[Performance] utils: Optimize performance under large data volumes,…

… reduce memory usage, and speed up processing
ljharb · Apr 11, 2024 · 6d7df02 · 6d7df02
1 parent 572533c
commit 6d7df02
Showing 1 changed file with 47 additions and 34 deletions.
diff --git a/lib/utils.js b/lib/utils.js
@@ -122,6 +122,10 @@ var decode = function (str, decoder, charset) {
     }
 };
 
+var limit = 1024;
+
+/* eslint operator-linebreak: [2, "before"] */
+
 var encode = function encode(str, defaultEncoder, charset, kind, format) {
     // This code was originally written by Brian White (mscdex) for the io.js core querystring library.
     // It has been adapted here for stricter adherence to RFC 3986
@@ -143,45 +147,54 @@ var encode = function encode(str, defaultEncoder, charset, kind, format) {
     }
 
     var out = '';
-    for (var i = 0; i < string.length; ++i) {
-        var c = string.charCodeAt(i);
-
-        if (
-            c === 0x2D // -
-            || c === 0x2E // .
-            || c === 0x5F // _
-            || c === 0x7E // ~
-            || (c >= 0x30 && c <= 0x39) // 0-9
-            || (c >= 0x41 && c <= 0x5A) // a-z
-            || (c >= 0x61 && c <= 0x7A) // A-Z
-            || (format === formats.RFC1738 && (c === 0x28 || c === 0x29)) // ( )
-        ) {
-            out += string.charAt(i);
-            continue;
-        }
+    for (var j = 0; j < string.length; j += limit) {
+        var segment = string.length >= limit ? string.slice(j, j + limit) : string;
+        var arr = [];
+
+        for (var i = 0; i < segment.length; ++i) {
+            var c = segment.charCodeAt(i);
+            if (
+                c === 0x2D // -
+                || c === 0x2E // .
+                || c === 0x5F // _
+                || c === 0x7E // ~
+                || (c >= 0x30 && c <= 0x39) // 0-9
+                || (c >= 0x41 && c <= 0x5A) // a-z
+                || (c >= 0x61 && c <= 0x7A) // A-Z
+                || (format === formats.RFC1738 && (c === 0x28 || c === 0x29)) // ( )
+            ) {
+                arr[arr.length] = segment.charAt(i);
+                continue;
+            }
 
-        if (c < 0x80) {
-            out += hexTable[c];
-            continue;
-        }
+            if (c < 0x80) {
+                arr[arr.length] = hexTable[c];
+                continue;
+            }
 
-        if (c < 0x800) {
-            out += hexTable[0xC0 | (c >> 6)] + hexTable[0x80 | (c & 0x3F)];
-            continue;
-        }
+            if (c < 0x800) {
+                arr[arr.length] = hexTable[0xC0 | (c >> 6)]
+                    + hexTable[0x80 | (c & 0x3F)];
+                continue;
+            }
+
+            if (c < 0xD800 || c >= 0xE000) {
+                arr[arr.length] = hexTable[0xE0 | (c >> 12)]
+                    + hexTable[0x80 | ((c >> 6) & 0x3F)]
+                    + hexTable[0x80 | (c & 0x3F)];
+                continue;
+            }
+
+            i += 1;
+            c = 0x10000 + (((c & 0x3FF) << 10) | (segment.charCodeAt(i) & 0x3FF));
 
-        if (c < 0xD800 || c >= 0xE000) {
-            out += hexTable[0xE0 | (c >> 12)] + hexTable[0x80 | ((c >> 6) & 0x3F)] + hexTable[0x80 | (c & 0x3F)];
-            continue;
+            arr[arr.length] = hexTable[0xF0 | (c >> 18)]
+                + hexTable[0x80 | ((c >> 12) & 0x3F)]
+                + hexTable[0x80 | ((c >> 6) & 0x3F)]
+                + hexTable[0x80 | (c & 0x3F)];
         }
 
-        i += 1;
-        c = 0x10000 + (((c & 0x3FF) << 10) | (string.charCodeAt(i) & 0x3FF));
-        /* eslint operator-linebreak: [2, "before"] */
-        out += hexTable[0xF0 | (c >> 18)]
-            + hexTable[0x80 | ((c >> 12) & 0x3F)]
-            + hexTable[0x80 | ((c >> 6) & 0x3F)]
-            + hexTable[0x80 | (c & 0x3F)];
+        out += arr.join('');
     }
 
     return out;