Fix high pkd CPU usage issue

Summary:
Running `instruments -s devices` causes the `pkd` process in catalina to spike to ~100% for a few seconds.

Flipper runs this command every 3 seconds to poll for devices.
This switches it to use `idb list-targets` instead which is much more performant.

Currently switched off in the open-source version while we make sure it's working well. If you set the GK value 'flipper_use_idb_to_list_devices' to true, then you'll get the new behaviour.

Reviewed By: passy

Differential Revision: D23102067

fbshipit-source-id: 9e17155d938a4fe326e082511f747444e4b533a2

desktop/app/src/dispatcher/iOSDevice.tsx

@@ -81,9 +81,11 @@ async function queryDevices(store: Store, logger: Logger): Promise<any> {
     getActiveSimulators().then((devices) => {
       processDevices(store, logger, devices, 'emulator');
     }),
-    getActiveDevices().then((devices) => {
-      processDevices(store, logger, devices, 'physical');
-    }),
+    getActiveDevices(store.getState().settingsState.idbPath).then(
+      (devices: IOSDeviceParams[]) => {
+        processDevices(store, logger, devices, 'physical');
+      },
+    ),
   ]);
 }
 
@@ -173,8 +175,8 @@ function getActiveSimulators(): Promise<Array<IOSDeviceParams>> {
     .catch((_) => []);
 }
 
-function getActiveDevices(): Promise<Array<IOSDeviceParams>> {
-  return iosUtil.targets().catch((e) => {
+function getActiveDevices(idbPath: string): Promise<Array<IOSDeviceParams>> {
+  return iosUtil.targets(idbPath).catch((e) => {
     console.error(e.message);
     return [];
   });
@@ -233,12 +235,12 @@ async function isXcodeDetected(): Promise<boolean> {
     .catch((_) => false);
 }
 
-export async function getActiveDevicesAndSimulators(): Promise<
-  Array<IOSDevice>
-> {
+export async function getActiveDevicesAndSimulators(
+  store: Store,
+): Promise<Array<IOSDevice>> {
   const activeDevices: Array<Array<IOSDeviceParams>> = await Promise.all([
     getActiveSimulators(),
-    getActiveDevices(),
+    getActiveDevices(store.getState().settingsState.idbPath),
   ]);
   const allDevices = activeDevices[0].concat(activeDevices[1]);
   return allDevices.map((device) => {