From: Feross Aboukhadijeh <feross@feross.org>
Date: Thu, 17 Jul 2014 05:51:36 +0000 (-0700)
Subject: remove private clamp and coerce functions
X-Git-Url: https://zoso.dev/?a=commitdiff_plain;h=34f83369a7f43c101b14b33ae21f0a53e5ab6561;p=buffer.git

remove private clamp and coerce functions

made the constructor and `slice` match node’s implementation more
closely
---

diff --git a/index.js b/index.js
index b3e3d41..746ecfd 100644
--- a/index.js
+++ b/index.js
@@ -53,18 +53,16 @@ function Buffer (subject, encoding, noZero) {
 
   var type = typeof subject
 
-  if (encoding === 'base64' && type === 'string') {
-    subject = base64clean(subject)
-  }
-
   // Find the length
   var length
   if (type === 'number')
-    length = coerce(subject)
-  else if (type === 'string')
+    length = subject > 0 ? subject >>> 0 : 0
+  else if (type === 'string') {
+    if (encoding === 'base64')
+      subject = base64clean(subject)
     length = Buffer.byteLength(subject, encoding)
-  else if (type === 'object')
-    length = coerce(subject.length) // assume that object is array-like
+  } else if (type === 'object') // assume object is array-like
+    length = +subject.length > 0 ? Math.floor(+subject.length) : 0
   else
     throw new Error('First argument needs to be a number, array or string.')
 
@@ -473,8 +471,27 @@ function utf16leSlice (buf, start, end) {
 
 Buffer.prototype.slice = function (start, end) {
   var len = this.length
-  start = clamp(start, len, 0)
-  end = clamp(end, len, len)
+  start = ~~start
+  end = end === undefined ? len : ~~end
+
+  if (start < 0) {
+    start += len;
+    if (start < 0)
+      start = 0
+  } else if (start > len) {
+    start = len
+  }
+
+  if (end < 0) {
+    end += len
+    if (end < 0)
+      end = 0
+  } else if (end > len) {
+    end = len
+  }
+
+  if (end < start)
+    end = start
 
   if (Buffer._useTypedArrays) {
     return Buffer._augment(this.subarray(start, end))
@@ -1028,25 +1045,6 @@ function stringtrim (str) {
   return str.replace(/^\s+|\s+$/g, '')
 }
 
-// slice(start, end)
-function clamp (index, len, defaultValue) {
-  if (typeof index !== 'number') return defaultValue
-  index = ~~index;  // Coerce to integer.
-  if (index >= len) return len
-  if (index >= 0) return index
-  index += len
-  if (index >= 0) return index
-  return 0
-}
-
-function coerce (length) {
-  // Coerce length to a number (possibly NaN), round up
-  // in case it's fractional (e.g. 123.456) then do a
-  // double negate to coerce a NaN to 0. Easy, right?
-  length = ~~Math.ceil(+length)
-  return length < 0 ? 0 : length
-}
-
 function isArray (subject) {
   return (Array.isArray || function (subject) {
     return Object.prototype.toString.call(subject) === '[object Array]'