Add an X-Cache-Channel header to all GET requests. Closes #53.

lib/cartodb/cartodb_windshaft.js

@@ -6,17 +6,6 @@ var _ = require('underscore')
 
 var CartodbWindshaft = function(serverOptions) {
 
-    // set the cache chanel info to invalidate the cache on the frontend server
-    serverOptions.afterTileRender = function(req, res, tile, headers, callback) {
-        var ttl = global.environment.varnish.ttl || 86400;
-        Cache.generateCacheChannel(req, function(channel){
-            res.header('X-Cache-Channel', channel);
-            res.header('Last-Modified', new Date().toUTCString());
-            res.header('Cache-Control', 'no-cache,max-age='+ttl+',must-revalidate, public');
-            callback(null, tile, headers);
-        });
-    };
-
     if(serverOptions.cache_enabled) {
         console.log("cache invalidation enabled, varnish on ", serverOptions.varnish_host, ' ', serverOptions.varnish_port);
         Cache.init(serverOptions.varnish_host, serverOptions.varnish_port);

lib/cartodb/server_options.js

@@ -1,6 +1,7 @@
 var   _          = require('underscore')
     , Step       = require('step')
-    , cartoData  = require('./carto_data');
+    , cartoData  = require('./carto_data')
+    , Cache = require('./cache_validator');
 
 module.exports = function(){
     var me = {
@@ -17,6 +18,28 @@ module.exports = function(){
         log_format: '[:date] :req[X-Real-IP] \033[90m:method\033[0m \033[36m:req[Host]:url\033[0m \033[90m:status :response-time ms -> :res[Content-Type]\033[0m'
     };
 
+    // Set the cache chanel info to invalidate the cache on the frontend server
+    //
+    // @param req The request object.
+    //            The function will have no effect unless req.res exists.
+    //            It is expected that req.params contains 'table' and 'dbname'
+    //
+    // @param cb function(err, channel) will be called when ready.
+    //           the channel parameter will be null if nothing was added
+    //
+    me.addCacheChannel = function(req, cb) {
+        // skip non-GET requests, or requests for which there's no response
+        if ( req.method != 'GET' || ! req.res ) { cb(null, null); return; }
+        var res = req.res;
+        var ttl = global.environment.varnish.ttl || 86400;
+        Cache.generateCacheChannel(req, function(channel){
+            res.header('X-Cache-Channel', channel);
+            res.header('Last-Modified', new Date().toUTCString());
+            res.header('Cache-Control', 'no-cache,max-age='+ttl+',must-revalidate, public');
+            cb(null, channel); // add last-modified too ?
+        });
+    }
+
     /**
      * Whitelist input and get database name & default geometry type from
      * subdomain/user metadata held in CartoDB Redis
@@ -45,6 +68,8 @@ module.exports = function(){
           callback(null, xml);
         }
 
+        var that = this;
+
         Step(
             function getPrivacy(){
                 cartoData.authorize(req, this);
@@ -66,10 +91,14 @@ module.exports = function(){
                 cartoData.getGeometryType(req, this);
             },
             function finishSetup(err, data){
+                if ( err ) { callback(err, req); return; }
+
                 if (!_.isNull(data))
                     _.extend(req.params, {geom_type: data});
 
+                that.addCacheChannel(req, function(err, chan) {
                   callback(err, req);
+                });
             }
         );
     };

test/acceptance/server.js

@@ -40,6 +40,7 @@ suite('server', function() {
             method: 'GET'
         },{
             status: 200,
+            headers: { 'X-Cache-Channel': 'cartodb_test_user_1_db:my_table' },
             body: '{"style":"#my_table {marker-fill: #FF6600;marker-opacity: 1;marker-width: 8;marker-line-color: white;marker-line-width: 3;marker-line-opacity: 0.9;marker-placement: point;marker-type: ellipse;marker-allow-overlap: true;}"}'
         }, function() { done(); });
     });
@@ -261,6 +262,7 @@ suite('server', function() {
             method: 'GET'
         },{
             status: 200,
+            headers: { 'X-Cache-Channel': 'cartodb_test_user_1_db:my_tablez' },
             body: '{"infowindow":null}'
         }, function() { done(); });
     });
@@ -326,7 +328,8 @@ suite('server', function() {
             method: 'GET'
         },{
             status: 200,
-            headers: { 'Content-Type': 'text/javascript; charset=utf-8; charset=utf-8' }
+            headers: { 'Content-Type': 'text/javascript; charset=utf-8; charset=utf-8',
+                       'X-Cache-Channel': 'cartodb_test_user_1_db:gadm4' }
         }, function() { done(); });
     });
     
@@ -391,7 +394,7 @@ suite('server', function() {
             method: 'GET'
         },{
             status: 200,
-            headers: { 'Content-Type': 'image/png' }
+            headers: { 'Content-Type': 'image/png', 'X-Cache-Channel': 'cartodb_test_user_1_db:gadm4' }
         }, function() { done(); });
     });