Avoid big strings on the stack

[mirror_novnc.git] / core / websock.js

diff --git a/core/websock.js b/core/websock.js
index 4dc9143854a77837a005519047a76df8a21710d9..6b0336157bb17ca7f806dbf999abd440bb654e9f 100644 (file)
--- a/core/websock.js
+++ b/core/websock.js
@@ -100,9 +100,14 @@ Websock.prototype = {
 
     rQshiftStr: function (len) {
         if (typeof(len) === 'undefined') { len = this.rQlen(); }
-        const arr = new Uint8Array(this._rQ.buffer, this._rQi, len);
-        this._rQi += len;
-        return String.fromCharCode.apply(null, arr);
+        const arr = this.rQshiftBytes(len);
+        let str = "";
+        // Handle large arrays in steps to avoid long strings on the stack
+        for (let i = 0; i < len; i += 4096) {
+            let part = arr.slice(i, i + Math.min(4096, len));
+            str = str.concat(String.fromCharCode.apply(null, part));
+        }
+        return str;
     },
 
     rQshiftBytes: function (len) {