From 4170c414faf3014636114b7cf4454809c2e6baf2 Mon Sep 17 00:00:00 2001
From: Jonas Jenwald <jonas.jenwald@gmail.com>
Date: Sat, 2 Mar 2019 11:36:30 +0100
Subject: [PATCH] Reduce usage of `Date.now()` in `src/core/worker.js`

Currently for every single parsed/rendered page there's no less than *four* `Date.now()` calls being made on the worker-side. This seems totally unnecessary, since the result of these calls are, by default, not used for anything *unless* the verbosity level is set to `INFO`.
---
 src/core/worker.js | 33 ++++++++++++++++++++-------------
 src/display/api.js |  4 ++--
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/src/core/worker.js b/src/core/worker.js
index 8827c1099..f0eba694f 100644
--- a/src/core/worker.js
+++ b/src/core/worker.js
@@ -14,10 +14,10 @@
  */
 
 import {
-  arrayByteLength, arraysToBytes, assert, createPromiseCapability, info,
-  InvalidPDFException, MissingPDFException, PasswordException,
-  setVerbosityLevel, UnexpectedResponseException, UnknownErrorException,
-  UNSUPPORTED_FEATURES, warn
+  arrayByteLength, arraysToBytes, assert, createPromiseCapability,
+  getVerbosityLevel, info, InvalidPDFException, MissingPDFException,
+  PasswordException, setVerbosityLevel, UnexpectedResponseException,
+  UnknownErrorException, UNSUPPORTED_FEATURES, VerbosityLevel, warn
 } from '../shared/util';
 import { LocalPdfManager, NetworkPdfManager } from './pdf_manager';
 import isNodeJS from '../shared/is_node';
@@ -222,6 +222,7 @@ var WorkerMessageHandler = {
     var terminated = false;
     var cancelXHRs = null;
     var WorkerTasks = [];
+    const verbosity = getVerbosityLevel();
 
     let apiVersion = docParams.apiVersion;
     let workerVersion =
@@ -578,8 +579,9 @@ var WorkerMessageHandler = {
         var task = new WorkerTask('RenderPageRequest: page ' + pageIndex);
         startWorkerTask(task);
 
-        var pageNum = pageIndex + 1;
-        var start = Date.now();
+        // NOTE: Keep this condition in sync with the `info` helper function.
+        const start = (verbosity >= VerbosityLevel.INFOS ? Date.now() : 0);
+
         // Pre compile the pdf page and fetch the fonts/images.
         page.getOperatorList({
           handler,
@@ -589,8 +591,10 @@ var WorkerMessageHandler = {
         }).then(function(operatorList) {
           finishWorkerTask(task);
 
-          info('page=' + pageNum + ' - getOperatorList: time=' +
-               (Date.now() - start) + 'ms, len=' + operatorList.totalLength);
+          if (start) {
+            info(`page=${pageIndex + 1} - getOperatorList: time=` +
+                 `${Date.now() - start}ms, len=${operatorList.totalLength}`);
+          }
         }, function(e) {
           finishWorkerTask(task);
           if (task.terminated) {
@@ -626,7 +630,7 @@ var WorkerMessageHandler = {
           }
 
           handler.send('PageError', {
-            pageNum,
+            pageIndex,
             error: wrappedException,
             intent: data.intent,
           });
@@ -643,8 +647,9 @@ var WorkerMessageHandler = {
         var task = new WorkerTask('GetTextContent: page ' + pageIndex);
         startWorkerTask(task);
 
-        var pageNum = pageIndex + 1;
-        var start = Date.now();
+        // NOTE: Keep this condition in sync with the `info` helper function.
+        const start = (verbosity >= VerbosityLevel.INFOS ? Date.now() : 0);
+
         page.extractTextContent({
           handler,
           task,
@@ -654,8 +659,10 @@ var WorkerMessageHandler = {
         }).then(function() {
           finishWorkerTask(task);
 
-          info('text indexing: page=' + pageNum + ' - time=' +
-               (Date.now() - start) + 'ms');
+          if (start) {
+            info(`page=${pageIndex + 1} - getTextContent: time=` +
+                 `${Date.now() - start}ms`);
+          }
           sink.close();
         }, function (reason) {
           finishWorkerTask(task);
diff --git a/src/display/api.js b/src/display/api.js
index 8041183ec..dfe7fec7b 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -2028,11 +2028,11 @@ class WorkerTransport {
         return; // Ignore any pending requests if the worker was terminated.
       }
 
-      const page = this.pageCache[data.pageNum - 1];
+      const page = this.pageCache[data.pageIndex];
       const intentState = page.intentStates[data.intent];
 
       if (intentState.displayReadyCapability) {
-        intentState.displayReadyCapability.reject(data.error);
+        intentState.displayReadyCapability.reject(new Error(data.error));
       } else {
         throw new Error(data.error);
       }