From a1b2c2176729a92009b9fc6e75a91055cc4c846e Mon Sep 17 00:00:00 2001
From: lion <chenxin619315@gmail.com>
Date: Sun, 19 Oct 2025 23:05:15 +0800
Subject: [PATCH 1/2] optimize the ipv6 bytes to string

---
 binding/javascript/package.json |  2 +-
 binding/javascript/util.js      | 21 ++++++++++++++++-----
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/binding/javascript/package.json b/binding/javascript/package.json
index 843ef99..797d3b6 100644
--- a/binding/javascript/package.json
+++ b/binding/javascript/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ip2region.js",
-  "version": "3.1.3",
+  "version": "3.1.4",
   "description": "official javascript binding for ip2region with both IPv4 and IPv6 supported ",
   "type": "module",
   "main": "index.js",
diff --git a/binding/javascript/util.js b/binding/javascript/util.js
index a8136bb..8545c42 100644
--- a/binding/javascript/util.js
+++ b/binding/javascript/util.js
@@ -155,20 +155,31 @@ function _ipv4_to_string(v4Bytes) {
 
 // ipv6 bytes to string
 function _ipv6_to_string(v6Bytes, compress) {
-    let ps = [];
+    let ps = [], needCompress = false;
+    let last_hex = -1, hex = 0;
     for (var i = 0; i < v6Bytes.length; i += 2) {
-        ps.push(v6Bytes.readUint16BE(i).toString(16));
+        hex = v6Bytes.readUint16BE(i).toString(16);
+        ps.push(hex);
+     
+        // check the necessity for compress
+        if (last_hex > -1 
+            && hex == 0 && last_hex == 0) {
+            needCompress = true;
+        }
+
+        // reset the last hex
+        last_hex = hex;
     }
 
-    if (compress === false) {
+    if (needCompress == false || compress === false) {
         return ps.join(':');
     }
 
     // auto compression of consecutive zero
-    let j = 0, mi = ps.length - 1;
+    let mi = ps.length - 1;
     let _ = [];
     for (i = 0; i < ps.length; i++) {
-        if (i >= mi || j > 0) {
+        if (i >= mi) {
             _.push(ps[i]);
             continue;
         }

From a30d9222258dec0b7b2d78030216499a0edf6ab5 Mon Sep 17 00:00:00 2001
From: lion <chenxin619315@gmail.com>
Date: Sun, 19 Oct 2025 23:07:00 +0800
Subject: [PATCH 2/2] lines merge

---
 binding/javascript/util.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/binding/javascript/util.js b/binding/javascript/util.js
index 8545c42..5243313 100644
--- a/binding/javascript/util.js
+++ b/binding/javascript/util.js
@@ -176,8 +176,7 @@ function _ipv6_to_string(v6Bytes, compress) {
     }
 
     // auto compression of consecutive zero
-    let mi = ps.length - 1;
-    let _ = [];
+    let _ = [], mi = ps.length - 1;
     for (i = 0; i < ps.length; i++) {
         if (i >= mi) {
             _.push(ps[i]);