Simple analysis of PHP keyword replacement class (avoid duplicate substitution, preserve and restore original link) _php instance

PHP keyword Replacement class (avoid duplicate substitution, preserve and restore original link)

The main contents of this section:

A keyword Replacement class

Can be used mainly for keyword filtering, or keyword search substitution.

Implementation Process Analysis:

Keyword replacement, in fact, is a str_replace () process, if it is pure str_replace face 10W keywords, 1W Word article also only need about 2 seconds.

The problem lies in:

Keywords are replaced more than once, such as a need to replace <a>a</a>, but the result may be <a><a>a</a></a> and so on.

To do this, you need a way to protect a label that has already been replaced, so before you process the article, replace it with a label such as [_tnum_] to restore it after the article has been processed.

Another problem, if the keyword or article in the [_tnum_] itself, then you need to eliminate this here can not use the str_replace and need to use the preg_replace to exclude.

Third, if there are two keywords A and ab How to do, hope that the long match off, short after matching, so you need to be sorted before matching.

The last question, when the str_replace changed to Preg_replace later, slowed down the same paragraph 10W match to 5 seconds, string processing functions in the strpos to be faster, then first use Strpos to find the keyword, 10W query less than 1 seconds. Even 1 million is 8 seconds more.

A keyword matching replacement class, code:

code example:

<?php * * keyword matching class * @author ylx <ylx@gmail.com> * @packet Mipang * Use instance * $str = "Green Shell layer" Edwin van der Sar next year, the next year of the spill
  Open room Lucas Defangjun ";
  * $key = new Keyreplace ($str, Array ("XXXX" => "SADF", "Next year" => ' http://baidu.com ', "next year" => ' google.com '));
  * Echo $key->getresulttext ();
  * Echo $key->getruntime ();
 * * Class Keyreplace {private $keys = array ();
 Private $text = "";
 Private $runtime =;
 Private $url = true;
 Private $stopkeys = Array ();
 Private $all = false; /** * @access public * @param string $text Specifies the article to be processed * @param array $keys The specified dictionary phrase array (key=>url,...) URL can be an array, if it is The array will randomly replace one of the * @param array $stopkeys Specify a stop word array (key,...) This word will not be processed * @param boolean $url True to replace the link or replace only * @par Am Boolean $all True indicates that all found words are replaced, otherwise only the first/public function __construct ($text = ', $keys =array (), $url =true, $stopkeys =arr
  Ay (), $all =false) {$this->keys = $keys;
  $this->text = $text;
  $this->url = $url;
  $this->stopkeys = $stopkeys;
 $this->all = $all; }
 /** * Get processed articles * @access public * @return String text */Public Function Getresulttext () {$start = Microti
  Me (true);
  $keys = $this->hits_keys ();
  $keys _tmp = Array_keys () ($keys);
   function cmp ($a, $b) {if (Mb_strlen ($a) = = Mb_strlen ($b)) {return; Return (Mb_strlen ($a) < Mb_strlen ($b))?
  : -;
  } usort ($keys _tmp, "CMP");
   foreach ($keys _tmp as $key) {if (Is_array ($keys [$key])) {$url = $keys [$key][rand (, Count ($keys [$key])];
   }else $url = $keys [$key];
  $this->text = $this->r_s ($this->text, $key, $url);
  $this->runtime = Microtime (True)-$start;
 return $this->text; 
 /** * Get processing time * @access public * @return Float/Public Function getruntime () {return $this->runtime;
  /** * Set Keywords * @access public * @param array $keys Array (Key=>url,...)
 * * Public Function SetKeys ($keys) {$this->keys = $keys;
  /** * Set Stop word * @access public * @param array $keys Array (key,...) * Public function Setstopkeys ($keys) {$this->stopkeys = $keys; /** * Set Article * @access public * @param string $text/Public Function SetText ($text) {$this->text = $t
 Ext
  /** * Used to find the keyword hit in the string * @access public * @return Array $keys Returns a matching word array (Key=>url,...)
  */Public Function Hits_keys () {$ar = $this->keys;
  $ar = $ar $ar: Array ();
  $result =array ();
  $str = $this->text;
   foreach ($ar as $k => $url) {$k = Trim ($k);
   if (! $k) continue;
   if (Strpos ($str, $k)!==false &&!in_array ($k, $this->stopkeys)) {$result [$k] = $url;
 return $result $result: Array ();
  /** * Used to find the stop word hit in the string * @access public * @return Array $keys returns the word array (key,...)
  */Public Function Hits_stop_keys () {$ar = $this->stopkeys;
  $ar = $ar $ar: Array ();
  $result =array ();
  $str = $this->text;
   foreach ($ar as $k) {$k = Trim ($k);
   if (! $k) continue; if (Strpos ($str, $k)!==false && in_array ($k, $this->stopkeys)) {$reSult[] = $k;
 return $result $result: Array ();
  /** * Process Substitution * @access private * @param string $text replaced * @param string $key keyword * @param string $url link
  * @return String $text processed articles */private function r_s ($text, $key, $url) {$tmp = $text;
  $stop _keys = $this->hits_stop_keys ();
  $stopkeys = $tags = $a = Array ();
   if (Preg_match_all ("#<a[^>]+>[^<]*</a[^>]*> #su", $tmp, $m)) {$a = $m [];
 foreach ($m [] as $k => $z) {$z = Preg_replace ("#\# #s", "\#", $z); $tmp = preg_replace (' # '. $z. ' #s ', ' [_a '. $k.]
   _] ", $tmp,);
  }
  };
   if (Preg_match_all ("#<[^>]+> #s", $tmp, $m)) {$tags = $m [];
 foreach ($m [] as $k => $z) {$z = Preg_replace ("#\# #s", "\#", $z); $tmp = preg_replace (' # '. $z. ' #s ', ' [_tag '. $k.]
   _] ", $tmp,); } if (!empty ($stop _keys)) {if Preg_match_all ("#". Implode ("|", $stop _keys). "
 #s ", $tmp, $m)) {$stopkeys = $m [];
  foreach ($m [] as $k => $z) {$z = Preg_replace ("#\# #s", "\#", $z); $tmp = preg_replace (' # '. $z. ' #s ', ' [_s '. $k."_]", $tmp,);
  }} $key = Preg_replace ("# ([\#\ (\) \[\]\*]) #s", "\\\\$", $key); if ($this->url) $tmp = Preg_replace ("#" (?!) \[_s|\[_a|\[_|\[_t|\[_ta|\[_tag) ". $key." (?! Ag\d+_\]|g\d+_\]|\d+_\]|s\d+_\]|_\] #us ", ' <a href= '. $url. '" > '. $key. '
  </a> ', $tmp, $this->all?-:); else $tmp = preg_replace ("#" (?!) \[_s|\[_a|\[_|\[_t|\[_ta|\[_tag) ". $key." (?!
  Ag\d+_\]|g\d+_\]|\d+_\]|s\d+_\]|_\]) #us ", $url, $tmp, $this->all?-:); if (!empty ($a)) {foreach ($a as $n => $at) {$tmp = Str_replace ("[_a". $n. "
   _] ", $at, $tmp); } if (!empty ($tags)) {foreach ($tags as $n => $at) {$tmp = Str_replace ("[_tag". $n. "
   _] ", $at, $tmp); } if (!empty ($stopkeys)) {foreach ($stopkeys as $n => $at) {$tmp = Str_replace ("[_s". $n. "
   _] ", $at, $tmp);
 } return $tmp; }
}

Above is the class that this article introduces to you to replace the PHP keyword (avoid duplicate substitution, keep and restore original link).