VarOffsetAccessor< network > Class Template Reference

VarOffsetAccessor accesses subsequent variable-width attributes that are NOT NULL. More...

#include <AttributeAccessorImpl.h>

Inheritance diagram for VarOffsetAccessor< network >:

List of all members.

Public Member Functions
void	unmarshalValue (TupleAccessor const &tupleAccessor, TupleDatum &value) const
	Unmarshals the attribute's value by setting up the data pointer, length, and null indicator; does not actually copy any data.
bool	unmarshalNullableValue (TupleAccessor const &tupleAccessor, TupleDatum &value) const
	Tests the null indicator for this attribute in the tuple's null bit array.
void	marshalValueData (PBuffer pDestData, TupleDatum const &value) const
	Marshals value data for the attribute.
Public Attributes
uint	iNullBit
	Index of this attribute's null indicator bit in the tuple's bit array, or MAXU for a NOT NULL attribute.
uint	iFixedOffset
	Byte offset of this attribute within a stored tuple image, or MAXU if the start is variable.
uint	iEndIndirectOffset
	Indirect offset of the end of this attribute within a stored tuple image, or MAXU if the end is fixed.
uint	iValueBit
	Index of this attribute's value in the tuple's bit array, or MAXU for a non-bit attribute.
TupleStorageByteLength	cbStorage
	Copied from TupleAttributeDescriptor.cbStorage.

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Detailed Description

template<bool network>
class VarOffsetAccessor< network >

VarOffsetAccessor accesses subsequent variable-width attributes that are NOT NULL.

Definition at line 204 of file AttributeAccessorImpl.h.

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Member Function Documentation

template<bool network>

void VarOffsetAccessor< network >::unmarshalValue	(	TupleAccessor const &	tupleAccessor,
		TupleDatum &	value
	)			const [inline, virtual]

Unmarshals the attribute's value by setting up the data pointer, length, and null indicator; does not actually copy any data.

Parameters:

	tupleAccessor	containing TupleAccessor set up with the current tuple image to be accessed
	value	receives the reference to the unmarshalled value

Implements AttributeAccessor.

Definition at line 208 of file AttributeAccessorImpl.h.

References TupleDatum::cbData, AttributeAccessor::cbStorage, TupleAccessor::getCurrentTupleBuf(), AttributeAccessor::iEndIndirectOffset, TupleDatum::pData, and TupleAccessor::referenceIndirectOffset().

    {
        TupleAccessor::StoredValueOffset const *pEndOffset =
            tupleAccessor.referenceIndirectOffset(iEndIndirectOffset);
        uint iOffset = pEndOffset[-1];
        uint iEndOffset = pEndOffset[0];
        if (network) {
            iOffset = ntohs(iOffset);
            iEndOffset = ntohs(iEndOffset);
        }
        value.pData = tupleAccessor.getCurrentTupleBuf() + iOffset;
        value.cbData = iEndOffset - iOffset;
        assert(value.cbData <= cbStorage);
    }

bool AttributeAccessorImpl::unmarshalNullableValue	(	TupleAccessor const &	tupleAccessor,
		TupleDatum &	value
	)			const [inline, inherited]

Tests the null indicator for this attribute in the tuple's null bit array.

Parameters:

	tupleAccessor	containing TupleAccessor set up with the current tuple image to be accessed
	value	receives the null bit

Returns:

true if value is null; false otherwise

Definition at line 60 of file AttributeAccessorImpl.h.

References TupleAccessor::getBitFields(), and TupleDatum::pData.

    {
        if (tupleAccessor.getBitFields()[iNullBit]) {
            value.pData = NULL;
            return true;
        } else {
            return false;
        }
    }

void AttributeAccessorImpl::marshalValueData	(	PBuffer	pDestData,
		TupleDatum const &	value
	)			const [inline, virtual, inherited]

Marshals value data for the attribute.

Only deals with the data bytes, not length and null indicators.

Parameters:

	pDestData	the target address where the data should be marshalled
	value	the value to be marshalled

Implements AttributeAccessor.

Reimplemented in FixedWidthNetworkAccessor16, FixedWidthNetworkAccessor32, and FixedWidthNetworkAccessor64.

Definition at line 71 of file AttributeAccessorImpl.h.

References TupleDatum::cbData, and TupleDatum::pData.

    {
        memcpy(pDestData,value.pData,value.cbData);
    }

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Member Data Documentation

uint AttributeAccessor::iNullBit [inherited]

Index of this attribute's null indicator bit in the tuple's bit array, or MAXU for a NOT NULL attribute.

Definition at line 53 of file AttributeAccessor.h.

Referenced by AttributeAccessorImpl::AttributeAccessorImpl(), TupleAccessor::compute(), Java_net_sf_farrago_fennel_FennelStorage_getAccessorXmiForTupleDescriptor(), TupleAccessor::marshal(), and TupleAccessor::unmarshal().

uint AttributeAccessor::iFixedOffset [inherited]

Byte offset of this attribute within a stored tuple image, or MAXU if the start is variable.

Definition at line 59 of file AttributeAccessor.h.

Referenced by AttributeAccessorImpl::AttributeAccessorImpl(), TupleAccessor::compute(), TupleAccessor::initFixedAccessors(), TupleAccessor::marshal(), TupleAccessor::unmarshal(), and FixedOffsetVarWidthAccessor< network >::unmarshalValue().

uint AttributeAccessor::iEndIndirectOffset [inherited]

Indirect offset of the end of this attribute within a stored tuple image, or MAXU if the end is fixed.

Definition at line 65 of file AttributeAccessor.h.

Referenced by AttributeAccessorImpl::AttributeAccessorImpl(), TupleAccessor::marshal(), TupleAccessor::unmarshal(), VarOffsetAccessor< network >::unmarshalValue(), and FixedOffsetVarWidthAccessor< network >::unmarshalValue().

uint AttributeAccessor::iValueBit [inherited]

Index of this attribute's value in the tuple's bit array, or MAXU for a non-bit attribute.

Definition at line 71 of file AttributeAccessor.h.

Referenced by AttributeAccessorImpl::AttributeAccessorImpl(), TupleAccessor::marshal(), and TupleAccessor::unmarshal().

TupleStorageByteLength AttributeAccessor::cbStorage [inherited]

Copied from TupleAttributeDescriptor.cbStorage.

This is not used for anything except assertions.

Definition at line 77 of file AttributeAccessor.h.

Referenced by AttributeAccessorImpl::AttributeAccessorImpl(), TupleAccessor::compute(), TupleAccessor::marshal(), TupleAccessor::unmarshal(), VarOffsetAccessor< network >::unmarshalValue(), and FixedOffsetVarWidthAccessor< network >::unmarshalValue().

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The documentation for this class was generated from the following file:

• /home/pub/open/dev/fennel/tuple/AttributeAccessorImpl.h

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