00001 /* 00002 // $Id: //open/dev/fennel/exec/BernoulliSamplingExecStream.h#4 $ 00003 // Fennel is a library of data storage and processing components. 00004 // Copyright (C) 2007-2009 The Eigenbase Project 00005 // Copyright (C) 2007-2009 SQLstream, Inc. 00006 // Copyright (C) 2007-2009 LucidEra, Inc. 00007 // 00008 // This program is free software; you can redistribute it and/or modify it 00009 // under the terms of the GNU General Public License as published by the Free 00010 // Software Foundation; either version 2 of the License, or (at your option) 00011 // any later version approved by The Eigenbase Project. 00012 // 00013 // This program is distributed in the hope that it will be useful, 00014 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00016 // GNU General Public License for more details. 00017 // 00018 // You should have received a copy of the GNU General Public License 00019 // along with this program; if not, write to the Free Software 00020 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00021 */ 00022 00023 #ifndef Fennel_BernoulliSamplingExecStream_Included 00024 #define Fennel_BernoulliSamplingExecStream_Included 00025 00026 #include <boost/scoped_ptr.hpp> 00027 #include "fennel/exec/ConduitExecStream.h" 00028 #include "fennel/common/BernoulliRng.h" 00029 #include "fennel/tuple/TupleData.h" 00030 00031 FENNEL_BEGIN_NAMESPACE 00032 00037 struct FENNEL_EXEC_EXPORT BernoulliSamplingExecStreamParams 00038 : public ConduitExecStreamParams 00039 { 00041 float samplingRate; 00042 00044 bool isRepeatable; 00045 00047 int32_t repeatableSeed; 00048 }; 00049 00057 class FENNEL_EXEC_EXPORT BernoulliSamplingExecStream 00058 : public ConduitExecStream 00059 { 00061 float samplingRate; 00062 00064 bool isRepeatable; 00065 00067 int32_t repeatableSeed; 00068 00072 boost::scoped_ptr<BernoulliRng> samplingRng; 00073 00077 bool producePending; 00078 00079 TupleData data; 00080 00081 public: 00082 virtual void prepare(BernoulliSamplingExecStreamParams const ¶ms); 00083 virtual void open(bool restart); 00084 virtual ExecStreamResult execute(ExecStreamQuantum const &quantum); 00085 }; 00086 00087 FENNEL_END_NAMESPACE 00088 00089 #endif 00090 00091 // End BernoulliSamplingExecStream.h