BTreeReadExecStream.cpp

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00001 /*
00002 // $Id: //open/dev/fennel/ftrs/BTreeReadExecStream.cpp#10 $
00003 // Fennel is a library of data storage and processing components.
00004 // Copyright (C) 2005-2009 The Eigenbase Project
00005 // Copyright (C) 2005-2009 SQLstream, Inc.
00006 // Copyright (C) 2005-2009 LucidEra, Inc.
00007 // Portions Copyright (C) 2004-2009 John V. Sichi
00008 //
00009 // This program is free software; you can redistribute it and/or modify it
00010 // under the terms of the GNU General Public License as published by the Free
00011 // Software Foundation; either version 2 of the License, or (at your option)
00012 // any later version approved by The Eigenbase Project.
00013 //
00014 // This program is distributed in the hope that it will be useful,
00015 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00016 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00017 // GNU General Public License for more details.
00018 //
00019 // You should have received a copy of the GNU General Public License
00020 // along with this program; if not, write to the Free Software
00021 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
00022 */
00023 
00024 #include "fennel/common/CommonPreamble.h"
00025 #include "fennel/ftrs/BTreeReadExecStream.h"
00026 #include "fennel/btree/BTreeReader.h"
00027 #include "fennel/exec/ExecStreamBufAccessor.h"
00028 
00029 FENNEL_BEGIN_CPPFILE("$Id: //open/dev/fennel/ftrs/BTreeReadExecStream.cpp#10 $");
00030 
00031 void BTreeReadExecStream::prepare(BTreeReadExecStreamParams const &params)
00032 {
00033     BTreeExecStream::prepare(params);
00034     outputProj.assign(params.outputProj.begin(), params.outputProj.end());
00035     tupleData.compute(params.outputTupleDesc);
00036 }
00037 
00038 void BTreeReadExecStream::getResourceRequirements(
00039     ExecStreamResourceQuantity &minQuantity,
00040     ExecStreamResourceQuantity &optQuantity)
00041 {
00042     BTreeExecStream::getResourceRequirements(minQuantity,optQuantity);
00043 
00044     // one page for BTreeReader
00045     minQuantity.nCachePages += 1;
00046 
00047     // TODO:  use opt to govern prefetch and come up with a good formula
00048     optQuantity = minQuantity;
00049 }
00050 
00051 void BTreeReadExecStream::open(bool restart)
00052 {
00053     BTreeExecStream::open(restart);
00054 
00055     if (restart) {
00056         return;
00057     }
00058 
00059     // Create the reader here rather than during prepare, in case the btree
00060     // was dynamically created during stream graph open
00061     pReader = newReader();
00062     projAccessor.bind(
00063         pReader->getTupleAccessorForRead(),
00064         outputProj);
00065 }
00066 
00067 // TODO: When not projecting anything away, we could do producer buffer
00068 // provision instead.  For BTreeCompactNodeAccessor, we can return multiple
00069 // tuples directly by referencing the node data.  For other node accessor
00070 // implementations, we can return single tuples by reference (although that's
00071 // not always a win).
00072 
00073 void BTreeReadExecStream::closeImpl()
00074 {
00075     BTreeExecStream::closeImpl();
00076 }
00077 
00078 FENNEL_END_CPPFILE("$Id: //open/dev/fennel/ftrs/BTreeReadExecStream.cpp#10 $");
00079 
00080 // End BTreeReadExecStream.cpp

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