Fennel: VarCharType Class Reference

typedef uint StoredTypeDescriptor::Ordinal [inherited]

Each type must have a unique positive integer ordinal associated with it.

This is used to reconstruct a StoredTypeDescriptor object from a stored attribute definition.

Definition at line 44 of file StoredTypeDescriptor.h.

virtual Ordinal VarCharType::getOrdinal ( ) const [inline, private, virtual]

Returns:: the ordinal representing this type.

Implements StoredTypeDescriptor.

Definition at line 252 of file StandardTypeDescriptor.cpp.

References STANDARD_TYPE_VARCHAR.

00253     {
00254         return STANDARD_TYPE_VARCHAR;
00255     }

virtual uint VarCharType::getBitCount ( ) const [inline, private, virtual]

Returns:: number of bits in marshalled representation, or 0 for a non-bit type; currently only 0 or 1 is supported

Implements StoredTypeDescriptor.

Definition at line 257 of file StandardTypeDescriptor.cpp.

00258     {
00259         return 0;
00260     }

virtual uint VarCharType::getFixedByteCount ( ) const [inline, private, virtual]

Returns:: the width in bytes for a fixed-width non-bit type which admits no per-attribute precision, or 0 for types with per-attribute precision; for bit types, this yields the size of the unmarshalled representation

Implements StoredTypeDescriptor.

Definition at line 262 of file StandardTypeDescriptor.cpp.

00263     {
00264         return 0;
00265     }

virtual uint VarCharType::getMinByteCount ( uint cbMaxWidth ) const [inline, private, virtual]

Gets the number of bytes required to store the narrowest value with this type, given a particular max byte count.

For a fixed-width type, the return value is the same as the input.

Parameters:

cbMaxWidth

maximum width for which to compute the minimum

Returns:: number of bytes

Implements StoredTypeDescriptor.

Definition at line 267 of file StandardTypeDescriptor.cpp.

00268     {
00269         return 0;
00270     }

virtual uint VarCharType::getAlignmentByteCount ( uint cbWidth ) const [inline, private, virtual]

Gets the alignment size in bytes required for values of this type, given a particular max byte count.

This must be 1, 2, 4, or 8, and may not be greater than 2 for variable-width datatypes. For fixed-width datatypes, the width must be a multiple of the alignment size.

Parameters:

cbWidth

width for which to compute the alignment

Returns:: number of bytes

Implements StoredTypeDescriptor.

Definition at line 272 of file StandardTypeDescriptor.cpp.

00273     {
00274         return 1;
00275     }

virtual void VarCharType::visitValue	(	DataVisitor &	dataVisitor,
		void const *	pData,
		TupleStorageByteLength	cbData
	)			const `[inline, private, virtual]`

Visits a value of this type.

Parameters:

	dataVisitor	the DataVisitor which should be called with the interpreted value
	pData	the address of the data value
	cbData	the number of bytes of data

Implements StoredTypeDescriptor.

Definition at line 277 of file StandardTypeDescriptor.cpp.

References DataVisitor::visitChars().

00281     {
00282         char const *pStr = static_cast<char const *>(pData);
00283         dataVisitor.visitChars(pStr,cbData);
00284     }

virtual int VarCharType::compareValues	(	void const *	pData1,
		TupleStorageByteLength	cbData1,
		void const *	pData2,
		TupleStorageByteLength	cbData2
	)			const `[inline, private, virtual]`

Compares two values of this type.

Parameters:

	pData1	the address of the first data value
	cbData1	the width of the first data value in bytes
	pData2	the address of the second data value
	cbData2	the width of the second data value in bytes

Returns:: negative if the first data value is less than the second; positive if greater; zero if equal

Implements StoredTypeDescriptor.

Definition at line 286 of file StandardTypeDescriptor.cpp.

References min().

00291     {
00292         TupleStorageByteLength cbMin = std::min(cbData1,cbData2);
00293         int rc = memcmp(pData1, pData2, cbMin);
00294         if (rc) {
00295             return rc;
00296         }
00297         if (cbData1 == cbData2) {
00298             return 0;
00299         }
00300         PConstBuffer pBuf1 = static_cast<PConstBuffer>(pData1);
00301         PConstBuffer pBuf2 = static_cast<PConstBuffer>(pData2);
00302         PConstBuffer trailStart,trailEnd;
00303         if (cbData1 > cbData2) {
00304             trailStart = pBuf1 + cbMin;
00305             trailEnd = pBuf1 + cbData1;
00306             rc = 1;
00307         } else {
00308             trailStart = pBuf2 + cbMin;
00309             trailEnd = pBuf2 + cbData2;
00310             rc = -1;
00311         }
00312         for (; trailStart < trailEnd; trailStart++) {
00313             if (*trailStart != ' ') {
00314                 return rc;
00315             }
00316         }
00317         return 0;
00318     }

VarCharType Class Reference

Public Types

Private Member Functions

Detailed Description

Member Typedef Documentation

Member Function Documentation


Public Types
typedef uint	Ordinal
	Each type must have a unique positive integer ordinal associated with it.
Private Member Functions
virtual Ordinal	getOrdinal () const
	Returns: the ordinal representing this type.
virtual uint	getBitCount () const
	Returns: number of bits in marshalled representation, or 0 for a non-bit type; currently only 0 or 1 is supported
virtual uint	getFixedByteCount () const
	Returns: the width in bytes for a fixed-width non-bit type which admits no per-attribute precision, or 0 for types with per-attribute precision; for bit types, this yields the size of the unmarshalled representation
virtual uint	getMinByteCount (uint cbMaxWidth) const
	Gets the number of bytes required to store the narrowest value with this type, given a particular max byte count.
virtual uint	getAlignmentByteCount (uint cbWidth) const
	Gets the alignment size in bytes required for values of this type, given a particular max byte count.
virtual void	visitValue (DataVisitor &dataVisitor, void const *pData, TupleStorageByteLength cbData) const
	Visits a value of this type.
virtual int	compareValues (void const pData1, TupleStorageByteLength cbData1, void const pData2, TupleStorageByteLength cbData2) const
	Compares two values of this type.