chore: improve length parsing performance

Author: BridgeAR

lib/parser.js

@@ -115,14 +115,22 @@ function parseSimpleString (parser) {
 }
 
 /**
- * Returns the string length via parseSimpleNumbers
+ * Returns the read length
  * @param parser
  * @returns {*}
  */
 function parseLength (parser) {
-  const string = parseSimpleNumbers(parser)
-  if (string !== undefined) {
-    return string
+  const length = parser.buffer.length - 1
+  var offset = parser.offset
+  var number = 0
+
+  while (offset < length) {
+    const c1 = parser.buffer[offset++]
+    if (c1 === 13) {
+      parser.offset = offset + 1
+      return number
+    }
+    number = (number * 10) + (c1 - 48)
   }
 }
 

test/parsers.spec.js

@@ -195,7 +195,7 @@ describe('parsers', function () {
         assert.strictEqual(replyCount, 6)
         parser.execute(Buffer.from('$-5'))
         assert.strictEqual(replyCount, 6)
-        parser.execute(Buffer.from('\r\n:12345\r\n*-\r\n*-1\r\n+t\r\n'))
+        parser.execute(Buffer.from('\r\n:12345\r\n*0\r\n*-1\r\n+t\r\n'))
         assert.strictEqual(replyCount, 11)
       })