buffa/buffer.js

/*!
 * The buffer module from node.js, for the browser.
 *
 * @author   Feross Aboukhadijeh <feross@feross.org> <http://feross.org>
 * @license  MIT
 */

var base64 = require('base64-js')
var ieee754 = require('ieee754')

exports.Buffer = Buffer
exports.SlowBuffer = Buffer
exports.INSPECT_MAX_BYTES = 50
Buffer.poolSize = 8192

/**
 * If `Buffer._useTypedArrays`:
 *   === true    Use Uint8Array implementation (fastest)
 *   === false   Use Object implementation (compatible down to IE6)
 */
Buffer._useTypedArrays = false; (function () {
  // Detect if browser supports Typed Arrays. Supported browsers are IE 10+, Firefox 4+,
  // Chrome 7+, Safari 5.1+, Opera 11.6+, iOS 4.2+. If the browser does not support adding
  // properties to `Uint8Array` instances, then that's the same as no `Uint8Array` support
  // because we need to be able to add all the node Buffer API methods. This is an issue
  // in Firefox 4-29. Now fixed: https://bugzilla.mozilla.org/show_bug.cgi?id=695438
  try {
    var buf = new ArrayBuffer(0)
    var arr = new Uint8Array(buf)
    arr.foo = function () { return 42 }
    return 42 === arr.foo() &&
        typeof arr.subarray === 'function' // Chrome 9-10 lack `subarray`
  } catch (e) {
    return false
  }
})()

/**
 * Class: Buffer
 * =============
 *
 * The Buffer constructor returns instances of `Uint8Array` that are augmented
 * with function properties for all the node `Buffer` API functions. We use
 * `Uint8Array` so that square bracket notation works as expected -- it returns
 * a single octet.
 *
 * By augmenting the instances, we can avoid modifying the `Uint8Array`
 * prototype.
 */
function Buffer (subject, encoding, noZero) {
  if (!(this instanceof Buffer))
    return new Buffer(subject, encoding, noZero)

  var type = typeof subject

  // Workaround: node's base64 implementation allows for non-padded strings
  // while base64-js does not.
  if (encoding === 'base64' && type === 'string') {
    subject = stringtrim(subject)
    while (subject.length % 4 !== 0) {
      subject = subject + '='
    }
  }

  // Find the length
  var length
  if (type === 'number')
    length = coerce(subject)
  else if (type === 'string')
    length = Buffer.byteLength(subject, encoding)
  else if (type === 'object')
    length = coerce(subject.length) // assume that object is array-like
  else
    throw new Error('First argument needs to be a number, array or string.')

  var buf
  if (Buffer._useTypedArrays) {
    // Preferred: Return an augmented `Uint8Array` instance for best performance
    buf = Buffer._augment(new Uint8Array(length))
  } else {
    // Fallback: Return THIS instance of Buffer (created by `new`)
    buf = this
    buf.length = length
    buf._isBuffer = true
  }

  var i
  if (Buffer._useTypedArrays && typeof subject.byteLength === 'number') {
    // Speed optimization -- use set if we're copying from a typed array
    buf._set(subject)
  } else if (isArrayish(subject)) {
    // Treat array-ish objects as a byte array
    for (i = 0; i < length; i++) {
      if (Buffer.isBuffer(subject))
        buf[i] = subject.readUInt8(i)
      else
        buf[i] = subject[i]
    }
  } else if (type === 'string') {
    buf.write(subject, 0, encoding)
  } else if (type === 'number' && !Buffer._useTypedArrays && !noZero) {
    for (i = 0; i < length; i++) {
      buf[i] = 0
    }
  }

  return buf
}

// STATIC METHODS
// ==============

Buffer.isEncoding = function (encoding) {
  switch (String(encoding).toLowerCase()) {
    case 'hex':
    case 'utf8':
    case 'utf-8':
    case 'ascii':
    case 'binary':
    case 'base64':
    case 'raw':
    case 'ucs2':
    case 'ucs-2':
    case 'utf16le':
    case 'utf-16le':
      return true
    default:
      return false
  }
}

Buffer.isBuffer = function (b) {
  return !!(b !== null && b !== undefined && b._isBuffer)
}

Buffer.byteLength = function (str, encoding) {
  var ret
  str = str + ''
  switch (encoding || 'utf8') {
    case 'hex':
      ret = str.length / 2
      break
    case 'utf8':
    case 'utf-8':
      ret = utf8ToBytes(str).length
      break
    case 'ascii':
    case 'binary':
    case 'raw':
      ret = str.length
      break
    case 'base64':
      ret = base64ToBytes(str).length
      break
    case 'ucs2':
    case 'ucs-2':
    case 'utf16le':
    case 'utf-16le':
      ret = str.length * 2
      break
    default:
      throw new Error('Unknown encoding')
  }
  return ret
}

Buffer.concat = function (list, totalLength) {
  assert(isArray(list), 'Usage: Buffer.concat(list, [totalLength])\n' +
      'list should be an Array.')

  if (list.length === 0) {
    return new Buffer(0)
  } else if (list.length === 1) {
    return list[0]
  }

  var i
  if (typeof totalLength !== 'number') {
    totalLength = 0
    for (i = 0; i < list.length; i++) {
      totalLength += list[i].length
    }
  }

  var buf = new Buffer(totalLength)
  var pos = 0
  for (i = 0; i < list.length; i++) {
    var item = list[i]
    item.copy(buf, pos)
    pos += item.length
  }
  return buf
}

// BUFFER INSTANCE METHODS
// =======================

function _hexWrite (buf, string, offset, length) {
  offset = Number(offset) || 0
  var remaining = buf.length - offset
  if (!length) {
    length = remaining
  } else {
    length = Number(length)
    if (length > remaining) {
      length = remaining
    }
  }

  // must be an even number of digits
  var strLen = string.length
  assert(strLen % 2 === 0, 'Invalid hex string')

  if (length > strLen / 2) {
    length = strLen / 2
  }
  for (var i = 0; i < length; i++) {
    var byte = parseInt(string.substr(i * 2, 2), 16)
    assert(!isNaN(byte), 'Invalid hex string')
    buf[offset + i] = byte
  }
  Buffer._charsWritten = i * 2
  return i
}

function _utf8Write (buf, string, offset, length) {
  var charsWritten = Buffer._charsWritten =
    blitBuffer(utf8ToBytes(string), buf, offset, length)
  return charsWritten
}

function _asciiWrite (buf, string, offset, length) {
  var charsWritten = Buffer._charsWritten =
    blitBuffer(asciiToBytes(string), buf, offset, length)
  return charsWritten
}

function _binaryWrite (buf, string, offset, length) {
  return _asciiWrite(buf, string, offset, length)
}

function _base64Write (buf, string, offset, length) {
  var charsWritten = Buffer._charsWritten =
    blitBuffer(base64ToBytes(string), buf, offset, length)
  return charsWritten
}

function _utf16leWrite (buf, string, offset, length) {
  var charsWritten = Buffer._charsWritten =
    blitBuffer(utf16leToBytes(string), buf, offset, length)
  return charsWritten
}

Buffer.prototype.write = function (string, offset, length, encoding) {
  // Support both (string, offset, length, encoding)
  // and the legacy (string, encoding, offset, length)
  if (isFinite(offset)) {
    if (!isFinite(length)) {
      encoding = length
      length = undefined
    }
  } else {  // legacy
    var swap = encoding
    encoding = offset
    offset = length
    length = swap
  }

  offset = Number(offset) || 0
  var remaining = this.length - offset
  if (!length) {
    length = remaining
  } else {
    length = Number(length)
    if (length > remaining) {
      length = remaining
    }
  }
  encoding = String(encoding || 'utf8').toLowerCase()

  var ret
  switch (encoding) {
    case 'hex':
      ret = _hexWrite(this, string, offset, length)
      break
    case 'utf8':
    case 'utf-8':
      ret = _utf8Write(this, string, offset, length)
      break
    case 'ascii':
      ret = _asciiWrite(this, string, offset, length)
      break
    case 'binary':
      ret = _binaryWrite(this, string, offset, length)
      break
    case 'base64':
      ret = _base64Write(this, string, offset, length)
      break
    case 'ucs2':
    case 'ucs-2':
    case 'utf16le':
    case 'utf-16le':
      ret = _utf16leWrite(this, string, offset, length)
      break
    default:
      throw new Error('Unknown encoding')
  }
  return ret
}

Buffer.prototype.toString = function (encoding, start, end) {
  var self = this

  encoding = String(encoding || 'utf8').toLowerCase()
  start = Number(start) || 0
  end = (end !== undefined)
    ? Number(end)
    : end = self.length

  // Fastpath empty strings
  if (end === start)
    return ''

  var ret
  switch (encoding) {
    case 'hex':
      ret = _hexSlice(self, start, end)
      break
    case 'utf8':
    case 'utf-8':
      ret = _utf8Slice(self, start, end)
      break
    case 'ascii':
      ret = _asciiSlice(self, start, end)
      break
    case 'binary':
      ret = _binarySlice(self, start, end)
      break
    case 'base64':
      ret = _base64Slice(self, start, end)
      break
    case 'ucs2':
    case 'ucs-2':
    case 'utf16le':
    case 'utf-16le':
      ret = _utf16leSlice(self, start, end)
      break
    default:
      throw new Error('Unknown encoding')
  }
  return ret
}

Buffer.prototype.toJSON = function () {
  return {
    type: 'Buffer',
    data: Array.prototype.slice.call(this._arr || this, 0)
  }
}

// copy(targetBuffer, targetStart=0, sourceStart=0, sourceEnd=buffer.length)
Buffer.prototype.copy = function (target, target_start, start, end) {
  var source = this

  if (!start) start = 0
  if (!end && end !== 0) end = this.length
  if (!target_start) target_start = 0

  // Copy 0 bytes; we're done
  if (end === start) return
  if (target.length === 0 || source.length === 0) return

  // Fatal error conditions
  assert(end >= start, 'sourceEnd < sourceStart')
  assert(target_start >= 0 && target_start < target.length,
      'targetStart out of bounds')
  assert(start >= 0 && start < source.length, 'sourceStart out of bounds')
  assert(end >= 0 && end <= source.length, 'sourceEnd out of bounds')

  // Are we oob?
  if (end > this.length)
    end = this.length
  if (target.length - target_start < end - start)
    end = target.length - target_start + start

  var len = end - start

  if (len < 100 || !Buffer._useTypedArrays) {
    for (var i = 0; i < len; i++)
      target[i + target_start] = this[i + start]
  } else {
    target._set(this.subarray(start, start + len), target_start)
  }
}

function _base64Slice (buf, start, end) {
  if (start === 0 && end === buf.length) {
    return base64.fromByteArray(buf)
  } else {
    return base64.fromByteArray(buf.slice(start, end))
  }
}

function _utf8Slice (buf, start, end) {
  var res = ''
  var tmp = ''
  end = Math.min(buf.length, end)

  for (var i = start; i < end; i++) {
    if (buf[i] <= 0x7F) {
      res += decodeUtf8Char(tmp) + String.fromCharCode(buf[i])
      tmp = ''
    } else {
      tmp += '%' + buf[i].toString(16)
    }
  }

  return res + decodeUtf8Char(tmp)
}

function _asciiSlice (buf, start, end) {
  var ret = ''
  end = Math.min(buf.length, end)

  for (var i = start; i < end; i++)
    ret += String.fromCharCode(buf[i])
  return ret
}

function _binarySlice (buf, start, end) {
  return _asciiSlice(buf, start, end)
}

function _hexSlice (buf, start, end) {
  var len = buf.length

  if (!start || start < 0) start = 0
  if (!end || end < 0 || end > len) end = len

  var out = ''
  for (var i = start; i < end; i++) {
    out += toHex(buf[i])
  }
  return out
}

function _utf16leSlice (buf, start, end) {
  var bytes = buf.slice(start, end)
  var res = ''
  for (var i = 0; i < bytes.length; i += 2) {
    res += String.fromCharCode(bytes[i] + bytes[i+1] * 256)
  }
  return res
}

Buffer.prototype.slice = function (start, end) {
  var len = this.length
  start = clamp(start, len, 0)
  end = clamp(end, len, len)

  if (Buffer._useTypedArrays) {
    return Buffer._augment(this.subarray(start, end))
  } else {
    var sliceLen = end - start
    var newBuf = new Buffer(sliceLen, undefined, true)
    for (var i = 0; i < sliceLen; i++) {
      newBuf[i] = this[i + start]
    }
    return newBuf
  }
}

// `get` will be removed in Node 0.13+
Buffer.prototype.get = function (offset) {
  console.log('.get() is deprecated. Access using array indexes instead.')
  return this.readUInt8(offset)
}

// `set` will be removed in Node 0.13+
Buffer.prototype.set = function (v, offset) {
  console.log('.set() is deprecated. Access using array indexes instead.')
  return this.writeUInt8(v, offset)
}

Buffer.prototype.readUInt8 = function (offset, noAssert) {
  if (!noAssert) {
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset < this.length, 'Trying to read beyond buffer length')
  }

  if (offset >= this.length)
    return

  return this[offset]
}

function _readUInt16 (buf, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 1 < buf.length, 'Trying to read beyond buffer length')
  }

  var len = buf.length
  if (offset >= len)
    return

  var val
  if (littleEndian) {
    val = buf[offset]
    if (offset + 1 < len)
      val |= buf[offset + 1] << 8
  } else {
    val = buf[offset] << 8
    if (offset + 1 < len)
      val |= buf[offset + 1]
  }
  return val
}

Buffer.prototype.readUInt16LE = function (offset, noAssert) {
  return _readUInt16(this, offset, true, noAssert)
}

Buffer.prototype.readUInt16BE = function (offset, noAssert) {
  return _readUInt16(this, offset, false, noAssert)
}

function _readUInt32 (buf, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 3 < buf.length, 'Trying to read beyond buffer length')
  }

  var len = buf.length
  if (offset >= len)
    return

  var val
  if (littleEndian) {
    if (offset + 2 < len)
      val = buf[offset + 2] << 16
    if (offset + 1 < len)
      val |= buf[offset + 1] << 8
    val |= buf[offset]
    if (offset + 3 < len)
      val = val + (buf[offset + 3] << 24 >>> 0)
  } else {
    if (offset + 1 < len)
      val = buf[offset + 1] << 16
    if (offset + 2 < len)
      val |= buf[offset + 2] << 8
    if (offset + 3 < len)
      val |= buf[offset + 3]
    val = val + (buf[offset] << 24 >>> 0)
  }
  return val
}

Buffer.prototype.readUInt32LE = function (offset, noAssert) {
  return _readUInt32(this, offset, true, noAssert)
}

Buffer.prototype.readUInt32BE = function (offset, noAssert) {
  return _readUInt32(this, offset, false, noAssert)
}

Buffer.prototype.readInt8 = function (offset, noAssert) {
  if (!noAssert) {
    assert(offset !== undefined && offset !== null,
        'missing offset')
    assert(offset < this.length, 'Trying to read beyond buffer length')
  }

  if (offset >= this.length)
    return

  var neg = this[offset] & 0x80
  if (neg)
    return (0xff - this[offset] + 1) * -1
  else
    return this[offset]
}

function _readInt16 (buf, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 1 < buf.length, 'Trying to read beyond buffer length')
  }

  var len = buf.length
  if (offset >= len)
    return

  var val = _readUInt16(buf, offset, littleEndian, true)
  var neg = val & 0x8000
  if (neg)
    return (0xffff - val + 1) * -1
  else
    return val
}

Buffer.prototype.readInt16LE = function (offset, noAssert) {
  return _readInt16(this, offset, true, noAssert)
}

Buffer.prototype.readInt16BE = function (offset, noAssert) {
  return _readInt16(this, offset, false, noAssert)
}

function _readInt32 (buf, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 3 < buf.length, 'Trying to read beyond buffer length')
  }

  var len = buf.length
  if (offset >= len)
    return

  var val = _readUInt32(buf, offset, littleEndian, true)
  var neg = val & 0x80000000
  if (neg)
    return (0xffffffff - val + 1) * -1
  else
    return val
}

Buffer.prototype.readInt32LE = function (offset, noAssert) {
  return _readInt32(this, offset, true, noAssert)
}

Buffer.prototype.readInt32BE = function (offset, noAssert) {
  return _readInt32(this, offset, false, noAssert)
}

function _readFloat (buf, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset + 3 < buf.length, 'Trying to read beyond buffer length')
  }

  return ieee754.read(buf, offset, littleEndian, 23, 4)
}

Buffer.prototype.readFloatLE = function (offset, noAssert) {
  return _readFloat(this, offset, true, noAssert)
}

Buffer.prototype.readFloatBE = function (offset, noAssert) {
  return _readFloat(this, offset, false, noAssert)
}

function _readDouble (buf, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset + 7 < buf.length, 'Trying to read beyond buffer length')
  }

  return ieee754.read(buf, offset, littleEndian, 52, 8)
}

Buffer.prototype.readDoubleLE = function (offset, noAssert) {
  return _readDouble(this, offset, true, noAssert)
}

Buffer.prototype.readDoubleBE = function (offset, noAssert) {
  return _readDouble(this, offset, false, noAssert)
}

Buffer.prototype.writeUInt8 = function (value, offset, noAssert) {
  if (!noAssert) {
    assert(value !== undefined && value !== null, 'missing value')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset < this.length, 'trying to write beyond buffer length')
    verifuint(value, 0xff)
  }

  if (offset >= this.length) return

  this[offset] = value
}

function _writeUInt16 (buf, value, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(value !== undefined && value !== null, 'missing value')
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 1 < buf.length, 'trying to write beyond buffer length')
    verifuint(value, 0xffff)
  }

  var len = buf.length
  if (offset >= len)
    return

  for (var i = 0, j = Math.min(len - offset, 2); i < j; i++) {
    buf[offset + i] =
        (value & (0xff << (8 * (littleEndian ? i : 1 - i)))) >>>
            (littleEndian ? i : 1 - i) * 8
  }
}

Buffer.prototype.writeUInt16LE = function (value, offset, noAssert) {
  _writeUInt16(this, value, offset, true, noAssert)
}

Buffer.prototype.writeUInt16BE = function (value, offset, noAssert) {
  _writeUInt16(this, value, offset, false, noAssert)
}

function _writeUInt32 (buf, value, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(value !== undefined && value !== null, 'missing value')
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 3 < buf.length, 'trying to write beyond buffer length')
    verifuint(value, 0xffffffff)
  }

  var len = buf.length
  if (offset >= len)
    return

  for (var i = 0, j = Math.min(len - offset, 4); i < j; i++) {
    buf[offset + i] =
        (value >>> (littleEndian ? i : 3 - i) * 8) & 0xff
  }
}

Buffer.prototype.writeUInt32LE = function (value, offset, noAssert) {
  _writeUInt32(this, value, offset, true, noAssert)
}

Buffer.prototype.writeUInt32BE = function (value, offset, noAssert) {
  _writeUInt32(this, value, offset, false, noAssert)
}

Buffer.prototype.writeInt8 = function (value, offset, noAssert) {
  if (!noAssert) {
    assert(value !== undefined && value !== null, 'missing value')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset < this.length, 'Trying to write beyond buffer length')
    verifsint(value, 0x7f, -0x80)
  }

  if (offset >= this.length)
    return

  if (value >= 0)
    this.writeUInt8(value, offset, noAssert)
  else
    this.writeUInt8(0xff + value + 1, offset, noAssert)
}

function _writeInt16 (buf, value, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(value !== undefined && value !== null, 'missing value')
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 1 < buf.length, 'Trying to write beyond buffer length')
    verifsint(value, 0x7fff, -0x8000)
  }

  var len = buf.length
  if (offset >= len)
    return

  if (value >= 0)
    _writeUInt16(buf, value, offset, littleEndian, noAssert)
  else
    _writeUInt16(buf, 0xffff + value + 1, offset, littleEndian, noAssert)
}

Buffer.prototype.writeInt16LE = function (value, offset, noAssert) {
  _writeInt16(this, value, offset, true, noAssert)
}

Buffer.prototype.writeInt16BE = function (value, offset, noAssert) {
  _writeInt16(this, value, offset, false, noAssert)
}

function _writeInt32 (buf, value, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(value !== undefined && value !== null, 'missing value')
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 3 < buf.length, 'Trying to write beyond buffer length')
    verifsint(value, 0x7fffffff, -0x80000000)
  }

  var len = buf.length
  if (offset >= len)
    return

  if (value >= 0)
    _writeUInt32(buf, value, offset, littleEndian, noAssert)
  else
    _writeUInt32(buf, 0xffffffff + value + 1, offset, littleEndian, noAssert)
}

Buffer.prototype.writeInt32LE = function (value, offset, noAssert) {
  _writeInt32(this, value, offset, true, noAssert)
}

Buffer.prototype.writeInt32BE = function (value, offset, noAssert) {
  _writeInt32(this, value, offset, false, noAssert)
}

function _writeFloat (buf, value, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(value !== undefined && value !== null, 'missing value')
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 3 < buf.length, 'Trying to write beyond buffer length')
    verifIEEE754(value, 3.4028234663852886e+38, -3.4028234663852886e+38)
  }

  var len = buf.length
  if (offset >= len)
    return

  ieee754.write(buf, value, offset, littleEndian, 23, 4)
}

Buffer.prototype.writeFloatLE = function (value, offset, noAssert) {
  _writeFloat(this, value, offset, true, noAssert)
}

Buffer.prototype.writeFloatBE = function (value, offset, noAssert) {
  _writeFloat(this, value, offset, false, noAssert)
}

function _writeDouble (buf, value, offset, littleEndian, noAssert) {
  if (!noAssert) {
    assert(value !== undefined && value !== null, 'missing value')
    assert(typeof littleEndian === 'boolean', 'missing or invalid endian')
    assert(offset !== undefined && offset !== null, 'missing offset')
    assert(offset + 7 < buf.length,
        'Trying to write beyond buffer length')
    verifIEEE754(value, 1.7976931348623157E+308, -1.7976931348623157E+308)
  }

  var len = buf.length
  if (offset >= len)
    return

  ieee754.write(buf, value, offset, littleEndian, 52, 8)
}

Buffer.prototype.writeDoubleLE = function (value, offset, noAssert) {
  _writeDouble(this, value, offset, true, noAssert)
}

Buffer.prototype.writeDoubleBE = function (value, offset, noAssert) {
  _writeDouble(this, value, offset, false, noAssert)
}

// fill(value, start=0, end=buffer.length)
Buffer.prototype.fill = function (value, start, end) {
  if (!value) value = 0
  if (!start) start = 0
  if (!end) end = this.length

  if (typeof value === 'string') {
    value = value.charCodeAt(0)
  }

  assert(typeof value === 'number' && !isNaN(value), 'value is not a number')
  assert(end >= start, 'end < start')

  // Fill 0 bytes; we're done
  if (end === start) return
  if (this.length === 0) return

  assert(start >= 0 && start < this.length, 'start out of bounds')
  assert(end >= 0 && end <= this.length, 'end out of bounds')

  for (var i = start; i < end; i++) {
    this[i] = value
  }
}

Buffer.prototype.inspect = function () {
  var out = []
  var len = this.length
  for (var i = 0; i < len; i++) {
    out[i] = toHex(this[i])
    if (i === exports.INSPECT_MAX_BYTES) {
      out[i + 1] = '...'
      break
    }
  }
  return '<Buffer ' + out.join(' ') + '>'
}

/**
 * Creates a new `ArrayBuffer` with the *copied* memory of the buffer instance.
 * Added in Node 0.12. Only available in browsers that support ArrayBuffer.
 */
Buffer.prototype.toArrayBuffer = function () {
  if (typeof Uint8Array !== 'undefined') {
    if (Buffer._useTypedArrays) {
      return (new Buffer(this)).buffer
    } else {
      var buf = new Uint8Array(this.length)
      for (var i = 0, len = buf.length; i < len; i += 1)
        buf[i] = this[i]
      return buf.buffer
    }
  } else {
    throw new Error('Buffer.toArrayBuffer not supported in this browser')
  }
}

require("./extend")(Buffer.prototype);







// HELPER FUNCTIONS
// ================

function stringtrim (str) {
  if (str.trim) return str.trim()
  return str.replace(/^\s+|\s+$/g, '')
}

var BP = Buffer.prototype

/**
 * Augment a Uint8Array *instance* (not the Uint8Array class!) with Buffer methods
 */
Buffer._augment = function (arr) {
  arr._isBuffer = true

  // save reference to original Uint8Array get/set methods before overwriting
  arr._get = arr.get
  arr._set = arr.set

  // deprecated, will be removed in node 0.13+
  arr.get = BP.get
  arr.set = BP.set

  arr.write = BP.write
  arr.toString = BP.toString
  arr.toLocaleString = BP.toString
  arr.toJSON = BP.toJSON
  arr.copy = BP.copy
  arr.slice = BP.slice
  arr.readUInt8 = BP.readUInt8
  arr.readUInt16LE = BP.readUInt16LE
  arr.readUInt16BE = BP.readUInt16BE
  arr.readUInt32LE = BP.readUInt32LE
  arr.readUInt32BE = BP.readUInt32BE
  arr.readInt8 = BP.readInt8
  arr.readInt16LE = BP.readInt16LE
  arr.readInt16BE = BP.readInt16BE
  arr.readInt32LE = BP.readInt32LE
  arr.readInt32BE = BP.readInt32BE
  arr.readFloatLE = BP.readFloatLE
  arr.readFloatBE = BP.readFloatBE
  arr.readDoubleLE = BP.readDoubleLE
  arr.readDoubleBE = BP.readDoubleBE
  arr.writeUInt8 = BP.writeUInt8
  arr.writeUInt16LE = BP.writeUInt16LE
  arr.writeUInt16BE = BP.writeUInt16BE
  arr.writeUInt32LE = BP.writeUInt32LE
  arr.writeUInt32BE = BP.writeUInt32BE
  arr.writeInt8 = BP.writeInt8
  arr.writeInt16LE = BP.writeInt16LE
  arr.writeInt16BE = BP.writeInt16BE
  arr.writeInt32LE = BP.writeInt32LE
  arr.writeInt32BE = BP.writeInt32BE
  arr.writeFloatLE = BP.writeFloatLE
  arr.writeFloatBE = BP.writeFloatBE
  arr.writeDoubleLE = BP.writeDoubleLE
  arr.writeDoubleBE = BP.writeDoubleBE
  arr.fill = BP.fill
  arr.inspect = BP.inspect
  arr.toArrayBuffer = BP.toArrayBuffer


  return arr
}

// 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]'
  })(subject)
}

function isArrayish (subject) {
  return isArray(subject) || Buffer.isBuffer(subject) ||
      subject && typeof subject === 'object' &&
      typeof subject.length === 'number'
}

function toHex (n) {
  if (n < 16) return '0' + n.toString(16)
  return n.toString(16)
}

function utf8ToBytes (str) {
  var byteArray = []
  for (var i = 0; i < str.length; i++) {
    var b = str.charCodeAt(i)
    if (b <= 0x7F)
      byteArray.push(str.charCodeAt(i))
    else {
      var start = i
      if (b >= 0xD800 && b <= 0xDFFF) i++
      var h = encodeURIComponent(str.slice(start, i+1)).substr(1).split('%')
      for (var j = 0; j < h.length; j++)
        byteArray.push(parseInt(h[j], 16))
    }
  }
  return byteArray
}

function asciiToBytes (str) {
  var byteArray = []
  for (var i = 0; i < str.length; i++) {
    // Node's code seems to be doing this and not & 0x7F..
    byteArray.push(str.charCodeAt(i) & 0xFF)
  }
  return byteArray
}

function utf16leToBytes (str) {
  var c, hi, lo
  var byteArray = []
  for (var i = 0; i < str.length; i++) {
    c = str.charCodeAt(i)
    hi = c >> 8
    lo = c % 256
    byteArray.push(lo)
    byteArray.push(hi)
  }

  return byteArray
}

function base64ToBytes (str) {
  return base64.toByteArray(str)
}

function blitBuffer (src, dst, offset, length) {
  var pos
  for (var i = 0; i < length; i++) {
    if ((i + offset >= dst.length) || (i >= src.length))
      break
    dst[i + offset] = src[i]
  }
  return i
}

function decodeUtf8Char (str) {
  try {
    return decodeURIComponent(str)
  } catch (err) {
    return String.fromCharCode(0xFFFD) // UTF 8 invalid char
  }
}

/*
 * We have to make sure that the value is a valid integer. This means that it
 * is non-negative. It has no fractional component and that it does not
 * exceed the maximum allowed value.
 */
function verifuint (value, max) {
  assert(typeof value === 'number', 'cannot write a non-number as a number')
  assert(value >= 0, 'specified a negative value for writing an unsigned value')
  assert(value <= max, 'value is larger than maximum value for type')
  assert(Math.floor(value) === value, 'value has a fractional component')
}

function verifsint (value, max, min) {
  assert(typeof value === 'number', 'cannot write a non-number as a number')
  assert(value <= max, 'value larger than maximum allowed value')
  assert(value >= min, 'value smaller than minimum allowed value')
  assert(Math.floor(value) === value, 'value has a fractional component')
}

function verifIEEE754 (value, max, min) {
  assert(typeof value === 'number', 'cannot write a non-number as a number')
  assert(value <= max, 'value larger than maximum allowed value')
  assert(value >= min, 'value smaller than minimum allowed value')
}

function assert (test, message) {
  if (!test) throw new Error(message || 'Failed assertion')
}