Cleanup and modernize S3Adapter to ES6 syntax.

src/Adapters/Files/GridStoreAdapter.js

@@ -0,0 +1,39 @@
+// GridStoreAdapter
+//
+// Stores files in Mongo using GridStore
+// Requires the database adapter to be based on mongoclient
+
+import { GridStore } from 'mongodb';
+import { FilesAdapter } from './FilesAdapter';
+
+export class GridStoreAdapter extends FilesAdapter {
+  // For a given config object, filename, and data, store a file
+  // Returns a promise
+  createFile(config, filename, data) {
+    return config.database.connect().then(() => {
+      let gridStore = new GridStore(config.database.db, filename, 'w');
+      return gridStore.open();
+    }).then((gridStore) => {
+      return gridStore.write(data);
+    }).then((gridStore) => {
+      return gridStore.close();
+    });
+  }
+
+  getFileData(config, filename) {
+    return config.database.connect().then(() => {
+      return GridStore.exist(config.database.db, filename);
+    }).then(() => {
+      let gridStore = new GridStore(config.database.db, filename, 'r');
+      return gridStore.open();
+    }).then((gridStore) => {
+      return gridStore.read();
+    });
+  }
+
+  getFileLocation(config, filename) {
+    return (config.mount + '/files/' + config.applicationId + '/' + encodeURIComponent(filename));
+  }
+}
+
+export default GridStoreAdapter;