185 lines
4.7 KiB
C++
185 lines
4.7 KiB
C++
/*
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----
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This file is part of SECONDO.
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Copyright (C) 2019, University in Hagen, Department of Computer Science,
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Database Systems for New Applications.
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SECONDO is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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SECONDO is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with SECONDO; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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----
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//paragraph [10] title: [{\Large \bf ] [}]
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//paragraph [21] table1column: [\begin{quote}\begin{tabular}{l}] [\end{tabular}\end{quote}]
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//paragraph [22] table2columns: [\begin{quote}\begin{tabular}{ll}] [\end{tabular}\end{quote}]
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//paragraph [23] table3columns: [\begin{quote}\begin{tabular}{lll}] [\end{tabular}\end{quote}]
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//paragraph [24] table4columns: [\begin{quote}\begin{tabular}{llll}] [\end{tabular}\end{quote}]
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//[--------] [\hline]
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//characters [1] verbatim: [$] [$]
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//characters [2] formula: [$] [$]
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//characters [3] capital: [\textsc{] [}]
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//characters [4] teletype: [\texttt{] [}]
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//[ae] [\"a]
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//[oe] [\"o]
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//[ue] [\"u]
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//[ss] [{\ss}]
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//[<=] [\leq]
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//[#] [\neq]
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//[tilde] [\verb|~|]
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//[Contents] [\tableofcontents]
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1 Header File: ConcurrentTupleBufferWriter
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September 2019, Fischer Thomas
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1.1 Overview
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The ~ConcurrentTupleBufferWriter~ is an interface for the ~ConcurrentTupleBuffer~
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to write tuples into tuple blocks.
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1.2 Imports
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*/
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#ifndef SECONDO_PARTHREAD_CONCURRENT_TUPLE_BUFFER_WRITER_H
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#define SECONDO_PARTHREAD_CONCURRENT_TUPLE_BUFFER_WRITER_H
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#include "ConcurrentTupleBuffer.h"
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namespace parthread
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{
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class ConcurrentTupleBufferWriter
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{
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public:
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/*
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1.3 Initalization and destruction
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*/
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ConcurrentTupleBufferWriter(ConcurrentTupleBuffer *buffer,
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DataPartitioner *partitioner)
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: m_buffer(buffer), m_tupleBlockVector(buffer->m_numPartitions),
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m_partitioner(partitioner->Copy()), m_numWrittenTuples(0),
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m_hasMemoryAllocated(false)
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{
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}
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virtual ~ConcurrentTupleBufferWriter()
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{
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if (m_buffer != NULL)
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{
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Flush();
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m_buffer->RemoveWriter(this);
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m_buffer = NULL;
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}
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if (m_partitioner != NULL)
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{
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delete m_partitioner;
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m_partitioner = NULL;
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}
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};
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/*
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The constructor connects a new ~ConcurrentTupleBufferWriter~ to the
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~TupleBuffer~. Additionally a copy of the partitioner needs to be passed to the
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constructor. The disconnection from the buffer and the deletion of the partitioner
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occurs on destruction of the writer.
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1.4 Methods
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*/
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bool Allocate()
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{
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if (!m_hasMemoryAllocated)
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{
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m_hasMemoryAllocated = m_buffer->AllocateTupleBlocks(m_tupleBlockVector);
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}
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return m_hasMemoryAllocated;
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}
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/*
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Allocates memory from the buffer to store new tuples in the internal tuple blocks.
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The method returns ~false~ if there is already memory allocated or it's not possible
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for to get an empty vector of tuple blocks from the buffer.
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*/
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bool HasFreeMemory()
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{
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return m_tupleBlockVector.FreeMemorySize() > 0;
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}
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/*
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Returns ~true~ if theres is memory left to store additional buffers, otherwise ~false~.
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*/
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virtual void WriteTuple(Tuple *tuple)
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{
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assert(m_hasMemoryAllocated);
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size_t partitionIdx = m_partitioner->DistributeValue(tuple);
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m_tupleBlockVector.AddTupleToPartition(tuple, partitionIdx);
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m_numWrittenTuples++;
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}
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/*
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Write a single tuple to the vector of tuple blocks. The internal ~DataPartitioner~
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is responsible to choose the tuple block. The writer must allocate a new tuple
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vector before using this method.
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*/
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void Flush()
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{
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if (m_hasMemoryAllocated)
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{
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m_buffer->ProvideTupleBlocks(m_tupleBlockVector);
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}
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m_hasMemoryAllocated = false;
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}
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/*
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Returns the tuple block back to the tuple buffer.
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*/
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size_t NumWrittenTuples()
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{
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return m_numWrittenTuples;
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}
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/*
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Counts all tuples processed by this writer independent of the number of allocated
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blocks or used tasks. For debug pruposes.
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*/
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private: //methods
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private: //member
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ConcurrentTupleBuffer *m_buffer;
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TupleBlockVector m_tupleBlockVector;
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DataPartitioner *m_partitioner;
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size_t m_numWrittenTuples;
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bool m_hasMemoryAllocated;
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};
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} // namespace parthread
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#endif //SECONDO_PARTHREAD_CONCURRENT_TUPLE_BUFFER_WRITER_H
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