Add pre-filters to adapter

Author: thegecko

src/adapter.ts

@@ -89,7 +89,7 @@ export interface Adapter {
     getConnected(handle: string): boolean;
     getOpened(handle: string): boolean;
 
-    listUSBDevices(): Promise<Array<USBDevice>>;
+    listUSBDevices(filters: Array<USBDeviceFilter>): Promise<Array<USBDevice>>;
     open(handle: string): Promise<void>;
     close(handle: string): Promise<void>;
     selectConfiguration(handle: string, id: number): Promise<void>;
@@ -234,13 +234,38 @@ export class USBAdapter extends EventEmitter implements Adapter {
         });
     }
 
-    private loadDevices(): Promise<Array<Device>> {
+    private loadDevices(filters: Array<USBDeviceFilter>): Promise<Array<Device>> {
         // Reset device cache
         this.devices = {};
-        const devices = getDeviceList();
+        let devices = getDeviceList();
+
+        // Pre-filter devices
+        devices = this.filterDevices(devices, filters);
         return this.serialPromises(this.loadDevice, devices);
     }
 
+    private filterDevices(devices: Array<Device>, filters: Array<USBDeviceFilter>): Array<Device> {
+        return devices.filter(device => filters.some(filter => {
+            // Vendor
+            if (filter.vendorId && filter.vendorId !== device.deviceDescriptor.idVendor) return false;
+
+            // Product
+            if (filter.productId && filter.productId !== device.deviceDescriptor.idProduct) return false;
+
+            // Class
+            if (filter.classCode && filter.classCode !== device.deviceDescriptor.bDeviceClass) return false;
+
+            // Subclass
+            if (filter.subclassCode && filter.subclassCode !== device.deviceDescriptor.bDeviceSubClass) return false;
+
+            // Protocol
+            if (filter.protocolCode && filter.protocolCode !== device.deviceDescriptor.bDeviceProtocol) return false;
+
+            // Ignore serial number for node-usb as it requires device connection
+            return true;
+        }));
+    }
+
     private loadDevice(device: Device, retries: number = 0): Promise<Device> {
 
         // Early guard against unsupported USB devices
@@ -590,8 +615,8 @@ export class USBAdapter extends EventEmitter implements Adapter {
         return (device.interfaces !== null);
     }
 
-    public listUSBDevices(): Promise<Array<USBDevice>> {
-        return this.loadDevices()
+    public listUSBDevices(filters: Array<USBDeviceFilter>): Promise<Array<USBDevice>> {
+        return this.loadDevices(filters)
         .then(() => {
             return this.serialPromises(this.devicetoUSBDevice, Object.keys(this.devices));
         });

src/usb.ts

@@ -210,8 +210,18 @@ export class USB extends (EventDispatcher as new() => TypedDispatcher<USBEvents>
      * @returns Promise containing an array of devices
      */
     public getDevices(): Promise<Array<USBDevice>> {
+        // Create pre-filters
+        const filters = this.allowedDevices.map(device => ({
+            vendorId: device.vendorId || undefined,
+            productId: device.productId || undefined,
+            classCode: device.deviceClass || undefined,
+            subclassCode: device.deviceSubclass || undefined,
+            protocolCode: device.deviceProtocol || undefined,
+            serialNumber: device.serialNumber || undefined
+        }));
+
         // Refresh devices and filter for allowed ones
-        return adapter.listUSBDevices()
+        return adapter.listUSBDevices(filters)
         .then(devices => {
             const allowed = devices.filter(device => {
                 if (!device.connected) {
@@ -278,7 +288,7 @@ export class USB extends (EventDispatcher as new() => TypedDispatcher<USBEvents>
 
             if (!check) return;
 
-            return adapter.listUSBDevices()
+            return adapter.listUSBDevices(options.filters)
             .then(devices => {
                 devices = devices.filter(device => this.filterDevice(options, device));