Allow limiting number of allowed user templates

Adds maxUserTemplates directive.
Closes #136

NEWS.md

@@ -11,6 +11,7 @@ Enhancements:
  * Tested with node-0.10 (#141)
  * Use single redis pooler for torque and grainstore
  * Reduce cost of garbage collection for localized resources
+ * Allow limiting number of templates for each user (#136)
 
 1.7.1 -- 2014-02-11
 -------------------

config/environments/development.js.example

@@ -24,6 +24,8 @@ var config = {
     // Maximum number of connections for one process
     // 128 is a good value with a limit of 1024 open file descriptors
     ,maxConnections:128
+    // Maximum number of templates per user. Unlimited by default.
+    ,maxUserTemplates:1024
     // idle socket timeout, in miliseconds 
     ,socket_timeout: 600000
     ,enable_cors: true

config/environments/production.js.example

@@ -24,6 +24,8 @@ var config = {
     // Maximum number of connections for one process
     // 128 is a good value with a limit of 1024 open file descriptors
     ,maxConnections:128
+    // Maximum number of templates per user. Unlimited by default.
+    ,maxUserTemplates:1024
     // idle socket timeout, in miliseconds
     ,socket_timeout: 600000 
     ,enable_cors: true

config/environments/staging.js.example

@@ -24,6 +24,8 @@ var config = {
     // Maximum number of connections for one process
     // 128 is a good value with a limit of 1024 open file descriptors
     ,maxConnections:128
+    // Maximum number of templates per user. Unlimited by default.
+    ,maxUserTemplates:1024
     // idle socket timeout, in miliseconds
     ,socket_timeout: 600000 
     ,enable_cors: true

config/environments/test.js.example

@@ -24,6 +24,8 @@ var config = {
     // Maximum number of connections for one process
     // 128 is a good value with a limit of 1024 open file descriptors
     ,maxConnections:128
+    // Maximum number of templates per user. Unlimited by default.
+    ,maxUserTemplates:1024
     // idle socket timeout, in miliseconds
     ,socket_timeout: 600000 
     ,enable_cors: true

lib/cartodb/cartodb_windshaft.js

@@ -30,6 +30,9 @@ var CartodbWindshaft = function(serverOptions) {
     }
 
     serverOptions.signedMaps = new SignedMaps(redisPool);
+    var templateMapsOps = {
+      max_user_templates: global.environment.maxUserTemplates
+    }
     var templateMaps = new TemplateMaps(redisPool, serverOptions.signedMaps);
 
     // boot

lib/cartodb/template_maps.js

@@ -17,9 +17,14 @@ var user_template_locks = {};
 // @param signed_maps an instance of a "signed_maps" class,
 //        See signed_maps.js
 //
-function TemplateMaps(redis_pool, signed_maps) {
+// @param opts TemplateMap options. Supported elements:
+//    'max_user_templates' limit on the number of per-user
+//
+// 
+function TemplateMaps(redis_pool, signed_maps, opts) {
   this.redis_pool = redis_pool;
   this.signed_maps = signed_maps;
+  this.opts = opts || {};
 
   // Database containing templates
   // TODO: allow configuring ?
@@ -49,6 +54,10 @@ var o = TemplateMaps.prototype;
 
 //--------------- PRIVATE METHODS --------------------------------
 
+o._userTemplateLimit = function() {
+  return this.opts['max_user_templates'] || 0;
+};
+
 o._acquireRedis = function(callback) {
   this.redis_pool.acquire(this.db_signatures, callback);
 };
@@ -189,6 +198,7 @@ o.addTemplate = function(owner, template, callback) {
 
   // Procedure:
   //
+  // - Check against limit
   // 0. Obtain a lock for user+template_name, fail if impossible
   // 1. Check no other template exists with the same name
   // 2. Install certificate extracted from template, extending
@@ -202,9 +212,18 @@ o.addTemplate = function(owner, template, callback) {
   var usr_tpl_key = _.template(this.key_usr_tpl, {owner:owner});
   var gotLock = false;
   var that = this;
+  var limit = that._userTemplateLimit();
   Step(
+    function checkLimit() {
+      if ( ! limit ) return 0;
+      that._redisCmd('HLEN', [ usr_tpl_key ], this);
+    },
     // try to obtain a lock
-    function obtainLock() {
+    function obtainLock(err, len) {
+      if ( err ) throw err;
+      if ( limit && len >= limit ) {
+        throw new Error("User '" + owner + "' reached limit on number of templates (" + len + "/" + limit + ")");
+      }
       that._obtainTemplateLock(owner, tplname, this);
     },
     function getExistingTemplate(err, locked) {
@@ -238,10 +257,7 @@ o.addTemplate = function(owner, template, callback) {
         // TODO: how to recover this ?!
       }
 
-      if ( ! gotLock ) {
-        if ( err ) throw err;
-        return null;
-      }
+      if ( err && ! gotLock ) throw err;
 
       // release the lock
       var next = this;

test/unit/cartodb/template_maps.test.js

@@ -421,4 +421,86 @@ suite('template_maps', function() {
     assert.ok(!err);
   });
 
+  // Can set a limit on the number of user templates
+  test('can limit number of user templates', function(done) {
+    var tmap = new TemplateMaps(redis_pool, signed_maps, {
+      max_user_templates: 2
+    });
+    assert.ok(tmap);
+    var tpl = { version:'0.0.1', auth: {}, layergroup: {} };
+    var expectErr = false;
+    var idMe = [];
+    var idYou = [];
+    Step(
+      function oneForMe() {
+        tpl.name = 'oneForMe';
+        tmap.addTemplate('me', tpl, this);
+      },
+      function twoForMe(err, id) {
+        if ( err ) throw err;
+        assert.ok(id);
+        idMe.push(id);
+        tpl.name = 'twoForMe';
+        tmap.addTemplate('me', tpl, this);
+      },
+      function threeForMe(err, id) {
+        if ( err ) throw err;
+        assert.ok(id);
+        idMe.push(id);
+        tpl.name = 'threeForMe';
+        expectErr = true;
+        tmap.addTemplate('me', tpl, this);
+      },
+      function errForMe(err, id) {
+        if ( err && ! expectErr ) throw err;
+        expectErr = false;
+        assert.ok(err);
+        assert.ok(err.message.match(/limit.*template/), err);
+        return null;
+      },
+      function delOneMe(err) {
+        if ( err ) throw err;
+        tmap.delTemplate('me', idMe.shift(), this);
+      },
+      function threeForMeRetry(err) {
+        if ( err ) throw err;
+        tpl.name = 'threeForMe';
+        tmap.addTemplate('me', tpl, this);
+      },
+      function oneForYou(err, id) {
+        if ( err ) throw err;
+        assert.ok(id);
+        idMe.push(id);
+        tpl.name = 'oneForYou';
+        tmap.addTemplate('you', tpl, this);
+      },
+      function twoForYou(err, id) {
+        if ( err ) throw err;
+        assert.ok(id);
+        idYou.push(id);
+        tpl.name = 'twoForYou';
+        tmap.addTemplate('you', tpl, this);
+      },
+      function threeForYou(err, id) {
+        if ( err ) throw err;
+        assert.ok(id);
+        idYou.push(id);
+        tpl.name = 'threeForYou';
+        expectErr = true;
+        tmap.addTemplate('you', tpl, this);
+      },
+      function errForYou(err, id) {
+        if ( err && ! expectErr ) throw err;
+        expectErr = false;
+        assert.ok(err);
+        assert.ok(err.message.match(/limit.*template/), err);
+        return null;
+      },
+      function finish(err) {
+        // TODO: delete all templates
+        done(err);
+      }
+    );
+  });
+    
 });