add kernelNames getter to profile object (#4144)

FEATURE

Author: tafsiri

tfjs-core/src/engine.ts

@@ -66,6 +66,7 @@ export type ProfileInfo = {
   newBytes: number; newTensors: number; peakBytes: number;
   kernels: KernelInfo[];
   result: TensorContainer;
+  kernelNames: string[];
 };
 
 export interface TimingInfo extends BackendTimingInfo {
@@ -119,8 +120,16 @@ class EngineState {
   }>();
 
   profiling = false;
-  activeProfile: ProfileInfo =
-      {newBytes: 0, newTensors: 0, peakBytes: 0, kernels: [], result: null};
+  activeProfile: ProfileInfo = {
+    newBytes: 0,
+    newTensors: 0,
+    peakBytes: 0,
+    kernels: [],
+    result: null,
+    get kernelNames() {
+      return Array.from(new Set(this.kernels.map(k => k.name)));
+    }
+  };
 
   dispose() {
     for (const variableName in this.registeredVariables) {

tfjs-core/src/engine_test.ts

@@ -482,6 +482,19 @@ describeWithFlags('profile', ALL_ENVS, () => {
       'extraInfo': profile.kernels[0].extraInfo
     });
   });
+
+  it('reports correct kernelNames', async () => {
+    const profile = await tf.profile(() => {
+      const x = tf.tensor1d([1, 2, 3]);
+      const x2 = x.square();
+      const x3 = x2.abs();
+      return x3;
+    });
+
+    expect(profile.kernelNames).toEqual(jasmine.arrayWithExactContents([
+      'Square', 'Abs'
+    ]));
+  });
 });
 
 describeWithFlags('disposeVariables', ALL_ENVS, () => {

tfjs-core/src/globals.ts

@@ -120,6 +120,8 @@ export function memory(): MemoryInfo {
  * - `kernels`: an array of objects for each kernel involved that reports
  * their input and output shapes, number of bytes used, and number of new
  * tensors created.
+ * - `kernelNames`: an array of unique strings with just the names of the
+ * kernels in the `kernels` array.
  *
  * ```js
  * const profile = await tf.profile(() => {