make .get() much faster by not copying anything

rvagg · Oct 7, 2018 · 172e3ee · 172e3ee
1 parent 6d71467
commit 172e3ee
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Showing 2 changed files with 7 additions and 5 deletions.
diff --git a/bl.js b/bl.js
@@ -3,8 +3,6 @@ var DuplexStream = require('readable-stream').Duplex
   , util         = require('util')
   , Buffer       = require('safe-buffer').Buffer
 
-var tempBuffer = Buffer.alloc(1)
-
 function BufferList (callback) {
   if (!(this instanceof BufferList))
     return new BufferList(callback)
@@ -120,8 +118,11 @@ BufferList.prototype.end = function end (chunk) {
 
 
 BufferList.prototype.get = function get (index) {
-  this.copy(tempBuffer, 0, index, index + 1)
-  return tempBuffer[0]
+  if (index > this.length || index < 0) {
+    return undefined
+  }
+  const offset = this._offset(index)
+  return this._bufs[offset[0]][offset[1]]
 }
 
 

diff --git a/test/test.js b/test/test.js
@@ -19,11 +19,12 @@ tape('single bytes from single buffer', function (t) {
   bl.append(Buffer.from('abcd'))
 
   t.equal(bl.length, 4)
-
+  t.equal(bl.get(-1), undefined)
   t.equal(bl.get(0), 97)
   t.equal(bl.get(1), 98)
   t.equal(bl.get(2), 99)
   t.equal(bl.get(3), 100)
+  t.equal(bl.get(4), undefined)
 
   t.end()
 })