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GCProfiler

[<Interface>]
type GCProfiler =
    static member Create (start: unit -> unit, stop: unit -> GCProfilerResult) : GCProfiler
    abstract member start () : unit
    abstract member stop () : GCProfilerResult
AssemblyXantham.Fable.Node
Attributes[<Interface>]

This API collects GC data in current thread.

@since v19.6.0, v18.15.0

Methods

static member Create (start: unit -> unit, stop: unit -> GCProfilerResult) : GCProfiler
abstract member start () : unit

Start collecting GC data.

@since v19.6.0, v18.15.0

abstract member stop () : GCProfilerResult

Stop collecting GC data and return an object. The content of object is as follows.

{
"version": 1,
"startTime": 1674059033862,
"statistics": [
{
"gcType": "Scavenge",
"beforeGC": {
"heapStatistics": {
"totalHeapSize": 5005312,
"totalHeapSizeExecutable": 524288,
"totalPhysicalSize": 5226496,
"totalAvailableSize": 4341325216,
"totalGlobalHandlesSize": 8192,
"usedGlobalHandlesSize": 2112,
"usedHeapSize": 4883840,
"heapSizeLimit": 4345298944,
"mallocedMemory": 254128,
"externalMemory": 225138,
"peakMallocedMemory": 181760
},
"heapSpaceStatistics": [
{
"spaceName": "read_only_space",
"spaceSize": 0,
"spaceUsedSize": 0,
"spaceAvailableSize": 0,
"physicalSpaceSize": 0
}
]
},
"cost": 1574.14,
"afterGC": {
"heapStatistics": {
"totalHeapSize": 6053888,
"totalHeapSizeExecutable": 524288,
"totalPhysicalSize": 5500928,
"totalAvailableSize": 4341101384,
"totalGlobalHandlesSize": 8192,
"usedGlobalHandlesSize": 2112,
"usedHeapSize": 4059096,
"heapSizeLimit": 4345298944,
"mallocedMemory": 254128,
"externalMemory": 225138,
"peakMallocedMemory": 181760
},
"heapSpaceStatistics": [
{
"spaceName": "read_only_space",
"spaceSize": 0,
"spaceUsedSize": 0,
"spaceAvailableSize": 0,
"physicalSpaceSize": 0
}
]
}
}
],
"endTime": 1674059036865
}

Here's an example.

import { GCProfiler } from 'node:v8';
const profiler = new GCProfiler();
profiler.start();
setTimeout(() => {
console.log(profiler.stop());
}, 1000);

@since v19.6.0, v18.15.0