[node] Benchmark/stress test

Tries to simulate the workload from api-gl.

platform/node/test/benchmark.js

@@ -0,0 +1,104 @@
+'use strict';
+
+var mockfs = require('./mockfs');
+var mbgl = require('../index');
+var test = require('tape');
+
+var firstRequest = "mapbox://sprites/mapbox/streets-v9@2x.json";
+
+var params = {
+    mapPoolSize: 10,
+    numRenderings: 1000,
+    failurePercentage: 0,
+    timeoutPercentage: 0,
+    renderingTimeout: 5000,
+    ratio: 2
+};
+
+test('Benchmark', function(t) {
+    console.time('Time');
+
+    var renderCount = 0;
+    var failureCount = 0;
+    var timeoutCount = 0;
+
+    var options = {
+        request: function(req, callback) {
+            setTimeout(function() {
+                var num = Math.floor(Math.random() * 100);
+
+                if (req.url == firstRequest && num < params.failurePercentage) {
+                    callback(new Error('Failure'));
+                } else if (req.url == firstRequest && num > 99 - params.timeoutPercentage) {
+                    setTimeout(function() { callback(new Error('Timeout')); }, params.renderingTimeout * 5);
+                } else {
+                    var data = mockfs.dataForRequest(req);
+                    callback(null, { data: mockfs.dataForRequest(req) });
+                }
+            }, 0);
+        },
+        ratio: params.ratio,
+    };
+
+    var mapPool = []
+
+    for (var i = 0; i < params.mapPoolSize; ++i) {
+        var map = new mbgl.Map(options);
+        mapPool.push(map);
+    }
+
+    var interval = setInterval(function () {
+        if (mapPool.length == 0 || renderCount == params.numRenderings) {
+            return;
+        }
+
+        var map = mapPool.shift();
+
+        map.load('{ "version": 8, "sources": {}, "layers": [] }');
+        map.load(mockfs.style_vector);
+
+        renderCount += 1;
+
+        if (renderCount % (params.numRenderings / 100) == 0) {
+            // Print some progress, so slow build bots don't timeout.
+            t.comment('Rendering (' + renderCount.toString() +
+                '/' + params.numRenderings.toString() + ')');
+        }
+
+        if (renderCount == params.numRenderings) {
+            clearInterval(interval);
+            t.end();
+            console.timeEnd('Time');
+            console.log('Failures: ' + failureCount);
+            console.log('Timeouts: ' + timeoutCount);
+
+            return;
+        }
+
+        var mapTimeout = setTimeout(function() {
+            map.release();
+            mapPool.push(new mbgl.Map(options));
+            timeoutCount += 1;
+        }, params.renderingTimeout);
+
+        map.render({ zoom: 16 }, function(err, pixels) {
+            clearTimeout(mapTimeout);
+
+            if (err) {
+                if (err.message == 'Failure') {
+                    failureCount += 1;
+                }
+
+                if (err.message == 'Timeout') {
+                    t.fail('should never happen');
+                }
+
+                map.release();
+                mapPool.push(new mbgl.Map(options));
+                return;
+            }
+
+            mapPool.push(map);
+        });
+    }, 1);
+});