From 747f4803bacc468dd634c1941e0daa9d3a226eb0 Mon Sep 17 00:00:00 2001
From: Sandro Santilli <strk@keybit.net>
Date: Mon, 10 Feb 2014 15:30:35 +0100
Subject: [PATCH] Include hash of template in the maptoken returned from
 instanciation

Doing so basically removes the need to include the template identifier
in the surrogate keys of the responses for resources fetched via
the instance whenever template is updated. See #105
---
 NEWS.md                          | 2 ++
 lib/cartodb/cartodb_windshaft.js | 3 ++-
 lib/cartodb/server_options.js    | 9 ++++++---
 lib/cartodb/template_maps.js     | 8 ++++++++
 4 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/NEWS.md b/NEWS.md
index 00e340ef..7faa90e2 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -11,6 +11,8 @@ New features:
 Enhancements:
 
  * Allow specifying fixed sqlapi host address (#117)
+ * Include template hash in template instance response, to keep caches
+   of different instances separated (#105)
 
 Bug fixes:
 
diff --git a/lib/cartodb/cartodb_windshaft.js b/lib/cartodb/cartodb_windshaft.js
index c6b19bfe..75e98bf5 100644
--- a/lib/cartodb/cartodb_windshaft.js
+++ b/lib/cartodb/cartodb_windshaft.js
@@ -484,7 +484,8 @@ var CartodbWindshaft = function(serverOptions) {
           if ( err ) throw err;
           //console.log("Response from createLayergroup: "); console.dir(response);
           // Add the signature part to the token!
-          response.layergroupid = cdbuser + '@' + response.layergroupid;
+          var tplhash = templateMaps.fingerPrint(template).substring(0,8);
+          response.layergroupid = cdbuser + '@' + tplhash + '@' + response.layergroupid;
           return response;
         },
         callback
diff --git a/lib/cartodb/server_options.js b/lib/cartodb/server_options.js
index f79551ca..4e7ab128 100644
--- a/lib/cartodb/server_options.js
+++ b/lib/cartodb/server_options.js
@@ -613,9 +613,12 @@ console.log("Checking authorization from signer " + signer + " for resource " +
           if ( tksplit.length > 1 ) req.params.cache_buster= tksplit[1];
           tksplit = req.params.token.split('@');
           if ( tksplit.length > 1 ) {
-            req.params.signer = this.userByReq(req);
-            if ( tksplit[0] ) req.params.signer = tksplit[0];
-            req.params.token = tksplit[1];
+            req.params.signer = tksplit.shift();
+            if ( ! req.params.signer ) req.params.signer = this.userByReq(req);
+            if ( tksplit.length > 1 ) {
+              var template_hash = tksplit.shift(); // unused
+            }
+            req.params.token = tksplit.shift(); 
             //console.log("Request for token " + req.params.token + " with signature from " + req.params.signer);
           }
         }
diff --git a/lib/cartodb/template_maps.js b/lib/cartodb/template_maps.js
index 172bdbcc..117146ff 100644
--- a/lib/cartodb/template_maps.js
+++ b/lib/cartodb/template_maps.js
@@ -588,4 +588,12 @@ o.instance = function(template, params) {
   return layergroup;
 };
 
+// Return a fingerPrint of the object
+o.fingerPrint = function(template) {
+  return crypto.createHash('md5')
+    .update(JSON.stringify(template))
+    .digest('hex')
+  ;
+};
+
 module.exports = TemplateMaps;