Nominatim/lib-php/TokenPartial.php
Sarah Hoffmann 4864bf1509 disallow search for partials without address
Very frequent partial terms take too long to look up and
do not return any valuable results unless the search is
further narrowed down by an address.
2021-10-26 12:00:13 +02:00

120 lines
3.4 KiB
PHP

<?php
namespace Nominatim\Token;
/**
* A standard word token.
*/
class Partial
{
/// Database word id, if applicable.
private $iId;
/// Number of appearances in the database.
private $iSearchNameCount;
/// True, if the token consists exclusively of digits and spaces.
private $bNumberToken;
public function __construct($iId, $sToken, $iSearchNameCount)
{
$this->iId = $iId;
$this->bNumberToken = (bool) preg_match('#^[0-9 ]+$#', $sToken);
$this->iSearchNameCount = $iSearchNameCount;
}
public function getId()
{
return $this->iId;
}
/**
* Check if the token can be added to the given search.
* Derive new searches by adding this token to an existing search.
*
* @param object $oSearch Partial search description derived so far.
* @param object $oPosition Description of the token position within
the query.
*
* @return True if the token is compatible with the search configuration
* given the position.
*/
public function isExtendable($oSearch, $oPosition)
{
return !$oPosition->isPhrase('country');
}
/**
* Derive new searches by adding this token to an existing search.
*
* @param object $oSearch Partial search description derived so far.
* @param object $oPosition Description of the token position within
the query.
*
* @return SearchDescription[] List of derived search descriptions.
*/
public function extendSearch($oSearch, $oPosition)
{
$aNewSearches = array();
// Partial token in Address.
if (($oPosition->isPhrase('') || !$oPosition->isFirstPhrase())
&& $oSearch->hasName()
) {
$iSearchCost = $this->bNumberToken ? 2 : 1;
if ($this->iSearchNameCount >= CONST_Max_Word_Frequency) {
$iSearchCost += 1;
}
$oNewSearch = $oSearch->clone($iSearchCost);
$oNewSearch->addAddressToken(
$this->iId,
$this->iSearchNameCount < CONST_Max_Word_Frequency
);
$aNewSearches[] = $oNewSearch;
}
// Partial token in Name.
if ((!$oSearch->hasPostcode() && !$oSearch->hasAddress())
&& (!$oSearch->hasName(true)
|| $oSearch->getNamePhrase() == $oPosition->getPhrase())
) {
$iSearchCost = 1;
if (!$oSearch->hasName(true)) {
$iSearchCost += 1;
}
if ($this->bNumberToken) {
$iSearchCost += 1;
}
$oNewSearch = $oSearch->clone($iSearchCost);
$oNewSearch->addPartialNameToken(
$this->iId,
$this->iSearchNameCount < CONST_Max_Word_Frequency,
$this->iSearchNameCount > CONST_Search_NameOnlySearchFrequencyThreshold,
$oPosition->getPhrase()
);
$aNewSearches[] = $oNewSearch;
}
return $aNewSearches;
}
public function debugInfo()
{
return array(
'ID' => $this->iId,
'Type' => 'partial',
'Info' => array(
'count' => $this->iSearchNameCount
)
);
}
public function debugCode()
{
return 'w';
}
}