benchmark: reduce string concatenations

PR-URL: #12455
Reviewed-By: Benjamin Gruenbaum <[email protected]>
Reviewed-By: James M Snell <[email protected]>

Author: vsemozhetbyt

benchmark/_benchmark_progress.js

@@ -3,12 +3,13 @@
 const readline = require('readline');
 
 function pad(input, minLength, fill) {
-  var result = input + '';
-  return fill.repeat(Math.max(0, minLength - result.length)) + result;
+  var result = String(input);
+  var padding = fill.repeat(Math.max(0, minLength - result.length));
+  return `${padding}${result}`;
 }
 
 function fraction(numerator, denominator) {
-  const fdenominator = denominator + '';
+  const fdenominator = String(denominator);
   const fnumerator = pad(numerator, fdenominator.length, ' ');
   return `${fnumerator}/${fdenominator}`;
 }
@@ -100,11 +101,12 @@ class BenchmarkProgress {
     const percent = pad(Math.floor(completedRate * 100), 3, ' ');
 
     const caption = finished ? 'Done\n' : this.currentFile;
-    return `[${getTime(diff)}|% ${percent}` +
-          `| ${fraction(completedFiles, scheduledFiles)} files ` +
-          `| ${fraction(completedRunsForFile, runsPerFile)} runs ` +
-          `| ${fraction(completedConfig, scheduledConfig)} configs]` +
-          `: ${caption} `;
+    return `[${getTime(diff)}|% ${
+               percent}| ${
+               fraction(completedFiles, scheduledFiles)} files | ${
+               fraction(completedRunsForFile, runsPerFile)} runs | ${
+               fraction(completedConfig, scheduledConfig)} configs]: ${
+               caption} `;
   }
 
   updateProgress(finished) {

benchmark/_http-benchmarkers.js

@@ -4,6 +4,9 @@ const child_process = require('child_process');
 const path = require('path');
 const fs = require('fs');
 
+const requirementsURL =
+  'https://github.com/nodejs/node/blob/master/doc/guides/writing-and-running-benchmarks.md##http-benchmark-requirements';
+
 // The port used by servers and wrk
 exports.PORT = process.env.PORT || 12346;
 
@@ -133,20 +136,19 @@ exports.run = function(options, callback) {
     benchmarker: exports.default_http_benchmarker
   }, options);
   if (!options.benchmarker) {
-    callback(new Error('Could not locate required http benchmarker. See ' +
-                       'https://github.com/nodejs/node/blob/master/doc/guides/writing-and-running-benchmarks.md##http-benchmark-requirements ' +
-                       'for further instructions.'));
+    callback(new Error(`Could not locate required http benchmarker. See ${
+                        requirementsURL} for further instructions.`));
     return;
   }
   const benchmarker = benchmarkers[options.benchmarker];
   if (!benchmarker) {
-    callback(new Error(`Requested benchmarker '${options.benchmarker}' is ` +
-                       'not supported'));
+    callback(new Error(`Requested benchmarker '${
+                        options.benchmarker}' is  not supported`));
     return;
   }
   if (!benchmarker.present) {
-    callback(new Error(`Requested benchmarker '${options.benchmarker}' is ` +
-                       'not installed'));
+    callback(new Error(`Requested benchmarker '${
+                        options.benchmarker}' is  not installed`));
     return;
   }
 
@@ -172,8 +174,8 @@ exports.run = function(options, callback) {
 
     const result = benchmarker.processResults(stdout);
     if (result === undefined) {
-      callback(new Error(`${options.benchmarker} produced strange output: ` +
-                         stdout, code));
+      callback(new Error(
+        `${options.benchmarker} produced strange output: ${stdout}`, code));
       return;
     }
 

benchmark/assert/deepequal-typedarrays.js

@@ -2,8 +2,17 @@
 const common = require('../common.js');
 const assert = require('assert');
 const bench = common.createBenchmark(main, {
-  type: ('Int8Array Uint8Array Int16Array Uint16Array Int32Array Uint32Array ' +
-    'Float32Array Float64Array Uint8ClampedArray').split(' '),
+  type: [
+    'Int8Array',
+    'Uint8Array',
+    'Int16Array',
+    'Uint16Array',
+    'Int32Array',
+    'Uint32Array',
+    'Float32Array',
+    'Float64Array',
+    'Uint8ClampedArray',
+  ],
   n: [1],
   method: ['strict', 'nonstrict'],
   len: [1e6]

benchmark/buffers/buffer-base64-decode-wrapped.js

@@ -12,7 +12,7 @@ function main(conf) {
   const linesCount = 8 << 16;
   const bytesCount = charsPerLine * linesCount / 4 * 3;
 
-  const line = 'abcd'.repeat(charsPerLine / 4) + '\n';
+  const line = `${'abcd'.repeat(charsPerLine / 4)}\n`;
   const data = line.repeat(linesCount);
   // eslint-disable-next-line no-unescaped-regexp-dot
   data.match(/./);  // Flatten the string

benchmark/buffers/buffer-bytelength.js

@@ -28,7 +28,7 @@ function main(conf) {
   } else {
     for (var string of chars) {
       // Strings must be built differently, depending on encoding
-      var data = buildString(string, len);
+      var data = string.repeat(len);
       if (encoding === 'utf8') {
         strings.push(data);
       } else if (encoding === 'base64') {
@@ -54,9 +54,3 @@ function main(conf) {
   }
   bench.end(n);
 }
-
-function buildString(str, times) {
-  if (times === 1) return str;
-
-  return str + buildString(str, times - 1);
-}

benchmark/buffers/buffer-read.js

@@ -30,14 +30,14 @@ function main(conf) {
   var len = +conf.millions * 1e6;
   var clazz = conf.buf === 'fast' ? Buffer : require('buffer').SlowBuffer;
   var buff = new clazz(8);
-  var fn = 'read' + conf.type;
+  var fn = `read${conf.type}`;
 
   buff.writeDoubleLE(0, 0, noAssert);
-  var testFunction = new Function('buff', [
-    'for (var i = 0; i !== ' + len + '; i++) {',
-    '  buff.' + fn + '(0, ' + JSON.stringify(noAssert) + ');',
-    '}'
-  ].join('\n'));
+  var testFunction = new Function('buff', `
+    for (var i = 0; i !== ${len}; i++) {
+      buff.${fn}(0, ${JSON.stringify(noAssert)});
+    }
+  `);
   bench.start();
   testFunction(buff);
   bench.end(len / 1e6);

benchmark/buffers/buffer-swap.js

@@ -64,11 +64,11 @@ function createBuffer(len, aligned) {
 }
 
 function genMethod(method) {
-  const fnString =
-      'return function ' + method + '(n, buf) {' +
-      '  for (var i = 0; i <= n; i++)' +
-      '    buf.' + method + '();' +
-      '}';
+  const fnString = `
+      return function ${method}(n, buf) {
+        for (var i = 0; i <= n; i++)
+          buf.${method}();
+      }`;
   return (new Function(fnString))();
 }
 

benchmark/buffers/buffer-write.js

@@ -50,7 +50,7 @@ function main(conf) {
   var len = +conf.millions * 1e6;
   var clazz = conf.buf === 'fast' ? Buffer : require('buffer').SlowBuffer;
   var buff = new clazz(8);
-  var fn = 'write' + conf.type;
+  var fn = `write${conf.type}`;
 
   if (fn.match(/Int/))
     benchInt(buff, fn, len, noAssert);
@@ -60,22 +60,22 @@ function main(conf) {
 
 function benchInt(buff, fn, len, noAssert) {
   var m = mod[fn];
-  var testFunction = new Function('buff', [
-    'for (var i = 0; i !== ' + len + '; i++) {',
-    '  buff.' + fn + '(i & ' + m + ', 0, ' + JSON.stringify(noAssert) + ');',
-    '}'
-  ].join('\n'));
+  var testFunction = new Function('buff', `
+    for (var i = 0; i !== ${len}; i++) {
+      buff.${fn}(i & ${m}, 0, ${JSON.stringify(noAssert)});
+    }
+  `);
   bench.start();
   testFunction(buff);
   bench.end(len / 1e6);
 }
 
 function benchFloat(buff, fn, len, noAssert) {
-  var testFunction = new Function('buff', [
-    'for (var i = 0; i !== ' + len + '; i++) {',
-    '  buff.' + fn + '(i, 0, ' + JSON.stringify(noAssert) + ');',
-    '}'
-  ].join('\n'));
+  var testFunction = new Function('buff', `
+    for (var i = 0; i !== ${len}; i++) {
+      buff.${fn}(i, 0, ${JSON.stringify(noAssert)});
+    }
+  `);
   bench.start();
   testFunction(buff);
   bench.end(len / 1e6);

benchmark/buffers/dataview-set.js

@@ -44,7 +44,7 @@ function main(conf) {
   var ab = new ArrayBuffer(8);
   var dv = new DataView(ab, 0, 8);
   var le = /LE$/.test(conf.type);
-  var fn = 'set' + conf.type.replace(/[LB]E$/, '');
+  var fn = `set${conf.type.replace(/[LB]E$/, '')}`;
 
   if (/int/i.test(fn))
     benchInt(dv, fn, len, le);

benchmark/common.js

@@ -44,7 +44,7 @@ Benchmark.prototype._parseArgs = function(argv, configs) {
   for (const arg of argv) {
     const match = arg.match(/^(.+?)=([\s\S]*)$/);
     if (!match) {
-      console.error('bad argument: ' + arg);
+      console.error(`bad argument: ${arg}`);
       process.exit(1);
     }
     const config = match[1];
@@ -206,7 +206,7 @@ function formatResult(data) {
   // Construct configuration string, " A=a, B=b, ..."
   let conf = '';
   for (const key of Object.keys(data.conf)) {
-    conf += ' ' + key + '=' + JSON.stringify(data.conf[key]);
+    conf += ` ${key}=${JSON.stringify(data.conf[key])}`;
   }
 
   var rate = data.rate.toString().split('.');