feat(benchmark): add a simple benchmark for context bindings

benchmark/package.json

@@ -19,6 +19,7 @@
     "test": "lb-mocha \"dist/__tests__/**/*.js\"",
     "prestart": "npm run build",
     "benchmark:routing": "node ./dist/rest-routing/routing-table",
+    "benchmark:context": "node ./dist/context-binding/context-binding",
     "start": "node ."
   },
   "author": "IBM Corp.",
@@ -32,6 +33,7 @@
     "!*/__tests__"
   ],
   "dependencies": {
+    "@loopback/context": "^3.7.0",
     "@loopback/example-todo": "^3.3.0",
     "@loopback/openapi-spec-builder": "^2.1.3",
     "@loopback/rest": "^4.0.0",

benchmark/src/context-binding/README.md

@@ -0,0 +1,71 @@
+# Context binding benchmark
+
+This directory contains a simple benchmarking to measure the performance of two
+context bindings.
+
+1. Use provider class
+
+```ts
+/**
+ * First option - use a provider class
+ */
+class GreetingProvider implements Provider<string> {
+  @inject('user')
+  private user: string;
+
+  value() {
+    return `Hello, ${this.user}`;
+  }
+}
+```
+
+2. Use dynamic value
+
+```ts
+/**
+ * Second option - use a factory function
+ */
+const factory: ValueFactory = _ctx => {
+  const user = _ctx.getSync('user');
+  return `Hello, ${user}`;
+};
+```
+
+3. Set up bindings
+
+```ts
+function setupContextBindings() {
+  const ctx = new Context();
+  ctx.bind('user').to('John');
+  ctx.bind('greeting1').toDynamicValue(factory);
+  ctx.bind('greeting2').toProvider(GreetingProvider);
+  return ctx;
+}
+```
+
+## Basic use
+
+```sh
+npm run -s benchmark:context // default to 1000 | runs
+```
+
+For example:
+
+```
+npm run -s benchmark:context -- 1000 |0
+```
+
+## Base lines
+
+| name     | duration (ns) | count  |
+| -------- | ------------- | ------ |
+| factory  | 0,1168336     | 100    |
+| provider | 0,3134085     | 100    |
+| factory  | 0,6276707     | 1000   |
+| provider | 0,28293889    | 1000   |
+| factory  | 0,22999109    | 5000   |
+| provider | 0,54420139    | 5000   |
+| factory  | 0,29685651    | 10000  |
+| provider | 0,62901844    | 10000  |
+| factory  | 0,91520844    | 100000 |
+| provider | 0,186124524   | 100000 |

benchmark/src/context-binding/context-binding.ts

@@ -0,0 +1,84 @@
+// Copyright IBM Corp. 2018,2020. All Rights Reserved.
+// Node module: @loopback/benchmark
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+import {Context, inject, Provider, ValueFactory} from '@loopback/context';
+
+/**
+ * First option - use a provider class
+ */
+class GreetingProvider implements Provider<string> {
+  @inject('user')
+  private user: string;
+
+  value() {
+    return `Hello, ${this.user}`;
+  }
+}
+
+/**
+ * Second option - use a factory function
+ */
+const factory: ValueFactory = _ctx => {
+  const user = _ctx.getSync('user');
+  return `Hello, ${user}`;
+};
+
+setupContextBindings();
+
+function setupContextBindings() {
+  const ctx = new Context();
+  ctx.bind('user').to('John');
+  ctx.bind('greeting1').toDynamicValue(factory);
+  ctx.bind('greeting2').toProvider(GreetingProvider);
+  return ctx;
+}
+
+function runBenchmark(ctx: Context, count = 1000) {
+  let result1 = process.hrtime();
+
+  for (let i = 0; i < count; i++) {
+    ctx.getSync('greeting1');
+  }
+
+  result1 = process.hrtime(result1);
+
+  let result2 = process.hrtime();
+
+  for (let i = 0; i < count; i++) {
+    ctx.getSync('greeting2');
+  }
+
+  result2 = process.hrtime(result2);
+
+  console.log(
+    '%s %s %s',
+    'name'.padEnd(12),
+    'duration'.padStart(16),
+    'count'.padStart(8),
+  );
+  for (const r of [
+    {name: 'factory', duration: result1},
+    {name: 'provider', duration: result2},
+  ]) {
+    console.log(
+      '%s %s %s',
+      `${r.name}`.padEnd(12),
+      `${r.duration}`.padStart(16),
+      `${count}`.padStart(8),
+    );
+  }
+}
+
+if (require.main === module) {
+  let tests = process.argv.slice(2);
+  if (!tests.length) {
+    tests = ['1000'];
+  }
+  const ctx = setupContextBindings();
+  tests.forEach(n => {
+    runBenchmark(ctx, +n);
+    console.log('\n');
+  });
+}

benchmark/tsconfig.json

@@ -13,6 +13,9 @@
     {
       "path": "../packages/testlab/tsconfig.json"
     },
+    {
+      "path": "../packages/context/tsconfig.json"
+    },
     {
       "path": "../examples/todo/tsconfig.json"
     },