react-native/Libraries/Performance/Systrace.js

325 lines
9.7 KiB
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*
* @providesModule Systrace
* @flow
*/
'use strict';
const invariant = require('fbjs/lib/invariant');
type RelayProfiler = {
attachProfileHandler(
name: string,
handler: (name: string, state?: any) => () => void
): void,
attachAggregateHandler(
name: string,
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;
let _enabled = false;
let _asyncCookie = 0;
const _markStack = [];
let _markStackIndex = -1;
let _canInstallReactHook = false;
let _useFiber = 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__ ? {
mark(markName: string) {
if (_enabled) {
_markStackIndex++;
_markStack[_markStackIndex] = markName;
let systraceLabel = markName;
// Since perf measurements are a shared namespace in User Timing API,
// we prefix all React results with a React emoji.
if (markName[0] === REACT_MARKER) {
// This is coming from React.
// Removing component IDs keeps trace colors stable.
const indexOfId = markName.lastIndexOf(' (#');
const cutoffIndex = indexOfId !== -1 ? indexOfId : markName.length;
// Also cut off the emoji because it breaks Systrace
systraceLabel = markName.slice(2, cutoffIndex);
}
Systrace.beginEvent(systraceLabel);
}
},
measure(measureName: string, startMark: ?string, endMark: ?string) {
if (_enabled) {
invariant(
typeof measureName === 'string' &&
typeof startMark === 'string' &&
typeof endMark === 'undefined',
'Only performance.measure(string, string) overload is supported.'
);
const topMark = _markStack[_markStackIndex];
invariant(
startMark === topMark,
'There was a mismatching performance.measure() call. ' +
'Expected "%s" but got "%s."',
topMark,
startMark,
);
_markStackIndex--;
// We can't use more descriptive measureName because Systrace doesn't
// let us edit labels post factum.
Systrace.endEvent();
}
},
clearMarks(markName: string) {
if (_enabled) {
if (_markStackIndex === -1) {
return;
}
if (markName === _markStack[_markStackIndex]) {
// React uses this for "cancelling" started measurements.
// Systrace doesn't support deleting measurements, so we just stop them.
if (userTimingPolyfill != null) {
userTimingPolyfill.measure(markName, markName);
}
}
}
},
clearMeasures() {
// React calls this to avoid memory leaks in browsers, but we don't keep
// measurements anyway.
},
} : null;
// A hook to get React Stack markers in Systrace.
const reactDebugToolHook = __DEV__ ? {
onBeforeMountComponent(debugID) {
const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
const displayName = ReactComponentTreeHook.getDisplayName(debugID);
Systrace.beginEvent(`ReactReconciler.mountComponent(${displayName})`);
},
onMountComponent(debugID) {
Systrace.endEvent();
},
onBeforeUpdateComponent(debugID) {
const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
const displayName = ReactComponentTreeHook.getDisplayName(debugID);
Systrace.beginEvent(`ReactReconciler.updateComponent(${displayName})`);
},
onUpdateComponent(debugID) {
Systrace.endEvent();
},
onBeforeUnmountComponent(debugID) {
const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
const displayName = ReactComponentTreeHook.getDisplayName(debugID);
Systrace.beginEvent(`ReactReconciler.unmountComponent(${displayName})`);
},
onUnmountComponent(debugID) {
Systrace.endEvent();
},
onBeginLifeCycleTimer(debugID, timerType) {
const ReactComponentTreeHook = require('ReactGlobalSharedState').ReactComponentTreeHook;
const displayName = ReactComponentTreeHook.getDisplayName(debugID);
Systrace.beginEvent(`${displayName}.${timerType}()`);
},
onEndLifeCycleTimer(debugID, timerType) {
Systrace.endEvent();
},
} : null;
const Systrace = {
installReactHook(useFiber: boolean) {
if (_enabled) {
if (__DEV__) {
if (useFiber) {
global.performance = userTimingPolyfill;
} else {
require('ReactDebugTool').addHook(reactDebugToolHook);
}
}
}
_useFiber = useFiber;
_canInstallReactHook = true;
},
setEnabled(enabled: boolean) {
if (_enabled !== enabled) {
if (__DEV__) {
if (enabled) {
global.nativeTraceBeginLegacy && global.nativeTraceBeginLegacy(TRACE_TAG_JS_VM_CALLS);
} else {
global.nativeTraceEndLegacy && global.nativeTraceEndLegacy(TRACE_TAG_JS_VM_CALLS);
}
if (_canInstallReactHook) {
if (_useFiber) {
if (enabled && global.performance === undefined) {
global.performance = userTimingPolyfill;
}
} else {
const ReactDebugTool = require('ReactDebugTool');
if (enabled) {
ReactDebugTool.addHook(reactDebugToolHook);
} else {
ReactDebugTool.removeHook(reactDebugToolHook);
}
}
}
}
_enabled = enabled;
}
},
isEnabled(): boolean {
return _enabled;
},
/**
* beginEvent/endEvent for starting and then ending a profile within the same call stack frame
**/
beginEvent(profileName?: any, args?: any) {
if (_enabled) {
profileName = typeof profileName === 'function' ?
profileName() : profileName;
global.nativeTraceBeginSection(TRACE_TAG_REACT_APPS, profileName, args);
}
},
endEvent() {
if (_enabled) {
global.nativeTraceEndSection(TRACE_TAG_REACT_APPS);
}
},
/**
* beginAsyncEvent/endAsyncEvent for starting and then ending a profile where the end can either
* occur on another thread or out of the current stack frame, eg await
* the returned cookie variable should be used as input into the endAsyncEvent call to end the profile
**/
beginAsyncEvent(profileName?: any): any {
const cookie = _asyncCookie;
if (_enabled) {
_asyncCookie++;
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);
}
},
/**
* counterEvent registers the value to the profileName on the systrace timeline
**/
counterEvent(profileName?: any, value?: any) {
if (_enabled) {
profileName = typeof profileName === 'function' ?
profileName() : profileName;
global.nativeTraceCounter &&
global.nativeTraceCounter(TRACE_TAG_REACT_APPS, profileName, value);
}
},
/**
* Relay profiles use await calls, so likely occur out of current stack frame
* therefore async variant of profiling is used
**/
attachToRelayProfiler(relayProfiler: RelayProfiler) {
relayProfiler.attachProfileHandler('*', (name) => {
const cookie = Systrace.beginAsyncEvent(name);
return () => {
Systrace.endAsyncEvent(name, cookie);
};
});
relayProfiler.attachAggregateHandler('*', (name, callback) => {
Systrace.beginEvent(name);
callback();
Systrace.endEvent();
});
},
/* 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'
]);
},
/**
* Measures multiple methods of a class. For example, you can do:
* Systrace.measureMethods(JSON, 'JSON', ['parse', 'stringify']);
*
* @param object
* @param objectName
* @param methodNames Map from method names to method display names.
*/
measureMethods(object: any, objectName: string, methodNames: Array<string>): void {
if (!__DEV__) {
return;
}
methodNames.forEach(methodName => {
object[methodName] = Systrace.measure(
objectName,
methodName,
object[methodName]
);
});
},
/**
* Returns an profiled version of the input function. For example, you can:
* JSON.parse = Systrace.measure('JSON', 'parse', JSON.parse);
*
* @param objName
* @param fnName
* @param {function} func
* @return {function} replacement function
*/
measure(objName: string, fnName: string, func: any): any {
if (!__DEV__) {
return func;
}
const profileName = `${objName}.${fnName}`;
return function() {
if (!_enabled) {
return func.apply(this, arguments);
}
Systrace.beginEvent(profileName);
const ret = func.apply(this, arguments);
Systrace.endEvent();
return ret;
};
},
};
if (__DEV__) {
// This is needed, because require callis in polyfills are not processed as
// other files. Therefore, calls to `require('moduleId')` are not replaced
// with numeric IDs
// TODO(davidaurelio) Scan polyfills for dependencies, too (t9759686)
(require: any).Systrace = Systrace;
}
module.exports = Systrace;