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#!/usr/bin/env -S deno run --unstable --allow-read --allow-run// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.import { join, ROOT_PATH as ROOT } from "./util.js";
async function bashOut(subcmd) {  const { success, stdout } = await Deno.spawn("bash", {    args: ["-c", subcmd],    stdout: "piped",    stderr: "null",  });
  // Check for failure  if (!success) {    throw new Error("subcmd failed");  }  // Gather output  const output = new TextDecoder().decode(stdout);
  return output.trim();}
async function bashThrough(subcmd, opts = {}) {  const { success, code } = await Deno.spawn("bash", {    ...opts,    args: ["-c", subcmd],    stdout: "inherit",    stderr: "inherit",  });
  // Exit process on failure  if (!success) {    Deno.exit(code);  }}
async function availableBenches() {  // TODO(AaronO): maybe reimplement with fs.walk  // it's important to prune the walked tree so this is fast (<50ms)  const prunedDirs = ["third_party", ".git", "target", "docs", "test_util"];  const pruneExpr = prunedDirs.map((d) => `-path ${ROOT}/${d}`).join(" -o ");  return (await bashOut(`  find ${ROOT} -type d \      \\( ${pruneExpr} \\) \      -prune -false -o  \      -path "${ROOT}/*/benches/*" -type f -name "*.rs" \      | xargs basename | cut -f1 -d.  `)).split("\n");}
function latestBenchBin(name) {  return bashOut(`ls -t "${ROOT}/target/release/deps/${name}"* | head -n 1`);}
function runFlamegraph(benchBin, benchFilter, outputFile) {  return bashThrough(    `sudo -E flamegraph -o ${outputFile} ${benchBin} ${benchFilter ?? ""}`,    // Set $PROFILING env so benches can improve their flamegraphs    { env: { "PROFILING": "1" } },  );}
async function binExists(bin) {  try {    await bashOut(`which ${bin}`);    return true;  } catch (_) {    return false;  }}
async function main() {  const { 0: benchName, 1: benchFilter } = Deno.args;  // Print usage if no bench specified  if (!benchName) {    console.log("flamebench.js <bench_name> [bench_filter]");    // Also show available benches    console.log("\nAvailable benches:");    const benches = await availableBenches();    console.log(benches.join("\n"));    return Deno.exit(1);  }
  // List available benches, hoping we don't have any benches called "ls" :D  if (benchName === "ls") {    const benches = await availableBenches();    console.log(benches.join("\n"));    return;  }
  // Ensure flamegraph is installed  if (!await binExists("flamegraph")) {    console.log(      "flamegraph (https://github.com/flamegraph-rs/flamegraph) not found, please run:",    );    console.log();    console.log("cargo install flamegraph");    return Deno.exit(1);  }
  // Build bench with frame pointers  await bashThrough(    `RUSTFLAGS='-C force-frame-pointers=y' cargo build --release --bench ${benchName}`,  );
  // Get the freshly built bench binary  const benchBin = await latestBenchBin(benchName);
  // Run flamegraph  const outputFile = join(ROOT, "flamebench.svg");  await runFlamegraph(benchBin, benchFilter, outputFile);
  // Open flamegraph (in your browser / SVG viewer)  if (await binExists("open")) {    await bashThrough(`open ${outputFile}`);  }}// Runawait main();