[Perf Tests] Helper methods from perf framework

sdk/test-utils/perfstress/src/index.ts

@@ -6,3 +6,4 @@ export * from "./options";
 export * from "./policy";
 export * from "./parallel";
 export * from "./program";
+export { getEnvVar } from "./utils";

sdk/test-utils/perfstress/src/parallel.ts

@@ -21,3 +21,37 @@ export interface PerfStressParallel {
    */
   lastMillisecondsElapsed: number;
 }
+
+/**
+ * Repeats the "async function" task for a "count" number of times by awaiting on
+ * "parallel" number of while loops in which each iteration executes the provided function once.
+ *
+ * @export
+ * @param {(count: number, parallelIndex: number) => Promise<void>} func "async function" task to be executed repeatedly
+ * @param {number} count Number of the times the func to be executed
+ * @param {number} parallel Number of parallel while loops to iterate over the function task
+ */
+export async function executeParallel(
+  func: (count: number, parallelIndex: number) => Promise<void>,
+  count: number,
+  parallel: number
+): Promise<void> {
+  async function executeParallelHelper(
+    func: (count: number, parallelIndex: number) => Promise<void>,
+    count: number,
+    parallelIndex: number,
+    completed: { count: number }
+  ) {
+    while (completed.count < count) {
+      const currentCount = completed.count++;
+      await func(currentCount, parallelIndex);
+    }
+  }
+
+  var completed = { count: 0 };
+  const tasks = [];
+  for (let i = 0; i < parallel; i++) {
+    tasks.push(executeParallelHelper(func, count, i, completed));
+  }
+  await Promise.all(tasks);
+}

sdk/test-utils/perfstress/src/utils.ts

@@ -0,0 +1,16 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+
+/**
+ * Returns the environment variable, throws an error if not defined.
+ *
+ * @export
+ * @param {string} name
+ */
+export function getEnvVar(name: string) {
+  const val = process.env[name];
+  if (!val) {
+    throw `Environment variable ${name} is not defined.`;
+  }
+  return val;
+}