Improve uniqueness of named map map config provider

lib/cartodb/cache/named_map_provider_cache.js

@@ -1,3 +1,5 @@
+var _ = require('underscore');
+var dot = require('dot');
 var NamedMapMapConfigProvider = require('../models/mapconfig/named_map_provider');
 var templateName = require('../backends/template_maps').templateName;
 
@@ -18,7 +20,7 @@ NamedMapProviderCache.prototype.get = function(user, templateId, config, authTok
     var namedMapKey = createNamedMapKey(user, templateId);
     var namedMapProviders = this.providerCache.get(namedMapKey) || {};
 
-    var providerKey = createProviderKey(config, authToken);
+    var providerKey = createProviderKey(config, authToken, params);
     if (!namedMapProviders.hasOwnProperty(providerKey)) {
         namedMapProviders[providerKey] = new NamedMapMapConfigProvider(
             this.templateMaps,
@@ -45,6 +47,16 @@ function createNamedMapKey(user, templateId) {
     return user + ':' + templateName(templateId);
 }
 
-function createProviderKey(config, authToken) {
-    return NamedMapMapConfigProvider.configHash(config) + ':' + authToken;
+var providerKey = '{{=it.authToken}}:{{=it.configHash}}:{{=it.format}}:{{=it.layer}}:{{=it.scale_factor}}';
+var providerKeyTpl = dot.template(providerKey);
+
+function createProviderKey(config, authToken, params) {
+    var tplValues = _.defaults({}, params, {
+        authToken: authToken || '',
+        configHash: NamedMapMapConfigProvider.configHash(config),
+        layer: '',
+        format: '',
+        scale_factor: 1
+    });
+    return providerKeyTpl(tplValues);
 }