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lift restrictions on search with frequent terms slightly
[nominatim.git] / lib-php / tokenizer / icu_tokenizer.php
1 <?php
2 /**
3  * SPDX-License-Identifier: GPL-2.0-only
4  *
5  * This file is part of Nominatim. (https://nominatim.org)
6  *
7  * Copyright (C) 2022 by the Nominatim developer community.
8  * For a full list of authors see the git log.
9  */
10
11 namespace Nominatim;
12
13 require_once(CONST_LibDir.'/SimpleWordList.php');
14
15 class Tokenizer
16 {
17     private $oDB;
18
19     private $oNormalizer;
20     private $oTransliterator;
21
22     public function __construct(&$oDB)
23     {
24         $this->oDB =& $oDB;
25         $this->oNormalizer = \Transliterator::createFromRules(CONST_Term_Normalization_Rules);
26         $this->oTransliterator = \Transliterator::createFromRules(CONST_Transliteration);
27     }
28
29     public function checkStatus()
30     {
31         $sSQL = 'SELECT word_id FROM word WHERE word_id is not null limit 1';
32         $iWordID = $this->oDB->getOne($sSQL);
33         if ($iWordID === false) {
34             throw new \Exception('Query failed', 703);
35         }
36         if (!$iWordID) {
37             throw new \Exception('No value', 704);
38         }
39     }
40
41
42     public function normalizeString($sTerm)
43     {
44         if ($this->oNormalizer === null) {
45             return $sTerm;
46         }
47
48         return $this->oNormalizer->transliterate($sTerm);
49     }
50
51
52     public function mostFrequentWords($iNum)
53     {
54         $sSQL = "SELECT word FROM word WHERE type = 'W'";
55         $sSQL .= "ORDER BY info->'count' DESC LIMIT ".$iNum;
56         return $this->oDB->getCol($sSQL);
57     }
58
59
60     private function makeStandardWord($sTerm)
61     {
62         return trim($this->oTransliterator->transliterate(' '.$sTerm.' '));
63     }
64
65
66     public function tokensForSpecialTerm($sTerm)
67     {
68         $aResults = array();
69
70         $sSQL = "SELECT word_id, info->>'class' as class, info->>'type' as type ";
71         $sSQL .= '   FROM word WHERE word_token = :term and type = \'S\'';
72
73         Debug::printVar('Term', $sTerm);
74         Debug::printSQL($sSQL);
75         $aSearchWords = $this->oDB->getAll($sSQL, array(':term' => $this->makeStandardWord($sTerm)));
76
77         Debug::printVar('Results', $aSearchWords);
78
79         foreach ($aSearchWords as $aSearchTerm) {
80             $aResults[] = new \Nominatim\Token\SpecialTerm(
81                 $aSearchTerm['word_id'],
82                 $aSearchTerm['class'],
83                 $aSearchTerm['type'],
84                 \Nominatim\Operator::TYPE
85             );
86         }
87
88         Debug::printVar('Special term tokens', $aResults);
89
90         return $aResults;
91     }
92
93
94     public function extractTokensFromPhrases(&$aPhrases)
95     {
96         $sNormQuery = '';
97         $aWordLists = array();
98         $aTokens = array();
99         foreach ($aPhrases as $iPhrase => $oPhrase) {
100             $sNormQuery .= ','.$this->normalizeString($oPhrase->getPhrase());
101             $sPhrase = $this->makeStandardWord($oPhrase->getPhrase());
102             Debug::printVar('Phrase', $sPhrase);
103
104             $oWordList = new SimpleWordList($sPhrase);
105             $aTokens = array_merge($aTokens, $oWordList->getTokens());
106             $aWordLists[] = $oWordList;
107         }
108
109         Debug::printVar('Tokens', $aTokens);
110         Debug::printVar('WordLists', $aWordLists);
111
112         $oValidTokens = $this->computeValidTokens($aTokens, $sNormQuery);
113
114         foreach ($aPhrases as $iPhrase => $oPhrase) {
115             $oPhrase->setWordSets($aWordLists[$iPhrase]->getWordSets($oValidTokens));
116         }
117
118         return $oValidTokens;
119     }
120
121
122     private function computeValidTokens($aTokens, $sNormQuery)
123     {
124         $oValidTokens = new TokenList();
125
126         if (!empty($aTokens)) {
127             $this->addTokensFromDB($oValidTokens, $aTokens, $sNormQuery);
128
129             // Try more interpretations for Tokens that could not be matched.
130             foreach ($aTokens as $sToken) {
131                 if ($sToken[0] != ' ' && !$oValidTokens->contains($sToken)) {
132                     if (preg_match('/^([0-9]{5}) [0-9]{4}$/', $sToken, $aData)) {
133                         // US ZIP+4 codes - merge in the 5-digit ZIP code
134                         $oValidTokens->addToken(
135                             $sToken,
136                             new Token\Postcode(null, $aData[1], 'us')
137                         );
138                     } elseif (preg_match('/^[0-9]+$/', $sToken)) {
139                         // Unknown single word token with a number.
140                         // Assume it is a house number.
141                         $oValidTokens->addToken(
142                             $sToken,
143                             new Token\HouseNumber(null, trim($sToken))
144                         );
145                     }
146                 }
147             }
148         }
149
150         return $oValidTokens;
151     }
152
153
154     private function addTokensFromDB(&$oValidTokens, $aTokens, $sNormQuery)
155     {
156         // Check which tokens we have, get the ID numbers
157         $sSQL = 'SELECT word_id, word_token, type, word,';
158         $sSQL .= "      info->>'op' as operator,";
159         $sSQL .= "      info->>'class' as class, info->>'type' as ctype,";
160         $sSQL .= "      info->>'count' as count,";
161         $sSQL .= "      info->>'lookup' as lookup";
162         $sSQL .= ' FROM word WHERE word_token in (';
163         $sSQL .= join(',', $this->oDB->getDBQuotedList($aTokens)).')';
164
165         Debug::printSQL($sSQL);
166
167         $aDBWords = $this->oDB->getAll($sSQL, null, 'Could not get word tokens.');
168
169         foreach ($aDBWords as $aWord) {
170             $iId = (int) $aWord['word_id'];
171             $sTok = $aWord['word_token'];
172
173             switch ($aWord['type']) {
174                 case 'C':  // country name tokens
175                     if ($aWord['word'] !== null) {
176                         $oValidTokens->addToken(
177                             $sTok,
178                             new Token\Country($iId, $aWord['word'])
179                         );
180                     }
181                     break;
182                 case 'H':  // house number tokens
183                     $sLookup = $aWord['lookup'] ?? $aWord['word_token'];
184                     $oValidTokens->addToken($sTok, new Token\HouseNumber($iId, $sLookup));
185                     break;
186                 case 'P':  // postcode tokens
187                     // Postcodes are not normalized, so they may have content
188                     // that makes SQL injection possible. Reject postcodes
189                     // that would need special escaping.
190                     if ($aWord['word'] !== null
191                         && pg_escape_string($aWord['word']) == $aWord['word']
192                     ) {
193                         $iSplitPos = strpos($aWord['word'], '@');
194                         if ($iSplitPos === false) {
195                             $sPostcode = $aWord['word'];
196                         } else {
197                             $sPostcode = substr($aWord['word'], 0, $iSplitPos);
198                         }
199
200                         $oValidTokens->addToken(
201                             $sTok,
202                             new Token\Postcode($iId, $sPostcode, null)
203                         );
204                     }
205                     break;
206                 case 'S':  // tokens for classification terms (special phrases)
207                     if ($aWord['class'] !== null && $aWord['ctype'] !== null) {
208                         $oValidTokens->addToken($sTok, new Token\SpecialTerm(
209                             $iId,
210                             $aWord['class'],
211                             $aWord['ctype'],
212                             (isset($aWord['operator'])) ? Operator::NEAR : Operator::NONE
213                         ));
214                     }
215                     break;
216                 case 'W': // full-word tokens
217                     $oValidTokens->addToken($sTok, new Token\Word(
218                         $iId,
219                         (int) $aWord['count'],
220                         substr_count($aWord['word_token'], ' ')
221                     ));
222                     break;
223                 case 'w':  // partial word terms
224                     $oValidTokens->addToken($sTok, new Token\Partial(
225                         $iId,
226                         $aWord['word_token'],
227                         (int) $aWord['count']
228                     ));
229                     break;
230                 default:
231                     break;
232             }
233         }
234     }
235 }