From 9b441c10481db52f0ba194626b8eeefc0e9d8e38 Mon Sep 17 00:00:00 2001
From: Sacha Greif <sacha357@gmail.com>
Date: Tue, 29 Oct 2013 13:30:35 +0900
Subject: [PATCH] make scoring client-side too for latency compensation

---
 client/views/posts/post_item.html |  2 --
 lib/scoring.js                    | 45 +++++++++++++++++++++++++++++
 lib/vote.js                       |  4 +--
 server/scoring.js                 | 47 -------------------------------
 4 files changed, 47 insertions(+), 51 deletions(-)
 create mode 100644 lib/scoring.js

diff --git a/client/views/posts/post_item.html b/client/views/posts/post_item.html
index 7cc0751a8..80caa40d6 100644
--- a/client/views/posts/post_item.html
+++ b/client/views/posts/post_item.html
@@ -4,10 +4,8 @@
     <ul class="post-actions">
       <li class="post-share desktop"><a href="#" class="share-link"><i class="icon-share"></i><span class="action">Share</span></a>
         <div class="share-options hidden">
-          {{#constant}}
           <div data-url="{{#if url}}{{url}}{{else}}{{current_domain}}/posts/{{_id}}{{/if}}" data-text="{{headline}}" class="share-replace">
           </div>
-          {{/constant}}
         </div>
       </li>
       <li class="post-discuss">
diff --git a/lib/scoring.js b/lib/scoring.js
new file mode 100644
index 000000000..c06ba394a
--- /dev/null
+++ b/lib/scoring.js
@@ -0,0 +1,45 @@
+updateScore = function (collection, id, forceUpdate) {
+  var forceUpdate = typeof forceUpdate !== 'undefined' ? forceUpdate : false;
+  // For performance reasons, the database is only updated if the difference between the old score and the new score
+  // is meaningful enough. To find out, we calculate the "power" of a single vote after n days.
+  // We assume that after n days, a single vote will not be powerful enough to affect posts' ranking order.
+  // Note: sites whose posts regularly get a lot of votes can afford to use a lower n. 
+
+  // n =  number of days after which a single vote will not have a big enough effect to trigger a score update
+  //      and posts can become inactive
+  var n = 30;
+  // x = score increase amount of a single vote after n days (for n=100, x=0.000040295)
+  var x = 1/Math.pow(n*24+2,1.3);
+  // time decay factor
+  var f = 1.3;
+
+  var object = collection.findOne(id);
+
+  // use submitted timestamp if available, else (for pending posts) calculate score using createdAt
+  var age = object.submitted || object.createdAt;
+
+  // use baseScore if defined, if not just use the number of votes
+  // note: for transition period, also use votes if there are more votes than baseScore
+  // var baseScore = Math.max(object.votes || 0, object.baseScore || 0);
+  var baseScore = object.baseScore;
+
+  // now multiply by 'age' exponentiated
+  // FIXME: timezones <-- set by server or is getTime() ok?
+  var ageInHours = (new Date().getTime() - age) / (60 * 60 * 1000);
+
+  // HN algorithm
+  var newScore = baseScore / Math.pow(ageInHours + 2, f);
+
+  // Note: before the first time updateScore runs on a new item, its score will be at 0
+  var scoreDiff = Math.abs(object.score - newScore);
+
+  // only update database if difference is larger than x to avoid unnecessary updates
+  if (forceUpdate || scoreDiff > x){
+    collection.update(id, {$set: {score: newScore, inactive: false}});
+    return 1;
+  }else if(ageInHours > n*24){
+    // only set a post as inactive if it's older than n days
+    collection.update(id, {$set: {inactive: true}});
+  }
+  return 0;
+};
diff --git a/lib/vote.js b/lib/vote.js
index 1af103603..ff82247f6 100644
--- a/lib/vote.js
+++ b/lib/vote.js
@@ -42,8 +42,8 @@
       $inc: {votes: vote, baseScore: votePower},
       $set: {inactive: false}
     });
-    if(!this.isSimulation)
-      updateScore(collection, id, true);
+
+    updateScore(collection, id, true);
 
     // Karma     
     // user's posts and comments do not impact his own karma:
diff --git a/server/scoring.js b/server/scoring.js
index 8267aadd7..f4183cc20 100644
--- a/server/scoring.js
+++ b/server/scoring.js
@@ -1,50 +1,3 @@
-// "secret" server code to recalculate scores
-
-updateScore = function (collection, id, forceUpdate) {
-  var forceUpdate = typeof forceUpdate !== 'undefined' ? forceUpdate : false;
-  // For performance reasons, the database is only updated if the difference between the old score and the new score
-  // is meaningful enough. To find out, we calculate the "power" of a single vote after n days.
-  // We assume that after n days, a single vote will not be powerful enough to affect posts' ranking order.
-  // Note: sites whose posts regularly get a lot of votes can afford to use a lower n. 
-
-  // n =  number of days after which a single vote will not have a big enough effect to trigger a score update
-  //      and posts can become inactive
-  var n = 30;
-  // x = score increase amount of a single vote after n days (for n=100, x=0.000040295)
-  var x = 1/Math.pow(n*24+2,1.3);
-  // time decay factor
-  var f = 1.3;
-
-  var object = collection.findOne(id);
-
-  // use submitted timestamp if available, else (for pending posts) calculate score using createdAt
-  var age = object.submitted || object.createdAt;
-
-  // use baseScore if defined, if not just use the number of votes
-  // note: for transition period, also use votes if there are more votes than baseScore
-  // var baseScore = Math.max(object.votes || 0, object.baseScore || 0);
-  var baseScore = object.baseScore;
-
-  // now multiply by 'age' exponentiated
-  // FIXME: timezones <-- set by server or is getTime() ok?
-  var ageInHours = (new Date().getTime() - age) / (60 * 60 * 1000);
-
-  // HN algorithm
-  var newScore = baseScore / Math.pow(ageInHours + 2, f);
-
-  // Note: before the first time updateScore runs on a new item, its score will be at 0
-  var scoreDiff = Math.abs(object.score - newScore);
-
-  // only update database if difference is larger than x to avoid unnecessary updates
-  if (forceUpdate || scoreDiff > x){
-    collection.update(id, {$set: {score: newScore, inactive: false}});
-    return 1;
-  }else if(ageInHours > n*24){
-    // only set a post as inactive if it's older than n days
-    collection.update(id, {$set: {inactive: true}});
-  }
-  return 0;
-};
 
 Meteor.startup(function () {
   var scoreInterval = getSetting("scoreUpdateInterval") || 30;