Only poll USB devices list when a change is detected

packages/hw-transport-node-hid/package.json

@@ -26,7 +26,9 @@
   "license": "Apache-2.0",
   "dependencies": {
     "@ledgerhq/hw-transport": "^4.21.0",
-    "node-hid": "^0.7.2"
+    "lodash": "^4.17.10",
+    "node-hid": "^0.7.2",
+    "usb": "^1.3.2"
   },
   "devDependencies": {
     "flow-bin": "^0.68.0",

packages/hw-transport-node-hid/src/TransportNodeHid.js

@@ -28,6 +28,7 @@ function defer<T>(): Defer<T> {
 
 let listenDevicesPollingInterval = 500;
 let listenDevicesPollingSkip = () => false;
+let listenDevicesDebug = () => {};
 
 /**
  * node-hid Transport implementation
@@ -68,6 +69,15 @@ export default class TransportNodeHid extends Transport<string> {
     listenDevicesPollingSkip = conditionToSkip;
   };
 
+  static setListenDevicesDebug = (debug: boolean | ((log: string) => void)) => {
+    listenDevicesDebug =
+      typeof debug === "function"
+        ? debug
+        : debug
+          ? (...log) => console.log("[listenDevices]", ...log)
+          : () => {};
+  };
+
   /**
    */
   static listen = (
@@ -85,7 +95,8 @@ export default class TransportNodeHid extends Transport<string> {
     });
     const { events, stop } = listenDevices(
       listenDevicesPollingInterval,
-      listenDevicesPollingSkip
+      listenDevicesPollingSkip,
+      listenDevicesDebug
     );
 
     const onAdd = device => {

packages/hw-transport-node-hid/src/getDevices.js

@@ -1,6 +1,6 @@
 // @flow
 import HID from "node-hid";
-import isLedgerDevice from "./isLedgerDevice";
+
 export default function getDevices(): Array<*> {
-  return HID.devices().filter(isLedgerDevice);
+  return HID.devices(0x2c97, 0x0);
 }

packages/hw-transport-node-hid/src/listenDevices.js

@@ -1,19 +1,21 @@
 // @flow
 
 import EventEmitter from "events";
+import usb from "usb";
+import debounce from "lodash/debounce";
 import getDevices from "./getDevices";
 
 export default (
   delay: number,
-  listenDevicesPollingSkip: () => boolean
+  listenDevicesPollingSkip: () => boolean,
+  debug: (...any) => void
 ): {
   events: EventEmitter,
   stop: () => void
 } => {
   const events = new EventEmitter();
   events.setMaxListeners(0);
 
-  let timeoutDetection;
   let listDevices = getDevices();
 
   const flatDevice = d => d.path;
@@ -27,37 +29,77 @@ export default (
 
   let lastDevices = getFlatDevices();
 
-  const checkDevices = () => {
+  const poll = () => {
     if (!listenDevicesPollingSkip()) {
-      const currentDevices = getFlatDevices();
+      debug("Polling for added or removed devices");
 
+      let changeFound = false;
+      const currentDevices = getFlatDevices();
       const newDevices = currentDevices.filter(d => !lastDevices.includes(d));
-      const removeDevices = lastDevices.filter(
-        d => !currentDevices.includes(d)
-      );
 
       if (newDevices.length > 0) {
+        debug("New device found:", newDevices);
+
         listDevices = getDevices();
         events.emit("add", getDeviceByPaths(newDevices));
+
+        changeFound = true;
+      } else {
+        debug("No new device found");
       }
 
+      const removeDevices = lastDevices.filter(
+        d => !currentDevices.includes(d)
+      );
+
       if (removeDevices.length > 0) {
+        debug("Removed device found:", removeDevices);
+
         events.emit("remove", getDeviceByPaths(removeDevices));
         listDevices = listDevices.filter(
           d => !removeDevices.includes(flatDevice(d))
         );
+
+        changeFound = true;
+      } else {
+        debug("No removed device found");
       }
 
-      lastDevices = currentDevices;
+      if (changeFound) {
+        lastDevices = currentDevices;
+      }
+    } else {
+      debug("Polling skipped, re-debouncing");
+      debouncedPoll();
     }
-    setTimeout(checkDevices, delay);
   };
 
-  timeoutDetection = setTimeout(checkDevices, delay);
+  const debouncedPoll = debounce(poll, delay);
+
+  const attachDetected = device => {
+    debug("Device add detected:", device);
+
+    debouncedPoll();
+  };
+  usb.on("attach", attachDetected);
+  debug("attach listener added");
+
+  const detachDetected = device => {
+    debug("Device removal detected:", device);
+
+    debouncedPoll();
+  };
+  usb.on("detach", detachDetected);
+  debug("detach listener added");
 
   return {
     stop: () => {
-      clearTimeout(timeoutDetection);
+      debug(
+        "Stop received, removing listeners and cancelling pending debounced polls"
+      );
+      debouncedPoll.cancel();
+      usb.removeListener("attach", attachDetected);
+      usb.removeListener("detach", detachDetected);
     },
     events
   };

yarn.lock

@@ -6761,7 +6761,7 @@ lodash.uniq@^4.5.0:
   version "4.17.5"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.5.tgz#99a92d65c0272debe8c96b6057bc8fbfa3bed511"
 
-lodash@^4.15.0, lodash@^4.17.4, lodash@^4.2.0:
+lodash@^4.15.0, lodash@^4.17.10, lodash@^4.17.4, lodash@^4.2.0:
   version "4.17.10"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.10.tgz#1b7793cf7259ea38fb3661d4d38b3260af8ae4e7"
 
@@ -7289,7 +7289,7 @@ mute-stream@0.0.7:
   version "0.0.7"
   resolved "https://registry.yarnpkg.com/mute-stream/-/mute-stream-0.0.7.tgz#3075ce93bc21b8fab43e1bc4da7e8115ed1e7bab"
 
-nan@^2.0.5, nan@^2.0.7, nan@^2.10.0, nan@^2.2.1, nan@^2.3.0, nan@^2.9.2:
+nan@^2.0.5, nan@^2.0.7, nan@^2.10.0, nan@^2.2.1, nan@^2.3.0, nan@^2.8.0, nan@^2.9.2:
   version "2.10.0"
   resolved "https://registry.yarnpkg.com/nan/-/nan-2.10.0.tgz#96d0cd610ebd58d4b4de9cc0c6828cda99c7548f"
 
@@ -7322,6 +7322,14 @@ needle@^2.2.0:
     iconv-lite "^0.4.4"
     sax "^1.2.4"
 
+needle@^2.2.1:
+  version "2.2.1"
+  resolved "https://registry.yarnpkg.com/needle/-/needle-2.2.1.tgz#b5e325bd3aae8c2678902fa296f729455d1d3a7d"
+  dependencies:
+    debug "^2.1.2"
+    iconv-lite "^0.4.4"
+    sax "^1.2.4"
+
 negotiator@0.6.1:
   version "0.6.1"
   resolved "https://registry.yarnpkg.com/negotiator/-/negotiator-0.6.1.tgz#2b327184e8992101177b28563fb5e7102acd0ca9"
@@ -7418,6 +7426,21 @@ node-notifier@^5.0.2:
     shellwords "^0.1.1"
     which "^1.3.0"
 
+node-pre-gyp@^0.10.0:
+  version "0.10.3"
+  resolved "https://registry.yarnpkg.com/node-pre-gyp/-/node-pre-gyp-0.10.3.tgz#3070040716afdc778747b61b6887bf78880b80fc"
+  dependencies:
+    detect-libc "^1.0.2"
+    mkdirp "^0.5.1"
+    needle "^2.2.1"
+    nopt "^4.0.1"
+    npm-packlist "^1.1.6"
+    npmlog "^4.0.2"
+    rc "^1.2.7"
+    rimraf "^2.6.1"
+    semver "^5.3.0"
+    tar "^4"
+
 node-pre-gyp@^0.6.39:
   version "0.6.39"
   resolved "https://registry.yarnpkg.com/node-pre-gyp/-/node-pre-gyp-0.6.39.tgz#c00e96860b23c0e1420ac7befc5044e1d78d8649"
@@ -8752,7 +8775,7 @@ rc@^1.0.1, rc@^1.1.7:
     minimist "^1.2.0"
     strip-json-comments "~2.0.1"
 
-rc@^1.1.6:
+rc@^1.1.6, rc@^1.2.7:
   version "1.2.8"
   resolved "https://registry.yarnpkg.com/rc/-/rc-1.2.8.tgz#cd924bf5200a075b83c188cd6b9e211b7fc0d3ed"
   dependencies:
@@ -10929,6 +10952,13 @@ url@^0.11.0, url@~0.11.0:
     punycode "1.3.2"
     querystring "0.2.0"
 
+usb@^1.3.2:
+  version "1.3.2"
+  resolved "https://registry.yarnpkg.com/usb/-/usb-1.3.2.tgz#4563a32323856e26c97dae374b34c66c3d83b5f4"
+  dependencies:
+    nan "^2.8.0"
+    node-pre-gyp "^0.10.0"
+
 use@^3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/use/-/use-3.1.0.tgz#14716bf03fdfefd03040aef58d8b4b85f3a7c544"