LhxPartitionWriter Class Reference

#include <LhxPartition.h>

List of all members.

Public Member Functions
void	open (SharedLhxPartition destPartitionInit, LhxHashInfo const &hashInfo)
void	open (SharedLhxPartition destPartitionInit, LhxHashInfo &hashInfo, AggComputerList *aggList, uint numWriterCachePages)
void	allocateResources ()
void	releaseResources ()
void	marshalTuple (TupleData const &inputTuple)
void	aggAndMarshalTuple (TupleData const &inputTuple)
void	close ()
Private Attributes
SharedLhxPartition	destPartition
	Partition to write to.
SharedSegOutputStream	pSegOutputStream
	Stream used for writing to a partition.
TupleAccessor	tupleAccessor
	Tuple accessor to marshal the tuple from join inputs.
bool	isAggregate
LhxHashTable	hashTable
	Each writer has a local hash table (which shares the scratch page quota with other writers) to compute partial aggregates before flushing them to disk.
LhxHashTableReader	hashTableReader
TupleData	partialAggTuple

---

Detailed Description

Definition at line 77 of file LhxPartition.h.

---

Member Function Documentation

void LhxPartitionWriter::open	(	SharedLhxPartition	destPartitionInit,
		LhxHashInfo const &	hashInfo
	)

Definition at line 30 of file LhxPartition.cpp.

References TupleAccessor::compute(), destPartition, LhxHashInfo::externalSegmentAccessor, LhxHashInfo::inputDesc, isAggregate, SegOutputStream::newSegOutputStream(), SegStreamAllocation::newSegStreamAllocation(), pSegOutputStream, and tupleAccessor.

Referenced by LhxPlan::createChildren(), and LhxHashTableTest::writeHashTable().

{
    destPartition = destPartitionInit;

    tupleAccessor.compute(hashInfo.inputDesc[destPartition->inputIndex]);

    pSegOutputStream = SegOutputStream::newSegOutputStream(
        hashInfo.externalSegmentAccessor);
    destPartition->segStream =
        SegStreamAllocation::newSegStreamAllocation();
    destPartition->segStream->beginWrite(pSegOutputStream);

    isAggregate = false;
}

void LhxPartitionWriter::open	(	SharedLhxPartition	destPartitionInit,
		LhxHashInfo &	hashInfo,
		AggComputerList *	aggList,
		uint	numWriterCachePages
	)

Definition at line 47 of file LhxPartition.cpp.

References LhxHashTable::calculateNumSlots(), LhxHashInfo::cndKeys, TupleData::compute(), TupleAccessor::compute(), destPartition, LhxHashInfo::externalSegmentAccessor, hashTable, hashTableReader, LhxHashTableReader::init(), LhxHashTable::init(), LhxHashInfo::inputDesc, isAggregate, LhxHashInfo::memSegmentAccessor, SegOutputStream::newSegOutputStream(), SegStreamAllocation::newSegStreamAllocation(), LhxHashInfo::numCachePages, partialAggTuple, SegmentAccessor::pSegment, pSegOutputStream, and tupleAccessor.

{
    destPartition = destPartitionInit;
    tupleAccessor.compute(hashInfo.inputDesc[destPartition->inputIndex]);

    pSegOutputStream = SegOutputStream::newSegOutputStream(
        hashInfo.externalSegmentAccessor);
    destPartition->segStream =
        SegStreamAllocation::newSegStreamAllocation();
    destPartition->segStream->beginWrite(pSegOutputStream);

    isAggregate = true;
    /*
     * Any partition level is fine since the data is hash partitioned already.
     */
    uint partitionLevel = 0;
    uint savedNumCachePages = hashInfo.numCachePages;
    hashInfo.numCachePages = numWriterCachePages;

    hashTable.init(
        partitionLevel,
        hashInfo,
        aggList,
        destPartition->inputIndex);
    hashTableReader.init(&hashTable, hashInfo, destPartition->inputIndex);

    hashInfo.numCachePages = savedNumCachePages;

    uint cndKeys = hashInfo.cndKeys.back();
    uint usablePageSize =
        (hashInfo.memSegmentAccessor.pSegment)->getUsablePageSize();

    hashTable.calculateNumSlots(cndKeys, usablePageSize, numWriterCachePages);

    partialAggTuple.compute(hashInfo.inputDesc[destPartition->inputIndex]);
}

void LhxPartitionWriter::allocateResources

(

)

[inline]

Definition at line 484 of file LhxPartition.h.

References LhxHashTable::allocateResources(), and hashTable.

{
    bool status = hashTable.allocateResources();
    assert(status);
}

void LhxPartitionWriter::releaseResources

(

)

[inline]

Definition at line 490 of file LhxPartition.h.

References hashTable, and LhxHashTable::releaseResources().

{
    hashTable.releaseResources();
}

void LhxPartitionWriter::marshalTuple

(

TupleData const &

inputTuple

)

Definition at line 107 of file LhxPartition.cpp.

References TupleAccessor::getByteCount(), TupleAccessor::marshal(), pSegOutputStream, and tupleAccessor.

Referenced by LhxPlan::createChildren(), and LhxHashTableTest::writeHashTable().

{
    uint tupleStorageLength = tupleAccessor.getByteCount(inputTuple);
    PBuffer pDestBuf = pSegOutputStream->getWritePointer(tupleStorageLength);
    tupleAccessor.marshal(inputTuple, pDestBuf);
    pSegOutputStream->consumeWritePointer(tupleStorageLength);
}

void LhxPartitionWriter::aggAndMarshalTuple

(

TupleData const &

inputTuple

)

Definition at line 115 of file LhxPartition.cpp.

References LhxHashTable::addTuple(), LhxHashTable::allocateResources(), LhxHashTableReader::bindKey(), TupleAccessor::getByteCount(), LhxHashTableReader::getNext(), hashTable, hashTableReader, TupleAccessor::marshal(), partialAggTuple, pSegOutputStream, and tupleAccessor.

{
    while (!hashTable.addTuple(inputTuple)) {
        /*
         * Write everything out to partition.
         */
        while (hashTableReader.getNext(partialAggTuple)) {
            uint tupleStorageLength =
                tupleAccessor.getByteCount(partialAggTuple);
            PBuffer pDestBuf =
                pSegOutputStream->getWritePointer(tupleStorageLength);
            tupleAccessor.marshal(partialAggTuple, pDestBuf);
            pSegOutputStream->consumeWritePointer(tupleStorageLength);
        }
        bool reuse = true;
        /*
         * hash table size remain unchanged
         */
        bool status = hashTable.allocateResources(reuse);
        assert(status);
        /*
         * Reset the reader and bind it to no particular key (will read the
         * whole hash table).
         */
        hashTableReader.bindKey(NULL);
    }
}

void LhxPartitionWriter::close

(

)

Definition at line 88 of file LhxPartition.cpp.

References destPartition, TupleAccessor::getByteCount(), LhxHashTableReader::getNext(), hashTableReader, isAggregate, TupleAccessor::marshal(), partialAggTuple, pSegOutputStream, and tupleAccessor.

Referenced by LhxHashTableTest::writeHashTable().

{
    if (isAggregate) {
        /*
         * Write out the remaining partial aggregates in the local hash table.
         */
        while (hashTableReader.getNext(partialAggTuple)) {
            uint tupleStorageLength =
                tupleAccessor.getByteCount(partialAggTuple);
            PBuffer pDestBuf =
                pSegOutputStream->getWritePointer(tupleStorageLength);
            tupleAccessor.marshal(partialAggTuple, pDestBuf);
            pSegOutputStream->consumeWritePointer(tupleStorageLength);
        }
    }
    destPartition->segStream->endWrite();
    pSegOutputStream->close();
}

---

Member Data Documentation

SharedLhxPartition LhxPartitionWriter::destPartition [private]

Partition to write to.

Definition at line 82 of file LhxPartition.h.

Referenced by close(), and open().

SharedSegOutputStream LhxPartitionWriter::pSegOutputStream [private]

Stream used for writing to a partition.

Definition at line 87 of file LhxPartition.h.

Referenced by aggAndMarshalTuple(), close(), marshalTuple(), and open().

TupleAccessor LhxPartitionWriter::tupleAccessor [private]

Tuple accessor to marshal the tuple from join inputs.

Definition at line 92 of file LhxPartition.h.

Referenced by aggAndMarshalTuple(), close(), marshalTuple(), and open().

bool LhxPartitionWriter::isAggregate [private]

Definition at line 94 of file LhxPartition.h.

Referenced by close(), and open().

LhxHashTable LhxPartitionWriter::hashTable [private]

Each writer has a local hash table (which shares the scratch page quota with other writers) to compute partial aggregates before flushing them to disk.

Definition at line 101 of file LhxPartition.h.

Referenced by aggAndMarshalTuple(), allocateResources(), open(), and releaseResources().

LhxHashTableReader LhxPartitionWriter::hashTableReader [private]

Definition at line 102 of file LhxPartition.h.

Referenced by aggAndMarshalTuple(), close(), and open().

TupleData LhxPartitionWriter::partialAggTuple [private]

Definition at line 103 of file LhxPartition.h.

Referenced by aggAndMarshalTuple(), close(), and open().

---

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

• /home/pub/open/dev/fennel/hashexe/LhxPartition.h
• /home/pub/open/dev/fennel/hashexe/LhxPartition.cpp

---