BTreeSearchUniqueExecStream.cpp

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/*
// $Id: //open/dev/fennel/ftrs/BTreeSearchUniqueExecStream.cpp#10 $
// Fennel is a library of data storage and processing components.
// Copyright (C) 2005-2009 The Eigenbase Project
// Copyright (C) 2005-2009 SQLstream, Inc.
// Copyright (C) 2005-2009 LucidEra, Inc.
// Portions Copyright (C) 2004-2009 John V. Sichi
//
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation; either version 2 of the License, or (at your option)
// any later version approved by The Eigenbase Project.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "fennel/common/CommonPreamble.h"
#include "fennel/ftrs/BTreeSearchUniqueExecStream.h"
#include "fennel/btree/BTreeReader.h"
#include "fennel/exec/ExecStreamBufAccessor.h"

FENNEL_BEGIN_CPPFILE("$Id: //open/dev/fennel/ftrs/BTreeSearchUniqueExecStream.cpp#10 $");

void BTreeSearchUniqueExecStream::prepare(
    BTreeSearchExecStreamParams const &params)
{
    // We don't allow directives for unique searches:  every input key
    // must be interpreted as a point search.
    assert(params.inputDirectiveProj.size() == 0);

    BTreeSearchExecStream::prepare(params);
}

ExecStreamResult BTreeSearchUniqueExecStream::execute(
    ExecStreamQuantum const &quantum)
{
    ExecStreamResult rc = precheckConduitBuffers();
    if (rc != EXECRC_YIELD) {
        return rc;
    }

    uint nTuples = 0;
    assert(quantum.nTuplesMax > 0);

    // outer loop
    for (;;) {
        if (!innerSearchLoop()) {
            return EXECRC_BUF_UNDERFLOW;
        }

        if (nTuples >= quantum.nTuplesMax) {
            return EXECRC_QUANTUM_EXPIRED;
        }

        if (pOutAccessor->produceTuple(tupleData)) {
            ++nTuples;
        } else {
            return EXECRC_BUF_OVERFLOW;
        }

        pReader->endSearch();
        pInAccessor->consumeTuple();
    }
}

FENNEL_END_CPPFILE("$Id: //open/dev/fennel/ftrs/BTreeSearchUniqueExecStream.cpp#10 $");

// End BTreeSearchUniqueExecStream.cpp

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