diff --git a/binding/php/XdbSearcher.class.php b/binding/php/XdbSearcher.class.php
index df8816e..283432a 100644
--- a/binding/php/XdbSearcher.class.php
+++ b/binding/php/XdbSearcher.class.php
@@ -9,16 +9,14 @@
 class XdbSearcher
 {
     const HeaderInfoLength = 256;
-    const VectorIndexRows  = 256;
-    const VectorIndexCols  = 256;
-    const VectorIndexSize  = 8;
+    const VectorIndexRows = 256;
+    const VectorIndexCols = 256;
+    const VectorIndexSize = 8;
     const SegmentIndexSize = 14;
 
     // xdb file handle
     private $handle = null;
 
-    // header info
-    private $header = null;
     private $ioCount = 0;
 
     // vector index in binary string.
@@ -32,23 +30,26 @@ class XdbSearcher
     // static function to create searcher
 
     /**
-     * @throws Exception
+     * @throws \Exception
      */
-    public static function newWithFileOnly($dbFile) {
+    public static function newWithFileOnly($dbFile)
+    {
         return new XdbSearcher($dbFile, null, null);
     }
 
     /**
-     * @throws Exception
+     * @throws \Exception
      */
-    public static function newWithVectorIndex($dbFile, $vIndex) {
+    public static function newWithVectorIndex($dbFile, $vIndex)
+    {
         return new XdbSearcher($dbFile, $vIndex);
     }
 
     /**
-     * @throws Exception
+     * @throws \Exception
      */
-    public static function newWithBuffer($cBuff) {
+    public static function newWithBuffer($cBuff)
+    {
         return new XdbSearcher(null, null, $cBuff);
     }
 
@@ -56,9 +57,10 @@ class XdbSearcher
 
     /**
      * initialize the xdb searcher
-     * @throws Exception
+     * @throws \Exception
      */
-    function __construct($dbFile, $vectorIndex=null, $cBuff=null) {
+    public function __construct($dbFile, $vectorIndex = null, $cBuff = null)
+    {
         // check the content buffer first
         if ($cBuff != null) {
             $this->vectorIndex = null;
@@ -67,33 +69,36 @@ class XdbSearcher
             // open the xdb binary file
             $this->handle = fopen($dbFile, "r");
             if ($this->handle === false) {
-                throw new Exception("failed to open xdb file '%s'", $dbFile);
+                throw new \Exception("failed to open xdb file '%s'", $dbFile);
             }
 
             $this->vectorIndex = $vectorIndex;
         }
     }
 
-    function close() {
+    public function close()
+    {
         if ($this->handle != null) {
             fclose($this->handle);
         }
     }
 
-    function getIOCount() {
+    public function getIOCount()
+    {
         return $this->ioCount;
     }
 
     /**
      * find the region info for the specified ip address
-     * @throws Exception
+     * @throws \Exception
      */
-    function search($ip) {
+    public function search($ip)
+    {
         // check and convert the sting ip to a 4-bytes long
         if (is_string($ip)) {
             $t = self::ip2long($ip);
             if ($t === null) {
-                throw new Exception("invalid ip address `$ip`");
+                throw new \Exception("invalid ip address `$ip`");
             }
             $ip = $t;
         }
@@ -108,14 +113,14 @@ class XdbSearcher
         if ($this->vectorIndex != null) {
             $sPtr = self::getLong($this->vectorIndex, $idx);
             $ePtr = self::getLong($this->vectorIndex, $idx + 4);
-        } else if ($this->contentBuff != null) {
+        } elseif ($this->contentBuff != null) {
             $sPtr = self::getLong($this->contentBuff, self::HeaderInfoLength + $idx);
             $ePtr = self::getLong($this->contentBuff, self::HeaderInfoLength + $idx + 4);
         } else {
             // read the vector index block
             $buff = $this->read(self::HeaderInfoLength + $idx, 8);
             if ($buff === null) {
-                throw new Exception("failed to read vector index at ${idx}");
+                throw new \Exception("failed to read vector index at ${idx}");
             }
 
             $sPtr = self::getLong($buff, 0);
@@ -136,7 +141,7 @@ class XdbSearcher
             // read the segment index
             $buff = $this->read($p, self::SegmentIndexSize);
             if ($buff == null) {
-                throw new Exception("failed to read segment index at ${p}");
+                throw new \Exception("failed to read segment index at ${p}");
             }
 
             $sip = self::getLong($buff, 0);
@@ -171,7 +176,8 @@ class XdbSearcher
     }
 
     // read specified bytes from the specified index
-    private function read($offset, $len) {
+    private function read($offset, $len)
+    {
         // check the in-memory buffer first
         if ($this->contentBuff != null) {
             return substr($this->contentBuff, $offset, $len);
@@ -217,8 +223,8 @@ class XdbSearcher
     // read a 4bytes long from a byte buffer
     public static function getLong($b, $idx)
     {
-        $val = (ord($b[$idx])) | (ord($b[$idx+1]) << 8)
-            | (ord($b[$idx+2]) << 16) | (ord($b[$idx+3]) << 24);
+        $val = (ord($b[$idx])) | (ord($b[$idx + 1]) << 8)
+            | (ord($b[$idx + 2]) << 16) | (ord($b[$idx + 3]) << 24);
 
         // convert signed int to unsigned int if on 32 bit operating system
         if ($val < 0 && PHP_INT_SIZE == 4) {
@@ -231,11 +237,12 @@ class XdbSearcher
     // read a 2bytes short from a byte buffer
     public static function getShort($b, $idx)
     {
-        return ((ord($b[$idx])) | (ord($b[$idx+1]) << 8));
+        return ((ord($b[$idx])) | (ord($b[$idx + 1]) << 8));
     }
 
     // load header info from a specified file handle
-    public static function loadHeader($handle) {
+    public static function loadHeader($handle)
+    {
         if (fseek($handle, 0) == -1) {
             return null;
         }
@@ -251,17 +258,18 @@ class XdbSearcher
         }
 
         // return the decoded header info
-        return array(
-            'version'       => self::getShort($buff, 0),
-            'indexPolicy'   => self::getShort($buff, 2),
-            'createdAt'     => self::getLong($buff, 4),
+        return [
+            'version' => self::getShort($buff, 0),
+            'indexPolicy' => self::getShort($buff, 2),
+            'createdAt' => self::getLong($buff, 4),
             'startIndexPtr' => self::getLong($buff, 8),
-            'endIndexPtr'   => self::getLong($buff, 12)
-        );
+            'endIndexPtr' => self::getLong($buff, 12)
+        ];
     }
 
     // load header info from the specified xdb file path
-    public static function loadHeaderFromFile($dbFile) {
+    public static function loadHeaderFromFile($dbFile)
+    {
         $handle = fopen($dbFile, 'r');
         if ($handle === false) {
             return null;
@@ -271,7 +279,8 @@ class XdbSearcher
     }
 
     // load vector index from a file handle
-    public static function loadVectorIndex($handle) {
+    public static function loadVectorIndex($handle)
+    {
         if (fseek($handle, self::HeaderInfoLength) == -1) {
             return null;
         }
@@ -290,7 +299,8 @@ class XdbSearcher
     }
 
     // load vector index from a specified xdb file path
-    public static function loadVectorIndexFromFile($dbFile) {
+    public static function loadVectorIndexFromFile($dbFile)
+    {
         $handle = fopen($dbFile, 'r');
         if ($handle === false) {
             return null;
@@ -300,7 +310,8 @@ class XdbSearcher
     }
 
     // load the xdb content from a file handle
-    public static function loadContent($handle) {
+    public static function loadContent($handle)
+    {
         if (fseek($handle, 0, SEEK_END) == -1) {
             return null;
         }
@@ -329,7 +340,8 @@ class XdbSearcher
     }
 
     // load the xdb content from a file path
-    public static function loadContentFromFile($dbFile) {
+    public static function loadContentFromFile($dbFile)
+    {
         $str = file_get_contents($dbFile, false);
         if ($str === false) {
             return null;
@@ -338,8 +350,8 @@ class XdbSearcher
         }
     }
 
-    public static function now() {
+    public static function now()
+    {
         return (microtime(true) * 1000);
     }
-
 }