Time synchronization for TTL

lib/javascript/es6/src/kusaba.new.js

@@ -1921,6 +1921,64 @@ function readyset() {
   }).trigger('change')
 }
 
+const NTP = {
+  calc: (t0, t1, t2, t3) => ((t1 - t0) + (t2 - t3)) / 2,
+  sync: function(force) {
+    this.pending = true
+    let _this = this
+    , t0 = (new Date()).valueOf()
+    $.ajax({
+      url: '/ntp.php',
+      success: function(servertime) {
+        let t1 = servertime,
+            t2 = servertime,
+            t3 = (new Date()).valueOf()
+
+        _this.offset = _this.calc(t0, t1, t2, t3)
+      },
+      error: function() {
+        pups.err('Failed to synchronize time with the server')
+      },
+      complete: function() {
+        _this.synced = true
+
+        while (_this.stack.length) {
+          _this.stack.shift().resolve(_this.timeWithOffset)
+        }
+      }
+    });
+  },
+  offset: 0,
+  stack: [],
+  get timeWithOffset() {
+    return new Date(new Date().getTime() + this.offset).getTime()
+  },
+  getServerTime: function() {
+    if (this.synced)
+      return Promise.resolve(this.timeWithOffset)
+
+    let promise = externallyResolvingPromise()
+    if (! this.pending)
+      this.sync()
+    this.stack.push(promise)
+    return promise.promise
+  }
+}
+
+function externallyResolvingPromise() {
+  let promiseResolve, promiseReject
+  , promise = new Promise((resolve, reject) => {
+    promiseResolve = resolve
+    promiseReject = reject
+  });
+
+  return {
+    promise: promise,
+    resolve: promiseResolve,
+    reject: promiseReject
+  }
+}
+
 // this will be applied to every new inserted node (post)
 function processNodeInsertion($node) {
   if(typeof $node === 'undefined')
@@ -1934,21 +1992,26 @@ function processNodeInsertion($node) {
   LatexIT.render($node);
 
   // Post time-to-live updating
-  $node.find('.post-ttl').each(function() {
+  $node.find('.post-ttl:not(._inserted_)').each(function() {
+    let $this = $(this)
+    $this.addClass('_inserted_')
     let iv
     , updateTTL = () => {
-      if ($(this).length) {
-        let time_left = $(this).data('deleted-timestamp') - Math.round((new Date().getTime())/1000)
-        if (time_left >= 0) {
-          time_left = time_left / 3600
-          $(this).text(`${_.padLeft(Math.floor(time_left), 2, '0')}:${_.padLeft(Math.round((time_left%1)*60), 2, '0')}`)
-        }
-        else {
-          $.get(document.forms.delform.action) // call board.php to force delete posts
-          deleteItems([{action: 'delete_post', id: $(this).parents('.posthead').find('.reflink > a:not(.shl)').text()}], false, updater.markOnly)
-          clearInterval(iv)
-        }
-        time_left = (time_left >= 0) ? time_left / 3600 : 0
+      if ($this.length) {
+        NTP.getServerTime().then(srvTime => {
+          let ms_left = $this.data('deleted-timestamp')*1000 - srvTime
+          if (ms_left >= 0) {
+            let min_left = Math.round(ms_left / 60000)
+            , h_left = Math.floor(min_left / 60)
+            min_left -= h_left * 60
+            $this.text(`${_.padLeft(h_left, 2, '0')}:${_.padLeft(min_left, 2, '0')}`)
+          }
+          else {
+            $.get(document.forms.delform.action) // call board.php to force delete posts
+            deleteItems([{action: 'delete_post', id: $this.parents('.posthead').find('.reflink > a:not(.shl)').text()}], false, updater.markOnly)
+            clearInterval(iv)
+          }
+        })
       }
       else
         clearInterval(iv)

ntp.php

@@ -0,0 +1 @@
+<?php echo (string) round($_SERVER['REQUEST_TIME_FLOAT'] * 1000);