perf: avoid replace

tsctx · Dec 1, 2023 · cd93cdb · cd93cdb
1 parent 99a9f09
commit cd93cdb
Showing 1 changed file with 7 additions and 4 deletions.
diff --git a/lib/fetch/dataURL.js b/lib/fetch/dataURL.js
@@ -412,17 +412,20 @@ function forgivingBase64 (data) {
   // 1. Remove all ASCII whitespace from data.
   data = data.replace(ASCII_WHITESPACE_REPLACE_REGEX, '')  // eslint-disable-line
 
+  let dataLength = data.length
   // 2. If data’s code point length divides by 4 leaving
   // no remainder, then:
-  if (data.length % 4 === 0) {
+  if (dataLength % 4 === 0) {
     // 1. If data ends with one or two U+003D (=) code points,
     // then remove them from data.
-    data = data.replace(/=?=$/, '')
+    if (data.charCodeAt(dataLength - 1) === 0x003D && data.charCodeAt(--dataLength) === 0x003D) {
+      --dataLength
+    }
   }
 
   // 3. If data’s code point length divides by 4 leaving
   // a remainder of 1, then return failure.
-  if (data.length % 4 === 1) {
+  if (dataLength % 4 === 1) {
     return 'failure'
   }
 
@@ -431,7 +434,7 @@ function forgivingBase64 (data) {
   //  U+002F (/)
   //  ASCII alphanumeric
   // then return failure.
-  if (/[^+/0-9A-Za-z]/.test(data)) {
+  if (/[^+/0-9A-Za-z]/.test(data.length === dataLength ? data : (data = data.substring(0, dataLength)))) {
     return 'failure'
   }