RN: Prettify Systrace

Reviewed By: TheSavior

Differential Revision: D7207468

fbshipit-source-id: 05ae6e003ae3e55bc2d3a905f41c28f7041dd7f0

Libraries/Performance/Systrace.js

@@ -6,7 +6,9 @@
  *
  * @providesModule Systrace
  * @flow
+ * @format
  */
+
 'use strict';
 
 const invariant = require('fbjs/lib/invariant');
@@ -14,18 +16,17 @@ const invariant = require('fbjs/lib/invariant');
 type RelayProfiler = {
   attachProfileHandler(
     name: string,
-    handler: (name: string, state?: any) => () => void
+    handler: (name: string, state?: any) => () => void,
   ): void,
 
   attachAggregateHandler(
     name: string,
-    handler: (name: string, callback: () => void) => void
+    handler: (name: string, callback: () => void) => void,
   ): void,
 };
 
-/* eslint no-bitwise: 0 */
-const TRACE_TAG_REACT_APPS = 1 << 17;
-const TRACE_TAG_JS_VM_CALLS = 1 << 27;
+const TRACE_TAG_REACT_APPS = 1 << 17; // eslint-disable-line no-bitwise
+const TRACE_TAG_JS_VM_CALLS = 1 << 27; // eslint-disable-line no-bitwise
 
 let _enabled = false;
 let _asyncCookie = 0;
@@ -36,7 +37,8 @@ let _canInstallReactHook = false;
 // Implements a subset of User Timing API necessary for React measurements.
 // https://developer.mozilla.org/en-US/docs/Web/API/User_Timing_API
 const REACT_MARKER = '\u269B';
-const userTimingPolyfill = __DEV__ ? {
+const userTimingPolyfill = __DEV__
+  ? {
       mark(markName: string) {
         if (_enabled) {
           _markStackIndex++;
@@ -61,7 +63,7 @@ const userTimingPolyfill = __DEV__ ? {
             typeof measureName === 'string' &&
               typeof startMark === 'string' &&
               typeof endMark === 'undefined',
-        'Only performance.measure(string, string) overload is supported.'
+            'Only performance.measure(string, string) overload is supported.',
           );
           const topMark = _markStack[_markStackIndex];
           invariant(
@@ -95,7 +97,8 @@ const userTimingPolyfill = __DEV__ ? {
         // React calls this to avoid memory leaks in browsers, but we don't keep
         // measurements anyway.
       },
-} : null;
+    }
+  : null;
 
 const Systrace = {
   installReactHook() {
@@ -111,9 +114,11 @@ const Systrace = {
     if (_enabled !== enabled) {
       if (__DEV__) {
         if (enabled) {
-          global.nativeTraceBeginLegacy && global.nativeTraceBeginLegacy(TRACE_TAG_JS_VM_CALLS);
+          global.nativeTraceBeginLegacy &&
+            global.nativeTraceBeginLegacy(TRACE_TAG_JS_VM_CALLS);
         } else {
-          global.nativeTraceEndLegacy && global.nativeTraceEndLegacy(TRACE_TAG_JS_VM_CALLS);
+          global.nativeTraceEndLegacy &&
+            global.nativeTraceEndLegacy(TRACE_TAG_JS_VM_CALLS);
         }
         if (_canInstallReactHook) {
           if (enabled && global.performance === undefined) {
@@ -134,8 +139,8 @@ const Systrace = {
    **/
   beginEvent(profileName?: any, args?: any) {
     if (_enabled) {
-      profileName = typeof profileName === 'function' ?
-        profileName() : profileName;
+      profileName =
+        typeof profileName === 'function' ? profileName() : profileName;
       global.nativeTraceBeginSection(TRACE_TAG_REACT_APPS, profileName, args);
     }
   },
@@ -155,18 +160,26 @@ const Systrace = {
     const cookie = _asyncCookie;
     if (_enabled) {
       _asyncCookie++;
-      profileName = typeof profileName === 'function' ?
-        profileName() : profileName;
-      global.nativeTraceBeginAsyncSection(TRACE_TAG_REACT_APPS, profileName, cookie);
+      profileName =
+        typeof profileName === 'function' ? profileName() : profileName;
+      global.nativeTraceBeginAsyncSection(
+        TRACE_TAG_REACT_APPS,
+        profileName,
+        cookie,
+      );
     }
     return cookie;
   },
 
   endAsyncEvent(profileName?: any, cookie?: any) {
     if (_enabled) {
-      profileName = typeof profileName === 'function' ?
-        profileName() : profileName;
-      global.nativeTraceEndAsyncSection(TRACE_TAG_REACT_APPS, profileName, cookie);
+      profileName =
+        typeof profileName === 'function' ? profileName() : profileName;
+      global.nativeTraceEndAsyncSection(
+        TRACE_TAG_REACT_APPS,
+        profileName,
+        cookie,
+      );
     }
   },
 
@@ -175,8 +188,8 @@ const Systrace = {
    **/
   counterEvent(profileName?: any, value?: any) {
     if (_enabled) {
-      profileName = typeof profileName === 'function' ?
-        profileName() : profileName;
+      profileName =
+        typeof profileName === 'function' ? profileName() : profileName;
       global.nativeTraceCounter &&
         global.nativeTraceCounter(TRACE_TAG_REACT_APPS, profileName, value);
     }
@@ -207,10 +220,7 @@ const Systrace = {
   /* This is not called by default due to perf overhead but it's useful
      if you want to find traces which spend too much time in JSON. */
   swizzleJSON() {
-    Systrace.measureMethods(JSON, 'JSON', [
-      'parse',
-      'stringify'
-    ]);
+    Systrace.measureMethods(JSON, 'JSON', ['parse', 'stringify']);
   },
 
   /**
@@ -221,7 +231,11 @@ const Systrace = {
    * @param objectName
    * @param methodNames Map from method names to method display names.
    */
- measureMethods(object: any, objectName: string, methodNames: Array<string>): void {
+  measureMethods(
+    object: any,
+    objectName: string,
+    methodNames: Array<string>,
+  ): void {
     if (!__DEV__) {
       return;
     }
@@ -230,7 +244,7 @@ const Systrace = {
       object[methodName] = Systrace.measure(
         objectName,
         methodName,
-       object[methodName]
+        object[methodName],
       );
     });
   },