chore: add benchmarks for to-string (#32)

Adds benchmarks to compare various stringification methods

benchmarks/to-string.js

@@ -0,0 +1,119 @@
+/* eslint-disable no-console */
+
+/*
+$ node benchmarks/to-string.js
+$ npx playwright-test benchmarks/to-string.js --runner benchmark
+*/
+
+import Benchmark from 'benchmark'
+import { fromString } from '../src/from-string.js'
+import { toString } from '../src/to-string.js'
+
+const string = 'Hello world, this is a Uint8Array created from a string'
+const DATA = fromString(string)
+
+// https://github.com/achingbrain/uint8arrays/issues/30#issuecomment-1199120924
+function utf8ReadFromCharCode (buffer, start, end) {
+  const len = end - start
+  if (len < 1) { return '' }
+  let parts = null
+  const chunk = []
+  let i = 0 // char offset
+  let t // temporary
+  while (start < end) {
+    t = buffer[start++]
+    if (t < 128) { chunk[i++] = t } else if (t > 191 && t < 224) { chunk[i++] = (t & 31) << 6 | buffer[start++] & 63 } else if (t > 239 && t < 365) {
+      t = ((t & 7) << 18 | (buffer[start++] & 63) << 12 | (buffer[start++] & 63) << 6 | buffer[start++] & 63) - 0x10000
+      chunk[i++] = 0xD800 + (t >> 10)
+      chunk[i++] = 0xDC00 + (t & 1023)
+    } else { chunk[i++] = (t & 15) << 12 | (buffer[start++] & 63) << 6 | buffer[start++] & 63 }
+    if (i > 8191) {
+      (parts || (parts = [])).push(String.fromCharCode.apply(String, chunk))
+      i = 0
+    }
+  }
+  if (parts) {
+    if (i) { parts.push(String.fromCharCode.apply(String, chunk.slice(0, i))) }
+    return parts.join('')
+  }
+  return String.fromCharCode.apply(String, chunk.slice(0, i))
+}
+
+// https://github.com/achingbrain/uint8arrays/issues/30#issuecomment-1199120924
+function utf8ReadConcat (buffer, start, end) {
+  if (end - start < 1) {
+    return ''
+  }
+
+  let str = ''
+  for (let i = start; i < end;) {
+    const t = buffer[i++]
+    if (t <= 0x7F) {
+      str += String.fromCharCode(t)
+    } else if (t >= 0xC0 && t < 0xE0) {
+      str += String.fromCharCode((t & 0x1F) << 6 | buffer[i++] & 0x3F)
+    } else if (t >= 0xE0 && t < 0xF0) {
+      str += String.fromCharCode((t & 0xF) << 12 | (buffer[i++] & 0x3F) << 6 | buffer[i++] & 0x3F)
+    } else if (t >= 0xF0) {
+      const t2 = ((t & 7) << 18 | (buffer[i++] & 0x3F) << 12 | (buffer[i++] & 0x3F) << 6 | buffer[i++] & 0x3F) - 0x10000
+      str += String.fromCharCode(0xD800 + (t2 >> 10))
+      str += String.fromCharCode(0xDC00 + (t2 & 0x3FF))
+    }
+  }
+
+  return str
+}
+
+const suite = new Benchmark.Suite()
+
+suite
+  .add('Uint8Arrays.toString', () => {
+    const res = toString(DATA)
+
+    if (res !== string) {
+      throw new Error('String encoding failed')
+    }
+  })
+  .add('TextDecoder', () => {
+    const res = new TextDecoder().decode(DATA)
+
+    if (res !== string) {
+      throw new Error('String encoding failed')
+    }
+  })
+  .add('utf8ReadFromCharCode', () => {
+    const res = utf8ReadFromCharCode(DATA, 0, DATA.byteLength)
+
+    if (res !== string) {
+      throw new Error('String encoding failed')
+    }
+  })
+  .add('utf8ReadConcat', () => {
+    const res = utf8ReadConcat(DATA, 0, DATA.byteLength)
+
+    if (res !== string) {
+      throw new Error('String encoding failed')
+    }
+  })
+
+if (globalThis.Buffer != null) {
+  suite.add('Buffer.toString', function () {
+    const buf = globalThis.Buffer.from(DATA.buffer, DATA.byteOffset, DATA.byteLength)
+    const res = buf.toString('utf8')
+
+    if (res !== string) {
+      throw new Error('String encoding failed')
+    }
+  })
+}
+
+suite
+  // add listeners
+  .on('cycle', (event) => {
+    console.log(String(event.target))
+  })
+  .on('complete', function () {
+    console.log('Fastest is ' + this.filter('fastest').map('name'))
+  })
+  // run async
+  .run({ async: true })

package.json

@@ -25,7 +25,9 @@
     "multiformats": "^9.4.2"
   },
   "devDependencies": {
+    "@types/benchmark": "^2.1.1",
     "aegir": "^35.0.0",
+    "benchmark": "^2.1.4",
     "util": "^0.12.4"
   },
   "eslintConfig": {