From 875eccba62131a7632b2657b178551e0cebb7902 Mon Sep 17 00:00:00 2001
From: Raul Ochoa <rochoaf@gmail.com>
Date: Mon, 7 Sep 2015 18:22:24 +0200
Subject: [PATCH] Stop adding X-Cache-Channel header when no tables were
 identified in SQL query

Fixes #238 and fixes #157
---
 app/controllers/app.js             |  2 +-
 test/acceptance/app.test.js        |  2 +-
 test/acceptance/x-cache-channel.js | 26 ++++++++++++++++++++++++++
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/app/controllers/app.js b/app/controllers/app.js
index 158b2827..46636ac8 100755
--- a/app/controllers/app.js
+++ b/app/controllers/app.js
@@ -488,7 +488,7 @@ function handleQuery(req, res) {
                 }
 
                 // Only set an X-Cache-Channel for responses we want Varnish to cache.
-                if ( tableCacheItem && ! tableCacheItem.may_write ) {
+                if ( tableCacheItem && tableCacheItem.affected_tables.length > 0 && !tableCacheItem.may_write ) {
                   res.header('X-Cache-Channel', generateCacheKey(dbopts.dbname, tableCacheItem, authenticated));
                 }
 
diff --git a/test/acceptance/app.test.js b/test/acceptance/app.test.js
index 78644c90..6db04df3 100644
--- a/test/acceptance/app.test.js
+++ b/test/acceptance/app.test.js
@@ -1082,7 +1082,7 @@ it('numeric arrays are rendered as such', function(done){
         assert.equal(out.rows[0].x.length, 2);
         assert.equal(out.rows[0].x[0], '8.7');
         assert.equal(out.rows[0].x[1], '4.3');
-        assert.equal(res.headers['x-cache-channel'], 'cartodb_test_user_1_db:'); // keep forever
+        assert.equal(res.headers.hasOwnProperty('x-cache-channel'), false);
         done();
     });
 });
diff --git a/test/acceptance/x-cache-channel.js b/test/acceptance/x-cache-channel.js
index b06bb420..53c58cc1 100644
--- a/test/acceptance/x-cache-channel.js
+++ b/test/acceptance/x-cache-channel.js
@@ -84,4 +84,30 @@ describe('X-Cache-Channel header', function() {
         ], done));
     });
 
+    it('should not add header for functions', function(done) {
+        var sql = "SELECT format('%s', 'wadus')";
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, function(res) {
+            assert.ok(!res.headers.hasOwnProperty('x-cache-channel'), res.headers['x-cache-channel']);
+            done();
+        });
+    });
+
+    it('should not add header for CDB_QueryTables', function(done) {
+        var sql = "SELECT CDB_QueryTablesText('select * from untitle_table_4')";
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, function(res) {
+            assert.ok(!res.headers.hasOwnProperty('x-cache-channel'), res.headers['x-cache-channel']);
+            done();
+        });
+    });
+
+    it('should not add header for non table results', function(done) {
+        var sql = "SELECT 'wadus'::text";
+        assert.response(app, createGetRequest(sql), RESPONSE_OK, function(res) {
+            assert.ok(!res.headers.hasOwnProperty('x-cache-channel'), res.headers['x-cache-channel']);
+            done();
+        });
+    });
+
+
+
 });