perf_hooks.importHistogram

History

perf_hooks.importHistogram(data): RecordableHistogram

Attributes

data:Uint8Array

A CBOR-encoded histogram previously produced by histogram.export().

Returns:RecordableHistogram

Reconstructs a histogram from a CBOR-encoded Uint8Array. The returned histogram is a full RecordableHistogram with all bucket data, configuration, and EWMA state restored. New values can be recorded into it.

Data in any format version produced by histogram.export() can be imported. See histogram export format compatibility for details.

const { createHistogram, importHistogram } = require('node:perf_hooks');

const h = createHistogram();
for (let i = 1; i <= 1000; i++) h.record(i);

// Serialize and reconstruct
const data = h.export();
const h2 = importHistogram(data);

console.log(h2.count);          // 1000
console.log(h2.percentile(99)); // Same as h.percentile(99)

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