switch out the accumulator reader for a faster buffer reader

README.md

@@ -1,20 +1,12 @@
 # varint
 
-decode [protobuf-style varint bytes](https://developers.google.com/protocol-buffers/docs/encoding#varints) and emit whole integers when enough have been accumulated that a number can be constructed; also encode whole numbers to an array of varint style bytes.
+encode whole numbers to an array of [protobuf-style varint bytes](https://developers.google.com/protocol-buffers/docs/encoding#varints) and also decode them.
 
 ```javascript
 var varint = require('varint')
 
 var bytes = varint.encode(300) // === [0xAC, 0x02]
-  , vi = varint()
-
-vi.once('data', function(num) {
-  console.log('got', num)
-})
-
-vi.write(bytes[0])
-vi.write(bytes[1]) // "got 300"
-
+varint.decode(bytes) // 300
 ```
 
 ## api
@@ -24,16 +16,11 @@ vi.write(bytes[1]) // "got 300"
 ### varint.encode(num[, output=[], offset=0]) -> array
 
 encodes `num` into either the array given by `offset` or a new array at `offset`
-and returns that array.
-
-### vi = varint() -> EventEmitter
-
-return a new `varint` instance.
+and returns that array filled with integers.
 
-### vi.write(byte) -> undefined
+### varint.decode(data[, offset=0]) -> number
 
-write a byte to the varint. if the byte is "final" (i.e., does not have the bit at `0x80` set),
-it will attempt to compile the number and emit it as a `data` event.
+decodes `data`, which can be either a buffer or array of integers, from position `offset` or default 0 and returns the decoded integer
 
 # License
 

decode.js

@@ -1,33 +1,21 @@
-module.exports = Decoder
+module.exports = read
 
 var MSB = 0x80
   , REST = 0x7F
 
-
-function Decoder() {
-  this.accum = []
+function read(buf, offset) {
+  var res    = 0
+    , offset = offset || 0
+    , shift  = 0
+    , b
+  
+  do {
+    b = buf[offset++]
+    res += shift < 28
+      ? (b & REST) << shift
+      : (b & REST) * Math.pow(2, shift)
+    shift += 7
+  } while (b >= MSB)
+  
+  return res
 }
-Decoder.prototype.write = write;
-
-function write(byte) {
-  var msb = byte & MSB
-    , accum = this.accum
-    , len
-    , out
-
-  accum[accum.length] = byte & REST
-  if(msb) {
-    return
-  }
-
-  len = accum.length
-  out = 0
-
-  for(var i = 0; i < len; ++i) {
-    out |= accum[i] << (7 * i)
-  }
-
-  accum.length = 0
-  this.ondata(out)
-  return
-}

encode.js

@@ -14,4 +14,4 @@ function encode(num, out, offset) {
   }
   out[offset] = num
   return out
-}
+}

index.js

@@ -1,22 +1,4 @@
-module.exports = varint
-
-varint.encode = require('./encode.js');
-
-var EE = require('events').EventEmitter
-  , Decoder = require('./decode.js')
-
-function varint() {
-  var ee = new EE
-    , dec = new Decoder
-
-  dec.ondata = function (item) {
-    ee.emit("data", item)
-  }
-
-  ee.write = function (item) {
-    dec.write(item);
-  }
-
-  return ee
+module.exports = {
+  encode: require('./encode.js'),
+  decode: require('./decode.js')
 }
-

package.json

@@ -1,7 +1,7 @@
 {
   "name": "varint",
   "version": "0.0.3",
-  "description": "use msb to create integer values of varying sizes",
+  "description": "protobuf-style varint bytes - use msb to create integer values of varying sizes",
   "main": "index.js",
   "scripts": {
     "test": "node test.js"

test.js

@@ -2,39 +2,25 @@ var varint = require('./index')
   , test = require('tape')
 
 test('fuzz test', function(assert) {
-  var vi = varint()
-    , expect
+  var expect
     , encoded
 
-  vi.on('data', function(data) {
-    assert.equal(expect, data, 'fuzz test: '+expect.toString(16))
-  })
-
   for(var i = 0, len = 100; i < len; ++i) {
     expect = randint(0x7FFFFFFF)
     encoded = varint.encode(expect)
- 
-    for(var x = 0; x < encoded.length; ++x) {
-      vi.write(encoded[x])
-    } 
+    var data = varint.decode(encoded)
+    assert.equal(expect, data, 'fuzz test: '+expect.toString())
   }
 
   assert.end()
 })
 
 test('test single byte works as expected', function(assert) {
-  var num = [0xAC, 0x02]
-  var acc = varint()
-
-  acc.on('data', function(data) {
-    assert.equal(data, 300, 'should equal 300 every time')
-  })
-
-  for(var i = 0, len = 10; i < len; ++i) {
-    acc.write(0xAC)
-    acc.write(0x02)
-  }
-
+  var buf = new Uint8Array(2)
+  buf[0] = 172
+  buf[1] = 2
+  var data = varint.decode(buf)
+  assert.equal(data, 300, 'should equal 300')
   assert.end()
 })
 
@@ -47,28 +33,22 @@ test('test encode works as expected', function(assert) {
 })
 
 test('test decode single bytes', function(assert) {
-  var vi = varint()
-    , expected = randint(parseInt('1111111', '2'))
-
-  vi.once('data', function(data) {
-    assert.equal(data, expected)
-    assert.end()
-  })
-
-  vi.write(expected)
+  var expected = randint(parseInt('1111111', '2'))
+  var buf = new Uint8Array(1)
+  buf[0] = expected
+  var data = varint.decode(buf)
+  assert.equal(data, expected)
+  assert.end()
 })
 
 test('test decode multiple bytes with zero', function(assert) {
-  var vi = varint()
-    , expected = randint(parseInt('1111111', '2'))
-
-  vi.once('data', function(data) {
-    assert.equal(data, expected << 7)
-    assert.end()
-  })
-
-  vi.write(0x80)
-  vi.write(expected)
+  var expected = randint(parseInt('1111111', '2'))
+  var buf = new Uint8Array(2)
+  buf[0] = 128
+  buf[1] = expected
+  var data = varint.decode(buf)
+  assert.equal(data, expected << 7)
+  assert.end()
 })
 
 test('encode single byte', function(assert) {
@@ -80,6 +60,7 @@ test('encode single byte', function(assert) {
 test('encode multiple byte with zero first byte', function(assert) {
   var expected = 0x0F00
   assert.deepEqual(varint.encode(expected), [0x80, 0x1E])
+  assert.end()
 })
 
 function randint(range) {