PLearn 0.1
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00001 // -*- C++ -*- 00002 00003 // VMatAccessBuffer.cc 00004 // 00005 // Copyright (C) 2006 Christian Dorion 00006 // 00007 // Redistribution and use in source and binary forms, with or without 00008 // modification, are permitted provided that the following conditions are met: 00009 // 00010 // 1. Redistributions of source code must retain the above copyright 00011 // notice, this list of conditions and the following disclaimer. 00012 // 00013 // 2. Redistributions in binary form must reproduce the above copyright 00014 // notice, this list of conditions and the following disclaimer in the 00015 // documentation and/or other materials provided with the distribution. 00016 // 00017 // 3. The name of the authors may not be used to endorse or promote 00018 // products derived from this software without specific prior written 00019 // permission. 00020 // 00021 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 00022 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 00023 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN 00024 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 00025 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 00026 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 00027 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 00028 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 00029 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00030 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00031 // 00032 // This file is part of the PLearn library. For more information on the PLearn 00033 // library, go to the PLearn Web site at www.plearn.org 00034 00035 // Authors: Christian Dorion 00036 00040 #include "VMatAccessBuffer.h" 00041 00042 namespace PLearn { 00043 using namespace std; 00044 00045 VMatAccessBuffer:: 00046 VMatAccessBuffer(VMat source, int max_size) 00047 : m_source( source ), 00048 m_current_row( -1 ), 00049 m_max_size( max_size ) 00050 { 00051 m_row_buffer.resize(m_source.width()); 00052 } 00053 00054 void 00055 VMatAccessBuffer:: 00056 getRow(int row, const Vec& rowbuf) 00057 { 00058 int last_row = m_current_row + m_cached_rows.size() - 1; 00059 00060 bool much_below = false; 00061 if ( row < m_current_row ) 00062 { 00063 int new_size = last_row - row + 1; 00064 much_below = ( new_size > m_max_size ); 00065 if ( !much_below ) 00066 while ( m_current_row > row ) { 00067 m_source->getRow(--m_current_row, m_row_buffer); 00068 m_cached_rows.push_front(m_row_buffer.copy()); 00069 } 00070 } 00071 00072 if ( much_below || row > last_row ) 00073 { 00074 m_source->getRow(row, m_row_buffer); 00075 00076 m_current_row = row; 00077 m_cached_rows.clear(); 00078 m_cached_rows.push_back(m_row_buffer.copy()); 00079 } 00080 00081 else 00082 { 00083 for ( ; m_current_row < row; ++m_current_row ) 00084 m_cached_rows.pop_front(); 00085 m_row_buffer << m_cached_rows[0]; 00086 } 00087 00088 // Finally 00089 rowbuf << m_row_buffer; 00090 PLASSERT( m_current_row == row ); 00091 PLASSERT( int(m_cached_rows.size()) <= m_max_size ); 00092 } 00093 00094 void 00095 VMatAccessBuffer:: 00096 lookAhead(int row, const Vec& rowbuf) 00097 { 00098 PLASSERT( row > m_current_row ); 00099 int last_row = m_current_row + m_cached_rows.size() - 1; 00100 00101 if ( row <= last_row ) 00102 m_row_buffer << m_cached_rows[row-m_current_row]; 00103 else 00104 while ( last_row < row ) 00105 { 00106 m_source->getRow(++last_row, m_row_buffer); 00107 m_cached_rows.push_back(m_row_buffer.copy()); 00108 } 00109 00110 // Finally 00111 rowbuf << m_row_buffer; 00112 PLASSERT( int(m_cached_rows.size()) <= m_max_size ); 00113 } 00114 00116 VMatAccessBuffer* VMatAccessBuffer::deepCopy(CopiesMap& copies) const 00117 { 00118 CopiesMap::iterator it = copies.find(this); 00119 if(it!=copies.end()) 00120 return (VMatAccessBuffer*) it->second; 00121 00123 VMatAccessBuffer* deep_copy = new VMatAccessBuffer(*this); 00124 00125 deepCopyField(this->m_source, copies); 00126 deepCopyField(this->m_row_buffer, copies); 00127 deepCopyField(this->m_cached_rows, copies); 00128 00130 copies[this] = deep_copy; 00131 00133 return deep_copy; 00134 } 00135 00136 00137 } // end of namespace PLearn 00138 00139 00140 /* 00141 Local Variables: 00142 mode:c++ 00143 c-basic-offset:4 00144 c-file-style:"stroustrup" 00145 c-file-offsets:((innamespace . 0)(inline-open . 0)) 00146 indent-tabs-mode:nil 00147 fill-column:79 00148 End: 00149 */ 00150 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :