Enforce 500k tile limit at the source, fail in serialization.

lib/stream-util.js

@@ -1,4 +1,5 @@
 var concurrency = Math.ceil(require('os').cpus().length * 16);
+var limits = require('mapbox-upload-limits');
 var util = require('util');
 
 module.exports = {};
@@ -54,6 +55,11 @@ function deserialize(data, property) {
 }
 
 function serializeTile(tile) {
+
+    if (tile.buffer instanceof Buffer && tile.buffer.length > limits.serialtiles.max_tilesize) {
+        throw new Error('Tile is larger than limit of ' + limits.serializetiles.max_tilesize / 1024 + 'k');
+    }
+
     var obj = {
         z: isNaN(tile.z) ? null : Number(tile.z),
         x: isNaN(tile.x) ? null : Number(tile.x),

package.json

@@ -31,10 +31,11 @@
     "Konstantin Käfer <kkaefer>"
   ],
   "dependencies": {
+    "mapbox-upload-limits": "^1.0.1",
     "minimist": "~0.2.0",
     "progress-stream": "~0.5.x",
-    "sphericalmercator": "~1.0.1",
-    "queue-async": "~1.0.7"
+    "queue-async": "~1.0.7",
+    "sphericalmercator": "~1.0.1"
   },
   "devDependencies": {
     "coveralls": "~2.11.1",

test/stream-util.test.js

@@ -164,6 +164,11 @@ test('Tile: serialize', function(t) {
     expected = '{"z":null,"x":null,"y":null,"buffer":null}';
     t.equal(util.serialize(tile), expected, 'serialize garbage tile as expected');
 
+    tile = new util.Tile(1, 2, 3, new Buffer(1e9));
+    t.throws(function() {
+        util.serialize(tile);
+    }, 'Tile is larger than limit');
+
     t.end();
 });