chore: add method to encode profile (#14)

* chore: add method to encode profile

* address comments

Author: nolanmar511

ts/src/index.ts

@@ -19,8 +19,10 @@ import {gzipSync} from 'zlib';
 import {perftools} from '../../proto/profile';
 
 import * as heapProfiler from './heap-profiler';
+import {encodeSync} from './profile-encoder';
 import * as timeProfiler from './time-profiler';
 
+export {encode, encodeSync} from './profile-encoder';
 export {SourceMapper} from './sourcemapper/sourcemapper';
 
 export const time = {
@@ -41,8 +43,7 @@ if (module.parent && module.parent.id === 'internal/preload') {
     // The process is going to terminate imminently. All work here needs to
     // be synchronous.
     const profile = stop();
-    const buffer = perftools.profiles.Profile.encode(profile).finish();
-    const compressed = gzipSync(buffer);
-    writeFileSync(`pprof-profile-${process.pid}.pb.gz`, compressed);
+    const buffer = encodeSync(profile);
+    writeFileSync(`pprof-profile-${process.pid}.pb.gz`, buffer);
   });
 }

ts/src/profile-encoder.ts

@@ -0,0 +1,33 @@
+/**
+ * Copyright 2019 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as pify from 'pify';
+import {gzip, gzipSync} from 'zlib';
+
+import {perftools} from '../../proto/profile';
+
+const gzipPromise = pify(gzip);
+
+export async function encode(profile: perftools.profiles.IProfile):
+    Promise<Buffer> {
+  const buffer = perftools.profiles.Profile.encode(profile).finish();
+  return gzipPromise(buffer);
+}
+
+export function encodeSync(profile: perftools.profiles.IProfile): Buffer {
+  const buffer = perftools.profiles.Profile.encode(profile).finish();
+  return gzipSync(buffer);
+}

ts/test/test-profile-encoder.ts

@@ -0,0 +1,47 @@
+/**
+ * Copyright 2019 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import * as pify from 'pify';
+import {gunzip as gunzipPromise, gunzipSync} from 'zlib';
+
+import {perftools} from '../../proto/profile';
+import {encode, encodeSync} from '../src/profile-encoder';
+
+import {decodedTimeProfile, timeProfile} from './profiles-for-tests';
+
+const assert = require('assert');
+const gunzip = pify(gunzipPromise);
+
+describe('profile-encoded', () => {
+  describe('encode', () => {
+    it('should encode profile such that the encoded profile can be decoded',
+       async () => {
+         const encoded = await encode(timeProfile);
+         const unzipped = await gunzip(encoded);
+         const decoded = perftools.profiles.Profile.decode(unzipped);
+         assert.deepEqual(decoded, decodedTimeProfile);
+       });
+  });
+  describe('encodeSync', () => {
+    it('should encode profile such that the encoded profile can be decoded',
+       () => {
+         const encoded = encodeSync(timeProfile);
+         const unzipped = gunzipSync(encoded);
+         const decoded = perftools.profiles.Profile.decode(unzipped);
+         assert.deepEqual(decoded, decodedTimeProfile);
+       });
+  });
+});