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tdepim/indexlib/ifile.cpp

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6.4 KiB

/* This file is part of indexlib.
* Copyright (C) 2005 Luís Pedro Coelho <luis@luispedro.org>
*
* Indexlib is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation and available as file
* GPL_V2 which is distributed along with indexlib.
*
* Indexlib 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., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA
*
* In addition, as a special exception, the copyright holders give
* permission to link the code of this program with any edition of
* the TQt library by Trolltech AS, Norway (or with modified versions
* of TQt that use the same license as TQt), and distribute linked
* combinations including the two. You must obey the GNU General
* Public License in all respects for all of the code used other than
* TQt. If you modify this file, you may extend this exception to
* your version of the file, but you are not obligated to do so. If
* you do not wish to do so, delete this exception statement from
* your version.
*/
#include "ifile.h"
#include "logfile.h"
#include "path.h"
#include "result.h"
#include <algorithm>
#include <iterator>
#include <set>
#include <functional>
#include <string.h>
#include "format.h"
#include "boost-compat/next_prior.h"
ifile::ifile( std::string name ):
docnames_( path_concat( name, "docnames" ) ),
words_( path_concat( name, "words" ) ),
stopwords_( path_concat( name, "stopwords" ) ),
files_( path_concat( name, "files" ) ),
tokenizer_( indexlib::detail::get_tokenizer( "latin-1:european" ) )
{
//logfile() << format( "ifile::ifile( \"%s\" )\n" ) % name;
}
void ifile::remove( std::string name ) {
stringarray::remove( path_concat( name, "docnames" ) );
stringset::remove( path_concat( name, "words" ) );
stringset::remove( path_concat( name, "stopwords" ) );
leafdatavector::remove( path_concat( name, "files" ) );
}
void ifile::add( const char* str, const char* doc ) {
using namespace boost;
//logfile() << format( "ifile::add( %s, %s )\n" ) % str % doc;
const unsigned docidx = docnames_.add( doc );
files_.resize( docidx + 1 );
std::vector<std::string> words = break_clean( str );
for ( std::vector<std::string>::const_iterator first = words.begin(), past = words.end(); first != past; ++first ) {
files_.add( words_.add( first->c_str() ) , docidx );
}
}
void ifile::remove_doc( const char* doc ) {
//logfile() << format( "%s( %s )\n" ) % __PRETTY_FUNCTION__ % doc;
unsigned idx;
for ( idx = 0; idx != ndocs(); ++idx ) {
if ( lookup_docname( idx ) == doc ) break;
}
if ( idx == ndocs() ) return;
//logfile() << format( "Removing %s\n" ) % idx;
docnames_.erase( idx );
files_.remove_references_to( idx );
// TODO: remove from words_ too if that's the case
}
std::unique_ptr<indexlib::result> ifile::everything() const {
std::vector<unsigned> res( ndocs() );
for ( unsigned i = 0; i != ndocs(); ++i ) res[ i ] = i;
return std::unique_ptr<indexlib::result>( new indexlib::detail::simple_result( res ) );
}
namespace {
inline
bool word_too_small( std::string str ) { return str.size() < 3; }
}
std::unique_ptr<indexlib::result> ifile::search( const char* str ) const {
using namespace indexlib::detail;
using indexlib::result;
assert( str );
if ( !*str ) return everything();
std::vector<std::string> words = break_clean( str );
if ( words.empty() ) return std::unique_ptr<result>( new empty_result );
words.erase( std::remove_if( words.begin(), words.end(), &word_too_small ), words.end() );
if ( words.empty() ) return everything();
std::set<unsigned> values = find_word( words[ 0 ] );
for ( std::vector<std::string>::const_iterator first = boost::next( words.begin() ), past = words.end();
first != past;
++first ) {
std::set<unsigned> now = find_word( *first );
// merge the two
std::set<unsigned> next;
std::set_intersection( now.begin(), now.end(), values.begin(), values.end(), std::inserter( next, next.begin() ) );
next.swap( values );
}
std::unique_ptr<result> r(new simple_result( std::vector<unsigned>( values.begin(), values.end() ) ) );
return r;
}
void ifile::maintenance() {
//logfile() << __PRETTY_FUNCTION__ << '\n';
calc_stopwords();
}
void ifile::calc_stopwords() {
//logfile() << __PRETTY_FUNCTION__ << '\n';
const unsigned needed = ndocs() / 4;
stopwords_.clear();
for ( stringset::const_iterator word = words_.begin(), past = words_.end(); word != past; ++word ) {
logfile() << format( "%s(): \"%s\" %s\n" )
% __PRETTY_FUNCTION__
% *word
% files_.get( word.id() ).size();
if ( files_.get( word.id() ).size() >= needed ) {
stopwords_.add( *word );
//files_.erase( word.id() );
}
}
}
bool ifile::is_stop_word( std::string str ) const {
return stopwords_.count( str.c_str() );
}
bool ifile::invalid_word( std::string str ) {
return str.find_first_of( "0123456789" ) != std::string::npos || str.size() > 32;
}
std::set<unsigned> ifile::find_word( std::string word ) const {
//logfile() << format( "ifile::find_word( \"%s\" ): " ) % word;
std::set<unsigned> res;
for ( std::pair<stringset::const_iterator,stringset::const_iterator> limits = words_.upper_lower( word.c_str() );
limits.first != limits.second; ++limits.first) {
std::vector<unsigned> here = files_.get( limits.first.id() );
//logfile() << format( "in ifile::search( \"%s\" ) seeing %s.\n" ) % word % limits.first.id();
//std::copy( here.begin(), here.end(), std::ostream_iterator<unsigned>( logfile(), " - " ) );
//logfile() << "\n";
res.insert( here.begin(), here.end() );
}
//logfile() << format( "%s docs found.\n" ) % res.size();
return res;
}
std::vector<std::string> ifile::break_clean( const char* complete ) const {
std::vector<std::string> words = tokenizer_->string_to_words( complete );
std::sort( words.begin(), words.end() );
words.erase( std::unique( words.begin(), words.end() ), words.end() );
words.erase( std::remove_if( words.begin(), words.end(), &ifile::invalid_word ), words.end() );
words.erase( std::remove_if( words.begin(), words.end(), std::bind( std::mem_fn( &ifile::is_stop_word ), this, std::placeholders::_1 ) ), words.end() );
return words;
}