to the collation method.

CollationMethodByIndex ( TInt )

IMPORT_C const TCollationMethod *

CollationMethodByIndex

(

TInt

aIndex

)

[static]

Gets the collation method identified by the specified index.

This function is only defined for 16 bit (Unicode) build variants. This means that the function is not defined for 8 bit build variants, even when an explicit 16 bit descriptor is used.

Parameters
aIndex	An index into the set of collation methods in this locale. This value is relative to zero; i.e. a zero value refers to the first collation method. This value must not be negative, and must be less than the total number of collation methods in this locale.

Return Value: A pointer to the collation method.

Panic Codes
USER	132 In debug builds only, if aIndex is negative or is greater than or equal to the total number of collation methods in this locale.

CollationMethodId ( TInt )

IMPORT_C TUint

CollationMethodId

(

TInt

aIndex

)

[static]

Gets the Uid associated with the specified collation method.

This function is only defined for 16 bit (Unicode) build variants. This means that the function is not defined for 8 bit build variants, even when an explicit 16 bit descriptor is used.

Parameters
aIndex	An index into the set of collation methods in thie locale. This value is relative to zero; i.e. a zero value refers to the first collation method. This value must not be negative, and must be less than the total number of collation methods in this locale.

Return Value: The Uid of the collation method.

Panic Codes
USER	132 In debug builds only, if aIndex is negative or is greater than or equal to the total number of collation methods in this locale.

CollationMethods ( )

IMPORT_C TInt

CollationMethods

(

)

[static]

Gets the number of collation methods in this locale.

This function is only defined for 16 bit (Unicode) build variants. This means that the function is not defined for 8 bit build variants, even when an explicit 16 bit descriptor is used.

Return Value: The number of collation methods.

Compare ( const TUint8 , TInt, const TUint8 , TInt )

IMPORT_C TInt	Compare	(	const TUint8 *	aLeft,
			TInt	aLeftL,
			const TUint8 *	aRight,
			TInt	aRightL
		)	[static]

Compares a block of data at one specified location with a block of data at another specified location.

The comparison proceeds on a byte for byte basis, the result of the comparison is based on the difference of the first bytes to disagree.

The data at the two locations are equal if they have the same length and content. Where the lengths are different and the shorter section of data is the same as the first part of the longer section of data, the shorter is considered to be less than the longer.

Parameters
aLeft	A pointer to the first (or left) block of 8 bit data to be compared.
aLeftL	The length of the first (or left) block of data to be compared, i.e. the number of bytes.
aRight	A pointer to the second (or right) block of 8 bit data to be compared.
aRightL	The length of the second (or right) block of data to be compared i.e. the number of bytes.

Return Value: Positive, if the first (or left) block of data is greater than the second (or right) block of data. Negative, if the first (or left) block of data is less than the second (or right) block of data. Zero, if both the first (or left) and second (or right) blocks of data have the same length and the same content.

Compare ( const TUint16 , TInt, const TUint16 , TInt )

IMPORT_C TInt	Compare	(	const TUint16 *	aLeft,
			TInt	aLeftL,
			const TUint16 *	aRight,
			TInt	aRightL
		)	[static]

Compares a block of data at one specified location with a block of data at another specified location.

The comparison proceeds on a double-byte for double-byte basis, the result of the comparison is based on the difference of the first pair of bytes to disagree.

Parameters
aLeft	A pointer to the first (or left) block of 16 bit data to be compared.
aLeftL	The length of the first (or left) block of data to be compared i.e. the number of double-bytes.
aRight	A pointer to the second (or right) block of 16 bit data to be compared.
aRightL	The length of the second (or right) block of data to be compared i.e. the number of double-bytes.

Return Value: Positive, if the first (or left) block of data is greater than the second (or right) block of data. Negative, if the first (or left) block of data is less than the second (or right) block of data. Zero, if both the first (or left) and second (or right) blocks of data have the same length and the same content.

CompareC ( const TUint8 , TInt, const TUint8 , TInt )

IMPORT_C TInt	CompareC	(	const TUint8 *	aLeft,
			TInt	aLeftL,
			const TUint8 *	aRight,
			TInt	aRightL
		)	[static]

Deprecated

Compares a block of data at one specified location with a block of data at another specified location using the standard collation method appropriate to the current locale.

See also: Mem::Compare

Parameters
aLeft	A pointer to the first (or left) block of 8 bit data to be compared.
aLeftL	The length of the first (or left) block of data to be compared i.e. the number of bytes.
aRight	A pointer to the second (or right) block of 8 bit data to be compared.
aRightL	The length of the second (or right) block of data to be compared i.e. the number of bytes.

Return Value: Positive, if the first (or left) block of data is greater than the second (or right) block of data. Negative, if the first (or left) block of data is less than the second (or right) block of data. Zero, if both the first (or left) and second (or right) blocks of data have the same length and the same content.

CompareC ( const TUint16 , TInt, const TUint16 , TInt )

IMPORT_C TInt	CompareC	(	const TUint16 *	aLeft,
			TInt	aLeftL,
			const TUint16 *	aRight,
			TInt	aRightL
		)	[static]

Compares a block of data at one specified location with a block of data at another specified location using the standard collation method appropriate to the current locale.

See also: Mem::Compare

Parameters
aLeft	A pointer to the first (or left) block of 16 bit data to be compared.
aLeftL	The length of the first (or left) block of data to be compared i.e. the number of double-bytes).
aRight	A pointer to the second (or right) block of 16 bit data to be compared.
aRightL	The length of the second (or right) block of data to be compared i.e. the number of double-bytes.

Return Value: Positive, if the first (or left) block of data is greater than the second (or right) block of data. Negative, if the first (or left) block of data is less than the second (or right) block of data. Zero, if both the first (or left) and second (or right) blocks of data have the same length and the same content.

CompareC ( const TUint16 , TInt, const TUint16 , TInt, TInt, const TCollationMethod * )

IMPORT_C TInt	CompareC	(	const TUint16 *	aLeft,
			TInt	aLeftL,
			const TUint16 *	aRight,
			TInt	aRightL,
			TInt	aMaxLevel,
			const TCollationMethod *	aCollationMethod
		)	[static]

Compares a block of data at one location with a block of data at another location using the specified collation method and collating to the specified maximum collation level.

If no collation method is supplied, a default method, appropriate to the current locale, is used.

This function is only defined for 16 bit (Unicode) build variants. This means that the function is not defined for 8 bit build variants, even when an explicit 16 bit descriptor is used.

Parameters
aLeft	A pointer to the first (or left) block of 16 bit data to be compared.
aLeftL	The length of the first (or left) block of data to be compared. This is the number of double-bytes.
aRight	A pointer to the second (or right) block of 16 bit data to be compared.
aRightL	The length of the second (or right) block of data to be compared. This is the number of double-bytes.
aMaxLevel	The maximum collation level.
aCollationMethod	A pointer to the collation method or NULL.

Return Value: Positive, if this descriptor is greater than the specified descriptor. Negative, if this descriptor is less than the specified descriptor. Zero, if both descriptors have the same length and their contents are the same.

CompareF ( const TUint8 , TInt, const TUint8 , TInt )

IMPORT_C TInt	CompareF	(	const TUint8 *	aLeft,
			TInt	aLeftL,
			const TUint8 *	aRight,
			TInt	aRightL
		)	[static]

Compares a block of data at one specified location with a block of data at another specified location, using the standard folding method appropriate to the current locale.

See also: Mem::Compare

Parameters
aLeft	A pointer to the first (or left) block of 8 bit data to be compared.
aLeftL	The length of the first (or left) block of data to be compared, i.e. the number of bytes.
aRight	A pointer to the second (or right) block of 8 bit data to be compared.
aRightL	The length of the second (or right) block of data to be compared, i.e. the number of bytes.

Return Value: Positive, if the first (or left) block of data is greater than the second (or right) block of data. Negative, if the first (or left) block of data is less than the second (or right) block of data. Zero, if both the first (or left) and second (or right) blocks of data have the same length and the same content.

CompareF ( const TUint16 , TInt, const TUint16 , TInt )

IMPORT_C TInt	CompareF	(	const TUint16 *	aLeft,
			TInt	aLeftL,
			const TUint16 *	aRight,
			TInt	aRightL
		)	[static]

Compares a block of data at one specified location with a block of data at another specified location, using the standard folding method appropriate to the current locale.

See also: Mem::Compare

Parameters
aLeft	A pointer to the first (or left) block of 16 bit data to be compared.
aLeftL	The length of the first (or left) block of data to be compared i.e. the number of double-bytes.
aRight	A pointer to the second (or right) block of 16 bit data to be compared.
aRightL	The length of the second (or right) block of data to be compared i.e the number of double-bytes.

Return Value: Positive, if the first (or left) block of data is greater than the second (or right) block of data. Negative, if the first (or left) block of data is less than the second (or right) block of data. Zero, if both the first (or left) and second (or right) blocks of data have the same length and the same content.

Copy ( TAny , const TAny , TInt )

TUint8 *	Copy	(	TAny *	aTrg,
			const TAny *	aSrc,
			TInt	aLength
		)	[static, inline]

Copies data from a source location to a target location and returns a pointer to the end of the copied data.

The source and target areas can overlap.

The copy operation is optimised so that if both source and target locations are aligned on a word boundary, the operation performs the copy on a word by word basis.

Parameters
aTrg	A pointer to the target location for the copy operation.
aSrc	A pointer to the source location for the copy operation.
aLength	The number of bytes to be copied. This value must not be negative.

Return Value: A pointer to a location aLength bytes beyond aTrg (i.e. the location aTrg+aLength).

Panic Codes
USER	90 In debug builds only, if aLength is negative.

Crc ( TUint16 &, const TAny *, TInt )

IMPORT_C void	Crc	(	TUint16 &	aCrc,
			const TAny *	aPtr,
			TInt	aLength
		)	[static]

Performs a CCITT CRC checksum on the specified data.

On return from this function, the referenced 16 bit integer contains the checksummed value.

Parameters
aCrc	A reference to a 16 bit integer to contain the checksummed value.
aPtr	A pointer to the start of the data to be checksummed.
aLength	The length of the data to be checksummed.

Crc32 ( TUint32 &, const TAny *, TInt )

IMPORT_C void	Crc32	(	TUint32 &	aCrc,
			const TAny *	aPtr,
			TInt	aLength
		)	[static]

Performs a CCITT CRC-32 checksum on the specified data.

On return from this function, the referenced 32 bit integer contains the CRC value.

Parameters
aCrc	A reference to a 32 bit integer to contain the CRC value.
aPtr	A pointer to the start of the data to be checksummed.
aLength	The length of the data to be checksummed.

Fill ( TAny *, TInt, TChar )

void	Fill	(	TAny *	aTrg,
			TInt	aLength,
			TChar	aChar
		)	[static, inline]

Fills a specified block of data with a specified character, replacing any existing content.

The function assumes that the fill character is a non-Unicode character.

Parameters
aTrg	A pointer to the location where filling is to start.
aLength	The number of bytes to be filled. This value must not be negative.
aChar	The fill character.

Panic Codes
USER	95 In debug builds only, if aLength is negative.

FillZ ( TAny *, TInt )

void	FillZ	(	TAny *	aTrg,
			TInt	aLength
		)	[static, inline]

Fills a specified block of data with binary zeroes (i.e. 0x00), replacing any existing content.

Parameters
aTrg	A pointer to the location where filling is to start.
aLength	The number of bytes to be filled. This value must not be negative.

Panic Codes
USER	95 In debug builds only, if aLength is negative.

GetDefaultMatchingTable ( )

IMPORT_C const TCollationMethod *

GetDefaultMatchingTable

(

)

[static]

Gets the collation method specific for matching purpose.

This function is only defined for 16 bit (Unicode) build variants. This means that the function is not defined for 8 bit build variants, even when an explicit 16 bit descriptor is used.

Return Value: A pointer to the collation method

Move ( TAny , const TAny , TInt )

TUint8 *	Move	(	TAny *	aTrg,
			const TAny *	aSrc,
			TInt	aLength
		)	[static, inline]

Moves a block of data from a source location to a target location and returns a pointer to the end of the moved data.

The source and target areas can overlap.

Both source and target locations must be aligned on a word boundary. The specified length must also be a multiple of 4.

Parameters
aTrg	A pointer to the target location for the move operation. This pointer must be word aligned.
aSrc	A pointer to the source location for the move operation. This pointer must be word aligned.
aLength	The number of bytes to be copied. This value must be a multiple of 4.

Return Value: A pointer to a location aLength bytes beyond aTrg (i.e. the location aTrg+aLength).

Panic Codes
USER	93 In debug builds only, if aTrg is not word aligned.
USER	92 In debug builds only, if aSrc is not word aligned.
USER	91 In debug builds only, if aLength is not a multiple of 4.

Swap ( TAny , TAny , TInt )

IMPORT_C void	Swap	(	TAny *	aPtr1,
			TAny *	aPtr2,
			TInt	aLength
		)	[static]

Swaps a number of bytes of data between two specified locations.

The source and target areas can overlap.

Parameters
aPtr1	A pointer to the first location taking part in the swap.
aPtr2	A pointer to second location taking part in the swap.
aLength	The number of bytes to be swapped between the two locations. This value must not be negative.

Panic Codes
USER	94 In debug builds only, if aLength is negative.

Mem Class Reference

Detailed Description

Member Function Documentation

CollationMethodById ( TUint )

CollationMethodByIndex ( TInt )

CollationMethodId ( TInt )

CollationMethods ( )

Compare ( const TUint8 *, TInt, const TUint8 *, TInt )

Compare ( const TUint16 *, TInt, const TUint16 *, TInt )

CompareC ( const TUint8 *, TInt, const TUint8 *, TInt )

CompareC ( const TUint16 *, TInt, const TUint16 *, TInt )

CompareC ( const TUint16 *, TInt, const TUint16 *, TInt, TInt, const TCollationMethod * )

CompareF ( const TUint8 *, TInt, const TUint8 *, TInt )

CompareF ( const TUint16 *, TInt, const TUint16 *, TInt )

Copy ( TAny *, const TAny *, TInt )

Crc ( TUint16 &, const TAny *, TInt )

Crc32 ( TUint32 &, const TAny *, TInt )

Fill ( TAny *, TInt, TChar )

FillZ ( TAny *, TInt )

GetDefaultMatchingTable ( )

Move ( TAny *, const TAny *, TInt )

Swap ( TAny *, TAny *, TInt )

Compare ( const TUint8 , TInt, const TUint8 , TInt )

Compare ( const TUint16 , TInt, const TUint16 , TInt )

CompareC ( const TUint8 , TInt, const TUint8 , TInt )

CompareC ( const TUint16 , TInt, const TUint16 , TInt )

CompareC ( const TUint16 , TInt, const TUint16 , TInt, TInt, const TCollationMethod * )

CompareF ( const TUint8 , TInt, const TUint8 , TInt )

CompareF ( const TUint16 , TInt, const TUint16 , TInt )

Copy ( TAny , const TAny , TInt )

Move ( TAny , const TAny , TInt )

Swap ( TAny , TAny , TInt )