indefero/src/IDF/Search.php
2009-08-20 15:20:15 +02:00

190 lines
6.8 KiB
PHP

<?php
/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
# ***** BEGIN LICENSE BLOCK *****
# This file is part of InDefero, an open source project management application.
# Copyright (C) 2008 Céondo Ltd and contributors.
#
# InDefero is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# InDefero 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 St, Fifth Floor, Boston, MA 02110-1301 USA
#
# Based on work under GNU LGPL copyright, from the Pluf Framework
# Copyright (C) 2001-2007 Loic d'Anterroches and contributors.
#
# ***** END LICENSE BLOCK ***** */
/**
* Class implementing the search engine
*
* It is a modified version of the Pluf_Search class to be able to
* cluster the results by project.
*/
class IDF_Search extends Pluf_Search
{
/**
* Search.
*
* Returns an array of array with model_class, model_id and
* score. The list is already sorted by score descending.
*
* You can then filter the list as you wish with another set of
* weights.
*
* @param string Query string.
* @param int Project id to limit the results (null)
* @param string Model class (null)
* @param string Stemmer class ('Pluf_Text_Stemmer_Porter')
* @return array Results
*/
public static function mySearch($query, $project=null, $model=null, $stemmer='Pluf_Text_Stemmer_Porter')
{
$query = Pluf_Text::cleanString(html_entity_decode($query, ENT_QUOTES, 'UTF-8'));
$words = Pluf_Text::tokenize($query);
if ($stemmer != null) {
$words = self::stem($words, $stemmer);
}
$words_flat = array();
foreach ($words as $word=>$c) {
$words_flat[] = $word;
}
$word_ids = self::getWordIds($words_flat);
if (in_array(null, $word_ids) or count($word_ids) == 0) {
return array();
}
return self::mySearchDocuments($word_ids, $project, $model);
}
/**
* Search documents.
*
* Only the total of the ponderated occurences is used to sort the
* results.
*
* @param array Ids.
* @param IDF_Project Project to limit the search.
* @param string Model class to limit the search.
* @return array Sorted by score, returns model_class, model_id and score.
*/
public static function mySearchDocuments($wids, $project, $model)
{
$db =& Pluf::db();
$gocc = new IDF_Search_Occ();
$where = array();
foreach ($wids as $id) {
$where[] = $db->qn('word').'='.(int)$id;
}
$prj = (is_null($project)) ? '' : ' AND project='.(int)$project->id;
$md = (is_null($model)) ? '' : ' AND model_class='.$db->esc($model);
$select = 'SELECT model_class, model_id, SUM(pondocc) AS score FROM '.$gocc->getSqlTable().' WHERE '.implode(' OR ', $where).$prj.$md.' GROUP BY model_class, model_id HAVING COUNT(*)='.count($wids).' ORDER BY score DESC';
return $db->select($select);
}
/**
* Index a document.
*
* See Pluf_Search for the disclaimer and informations.
*
* @param Pluf_Model Document to index.
* @param Stemmer used. ('Pluf_Text_Stemmer_Porter')
* @return array Statistics.
*/
public static function index($doc, $stemmer='Pluf_Text_Stemmer_Porter')
{
$words = Pluf_Text::tokenize($doc->_toIndex());
if ($stemmer != null) {
$words = self::stem($words, $stemmer);
}
// Get the total number of words.
$total = 0.0;
$words_flat = array();
foreach ($words as $word => $occ) {
$total += (float) $occ;
$words_flat[] = $word;
}
// Drop the last indexation.
$gocc = new IDF_Search_Occ();
$sql = new Pluf_SQL('DELETE FROM '.$gocc->getSqlTable().' WHERE model_class=%s AND model_id=%s', array($doc->_model, $doc->id));
$db =& Pluf::db();
$db->execute($sql->gen());
// Get the ids for each word.
$ids = self::getWordIds($words_flat);
// Insert a new word for the missing words and add the occ.
$n = count($ids);
$new_words = 0;
$done = array();
for ($i=0;$i<$n;$i++) {
if ($ids[$i] === null) {
$word = new Pluf_Search_Word();
$word->word = $words_flat[$i];
$word->create();
$ids[$i] = $word->id;
$new_words++;
}
if (isset($done[$ids[$i]])) {
continue;
}
$done[$ids[$i]] = true;
$occ = new IDF_Search_Occ();
$occ->word = new Pluf_Search_Word($ids[$i]);
$occ->model_class = $doc->_model;
$occ->model_id = $doc->id;
$occ->project = $doc->get_project();
$occ->occ = $words[$words_flat[$i]];
$occ->pondocc = $words[$words_flat[$i]]/$total;
$occ->create();
}
// update the stats
$sql = new Pluf_SQL('model_class=%s AND model_id=%s',
array($doc->_model, $doc->id));
$last_index = Pluf::factory('Pluf_Search_Stats')->getList(array('filter' => $sql->gen()));
if ($last_index->count() == 0) {
$stats = new Pluf_Search_Stats();
$stats->model_class = $doc->_model;
$stats->model_id = $doc->id;
$stats->indexations = 1;
$stats->create();
} else {
$last_index[0]->indexations += 1;
$last_index[0]->update();
}
return array('total' => $total, 'new' => $new_words, 'unique'=>$n);
}
/**
* Remove an item from the index.
*
* You must call this function when you delete items wich are
* indexed. Just add the call:
*
* IDF_Search::remove($this);
*
* in the preDelete() method of your object.
*
* @param mixed Item to be removed
* @return bool Success
*/
public static function remove($item)
{
if ($item->id > 0) {
$sql = new Pluf_SQL('model_id=%s AND model_class=%s',
array($item->id, $item->_model));
$items = Pluf::factory('IDF_Search_Occ')->getList(array('filter'=>$sql->gen()));
foreach ($items as $tl) {
$tl->delete();
}
}
return true;
}
}