Encapsulate and test some Bucket logic that was broken by a prior commit

js/data/bucket.js

@@ -265,6 +265,38 @@ Bucket.prototype.trimArrays = function() {
     }
 };
 
+Bucket.prototype.isEmpty = function() {
+    for (var programName in this.arrayGroups) {
+        var arrayGroups = this.arrayGroups[programName];
+        for (var i = 0; i < arrayGroups.length; i++) {
+            var arrayGroup = arrayGroups[i];
+            if (arrayGroup.vertexArray.length > 0) {
+                return false;
+            }
+        }
+    }
+    return true;
+};
+
+Bucket.prototype.getTransferables = function(transferables) {
+    for (var programName in this.arrayGroups) {
+        var arrayGroups = this.arrayGroups[programName];
+        for (var i = 0; i < arrayGroups.length; i++) {
+            var arrayGroup = arrayGroups[i];
+            transferables.push(arrayGroup.vertexArray.arrayBuffer);
+            if (arrayGroup.elementArray) {
+                transferables.push(arrayGroup.elementArray.arrayBuffer);
+            }
+            if (arrayGroup.elementArray2) {
+                transferables.push(arrayGroup.elementArray2.arrayBuffer);
+            }
+            for (var paintArray in arrayGroup.paintArrays) {
+                transferables.push(arrayGroup.paintArrays[paintArray].arrayBuffer);
+            }
+        }
+    }
+};
+
 Bucket.prototype.setUniforms = function(gl, programName, program, layer, globalProperties) {
     var uniforms = this.paintAttributes[programName][layer.id].uniforms;
     for (var i = 0; i < uniforms.length; i++) {

js/source/worker_tile.js

@@ -216,8 +216,7 @@ WorkerTile.prototype.parse = function(data, layerFamilies, actor, rawTileData, c
         var symbolInstancesArray = tile.symbolInstancesArray.serialize();
         var symbolQuadsArray = tile.symbolQuadsArray.serialize();
         var transferables = [rawTileData].concat(featureIndex_.transferables).concat(collisionTile_.transferables);
-
-        var nonEmptyBuckets = buckets.filter(isBucketEmpty);
+        var nonEmptyBuckets = buckets.filter(isBucketNonEmpty);
 
         callback(null, {
             buckets: nonEmptyBuckets.map(serializeBucket),
@@ -248,8 +247,7 @@ WorkerTile.prototype.redoPlacement = function(angle, pitch, showCollisionBoxes)
     }
 
     var collisionTile_ = collisionTile.serialize();
-
-    var nonEmptyBuckets = buckets.filter(isBucketEmpty);
+    var nonEmptyBuckets = buckets.filter(isBucketNonEmpty);
 
     return {
         result: {
@@ -260,20 +258,8 @@ WorkerTile.prototype.redoPlacement = function(angle, pitch, showCollisionBoxes)
     };
 };
 
-function isBucketEmpty(bucket) {
-    for (var programName in bucket.arrayGroups) {
-        var programArrayGroups = bucket.arrayGroups[programName];
-        for (var k = 0; k < programArrayGroups.length; k++) {
-            var programArrayGroup = programArrayGroups[k];
-            for (var layoutOrPaint in programArrayGroup) {
-                var arrays = programArrayGroup[layoutOrPaint];
-                for (var bufferName in arrays) {
-                    if (arrays[bufferName].length > 0) return true;
-                }
-            }
-        }
-    }
-    return false;
+function isBucketNonEmpty(bucket) {
+    return !bucket.isEmpty();
 }
 
 function serializeBucket(bucket) {
@@ -283,19 +269,7 @@ function serializeBucket(bucket) {
 function getTransferables(buckets) {
     var transferables = [];
     for (var i in buckets) {
-        var bucket = buckets[i];
-        for (var programName in bucket.arrayGroups) {
-            var programArrayGroups = bucket.arrayGroups[programName];
-            for (var k = 0; k < programArrayGroups.length; k++) {
-                var programArrayGroup = programArrayGroups[k];
-                for (var layoutOrPaint in programArrayGroup) {
-                    var arrays = programArrayGroup[layoutOrPaint];
-                    for (var bufferName in arrays) {
-                        transferables.push(arrays[bufferName].arrayBuffer);
-                    }
-                }
-            }
-        }
+        buckets[i].getTransferables(transferables);
     }
     return transferables;
 }

test/js/data/bucket.test.js

@@ -215,6 +215,37 @@ test('Bucket', function(t) {
         t.end();
     });
 
+    t.test('isEmpty', function(t) {
+        var bucket = create()
+        t.ok(bucket.isEmpty());
+
+        bucket.createArrays();
+        t.ok(bucket.isEmpty());
+
+        bucket.features = [createFeature(17, 42)];
+        bucket.populateArrays();
+        t.ok(!bucket.isEmpty());
+
+        t.end();
+    });
+
+    t.test('getTransferables', function(t) {
+        var bucket = create();
+        bucket.features = [createFeature(17, 42)];
+        bucket.populateArrays();
+
+        var transferables = [];
+        bucket.getTransferables(transferables);
+
+        t.equal(4, transferables.length);
+        t.equal(bucket.arrayGroups.test[0].vertexArray.arrayBuffer, transferables[0]);
+        t.equal(bucket.arrayGroups.test[0].elementArray.arrayBuffer, transferables[1]);
+        t.equal(bucket.arrayGroups.test[0].elementArray2.arrayBuffer, transferables[2]);
+        t.equal(bucket.arrayGroups.test[0].paintArrays.layerid.arrayBuffer, transferables[3]);
+
+        t.end();
+    });
+
     t.test('add features after resetting buffers', function(t) {
         var bucket = create();