Add support for large integers

bignum/index.js

@@ -0,0 +1,18 @@
+var BigNumber = require('bignumber.js')
+var bencode = module.exports
+
+bencode.encode = require('../lib/encode')
+bencode.decode = require('../lib/decode')
+
+bencode.encode.number = function (buffers, data) {
+  buffers.push(new Buffer('i' + data.toString() + 'e'))
+}
+
+bencode.decode.integer = function () {
+  var end = bencode.decode.find(0x65)
+  var number = bencode.decode.data.toString('ascii', bencode.decode.position + 1, end)
+
+  bencode.decode.position += end + 1 - bencode.decode.position
+
+  return new BigNumber(number, 10)
+}

lib/decoder.js

@@ -0,0 +1,128 @@
+/**
+ * Decoder
+ * @return {Decoder}
+ */
+function Decoder () {
+  if (!(this instanceof Decoder)) {
+    return new Decoder()
+  }
+
+  this.bytes = 0
+  this.position = 0
+  this.data = null
+  this.encoding = null
+}
+
+/**
+ * Decoder prototype
+ * @type {Object}
+ */
+Decoder.prototype = {
+
+  constructor: Decoder,
+
+  use: function (type, fn) {
+    this[type] = fn
+  },
+
+  decode: function (data, start, end, encoding) {
+    if (typeof start !== 'number' && encoding == null) {
+      encoding = start
+      start = undefined
+    }
+
+    if (typeof end !== 'number' && encoding == null) {
+      encoding = end
+      end = undefined
+    }
+
+    this.position = 0
+    this.encoding = encoding || null
+
+    this.data = !(Buffer.isBuffer(data))
+      ? new Buffer(data)
+      : data.slice(start, end)
+
+    this.bytes = this.data.length
+
+    return this.next()
+  },
+
+  next: function () {
+    switch (this.data[this.position]) {
+      case 0x64: return this.object()
+      case 0x6C: return this.array()
+      case 0x69: return this.number()
+      default: return this.buffer()
+    }
+  },
+
+  find: function (chr) {
+    var i = this.position
+    var c = this.data.length
+    var d = this.data
+
+    while (i < c) {
+      if (d[i] === chr) return i
+      i++
+    }
+
+    throw new Error(
+      'Invalid data: Missing delimiter "' + String.fromCharCode(chr) +
+      '" [0x' + chr.toString(16) + ']'
+    )
+  },
+
+  object: function () {
+    this.position++
+
+    var dict = {}
+
+    while (this.data[this.position] !== 0x65) {
+      dict[this.buffer()] = this.next()
+    }
+
+    this.position++
+
+    return dict
+  },
+
+  array: function () {
+    this.position++
+
+    var lst = []
+
+    while (this.data[this.position] !== 0x65) {
+      lst.push(this.next())
+    }
+
+    this.position++
+
+    return lst
+  },
+
+  number: function () {
+    var end = this.find(0x65)
+    var number = this.data.toString('ascii', this.position + 1, end)
+
+    this.position += end + 1 - this.position
+
+    return parseInt(number, 10)
+  },
+
+  buffer: function () {
+    var sep = this.find(0x3A)
+    var length = parseInt(this.data.toString('ascii', this.position, sep), 10)
+    var end = ++sep + length
+
+    this.position = end
+
+    return this.encoding
+      ? this.data.toString(this.encoding, sep, end)
+      : this.data.slice(sep, end)
+  }
+
+}
+
+// Exports
+module.exports = Decoder