LhxPartitionReader Class Reference

#include <LhxPartition.h>

List of all members.

Public Member Functions
void	open (SharedLhxPartition srcPartition, LhxHashInfo const &hashInfo)
bool	isTupleConsumptionPending ()
bool	demandData ()
void	unmarshalTuple (TupleData &outputTuple)
void	consumeTuple ()
void	close ()
ExecStreamBufState	getState () const
TupleDescriptor const &	getTupleDesc () const
SharedLhxPartition	getSourcePartition () const
Private Attributes
SharedLhxPartition	srcPartition
	Partition to read from.
SharedSegInputStream	pSegInputStream
	Helper used for reading a partition.
TupleAccessor	tupleAccessor
	Tuple accessor to unmarshal the disk content to the outputTuple.
uint	tupleStorageLength
	Storage Length of last tuple read from the underlying partition.
bool	srcIsInputStream
ExecStreamBufState	bufState
TupleDescriptor	outputTupleDesc
SharedExecStreamBufAccessor	streamBufAccessor
	If reader is on a partition which comes from the input exec stream, (this is when this accessor is opened on a partition without valid segStream), use an exec stream buf accessor to read tuples.

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Detailed Description

Definition at line 123 of file LhxPartition.h.

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Member Function Documentation

void LhxPartitionReader::open	(	SharedLhxPartition	srcPartition,
		LhxHashInfo const &	hashInfo
	)

Definition at line 143 of file LhxPartition.cpp.

References bufState, TupleAccessor::compute(), EXECBUF_NONEMPTY, LhxHashInfo::inputDesc, outputTupleDesc, pSegInputStream, TupleAccessor::resetCurrentTupleBuf(), srcIsInputStream, srcPartition, LhxHashInfo::streamBufAccessor, streamBufAccessor, and tupleAccessor.

Referenced by LhxPlan::createChildren(), LhxJoinExecStream::execute(), LhxAggExecStream::execute(), LhxPartitionInfo::open(), LhxJoinExecStream::open(), LhxAggExecStream::open(), and LhxHashTableTest::readPartition().

{
    bufState = EXECBUF_NONEMPTY;
    srcPartition = srcPartitionInit;

    if (!srcPartition->segStream) {
        /*
         * source has never been written to, which means the source
         * is not from the disk but from input stream.
         */
        srcIsInputStream = true;
    } else {
        srcIsInputStream = false;
    }

    if (srcIsInputStream) {
        streamBufAccessor =
            hashInfo.streamBufAccessor[srcPartition->inputIndex];
        outputTupleDesc = streamBufAccessor->getTupleDesc();
    } else {
        outputTupleDesc = hashInfo.inputDesc[srcPartition->inputIndex];
        tupleAccessor.compute(outputTupleDesc);
        tupleAccessor.resetCurrentTupleBuf();

        /*
         * Since reader now gets input stream from the partition,
         * this inputStream will delete content that is read.
         * This also means each partition can only be read once.
         */
        pSegInputStream = srcPartition->segStream->getInputStream();
        pSegInputStream->startPrefetch();
    }
}

bool LhxPartitionReader::isTupleConsumptionPending

(

)

Definition at line 212 of file LhxPartition.cpp.

References TupleAccessor::getCurrentTupleBuf(), srcIsInputStream, streamBufAccessor, and tupleAccessor.

Referenced by LhxPlan::createChildren(), LhxJoinExecStream::execute(), LhxAggExecStream::execute(), LhxPlan::generatePartitions(), and LhxHashTableTest::readPartition().

{
    if (srcIsInputStream) {
        return streamBufAccessor->isTupleConsumptionPending();
    } else {
        if (tupleAccessor.getCurrentTupleBuf()) {
            return true;
        } else {
            return false;
        }
    }
}

bool LhxPartitionReader::demandData

(

)

Definition at line 225 of file LhxPartition.cpp.

References bufState, EXECBUF_EOS, TupleAccessor::getBufferByteCount(), pSegInputStream, TupleAccessor::setCurrentTupleBuf(), srcIsInputStream, srcPartition, streamBufAccessor, tupleAccessor, and tupleStorageLength.

Referenced by LhxPlan::createChildren(), LhxJoinExecStream::execute(), LhxAggExecStream::execute(), LhxPlan::generatePartitions(), and LhxHashTableTest::readPartition().

{
    if (srcIsInputStream) {
        return streamBufAccessor->demandData();
    } else {
        /*
         * Read from disk.
         */
        uint bytesReadable = 0;
        PConstBuffer pSrcBuf =
            pSegInputStream->getReadPointer(1, &bytesReadable);

        /*
         * If readable data does not fill a tuple, it means the segment stream
         * has reached EOD.
         */
        if (!pSrcBuf) {
            bufState = EXECBUF_EOS;
            return false;
        } else {
            tupleStorageLength = tupleAccessor.getBufferByteCount(pSrcBuf);
            assert(bytesReadable >= tupleStorageLength);
            if (bytesReadable == tupleStorageLength) {
                // We're processing the last tuple in a buffer,
                // so now is a good time to check for abort.
                if (srcPartition->pExecStream) {
                    srcPartition->pExecStream->checkAbort();
                }
            }
            tupleAccessor.setCurrentTupleBuf(pSrcBuf);
            return true;
        }
    }
}

void LhxPartitionReader::unmarshalTuple

(

TupleData &

outputTuple

)

Definition at line 190 of file LhxPartition.cpp.

References srcIsInputStream, streamBufAccessor, tupleAccessor, and TupleAccessor::unmarshal().

Referenced by LhxPlan::createChildren(), LhxJoinExecStream::execute(), LhxAggExecStream::execute(), LhxPlan::generatePartitions(), and LhxHashTableTest::readPartition().

{
    if (srcIsInputStream) {
        /*
         * Read from stream.
         */
        streamBufAccessor->unmarshalTuple(outputTuple);
    } else {
        tupleAccessor.unmarshal(outputTuple);
    }
}

void LhxPartitionReader::consumeTuple

(

)

Definition at line 202 of file LhxPartition.cpp.

References pSegInputStream, TupleAccessor::resetCurrentTupleBuf(), srcIsInputStream, streamBufAccessor, tupleAccessor, and tupleStorageLength.

Referenced by LhxPlan::createChildren(), LhxJoinExecStream::execute(), LhxAggExecStream::execute(), LhxPlan::generatePartitions(), and LhxHashTableTest::readPartition().

{
    if (srcIsInputStream) {
        streamBufAccessor->consumeTuple();
    } else {
        tupleAccessor.resetCurrentTupleBuf();
        pSegInputStream->consumeReadPointer(tupleStorageLength);
    }
}

void LhxPartitionReader::close

(

)

Definition at line 179 of file LhxPartition.cpp.

References pSegInputStream, and srcIsInputStream.

Referenced by LhxPartitionInfo::close(), LhxPlan::createChildren(), LhxJoinExecStream::execute(), LhxAggExecStream::execute(), LhxPlan::generatePartitions(), and LhxHashTableTest::readPartition().

{
    if (srcIsInputStream) {
        /*
         * Do nothing if reading from stream.
         */
    } else {
        pSegInputStream->close();
    }
}

ExecStreamBufState LhxPartitionReader::getState

(

)

const [inline]

Definition at line 465 of file LhxPartition.h.

References bufState, srcIsInputStream, and streamBufAccessor.

Referenced by LhxPlan::createChildren(), LhxJoinExecStream::execute(), LhxAggExecStream::execute(), LhxPlan::generatePartitions(), and LhxHashTableTest::readPartition().

{
    if (srcIsInputStream) {
        return streamBufAccessor->getState();
    } else {
        return bufState;
    }
}

TupleDescriptor const & LhxPartitionReader::getTupleDesc

(

)

const [inline]

Definition at line 479 of file LhxPartition.h.

References outputTupleDesc.

Referenced by LhxAggExecStream::execute(), and LhxPlan::generatePartitions().

{
    return outputTupleDesc;
}

SharedLhxPartition LhxPartitionReader::getSourcePartition

(

)

const [inline]

Definition at line 474 of file LhxPartition.h.

References srcPartition.

Referenced by LhxPartitionInfo::open().

{
    return srcPartition;
}

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Member Data Documentation

SharedLhxPartition LhxPartitionReader::srcPartition [private]

Partition to read from.

Definition at line 128 of file LhxPartition.h.

Referenced by demandData(), getSourcePartition(), and open().

SharedSegInputStream LhxPartitionReader::pSegInputStream [private]

Helper used for reading a partition.

Definition at line 133 of file LhxPartition.h.

Referenced by close(), consumeTuple(), demandData(), and open().

TupleAccessor LhxPartitionReader::tupleAccessor [private]

Tuple accessor to unmarshal the disk content to the outputTuple.

Definition at line 138 of file LhxPartition.h.

Referenced by consumeTuple(), demandData(), isTupleConsumptionPending(), open(), and unmarshalTuple().

uint LhxPartitionReader::tupleStorageLength [private]

Storage Length of last tuple read from the underlying partition.

Definition at line 143 of file LhxPartition.h.

Referenced by consumeTuple(), and demandData().

bool LhxPartitionReader::srcIsInputStream [private]

Definition at line 145 of file LhxPartition.h.

Referenced by close(), consumeTuple(), demandData(), getState(), isTupleConsumptionPending(), open(), and unmarshalTuple().

ExecStreamBufState LhxPartitionReader::bufState [private]

Definition at line 146 of file LhxPartition.h.

Referenced by demandData(), getState(), and open().

TupleDescriptor LhxPartitionReader::outputTupleDesc [private]

Definition at line 147 of file LhxPartition.h.

Referenced by getTupleDesc(), and open().

SharedExecStreamBufAccessor LhxPartitionReader::streamBufAccessor [private]

If reader is on a partition which comes from the input exec stream, (this is when this accessor is opened on a partition without valid segStream), use an exec stream buf accessor to read tuples.

Definition at line 154 of file LhxPartition.h.

Referenced by consumeTuple(), demandData(), getState(), isTupleConsumptionPending(), open(), and unmarshalTuple().

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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

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