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Diffstat (limited to 'doc/api/perf_hooks.md')
| -rw-r--r-- | doc/api/perf_hooks.md | 69 |
1 files changed, 60 insertions, 9 deletions
diff --git a/doc/api/perf_hooks.md b/doc/api/perf_hooks.md index 553cf3dc79..34d2a58bd0 100644 --- a/doc/api/perf_hooks.md +++ b/doc/api/perf_hooks.md @@ -36,6 +36,7 @@ doSomeLongRunningProcess(() => { ``` ## `perf_hooks.performance` + <!-- YAML added: v8.5.0 --> @@ -44,6 +45,7 @@ An object that can be used to collect performance metrics from the current Node.js instance. It is similar to [`window.performance`][] in browsers. ### `performance.clearMarks([name])` + <!-- YAML added: v8.5.0 --> @@ -54,6 +56,7 @@ If `name` is not provided, removes all `PerformanceMark` objects from the Performance Timeline. If `name` is provided, removes only the named mark. ### `performance.eventLoopUtilization([utilization1[, utilization2]])` + <!-- YAML added: - v14.10.0 @@ -61,9 +64,9 @@ added: --> * `utilization1` {Object} The result of a previous call to - `eventLoopUtilization()`. + `eventLoopUtilization()`. * `utilization2` {Object} The result of a previous call to - `eventLoopUtilization()` prior to `utilization1`. + `eventLoopUtilization()` prior to `utilization1`. * Returns {Object} * `idle` {number} * `active` {number} @@ -116,6 +119,7 @@ Passing in a user-defined object instead of the result of a previous call to are not guaranteed to reflect any correct state of the event loop. ### `performance.mark([name[, options]])` + <!-- YAML added: v8.5.0 changes: @@ -137,6 +141,7 @@ Creates a new `PerformanceMark` entry in the Performance Timeline. A to mark specific significant moments in the Performance Timeline. ### `performance.measure(name[, startMarkOrOptions[, endMark]])` + <!-- YAML added: v8.5.0 changes: @@ -167,18 +172,19 @@ Creates a new `PerformanceMeasure` entry in the Performance Timeline. A `performanceEntry.duration` measures the number of milliseconds elapsed since `startMark` and `endMark`. -The `startMark` argument may identify any *existing* `PerformanceMark` in the -Performance Timeline, or *may* identify any of the timestamp properties +The `startMark` argument may identify any _existing_ `PerformanceMark` in the +Performance Timeline, or _may_ identify any of the timestamp properties provided by the `PerformanceNodeTiming` class. If the named `startMark` does not exist, an error is thrown. -The optional `endMark` argument must identify any *existing* `PerformanceMark` +The optional `endMark` argument must identify any _existing_ `PerformanceMark` in the Performance Timeline or any of the timestamp properties provided by the `PerformanceNodeTiming` class. `endMark` will be `performance.now()` if no parameter is passed, otherwise if the named `endMark` does not exist, an error will be thrown. ### `performance.nodeTiming` + <!-- YAML added: v8.5.0 --> @@ -191,6 +197,7 @@ An instance of the `PerformanceNodeTiming` class that provides performance metrics for specific Node.js operational milestones. ### `performance.now()` + <!-- YAML added: v8.5.0 --> @@ -201,6 +208,7 @@ Returns the current high resolution millisecond timestamp, where 0 represents the start of the current `node` process. ### `performance.timeOrigin` + <!-- YAML added: v8.5.0 --> @@ -211,6 +219,7 @@ The [`timeOrigin`][] specifies the high resolution millisecond timestamp at which the current `node` process began, measured in Unix time. ### `performance.timerify(fn[, options])` + <!-- YAML added: v8.5.0 changes: @@ -262,6 +271,7 @@ to the promise and the duration will be reported once the finally handler is invoked. ### `performance.toJSON()` + <!-- YAML added: v16.1.0 --> @@ -270,11 +280,13 @@ An object which is JSON representation of the `performance` object. It is similar to [`window.performance.toJSON`][] in browsers. ## Class: `PerformanceEntry` + <!-- YAML added: v8.5.0 --> ### `performanceEntry.detail` + <!-- YAML added: v16.0.0 --> @@ -284,6 +296,7 @@ added: v16.0.0 Additional detail specific to the `entryType`. ### `performanceEntry.duration` + <!-- YAML added: v8.5.0 --> @@ -294,6 +307,7 @@ The total number of milliseconds elapsed for this entry. This value will not be meaningful for all Performance Entry types. ### `performanceEntry.entryType` + <!-- YAML added: v8.5.0 --> @@ -311,6 +325,7 @@ The type of the performance entry. It may be one of: * `'http'` (Node.js only) ### `performanceEntry.flags` + <!-- YAML added: - v13.9.0 @@ -339,6 +354,7 @@ The value may be one of: * `perf_hooks.constants.NODE_PERFORMANCE_GC_FLAGS_SCHEDULE_IDLE` ### `performanceEntry.name` + <!-- YAML added: v8.5.0 --> @@ -348,6 +364,7 @@ added: v8.5.0 The name of the performance entry. ### `performanceEntry.kind` + <!-- YAML added: v8.5.0 changes: @@ -371,6 +388,7 @@ The value may be one of: * `perf_hooks.constants.NODE_PERFORMANCE_GC_WEAKCB` ### `performanceEntry.startTime` + <!-- YAML added: v8.5.0 --> @@ -447,6 +465,7 @@ When `performanceEntry.type` is equal to `'function'`, the the input arguments to the timed function. ## Class: `PerformanceNodeTiming` + <!-- YAML added: v8.5.0 --> @@ -459,6 +478,7 @@ Provides timing details for Node.js itself. The constructor of this class is not exposed to users. ### `performanceNodeTiming.bootstrapComplete` + <!-- YAML added: v8.5.0 --> @@ -470,6 +490,7 @@ completed bootstrapping. If bootstrapping has not yet finished, the property has the value of -1. ### `performanceNodeTiming.environment` + <!-- YAML added: v8.5.0 --> @@ -480,6 +501,7 @@ The high resolution millisecond timestamp at which the Node.js environment was initialized. ### `performanceNodeTiming.idleTime` + <!-- YAML added: - v14.10.0 @@ -495,6 +517,7 @@ started (e.g., in the first tick of the main script), the property has the value of 0. ### `performanceNodeTiming.loopExit` + <!-- YAML added: v8.5.0 --> @@ -506,6 +529,7 @@ exited. If the event loop has not yet exited, the property has the value of -1. It can only have a value of not -1 in a handler of the [`'exit'`][] event. ### `performanceNodeTiming.loopStart` + <!-- YAML added: v8.5.0 --> @@ -517,6 +541,7 @@ started. If the event loop has not yet started (e.g., in the first tick of the main script), the property has the value of -1. ### `performanceNodeTiming.nodeStart` + <!-- YAML added: v8.5.0 --> @@ -527,6 +552,7 @@ The high resolution millisecond timestamp at which the Node.js process was initialized. ### `performanceNodeTiming.v8Start` + <!-- YAML added: v8.5.0 --> @@ -539,6 +565,7 @@ initialized. ## Class: `perf_hooks.PerformanceObserver` ### `new PerformanceObserver(callback)` + <!-- YAML added: v8.5.0 --> @@ -576,12 +603,15 @@ notified about new `PerformanceEntry` instances. The callback receives a `PerformanceObserver`. ### `performanceObserver.disconnect()` + <!-- YAML added: v8.5.0 --> + Disconnects the `PerformanceObserver` instance from all notifications. ### `performanceObserver.observe(options)` + <!-- YAML added: v8.5.0 changes: @@ -598,7 +628,7 @@ changes: * `options` {Object} * `type` {string} A single {PerformanceEntry} type. Must not be given if `entryTypes` is already specified. - * `entryTypes` {string[]} An array of strings identifying the types of + * `entryTypes` {string\[]} An array of strings identifying the types of {PerformanceEntry} instances the observer is interested in. If not provided an error will be thrown. * `buffered` {boolean} If true, the observer callback is called with a @@ -626,6 +656,7 @@ for (let n = 0; n < 3; n++) ``` ## Class: `PerformanceObserverEntryList` + <!-- YAML added: v8.5.0 --> @@ -635,11 +666,12 @@ The `PerformanceObserverEntryList` class is used to provide access to the The constructor of this class is not exposed to users. ### `performanceObserverEntryList.getEntries()` + <!-- YAML added: v8.5.0 --> -* Returns: {PerformanceEntry[]} +* Returns: {PerformanceEntry\[]} Returns a list of `PerformanceEntry` objects in chronological order with respect to `performanceEntry.startTime`. @@ -677,13 +709,14 @@ performance.mark('meow'); ``` ### `performanceObserverEntryList.getEntriesByName(name[, type])` + <!-- YAML added: v8.5.0 --> * `name` {string} * `type` {string} -* Returns: {PerformanceEntry[]} +* Returns: {PerformanceEntry\[]} Returns a list of `PerformanceEntry` objects in chronological order with respect to `performanceEntry.startTime` whose `performanceEntry.name` is @@ -731,12 +764,13 @@ performance.mark('meow'); ``` ### `performanceObserverEntryList.getEntriesByType(type)` + <!-- YAML added: v8.5.0 --> * `type` {string} -* Returns: {PerformanceEntry[]} +* Returns: {PerformanceEntry\[]} Returns a list of `PerformanceEntry` objects in chronological order with respect to `performanceEntry.startTime` whose `performanceEntry.entryType` @@ -775,6 +809,7 @@ performance.mark('meow'); ``` ## `perf_hooks.createHistogram([options])` + <!-- YAML added: - v15.9.0 @@ -793,6 +828,7 @@ added: Returns a {RecordableHistogram}. ## `perf_hooks.monitorEventLoopDelay([options])` + <!-- YAML added: v11.10.0 --> @@ -829,11 +865,13 @@ console.log(h.percentile(99)); ``` ## Class: `Histogram` + <!-- YAML added: v11.10.0 --> ### `histogram.exceeds` + <!-- YAML added: v11.10.0 --> @@ -844,6 +882,7 @@ The number of times the event loop delay exceeded the maximum 1 hour event loop delay threshold. ### `histogram.max` + <!-- YAML added: v11.10.0 --> @@ -853,6 +892,7 @@ added: v11.10.0 The maximum recorded event loop delay. ### `histogram.mean` + <!-- YAML added: v11.10.0 --> @@ -862,6 +902,7 @@ added: v11.10.0 The mean of the recorded event loop delays. ### `histogram.min` + <!-- YAML added: v11.10.0 --> @@ -871,6 +912,7 @@ added: v11.10.0 The minimum recorded event loop delay. ### `histogram.percentile(percentile)` + <!-- YAML added: v11.10.0 --> @@ -881,6 +923,7 @@ added: v11.10.0 Returns the value at the given percentile. ### `histogram.percentiles` + <!-- YAML added: v11.10.0 --> @@ -890,6 +933,7 @@ added: v11.10.0 Returns a `Map` object detailing the accumulated percentile distribution. ### `histogram.reset()` + <!-- YAML added: v11.10.0 --> @@ -897,6 +941,7 @@ added: v11.10.0 Resets the collected histogram data. ### `histogram.stddev` + <!-- YAML added: v11.10.0 --> @@ -910,6 +955,7 @@ The standard deviation of the recorded event loop delays. A `Histogram` that is periodically updated on a given interval. ### `histogram.disable()` + <!-- YAML added: v11.10.0 --> @@ -920,6 +966,7 @@ Disables the update interval timer. Returns `true` if the timer was stopped, `false` if it was already stopped. ### `histogram.enable()` + <!-- YAML added: v11.10.0 --> @@ -936,6 +983,7 @@ end, the histogram is cloned as a plain {Histogram} object that does not implement the `enable()` and `disable()` methods. ## Class: `RecordableHistogram extends Histogram` + <!-- YAML added: - v15.9.0 @@ -943,6 +991,7 @@ added: --> ### `histogram.record(val)` + <!-- YAML added: - v15.9.0 @@ -952,6 +1001,7 @@ added: * `val` {number|bigint} The amount to record in the histogram. ### `histogram.recordDelta()` + <!-- YAML added: - v15.9.0 @@ -1013,6 +1063,7 @@ The following example measures the duration of `require()` operations to load dependencies: <!-- eslint-disable no-global-assign --> + ```js 'use strict'; const { |