/**
* 禁词过滤
* 执行效率：每篇用时0.05秒
* @author liuxu
*
*/
class Logic_BlackWord
{

const APP_FORUM = 1;
const APP_BLOG = 2;
const APP_VOTE = 3;

/**
* 过滤得到禁词
* @param unknown $txt
* @return Ambigous 
*/
public function getHitList($txt)
{
$hitList = array();

//对禁词分批过滤
$max = $this->getMax();
if($max)
{
$size = 1000;
$last = ceil($max/$size);
for($page=1;$page<=$last;$page++)
{
$result = $this->getHitListByPage($txt,$page,$size);
if($result) $hitList = array_merge($hitList,$result);
}
}

$hitList2 = array();
foreach($hitList as $hit=>$type)
{
$hitList2[$type][] = $hit;
}

return $hitList2;
}

private function getMax()
{
$redis = Rds::factory();
$memKey = ‘blackWord_max’;
$max = $redis->get($memKey);
if($max===false)
{
$max = 0;
$blackWord = new Model_BlackWord_BlackWord();
$para['field'] = “MAX(id) AS max”;
$result = $blackWord->search($para);
if(isset($result[0]['max'])) $max = $result[0]['max'];

$redis->setex($memKey,300,$max);
}

return $max;
}

/**
* 分批过滤得到禁词
* @param unknown $txt
* @param number $page
* @param number $size
* @return multitype:Ambigous 
*/
private function getHitListByPage($txt,$page=1,$size=1000)
{
$hitList = array();

//分批得到禁词树
$wordTree = $this->getWordTreeByPage($page,$size);

$txt = strip_tags($txt);
$txt = preg_replace(‘/[^a-zA-Z0-9\x{4e00}-\x{9fa5}]/iu’,”,$txt);

$len = mb_strlen($txt,’UTF-8′);
for($i=0;$i<$len;$i++)
{
$char = mb_substr($txt,$i,1,'UTF-8');
if(isset($wordTree[$char]))
{
$result = $this->getHitListByTree(mb_substr($txt,$i,50,’UTF-8′),$wordTree);
if($result)
{
foreach($result as $hit=>$type)
{
$hitList[$hit] = $type;
}
}
}
}

return $hitList;
}

/**
* 是否禁词
* @param str $txt
* @param arr $wordTree
* @return multitype:unknown
*/
private function getHitListByTree($txt,&$wordTree)
{
$len = mb_strlen($txt,’UTF-8′);
$point = & $wordTree;
$hit = ”;
$hitList = array();
for($i=0;$i<$len;$i++)
{
$char = mb_substr($txt,$i,1,'UTF-8');
if(isset($point[$char]))
{
$hit .= $char;
$point = & $point[$char];

if(isset($point['type']))//匹配成功
{
$hitList[$hit] = $point['type'];
}
}
else
{
break;
}

}

return $hitList;
}

/**
* 分批得到禁词树
* @param int $page
* @param int $size
* @return arr:
*/
private function getWordTreeByPage($page=1,$size=1000)
{
$redis = Rds::factory();
$memKey = 'blackWord_tree_'.$page.'_'.$size;
$wordTree = $redis->get($memKey);
if($wordTree===false)
{
$wordTree = array();
$blackWord = new Model_BlackWord_BlackWord();
$start = ($page-1)*$size;
$end = $start + $size;
$para['where'] = “status=1 AND id>”.$start.” AND id<=".$end;
$result = $blackWord->search($para);
if($result)
{
foreach($result as $value)
{
if($value['word'])
{
$value['word'] = preg_split(‘/(? $point = & $wordTree;
foreach($value['word'] as $char)
{
$point = & $point[$char];
}

$point['type'] = $value['type'];
}
}
}

$redis->setex($memKey,300,$wordTree);
}

return $wordTree;
}

}