From 406da9fa2c8bc5b40e16b9dbb7251966f03a413c Mon Sep 17 00:00:00 2001
From: n1474335 <n1474335@gmail.com>
Date: Fri, 2 Sep 2022 20:15:07 +0100
Subject: [PATCH] Efficiency improvements to reduce unnecessary casting

---
 src/core/Utils.mjs               |  9 +++++-
 src/web/waiters/InputWaiter.mjs  |  1 -
 src/web/waiters/OutputWaiter.mjs | 47 ++++++++++++++++----------------
 3 files changed, 31 insertions(+), 26 deletions(-)

diff --git a/src/core/Utils.mjs b/src/core/Utils.mjs
index 604b7b8c..fec3b9be 100755
--- a/src/core/Utils.mjs
+++ b/src/core/Utils.mjs
@@ -407,6 +407,7 @@ class Utils {
      */
     static strToArrayBuffer(str) {
         log.debug("Converting string to array buffer");
+        if (!str) return new ArrayBuffer;
         const arr = new Uint8Array(str.length);
         let i = str.length, b;
         while (i--) {
@@ -434,6 +435,7 @@ class Utils {
      */
     static strToUtf8ArrayBuffer(str) {
         log.debug("Converting string to UTF8 array buffer");
+        if (!str) return new ArrayBuffer;
         const utf8Str = utf8.encode(str);
 
         if (str.length !== utf8Str.length) {
@@ -464,6 +466,7 @@ class Utils {
      */
     static strToByteArray(str) {
         log.debug("Converting string to byte array");
+        if (!str) return [];
         const byteArray = new Array(str.length);
         let i = str.length, b;
         while (i--) {
@@ -491,6 +494,7 @@ class Utils {
      */
     static strToUtf8ByteArray(str) {
         log.debug("Converting string to UTF8 byte array");
+        if (!str) return [];
         const utf8Str = utf8.encode(str);
 
         if (str.length !== utf8Str.length) {
@@ -520,6 +524,7 @@ class Utils {
      */
     static strToCharcode(str) {
         log.debug("Converting string to charcode");
+        if (!str) return [];
         const charcode = [];
 
         for (let i = 0; i < str.length; i++) {
@@ -555,6 +560,7 @@ class Utils {
      */
     static byteArrayToUtf8(byteArray) {
         log.debug("Converting byte array to UTF8");
+        if (!byteArray || !byteArray.length) return "";
         const str = Utils.byteArrayToChars(byteArray);
         try {
             const utf8Str = utf8.decode(str);
@@ -588,7 +594,7 @@ class Utils {
      */
     static byteArrayToChars(byteArray) {
         log.debug("Converting byte array to chars");
-        if (!byteArray) return "";
+        if (!byteArray || !byteArray.length) return "";
         let str = "";
         // String concatenation appears to be faster than an array join
         for (let i = 0; i < byteArray.length;) {
@@ -611,6 +617,7 @@ class Utils {
      */
     static arrayBufferToStr(arrayBuffer, utf8=true) {
         log.debug("Converting array buffer to str");
+        if (!arrayBuffer || !arrayBuffer.byteLength) return "";
         const arr = new Uint8Array(arrayBuffer);
         return utf8 ? Utils.byteArrayToUtf8(arr) : Utils.byteArrayToChars(arr);
     }
diff --git a/src/web/waiters/InputWaiter.mjs b/src/web/waiters/InputWaiter.mjs
index 000940a4..86ad9873 100644
--- a/src/web/waiters/InputWaiter.mjs
+++ b/src/web/waiters/InputWaiter.mjs
@@ -997,7 +997,6 @@ class InputWaiter {
         this.setupInputWorker();
         this.manager.worker.setupChefWorker();
         this.addInput(true);
-        this.bakeAll();
 
         // Fire the statechange event as the input has been modified
         window.dispatchEvent(this.manager.statechange);
diff --git a/src/web/waiters/OutputWaiter.mjs b/src/web/waiters/OutputWaiter.mjs
index f0b03d72..a247375e 100755
--- a/src/web/waiters/OutputWaiter.mjs
+++ b/src/web/waiters/OutputWaiter.mjs
@@ -49,6 +49,8 @@ class OutputWaiter {
             html: "",
             changed: false
         };
+        // Hold a copy of the currently displayed output so that we don't have to update it unnecessarily
+        this.currentOutputCache = null;
         this.outputChrEnc = 0;
         this.initEditor();
 
@@ -170,9 +172,26 @@ class OutputWaiter {
 
     /**
      * Sets the value of the current output
-     * @param {string} data
+     * @param {string|ArrayBuffer} data
      */
     setOutput(data) {
+        // Don't do anything if the output hasn't changed
+        if (data === this.currentOutputCache) return;
+        this.currentOutputCache = data;
+
+        // If data is an ArrayBuffer, convert to a string in the correct character encoding
+        if (data instanceof ArrayBuffer) {
+            if (this.outputChrEnc === 0) {
+                data = Utils.arrayBufferToStr(data);
+            } else {
+                try {
+                    data = cptable.utils.decode(this.outputChrEnc, new Uint8Array(data));
+                } catch (err) {
+                    data = err;
+                }
+            }
+        }
+
         // Turn drawSelection back on
         this.outputEditorView.dispatch({
             effects: this.outputEditorConf.drawSelection.reconfigure(
@@ -508,28 +527,7 @@ class OutputWaiter {
 
                         this.setHTMLOutput(output.data.result);
                         break;
-                    case "ArrayBuffer": {
-                        this.outputTextEl.style.display = "block";
-                        outputFile.style.display = "none";
-
-                        this.clearHTMLOutput();
-
-                        let outputVal = "";
-                        if (this.outputChrEnc === 0) {
-                            outputVal = Utils.arrayBufferToStr(output.data.result);
-                        } else {
-                            try {
-                                outputVal = cptable.utils.decode(this.outputChrEnc, new Uint8Array(output.data.result));
-                            } catch (err) {
-                                outputVal = err;
-                            }
-                        }
-
-                        this.setOutput(outputVal);
-
-                        // this.setFile(await this.getDishBuffer(output.data.dish), activeTab);
-                        break;
-                    }
+                    case "ArrayBuffer":
                     case "string":
                     default:
                         this.outputTextEl.style.display = "block";
@@ -1136,7 +1134,8 @@ class OutputWaiter {
      * @param {number} inputNum
      */
     async displayTabInfo(inputNum) {
-        if (!this.outputExists(inputNum)) return;
+        // Don't display anything if there are no, or only one, tabs
+        if (!this.outputExists(inputNum) || Object.keys(this.outputs).length <= 1) return;
 
         const dish = this.getOutputDish(inputNum);
         let tabStr = "";