CLDSRV-894: Report turn-around time for PutObject and UploadPart

Server access logs did not report turn-around time for PutObject and
UploadPart while all other operations reported it correctly.
AWS reports turn-around time for these operations.

(cherry picked from commit 314ba8c)

Author: dvasilas

lib/api/api.js

@@ -263,6 +263,19 @@ const api = {
                     request.serverAccessLog.analyticsUserName    = authNames.userName;
                 }
                 if (apiMethod === 'objectPut' || apiMethod === 'objectPutPart') {
+                    const setStartTurnAroundTime = () => {
+                        if (request.serverAccessLog) {
+                            request.serverAccessLog.startTurnAroundTime = process.hrtime.bigint();
+                        }
+                    };
+                    // For 0-byte uploads, downstream handlers do not consume
+                    // the request stream, so 'end' never fires. Set
+                    // startTurnAroundTime synchronously in that case.
+                    if (request.headers['content-length'] === '0') {
+                        setStartTurnAroundTime();
+                    } else {
+                        request.on('end', setStartTurnAroundTime);
+                    }
                     return next(null, userInfo, authorizationResults, streamingV4Params, infos);
                 }
                 // issue 100 Continue to the client

tests/unit/api/api.js

@@ -115,6 +115,40 @@ describe('api.callApiMethod', () => {
         api.callApiMethod('multipartDelete', request, response, log);
     });
 
+    ['objectPut', 'objectPutPart'].forEach(method => {
+        it(`should set startTurnAroundTime on request end for ${method}`, done => {
+            sandbox.stub(api, method).callsFake(
+                (userInfo, _request, streamingV4Params, _log, cb) => {
+                    request.on('end', () => {
+                        assert.strictEqual(typeof request.serverAccessLog.startTurnAroundTime, 'bigint');
+                        cb();
+                    });
+                    request.resume();
+                });
+            request.objectKey = 'testobject';
+            request.serverAccessLog = {};
+            api.callApiMethod(method, request, response, log, err => {
+                assert.ifError(err);
+                done();
+            });
+        });
+
+        it(`should set startTurnAroundTime synchronously for 0-byte ${method}`, done => {
+            sandbox.stub(api, method).callsFake(
+                (userInfo, _request, streamingV4Params, _log, cb) => {
+                    assert.strictEqual(typeof request.serverAccessLog.startTurnAroundTime, 'bigint');
+                    cb();
+                });
+            request.objectKey = 'testobject';
+            request.serverAccessLog = {};
+            request.headers = Object.assign({}, request.headers, { 'content-length': '0' });
+            api.callApiMethod(method, request, response, log, err => {
+                assert.ifError(err);
+                done();
+            });
+        });
+    });
+
     describe('MD5 checksum validation', () => {
         const methodsWithChecksumValidation = [
             'bucketPutACL',