Add profiling script

Author: cmdcolin

benchmark/profile-cpu.mjs

@@ -0,0 +1,44 @@
+import { TabixIndexedFile } from './esm/index.js'
+import { fileURLToPath } from 'url'
+import { dirname, join } from 'path'
+import inspector from 'inspector'
+import fs from 'fs'
+
+const __dirname = dirname(fileURLToPath(import.meta.url))
+
+async function runBenchmark() {
+  const f = new TabixIndexedFile({
+    path: join(__dirname, 'test/data/1kg.chr1.subset.vcf.gz'),
+  })
+
+  let totalLines = 0
+  const iterations = 100
+
+  const session = new inspector.Session()
+  session.connect()
+
+  session.post('Profiler.enable', () => {
+    session.post('Profiler.start', async () => {
+      for (let iter = 0; iter < iterations; iter++) {
+        let count = 0
+        await f.getLines('chr1', 10109, 11000, () => {
+          count++
+        })
+        totalLines += count
+      }
+
+      console.log(`Total lines processed: ${totalLines}`)
+
+      session.post('Profiler.stop', (err, { profile }) => {
+        if (!err) {
+          fs.writeFileSync('profile.cpuprofile', JSON.stringify(profile))
+          console.log('CPU profile written to profile.cpuprofile')
+          console.log('View with: npx speedscope profile.cpuprofile')
+        }
+        session.disconnect()
+      })
+    })
+  })
+}
+
+runBenchmark().catch(console.error)