alexion
6081e3e325
Imported as a linear vendor commit so forge rebases do not replay the upstream root tree. git-subtree-dir: third_party/pi git-subtree-split: 71023aec1546d6d677a65669c5665c0927ce0dd0
27 lines
1.1 KiB
TypeScript
27 lines
1.1 KiB
TypeScript
// For benchmarks: the bytes live objects hold, from a heap snapshot. `heapUsed` after `gc()` also counts what the
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// collector has not compacted yet, which hides a small leak or invents a large one.
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import { Session } from "node:inspector/promises";
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/** Sum of the self sizes of every object in a fresh heap snapshot, which collects garbage first. */
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export async function retainedBytes(): Promise<number> {
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const inspector = new Session();
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inspector.connect();
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const chunks: string[] = [];
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inspector.on("HeapProfiler.addHeapSnapshotChunk", (message) => chunks.push(message.params.chunk));
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try {
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await inspector.post("HeapProfiler.takeHeapSnapshot", { reportProgress: false });
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} finally {
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inspector.disconnect();
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}
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const snapshot = JSON.parse(chunks.join("")) as {
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snapshot: { meta: { node_fields: string[] } };
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nodes: number[];
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};
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const fields = snapshot.snapshot.meta.node_fields;
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const width = fields.length;
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const size = fields.indexOf("self_size");
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let total = 0;
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for (let index = size; index < snapshot.nodes.length; index += width) total += snapshot.nodes[index]!;
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return total;
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}
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