From 5e2a20fbe03fe074301971c65c3df013bb8120bc Mon Sep 17 00:00:00 2001
From: Raul Ochoa <rochoaf@gmail.com>
Date: Mon, 13 Jul 2015 16:15:34 +0200
Subject: [PATCH] Tags layergroup instantiation with surrogate keys per
 affected tables

---
 .../cache/model/database_tables_entry.js      | 20 ++++++++++++++
 lib/cartodb/cache/surrogate_keys_cache.js     | 14 +++++++++-
 lib/cartodb/controllers/map.js                | 27 ++++++++++---------
 3 files changed, 48 insertions(+), 13 deletions(-)
 create mode 100644 lib/cartodb/cache/model/database_tables_entry.js

diff --git a/lib/cartodb/cache/model/database_tables_entry.js b/lib/cartodb/cache/model/database_tables_entry.js
new file mode 100644
index 00000000..9bdb6e3d
--- /dev/null
+++ b/lib/cartodb/cache/model/database_tables_entry.js
@@ -0,0 +1,20 @@
+var crypto = require('crypto');
+
+function DatabaseTables(dbName, tableNames) {
+    this.namespace = 't';
+    this.dbName = dbName;
+    this.tableNames = tableNames;
+}
+
+module.exports = DatabaseTables;
+
+
+DatabaseTables.prototype.key = function() {
+    return this.tableNames.map(function(tableName) {
+        return this.namespace + ':' + shortHashKey(this.dbName + ':' + tableName);
+    }.bind(this));
+};
+
+function shortHashKey(target) {
+    return crypto.createHash('sha256').update(target).digest('base64').substring(0,6);
+}
diff --git a/lib/cartodb/cache/surrogate_keys_cache.js b/lib/cartodb/cache/surrogate_keys_cache.js
index 77147917..237ac906 100644
--- a/lib/cartodb/cache/surrogate_keys_cache.js
+++ b/lib/cartodb/cache/surrogate_keys_cache.js
@@ -16,9 +16,21 @@ module.exports = SurrogateKeysCache;
  * @param cacheObject should respond to `key() -> String` method
  */
 SurrogateKeysCache.prototype.tag = function(response, cacheObject) {
-    response.header('Surrogate-Key', cacheObject.key());
+    var newKey = cacheObject.key();
+    response.header('Surrogate-Key', appendSurrogateKey(
+        response.header('Surrogate-Key'),
+        Array.isArray(newKey) ? cacheObject.key().join(' ') : newKey
+    ));
+
 };
 
+function appendSurrogateKey(currentKey, newKey) {
+    if (!!currentKey) {
+        newKey = currentKey + ' ' + newKey;
+    }
+    return newKey;
+}
+
 /**
  * @param cacheObject should respond to `key() -> String` method
  * @param {Function} callback
diff --git a/lib/cartodb/controllers/map.js b/lib/cartodb/controllers/map.js
index d5b43425..9e6fcf44 100644
--- a/lib/cartodb/controllers/map.js
+++ b/lib/cartodb/controllers/map.js
@@ -9,6 +9,7 @@ var MapConfig = windshaft.model.MapConfig;
 var Datasource = windshaft.model.Datasource;
 
 var NamedMapsCacheEntry = require('../cache/model/named_maps_entry');
+var TablesCacheEntry = require('../cache/model/database_tables_entry');
 
 var MapConfigNamedLayersAdapter = require('../models/mapconfig_named_layers_adapter');
 var NamedMapMapConfigProvider = require('../models/mapconfig/named_map_provider');
@@ -147,13 +148,14 @@ MapController.prototype.create = function(req, res, prepareConfigFn) {
         },
         function afterLayergroupCreate(err, layergroup) {
             assert.ifError(err);
-            self.afterLayergroupCreate(req, mapConfig, layergroup, this);
+            self.afterLayergroupCreate(req, res, mapConfig, layergroup, this);
         },
         function finish(err, layergroup) {
             if (err) {
                 var statusCode = self.app.findStatusCode(err);
                 self.app.sendError(res, { errors: [ err.message ] }, statusCode, 'ANONYMOUS LAYERGROUP', err);
             } else {
+                res.header('X-Layergroup-Id', layergroup.layergroupid);
                 self.app.sendResponse(res, [layergroup, 200]);
             }
         }
@@ -169,6 +171,9 @@ MapController.prototype.instantiateTemplate = function(req, res, prepareParamsFn
     var mapConfig;
 
     step(
+        function setupParams(){
+            self.app.req2params(req, this);
+        },
         function getTemplateParams() {
             prepareParamsFn(this);
         },
@@ -197,7 +202,7 @@ MapController.prototype.instantiateTemplate = function(req, res, prepareParamsFn
         },
         function afterLayergroupCreate(err, layergroup) {
             assert.ifError(err);
-            self.afterLayergroupCreate(req, mapConfig, layergroup, this);
+            self.afterLayergroupCreate(req, res, mapConfig, layergroup, this);
         },
         function finishTemplateInstantiation(err, layergroup) {
             if (err) {
@@ -217,7 +222,7 @@ MapController.prototype.instantiateTemplate = function(req, res, prepareParamsFn
 };
 
 
-MapController.prototype.afterLayergroupCreate = function(req, mapconfig, layergroup, callback) {
+MapController.prototype.afterLayergroupCreate = function(req, res, mapconfig, layergroup, callback) {
     var self = this;
 
     var username = req.context.user;
@@ -276,16 +281,14 @@ MapController.prototype.afterLayergroupCreate = function(req, mapconfig, layergr
             layergroup.layergroupid = layergroup.layergroupid + ':' + result.lastUpdatedTime;
             layergroup.last_updated = new Date(result.lastUpdatedTime).toISOString();
 
-            var res = req.res;
-            if (res) {
-                if (req.method === 'GET') {
-                    var ttl = global.environment.varnish.layergroupTtl || 86400;
-                    res.header('Cache-Control', 'public,max-age='+ttl+',must-revalidate');
-                    res.header('Last-Modified', (new Date()).toUTCString());
-                    res.header('X-Cache-Channel', cacheChannel);
+            if (req.method === 'GET') {
+                var ttl = global.environment.varnish.layergroupTtl || 86400;
+                res.header('Cache-Control', 'public,max-age='+ttl+',must-revalidate');
+                res.header('Last-Modified', (new Date()).toUTCString());
+                res.header('X-Cache-Channel', cacheChannel);
+                if (result.affectedTables && result.affectedTables.length > 0) {
+                    self.surrogateKeysCache.tag(res, new TablesCacheEntry(dbName, result.affectedTables));
                 }
-
-                res.header('X-Layergroup-Id', layergroup.layergroupid);
             }
 
             return null;