LhxHashNodeAccessor Class Reference

Class implementing the hash table used in Hybrid Hash Join. More...

#include <LhxHashTable.h>

Inheritance diagram for LhxHashNodeAccessor:

List of all members.

Public Member Functions
	LhxHashNodeAccessor ()
	LhxHashNodeAccessor (uint nextNodeOffsetInit)
	Constructor for derived classes with fields before the next node pointer.
PBuffer	getCurrent ()
	Returns: current node associated with this accessor
void	setCurrent (PBuffer nodePtrInit)
	Set the current node pointer for this accessor.
void	reset ()
	Reset the node pointer to NULL.
PBuffer	getBuffer ()
	Returns: buffer to the payload in this node
PBuffer	getNext ()
	Returns: the next node
PBuffer	getNextLocation ()
	Returns: the location which stores the next node pointer
void	setNext (PBuffer nextNode)
	Set the next node pointer for node associated with this accessor.
void	setNext (PBuffer inputNode, PBuffer nextNode)
	Set the next node pointer for an input node.
uint	getNextFieldSize ()
	Returns: number of bytes required to store the next node pointer
uint	getBufferOffset ()
	Returns: offset to the .
Private Attributes
uint	nextNodeOffset
uint	nodeBufferOffset
PBuffer	nodePtr

---

Detailed Description

Class implementing the hash table used in Hybrid Hash Join.

The hash table class also has the ability to aggregate in place.

Author:

Rushan Chen

Version:

Id

//open/dev/fennel/hashexe/LhxHashTable.h#4

Definition at line 55 of file LhxHashTable.h.

---

Constructor & Destructor Documentation

LhxHashNodeAccessor::LhxHashNodeAccessor

(

)

[inline]

Definition at line 1039 of file LhxHashTable.h.

References getNextFieldSize(), nextNodeOffset, and nodeBufferOffset.

{
    nextNodeOffset = 0;
    nodeBufferOffset = nextNodeOffset + getNextFieldSize();
}

LhxHashNodeAccessor::LhxHashNodeAccessor

(

uint

nextNodeOffsetInit

)

[inline]

Constructor for derived classes with fields before the next node pointer.

The idea is to store the variable length payload at the end.

Parameters:

[in]

nextNodeOffsetInit

offset to store the next node pointer.

Definition at line 1045 of file LhxHashTable.h.

References getNextFieldSize(), nextNodeOffset, and nodeBufferOffset.

{
    nextNodeOffset = nextNodeOffsetInit;
    nodeBufferOffset = nextNodeOffset + getNextFieldSize();
}

---

Member Function Documentation

PBuffer LhxHashNodeAccessor::getCurrent

(

)

[inline]

Returns:

current node associated with this accessor

Definition at line 1051 of file LhxHashTable.h.

References nodePtr.

Referenced by LhxHashKeyAccessor::getFirstData(), LhxHashKeyAccessor::getNextSlot(), LhxHashBlockAccessor::getSlot(), LhxHashKeyAccessor::isMatched(), LhxHashKeyAccessor::setFirstData(), LhxHashKeyAccessor::setMatched(), and LhxHashKeyAccessor::setNextSlot().

{
    return nodePtr;
}

void LhxHashNodeAccessor::setCurrent

(

PBuffer

nodePtrInit

)

[inline]

Set the current node pointer for this accessor.

Parameters:

[in]

nodePtrInit

pointer to node that will be associated with this accessor

Definition at line 1061 of file LhxHashTable.h.

References nodePtr.

Referenced by reset(), LhxHashKeyAccessor::setCurrent(), LhxHashDataAccessor::setCurrent(), and LhxHashBlockAccessor::setCurrent().

{
    nodePtr = nodePtrInit;
}

void LhxHashNodeAccessor::reset

(

)

[inline]

Reset the node pointer to NULL.

Reimplemented in LhxHashBlockAccessor.

Definition at line 1066 of file LhxHashTable.h.

References setCurrent().

Referenced by LhxHashTable::releaseResources(), and LhxHashBlockAccessor::reset().

{
    setCurrent(NULL);
}

PBuffer LhxHashNodeAccessor::getBuffer

(

)

[inline]

Returns:

buffer to the payload in this node

Definition at line 1056 of file LhxHashTable.h.

References nodeBufferOffset, and nodePtr.

Referenced by LhxHashBlockAccessor::getSlot(), LhxHashDataAccessor::pack(), LhxHashKeyAccessor::pack(), LhxHashKeyAccessor::setCurrent(), LhxHashDataAccessor::setCurrent(), LhxHashBlockAccessor::setCurrent(), LhxHashKeyAccessor::unpack(), and LhxHashDataAccessor::unpack().

{
    return (nodePtr + nodeBufferOffset);
}

PBuffer LhxHashNodeAccessor::getNext

(

)

[inline]

Returns:

the next node

Definition at line 1071 of file LhxHashTable.h.

References nextNodeOffset, and nodePtr.

Referenced by LhxHashTableReader::advanceData(), LhxHashTableReader::advanceKey(), LhxHashTableReader::advanceSlot(), LhxHashTable::aggData(), LhxHashTable::allocateResources(), LhxHashTable::allocBuffer(), LhxHashTable::findKeyLocation(), and LhxHashTable::printSlot().

{
    // REVIEW jvs 25-Aug-2006:  Under what circumstances would
    // alignment be off?  Tuple sizes are always aligned.  Is it
    // because of the match indicator?  If so, it might make sense to
    // fold that into the tuple.
    /*
     * nodePtr+nextNodeOffset might not be aligned so copy the pointer
     * value out.
     */
    PBuffer returnPtr;
    memcpy((PBuffer)&returnPtr, nodePtr+nextNodeOffset, sizeof(PBuffer));
    return returnPtr;
}

PBuffer LhxHashNodeAccessor::getNextLocation

(

)

[inline]

Returns:

the location which stores the next node pointer

Definition at line 1086 of file LhxHashTable.h.

References nextNodeOffset, and nodePtr.

Referenced by LhxHashTable::findKeyLocation().

{
    return nodePtr + nextNodeOffset;
}

void LhxHashNodeAccessor::setNext

(

PBuffer

nextNode

)

[inline]

Set the next node pointer for node associated with this accessor.

Parameters:

[in]

nextNode

pointer to the next node

Definition at line 1091 of file LhxHashTable.h.

References getNextFieldSize(), nextNodeOffset, and nodePtr.

Referenced by LhxHashKeyAccessor::addData(), LhxHashTable::addKeyData(), LhxHashTable::aggData(), LhxHashTable::allocateResources(), LhxHashTable::allocBlock(), and LhxHashTable::allocBuffer().

{
    memcpy(nodePtr+nextNodeOffset, (PBuffer)&nextNode, getNextFieldSize());
}

void LhxHashNodeAccessor::setNext	(	PBuffer	inputNode,
		PBuffer	nextNode
	)			[inline]

Set the next node pointer for an input node.

Parameters:

[in]	inputNode	input node to set the next node pointer
[in]	nextNode	pointer to the next node

Definition at line 1096 of file LhxHashTable.h.

References getNextFieldSize(), and nextNodeOffset.

{
    memcpy(inputNode+nextNodeOffset, (PBuffer)&nextNode, getNextFieldSize());
}

uint LhxHashNodeAccessor::getNextFieldSize

(

)

[inline]

Returns:

number of bytes required to store the next node pointer

Definition at line 1101 of file LhxHashTable.h.

Referenced by LhxHashNodeAccessor(), and setNext().

{
    return sizeof(PBuffer);
}

uint LhxHashNodeAccessor::getBufferOffset

(

)

[inline]

Returns:

offset to the .

This is equivalent to the total space used for the variable length payload.

Definition at line 1106 of file LhxHashTable.h.

References nodeBufferOffset.

Referenced by LhxHashKeyAccessor::getAvgStorageSize(), LhxHashDataAccessor::getAvgStorageSize(), LhxHashKeyAccessor::getStorageSize(), LhxHashDataAccessor::getStorageSize(), and LhxHashBlockAccessor::init().

{
    return nodeBufferOffset;
}

---

Member Data Documentation

uint LhxHashNodeAccessor::nextNodeOffset [private]

Definition at line 62 of file LhxHashTable.h.

Referenced by getNext(), getNextLocation(), LhxHashNodeAccessor(), and setNext().

uint LhxHashNodeAccessor::nodeBufferOffset [private]

Definition at line 67 of file LhxHashTable.h.

Referenced by getBuffer(), getBufferOffset(), and LhxHashNodeAccessor().

PBuffer LhxHashNodeAccessor::nodePtr [private]

Definition at line 72 of file LhxHashTable.h.

Referenced by getBuffer(), getCurrent(), getNext(), getNextLocation(), setCurrent(), and setNext().

---

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

• /home/pub/open/dev/fennel/hashexe/LhxHashTable.h

---