diff --git a/backend/getCountry.php b/backend/getCountry.php
index 4cd93d6..6ba12aa 100644
--- a/backend/getCountry.php
+++ b/backend/getCountry.php
@@ -1,16 +1,13 @@
 <?php
-$db_path = 'country.db';
-$db = new SQLiteDB;
 
-class SQLiteDB extends SQLite3 {
+class countryDB extends SQLite3 {
     function __construct() {
-        global $db_path;
-        $this->open($db_path);
+        $this->open('country.db'); // 国家地区缩写及代号数据库
     }
 }
 
-function get_country($code) {
-    global $db;
+function getCountry($code) { // 根据两位国家代码获取英文与中文全称
+    $db = new countryDB;
     if ($code == null) {
         return null;
     }
diff --git a/backend/getInfo.php b/backend/getInfo.php
index e36f6fb..d8d2466 100644
--- a/backend/getInfo.php
+++ b/backend/getInfo.php
@@ -4,10 +4,10 @@ include("getCountry.php");
 include("qqwry.php");
 
 function getIPInfo($ip) {
-    $qqwry = new IpLocation();
+    $qqwry = new QQWry();
     $detail = $qqwry->getDetail($ip);
-    $specialIpInfo = getSpecialIpInfo($ip);
-    if (is_string($specialIpInfo)) {
+    $specialInfo = getSpecialInfo($ip);
+    if (is_string($specialInfo)) {
         $info['ip'] = $ip;
         $info['as'] = null;
         $info['city'] = null;
@@ -15,25 +15,23 @@ function getIPInfo($ip) {
         $info['country'] = null;
         $info['timezone'] = null;
         $info['loc'] = null;
-        $info['isp'] = $specialIpInfo;
-        $info['cidr'] = $detail['cidr'];
-        $info['detail'] = $detail['addr'];
+        $info['isp'] = $specialInfo;
     } else {
-        $rawIspInfo = getIspInfo($ip);
+        $rawIspInfo = getInfo($ip);
         $info['ip'] = $ip;
         $info['as'] = getAS($rawIspInfo);
         $info['city'] = $rawIspInfo['city'];
         $info['region'] = $rawIspInfo['region'];
-        $info['country'] = get_country($rawIspInfo['country'])['en'];
-        $info['country'] .= "（".get_country($rawIspInfo['country'])['cn']."）";
+        $info['country'] = getCountry($rawIspInfo['country'])['en'];
+        $info['country'] .= "（".getCountry($rawIspInfo['country'])['cn']."）";
         $info['timezone'] = $rawIspInfo['timezone'];
         $info['loc'] = $rawIspInfo['loc'];
         $info['isp'] = getIsp($rawIspInfo);
-        $info['cidr'] = $detail['cidr'];
-        $info['detail'] = $detail['addr'];
     }
+    $info['cidr'] = $detail['beginIP'] . ' - ' . $detail['endIP'];
+    $info['detail'] = $detail['dataA'] . $detail['dataB'];
 
-    if ($_GET['cli'] == "true") {
+    if ($_GET['cli'] == "true") { // 使用命令行模式
         $cli = "IP: ".$info['ip'].PHP_EOL;
         $cli .= "AS: ".$info['as'].PHP_EOL;
         $cli .= "City: ".$info['city'].PHP_EOL;
@@ -47,11 +45,11 @@ function getIPInfo($ip) {
         return $cli;
     }
 
-    header('Content-Type: application/json; charset=utf-8');
+    header('Content-Type: application/json; charset=utf-8'); // 以JSON格式发送
     return json_encode($info);
 }
 
-function getSpecialIpInfo($ip) {
+function getSpecialInfo($ip) { // 识别特殊IP地址
     if ('::1' === $ip) {
         return 'localhost IPv6 access';
     }
@@ -76,12 +74,11 @@ function getSpecialIpInfo($ip) {
     return null;
 }
 
-function getIspInfo($ip) {
-    $json = file_get_contents('https://ipinfo.io/'.$ip.'/json');
+function getInfo($ip) { // 获取IP详细信息
+    $json = file_get_contents('https://ipinfo.io/' . $ip . '/json');
     if (!is_string($json)) {
         return null;
     }
-
     $data = json_decode($json, true);
     if (!is_array($data)) {
         return null;
@@ -89,7 +86,7 @@ function getIspInfo($ip) {
     return $data;
 }
 
-function getIsp($rawIspInfo) {
+function getIsp($rawIspInfo) { // 提取ISP信息
     if (
         !is_array($rawIspInfo)
         || !array_key_exists('org', $rawIspInfo)
@@ -101,7 +98,7 @@ function getIsp($rawIspInfo) {
     return preg_replace('/AS\\d+\\s/', '', $rawIspInfo['org']);
 }
 
-function getAS($rawIspInfo) {
+function getAS($rawIspInfo) { // 提取AS信息
     if (
         !is_array($rawIspInfo)
         || !array_key_exists('org', $rawIspInfo)
diff --git a/backend/qqwry.php b/backend/qqwry.php
index 2cae774..a6584cf 100644
--- a/backend/qqwry.php
+++ b/backend/qqwry.php
@@ -1,17 +1,17 @@
 <?php
 
-class IpLocation {
+class QQWry {
     private $fp; // 文件指针
-    private $firstip; // 第一条记录的偏移地址
-    private $lastip; // 最后一条记录的偏移地址
-    private $totalip; // 总记录条数
+    private $firstRecord; // 第一条记录的偏移地址
+    private $lastRecord; // 最后一条记录的偏移地址
+    private $recordNum; // 总记录条数
 
     public function __construct() { // 构造函数
         $this->fp = 0;
-        if (($this->fp = fopen(__DIR__.'/qqwry.dat', 'rb')) !== false) {
-            $this->firstip = $this->getlong();
-            $this->lastip  = $this->getlong();
-            $this->totalip = ($this->lastip - $this->firstip) / 7;
+        if (($this->fp = fopen(__DIR__ . '/qqwry.dat', 'rb')) !== false) {
+            $this->firstRecord = $this->read4byte();
+            $this->lastRecord  = $this->read4byte();
+            $this->recordNum = ($this->lastRecord - $this->firstRecord) / 7; // 每条索引长度为7字节
         }
     }
 
@@ -22,129 +22,132 @@ class IpLocation {
         $this->fp = 0;
     }
 
-    public function getDetail($ip) { // 获取IP地址区段及所在位置
-        if (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) { // 判断IP是否有效
-            return null;
-        }
-        $location = $this->getLocation($ip);
-        if (!$location) {
-            return null;
-        }
-        $detail['cidr'] = $location['beginip'] . ' - ' . $location['endip'];
-        $detail['addr'] = $location['country'] . $location['area'];
-        return $detail;
-    }
-
-    private function getlong() { // 将读取的4字节转化为长整型数
+    private function read4byte() { // 读取4字节并转为long
         return unpack('Vlong', fread($this->fp, 4))['long'];
     }
 
-    private function getlong3() { // 将读取的3字节转化为长整型数
+    private function read3byte() { // 读取3字节并转为long
         return unpack('Vlong', fread($this->fp, 3) . chr(0))['long'];
     }
 
-    private function ip2long($ip) { // 将IP地址转为数字地址
+    private function readString() { // 读取字符串
+        $str = '';
+        $char = fread($this->fp, 1);
+        while (ord($char) != 0) { // 读到二进制0结束
+            $str .= $char;
+            $char = fread($this->fp, 1);
+        }
+        return $str;
+    }
+
+    private function zipIP($ip) { // IP地址转为数字
         $ip_arr = explode('.', $ip);
-        return (16777216 * intval($ip_arr[0])) + (65536 * intval($ip_arr[1])) + (256 * intval($ip_arr[2])) + intval($ip_arr[3]);
+        $tmp = (16777216 * intval($ip_arr[0])) + (65536 * intval($ip_arr[1])) + (256 * intval($ip_arr[2])) + intval($ip_arr[3]);
+        return pack('N', intval($tmp)); // 32位无符号大端序长整型
     }
 
-    private function packip($ip) { // 计算压缩后的IP地址
-        return pack('N', intval($this->ip2long($ip)));
+    private function unzipIP($ip) { // 数字转为IP地址
+        return long2ip($ip);
     }
 
-    private function getstring($data = "") { // 读取字符串
-        $char = fread($this->fp, 1);
-        while (ord($char) > 0) { // 字符串读取到\0结束
-            $data .= $char;
-            $char = fread($this->fp, 1);
-        }
-        return $data;
+    public function getVersion() { // 获取当前数据库的版本
+        fseek($this->fp, $this->lastRecord + 4);
+        $tmp = $this->getRecord($this->read3byte())['B'];
+        return substr($tmp, 0, 4) . substr($tmp, 7, 2) . substr($tmp, 12, 2);
     }
 
-    private function getArea() { // 获取地区信息
-        $flag = fread($this->fp, 1); // 标志字节
-        if (ord($flag) == 0) { // 无区域信息
-            return '';
-        } else if (ord($flag) == 1 || ord($flag) == 2) { // 区域信息被重定向
-            fseek($this->fp, $this->getlong3());
-            return $this->getstring();
-        } else { // 区域信息未被重定向
-            return $this->getstring($flag);
+    public function getDetail($ip) { // 获取IP地址区段及所在位置
+        if (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) { // 判断是否为IPv4地址
+            return null;
         }
-    }
+        
+        fseek($this->fp, $this->searchRecord($ip)); // 跳转到对应IP记录的位置
+        $detail['beginIP'] = $this->unzipIP($this->read4byte()); // 目标IP所在网段的起始IP
+        $offset = $this->read3byte(); // 索引后3字节为对应记录的偏移量
+        fseek($this->fp, $offset);
+        $detail['endIP'] = $this->unzipIP($this->read4byte()); // 目标IP所在网段的结束IP
 
-    private function getLocation($ip) { // 根据IP地址返回地区信息
-        $ip = $this->packip($ip);
-        $l = 0; // 搜索下边界
-        $u = $this->totalip; // 搜索上边界
-        $findip = $this->lastip; // 若未找到则返回最后一条记录
+        $tmp = $this->getRecord($offset); // 获取记录的dataA与dataB
+        $detail['dataA'] = $tmp['A'];
+        $detail['dataB'] = $tmp['B'];
+
+        if ($detail['beginIP'] == '255.255.255.0') { // 去除附加信息
+            $detail['dataA'] = 'IANA';
+            $detail['dataB'] = '保留地址';
+        }
+        if ($detail['dataA'] == ' CZ88.NET' || $detail['dataA'] == '纯真网络') {
+            $detail['dataA'] = '';
+        }
+        if ($detail['dataB'] == ' CZ88.NET') {
+            $detail['dataB'] = '';
+        }
+        return $detail;
+    }
 
-        while ($l <= $u) { // 发起查找
-            $i = floor(($l + $u) / 2); // 计算二分点
-            fseek($this->fp, $this->firstip + $i * 7);
-            $beginip = strrev(fread($this->fp, 4)); // 获取二分点所在区域的下边界
-            if ($ip < $beginip) { // 目标IP小于二分区域的下边界
-                $u = $i - 1; // 搜索的上边界缩小到二分点以下
-            } else { // 目标IP大于或等于二分区域的下边界
-                fseek($this->fp, $this->getlong3());
+    private function searchRecord($ip) { // 根据IP地址获取索引的绝对偏移量
+        $ip = $this->zipIP($ip); // 转为数字以比较大小
+        $down = 0;
+        $up = $this->recordNum;
+        while ($down <= $up) { // 二分法查找
+            $mid = floor(($down + $up) / 2); // 计算二分点
+            fseek($this->fp, $this->firstRecord + $mid * 7);
+            $beginip = strrev(fread($this->fp, 4)); // 获取二分区域的下边界
+            if ($ip < $beginip) { // 目标IP在二分区域以下
+                $up = $mid - 1; // 缩小搜索的上边界
+            } else {
+                fseek($this->fp, $this->read3byte());
                 $endip = strrev(fread($this->fp, 4)); // 获取二分区域的上边界
-                if ($ip > $endip) { // 目标IP大于二分区域的上边界
-                    $l = $i + 1; // 搜索的下边界缩小到二分点以上
+                if ($ip > $endip) { // 目标IP在二分区域以上
+                    $down = $mid + 1; // 缩小搜索的下边界
                 } else { // 目标IP在二分区域内
-                    $findip = $this->firstip + $i * 7;
-                    break;
+                    return $this->firstRecord + $mid * 7; // 返回索引的偏移量
                 }
             }
         }
-        fseek($this->fp, $findip);
-        $location['beginip'] = long2ip($this->getlong()); // 目标IP所在区域的下边界
-        $offset = $this->getlong3();
-        fseek($this->fp, $offset);
-        $location['endip'] = long2ip($this->getlong()); // 目标IP所在区域的上边界
+        return $this->lastRecord; // 无法找到对应索引，返回最后一条记录的偏移量
+    }
 
-        //获取目标IP的位置信息
-        $byte = fread($this->fp, 1); // 标志字节
-        switch (ord($byte)) {
-            case 1: // 国家和区域信息均被重定向
-                $countryOffset = $this->getlong3(); // 重定向地址
-                fseek($this->fp, $countryOffset);
-                $byte = fread($this->fp, 1); // 标志字节
-                switch (ord($byte)) {
-                    case 2: // 国家信息被重定向
-                        fseek($this->fp, $this->getlong3());
-                        $location['country'] = $this->getstring();
-                        fseek($this->fp, $countryOffset + 4);
-                        $location['area'] = $this->getArea();
-                        break;
-                    default: // 国家信息未被重定向
-                        $location['country'] = $this->getstring($byte);
-                        $location['area']    = $this->getArea();
-                        break;
-                }
-                break;
-            case 2: // 国家信息被重定向
-                fseek($this->fp, $this->getlong3());
-                $location['country'] = $this->getstring();
-                fseek($this->fp, $offset + 8);
-                $location['area'] = $this->getArea();
-                break;
-            default: // 国家信息未被重定向
-                $location['country'] = $this->getstring($byte);
-                $location['area'] = $this->getArea();
-                break;
+    private function getRecord($offset) { // 读取IP记录的数据
+        fseek($this->fp, $offset + 4);
+        $flag = ord(fread($this->fp, 1));
+        if ($flag == 1) { // dataA与dataB均重定向
+            $offset = $this->read3byte(); // 重定向偏移
+            fseek($this->fp, $offset);
+            if (ord(fread($this->fp, 1)) == 2) { // dataA再次重定向
+                fseek($this->fp, $this->read3byte());
+                $data['A'] = $this->readString();
+                fseek($this->fp, $offset + 4);
+                $data['B'] = $this->getDataB();
+            } else { // dataA无重定向
+                fseek($this->fp, -1, SEEK_CUR); // 文件指针回退1字节
+                $data['A'] = $this->readString();
+                $data['B'] = $this->getDataB();
+            }
+        } else if ($flag == 2) { // dataA重定向
+            fseek($this->fp, $this->read3byte());
+            $data['A'] = $this->readString();
+            fseek($this->fp, $offset + 8); // IP占4字节, 重定向标志占1字节, dataA指针占3字节
+            $data['B'] = $this->getDataB();
+        } else { // dataA无重定向
+            fseek($this->fp, -1, SEEK_CUR); // 文件指针回退1字节
+            $data['A'] = $this->readString();
+            $data['B'] = $this->getDataB();
         }
+        $data['A'] = iconv("GBK", "UTF-8", $data['A']); // GBK -> UTF-8
+        $data['B'] = iconv("GBK", "UTF-8", $data['B']);
+        return $data;
+    }
 
-        // 转为UTF-8编码
-        $location['country'] = iconv("GBK", "UTF-8", $location['country']);
-        $location['area'] = iconv("GBK", "UTF-8", $location['area']);
-
-        // 去除附带信息
-        if ($location['country'] == " CZ88.NET" || $location['country'] == "纯真网络") {
-            $location['country'] = "Unknow";
-        }
-        if ($location['area'] == " CZ88.NET") {
-            $location['area'] = "";
+    private function getDataB() { // 从fp指定偏移获取dataB
+        $flag = ord(fread($this->fp, 1));
+        if ($flag == 0) { // dataB无信息
+            return '';
+        } else if ($flag == 1 || $flag == 2) { // dataB重定向
+            fseek($this->fp, $this->read3byte());
+            return $this->readString();
+        } else { // dataB无重定向
+            fseek($this->fp, -1, SEEK_CUR); // 文件指针回退1字节
+            return $this->readString();
         }
-        return $location;
     }
 }