Sensitive word replacement algorithm, 4 times more efficient than str_replace (with 6,000 sensitive words attached)-PHP Tutorial-php.cn

Sensitive word replacement algorithm, 4 times more efficient than str_replace (with 6,000 sensitive words attached)

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Release： 2016-07-25 09:08:00

Original

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Efficiency comparison (12688 characters, 1 replacement):

str_replace: 0.109937906265 seconds
strtr: 0.0306839942932 seconds

Comparison of replacement results

For example: "Zhang San", "Zhang Sanfeng", "Zhang San Toyota" are all prohibited words (Why is there such a distinction? Please see "法X", "法Xgong")
Original text: "I drove a Honda Toyota to work today"
strtr: "I drove **** to work today" (replace all four words with *)
str_replace: "I drove **Toyota to work today" (only the first match was replaced)

So using str_replace to replace cannot essentially solve the problem.

Time comparison:
Number of keywords: 6712 (no duplication) self init:0.00789093971252 (load xcache) self:0.0354378223419 strtr:0.0311169624329 strtr_array:0.432713985443 str_replace:0.109627008438

require('badword.src.php');
$badword1 = array_combine($badword,array_fill(0,count($badword),'*'));
$bb = 'I am open today San Toyota goes to work';
$str = strtr($bb, $badword1);

Copy code

//Interested friends can study it
function strtr_array(&$str,&$replace_arr) {
$maxlen = 0;$minlen = 1024*128;
if (empty($replace_arr)) return $ str;
foreach($replace_arr as $k => $v) {
$len = strlen($k);
if ($len < 1) continue;
if ($len > $maxlen) $maxlen = $len;
if ($len < $minlen) $minlen = $len;
}
$len = strlen($str);
$pos = 0;$result = '';
while ($pos < ; $len) {
if ($pos + $maxlen > $len) $maxlen = $len - $pos;
$found = false;$key = '';
for($i = 0;$i< $maxlen;++$i) $key .= $str[$i+$pos]; //Original text: memcpy(key,str+$pos,$maxlen)
for($i = $maxlen;$i >= $minlen;--$i) {
$key1 = substr($key, 0, $i); //Original text: key[$i] = '