Middlewarify tile and layer endpoints

lib/cartodb/controllers/layergroup.js

@@ -51,7 +51,8 @@ LayergroupController.prototype.register = function(app) {
         cors(),
         userMiddleware,
         this.prepareContext,
-        this.tile.bind(this),
+        this.getMapStoreMapConfigProvider(this.mapStore, this.userLimitsApi),
+        this.tile(this.tileBackend),
         vectorError()
     );
 
@@ -60,7 +61,8 @@ LayergroupController.prototype.register = function(app) {
         cors(),
         userMiddleware,
         this.prepareContext,
-        this.tile.bind(this),
+        this.getMapStoreMapConfigProvider(this.mapStore, this.userLimitsApi),
+        this.tile(this.tileBackend),
         vectorError()
     );
 
@@ -70,7 +72,8 @@ LayergroupController.prototype.register = function(app) {
         userMiddleware,
         validateLayerRouteMiddleware,
         this.prepareContext,
-        this.layer.bind(this),
+        this.getMapStoreMapConfigProvider(this.mapStore, this.userLimitsApi),
+        this.layer(this.tileBackend),
         vectorError()
     );
 
@@ -269,80 +272,102 @@ LayergroupController.prototype.attributes = function (attributesBackend) {
     }.bind(this);
 };
 
-// Gets a tile for a given token and set of tile ZXY coords. (OSM style)
-LayergroupController.prototype.tile = function(req, res, next) {
-    req.profiler.start('windshaft.map_tile');
-    this.tileOrLayer(req, res, next);
-};
-
-// Gets a tile for a given token, layer set of tile ZXY coords. (OSM style)
-LayergroupController.prototype.layer = function(req, res, next) {
-    req.profiler.start('windshaft.maplayer_tile');
-    this.tileOrLayer(req, res, next);
-};
-
-LayergroupController.prototype.tileOrLayer = function (req, res, next) {
-    var self = this;
-
-    step(
-        function mapController$getTileOrGrid() {
-            self.tileBackend.getTile(
-                new MapStoreMapConfigProvider(self.mapStore, res.locals.user, self.userLimitsApi, res.locals),
-                res.locals, this
-            );
-        },
-        function mapController$finalize(err, tile, headers, stats) {
-            req.profiler.add(stats);
-            self.finalizeGetTileOrGrid(err, req, res, tile, headers, next);
-        }
-    );
-};
-
 function getStatusCode(tile, format){
     return tile.length===0 && format==='mvt'? 204:200;
 }
 
-// This function is meant for being called as the very last
-// step by all endpoints serving tiles or grids
-LayergroupController.prototype.finalizeGetTileOrGrid = function(err, req, res, tile, headers, next) {
-    var supportedFormats = {
-        grid_json: true,
-        json_torque: true,
-        torque_json: true,
-        png: true,
-        png32: true,
-        mvt: true
-    };
+const supportedFormats = {
+    grid_json: true,
+    json_torque: true,
+    torque_json: true,
+    png: true,
+    png32: true,
+    mvt: true
+};
 
-    var formatStat = 'invalid';
-    if (req.params.format) {
-        var format = req.params.format.replace('.', '_');
-        if (supportedFormats[format]) {
-            formatStat = format;
-        }
+function parseFormat (format = null) {
+    const prettyFormat = format.replace('.', '_');
+    let formatStat = 'invalid';
+
+    if (supportedFormats[prettyFormat]) {
+        formatStat = prettyFormat;
     }
 
-    if (err) {
-        // See https://github.com/Vizzuality/Windshaft-cartodb/issues/68
-        var errMsg = err.message ? ( '' + err.message ) : ( '' + err );
+    return formatStat;
+}
 
-        // Rewrite mapnik parsing errors to start with layer number
-        var matches = errMsg.match("(.*) in style 'layer([0-9]+)'");
-        if (matches) {
-            errMsg = 'style'+matches[2]+': ' + matches[1];
-        }
-        err.message = errMsg;
+function augmentError (err) {
+    // See https://github.com/Vizzuality/Windshaft-cartodb/issues/68
+    let errMsg = err.message ? ( '' + err.message ) : ( '' + err );
 
-        err.label = 'TILE RENDER';
-        next(err);
+    // Rewrite mapnik parsing errors to start with layer number
+    const matches = errMsg.match("(.*) in style 'layer([0-9]+)'");
 
-        global.statsClient.increment('windshaft.tiles.error');
-        global.statsClient.increment('windshaft.tiles.' + formatStat + '.error');
-    } else {
-        this.sendResponse(req, res, tile, getStatusCode(tile, formatStat), headers);
-        global.statsClient.increment('windshaft.tiles.success');
-        global.statsClient.increment('windshaft.tiles.' + formatStat + '.success');
+    if (matches) {
+        errMsg = 'style' + matches[2] + ': ' + matches[1];
     }
+
+    err.message = errMsg;
+    err.label = 'TILE RENDER';
+
+    return err;
+}
+
+LayergroupController.prototype.tile = function (tileBackend) {
+    return function tileMiddleware (req, res, next) {
+        req.profiler.start('windshaft.map_tile');
+
+        const { mapConfigProvider } = res.locals;
+        const params = getRequestParams(res.locals);
+
+        tileBackend.getTile(mapConfigProvider, params, (err, tile, headers, stats) => {
+            req.profiler.add(stats);
+
+            const formatStat = parseFormat(req.params.format);
+
+            if (err) {
+                next(augmentError(err));
+
+                global.statsClient.increment('windshaft.tiles.error');
+                global.statsClient.increment('windshaft.tiles.' + formatStat + '.error');
+
+                return;
+            }
+
+            this.sendResponse(req, res, tile, getStatusCode(tile, formatStat), headers);
+
+            global.statsClient.increment('windshaft.tiles.success');
+            global.statsClient.increment('windshaft.tiles.' + formatStat + '.success');
+        });
+    }.bind(this);
+};
+
+LayergroupController.prototype.layer = function (tileBackend) {
+    return function layerMiddleware (req, res, next) {
+        req.profiler.start('windshaft.maplayer_tile');
+
+        const { mapConfigProvider } = res.locals;
+        const params = getRequestParams(res.locals);
+
+        tileBackend.getTile(mapConfigProvider, params, (err, tile, headers, stats) => {
+            req.profiler.add(stats);
+
+            const formatStat = parseFormat(req.params.format);
+
+            if (err) {
+                next(augmentError(err));
+
+                global.statsClient.increment('windshaft.tiles.error');
+                global.statsClient.increment('windshaft.tiles.' + formatStat + '.error');
+
+                return;
+            }
+
+            this.sendResponse(req, res, tile, getStatusCode(tile, formatStat), headers);
+            global.statsClient.increment('windshaft.tiles.success');
+            global.statsClient.increment('windshaft.tiles.' + formatStat + '.success');
+        });
+    }.bind(this);
 };
 
 LayergroupController.prototype.center = function (previewBackend) {