From 216c877f4bab9648ff693ce62fef03d9c63906e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Simon=20Mart=C3=ADn?= <oleurud@gmail.com>
Date: Tue, 7 Nov 2017 11:07:38 +0100
Subject: [PATCH] verctor error middleware

---
 lib/cartodb/controllers/layergroup.js  | 10 ++++++---
 lib/cartodb/middleware/vector-error.js | 30 ++++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 3 deletions(-)
 create mode 100644 lib/cartodb/middleware/vector-error.js

diff --git a/lib/cartodb/controllers/layergroup.js b/lib/cartodb/controllers/layergroup.js
index c5e4c53a..573c53ee 100644
--- a/lib/cartodb/controllers/layergroup.js
+++ b/lib/cartodb/controllers/layergroup.js
@@ -7,6 +7,7 @@ var BaseController = require('./base');
 var cors = require('../middleware/cors');
 var userMiddleware = require('../middleware/user');
 var allowQueryParams = require('../middleware/allow-query-params');
+var vectorError = require('../middleware/vector-error');
 
 var DataviewBackend = require('../backends/dataview');
 var AnalysisStatusBackend = require('../backends/analysis-status');
@@ -57,7 +58,8 @@ LayergroupController.prototype.register = function(app) {
         cors(),
         userMiddleware,
         this.prepareContext,
-        this.tile.bind(this)
+        this.tile.bind(this),
+        vectorError()
     );
 
     app.get(
@@ -65,7 +67,8 @@ LayergroupController.prototype.register = function(app) {
         cors(),
         userMiddleware,
         this.prepareContext,
-        this.tile.bind(this)
+        this.tile.bind(this),
+        vectorError()
     );
 
     app.get(
@@ -74,7 +77,8 @@ LayergroupController.prototype.register = function(app) {
         userMiddleware,
         validateLayerRouteMiddleware,
         this.prepareContext,
-        this.layer.bind(this)
+        this.layer.bind(this),
+        vectorError()
     );
 
     app.get(
diff --git a/lib/cartodb/middleware/vector-error.js b/lib/cartodb/middleware/vector-error.js
new file mode 100644
index 00000000..3da6ff3b
--- /dev/null
+++ b/lib/cartodb/middleware/vector-error.js
@@ -0,0 +1,30 @@
+const fs = require('fs');
+
+const timeoutErrorVectorTile = fs.readFileSync(__dirname + '/../../../assets/render-timeout-fallback.mvt', {encoding: null});
+
+module.exports = function vectorError() {
+    return function vectorErrorMiddleware(err, req, res, next) {
+        if(req.params.format === 'mvt') {
+
+            if (isTimeoutError(err)) {
+                res.set('Content-Type', 'application/x-protobuf');
+                return res.status(429).send(timeoutErrorVectorTile);
+            }
+        }
+
+        next(err);
+    }
+}
+
+
+function isRenderTimeoutError (err) {
+    return err.message === 'Render timed out';
+}
+
+function isDatasourceTimeoutError (err) {
+    return err.message && err.message.match(/canceling statement due to statement timeout/i);
+}
+
+function isTimeoutError (err) {
+    return isRenderTimeoutError(err) || isDatasourceTimeoutError(err);
+}
\ No newline at end of file