Merge for #72 and #73 (instanceof, bl-without-streams)

BufferList.js

@@ -0,0 +1,344 @@
+'use strict'
+
+var symbol = Symbol.for('BufferList')
+
+function BufferList (buf) {
+  if (!(this instanceof BufferList))
+    return new BufferList(buf)
+
+  BufferList._init.call(this, buf)
+}
+
+BufferList._init = function _init (buf) {
+  Object.defineProperty(this, symbol, { value: true })
+
+  this._bufs = []
+  this.length = 0
+  if (buf) this.append(buf)
+}
+
+BufferList.prototype._new = function _new (buf) {
+  return new BufferList(buf)
+}
+
+BufferList.prototype._offset = function _offset (offset) {
+  var tot = 0, i = 0, _t
+  if (offset === 0) return [ 0, 0 ]
+  for (; i < this._bufs.length; i++) {
+    _t = tot + this._bufs[i].length
+    if (offset < _t || i == this._bufs.length - 1) {
+      return [ i, offset - tot ]
+    }
+    tot = _t
+  }
+}
+
+BufferList.prototype._reverseOffset = function (blOffset) {
+  var bufferId = blOffset[0]
+  var offset = blOffset[1]
+  for (var i = 0; i < bufferId; i++) {
+    offset += this._bufs[i].length
+  }
+  return offset
+}
+
+BufferList.prototype.get = function get (index) {
+  if (index > this.length || index < 0) {
+    return undefined
+  }
+  var offset = this._offset(index)
+  return this._bufs[offset[0]][offset[1]]
+}
+
+BufferList.prototype.slice = function slice (start, end) {
+  if (typeof start == 'number' && start < 0)
+    start += this.length
+  if (typeof end == 'number' && end < 0)
+    end += this.length
+  return this.copy(null, 0, start, end)
+}
+
+
+BufferList.prototype.copy = function copy (dst, dstStart, srcStart, srcEnd) {
+  if (typeof srcStart != 'number' || srcStart < 0)
+    srcStart = 0
+  if (typeof srcEnd != 'number' || srcEnd > this.length)
+    srcEnd = this.length
+  if (srcStart >= this.length)
+    return dst || Buffer.alloc(0)
+  if (srcEnd <= 0)
+    return dst || Buffer.alloc(0)
+
+  var copy   = !!dst
+    , off    = this._offset(srcStart)
+    , len    = srcEnd - srcStart
+    , bytes  = len
+    , bufoff = (copy && dstStart) || 0
+    , start  = off[1]
+    , l
+    , i
+
+  // copy/slice everything
+  if (srcStart === 0 && srcEnd == this.length) {
+    if (!copy) { // slice, but full concat if multiple buffers
+      return this._bufs.length === 1
+        ? this._bufs[0]
+        : Buffer.concat(this._bufs, this.length)
+    }
+
+    // copy, need to copy individual buffers
+    for (i = 0; i < this._bufs.length; i++) {
+      this._bufs[i].copy(dst, bufoff)
+      bufoff += this._bufs[i].length
+    }
+
+    return dst
+  }
+
+  // easy, cheap case where it's a subset of one of the buffers
+  if (bytes <= this._bufs[off[0]].length - start) {
+    return copy
+      ? this._bufs[off[0]].copy(dst, dstStart, start, start + bytes)
+      : this._bufs[off[0]].slice(start, start + bytes)
+  }
+
+  if (!copy) // a slice, we need something to copy in to
+    dst = Buffer.allocUnsafe(len)
+
+  for (i = off[0]; i < this._bufs.length; i++) {
+    l = this._bufs[i].length - start
+
+    if (bytes > l) {
+      this._bufs[i].copy(dst, bufoff, start)
+    } else {
+      this._bufs[i].copy(dst, bufoff, start, start + bytes)
+      break
+    }
+
+    bufoff += l
+    bytes -= l
+
+    if (start)
+      start = 0
+  }
+
+  return dst
+}
+
+BufferList.prototype.shallowSlice = function shallowSlice (start, end) {
+  start = start || 0
+  end = typeof end !== 'number' ? this.length : end
+
+  if (start < 0)
+    start += this.length
+  if (end < 0)
+    end += this.length
+
+  if (start === end) {
+    return this._new()
+  }
+  var startOffset = this._offset(start)
+    , endOffset = this._offset(end)
+    , buffers = this._bufs.slice(startOffset[0], endOffset[0] + 1)
+
+  if (endOffset[1] == 0)
+    buffers.pop()
+  else
+    buffers[buffers.length-1] = buffers[buffers.length-1].slice(0, endOffset[1])
+
+  if (startOffset[1] != 0)
+    buffers[0] = buffers[0].slice(startOffset[1])
+
+  return this._new(buffers)
+}
+
+BufferList.prototype.toString = function toString (encoding, start, end) {
+  return this.slice(start, end).toString(encoding)
+}
+
+BufferList.prototype.consume = function consume (bytes) {
+  while (this._bufs.length) {
+    if (bytes >= this._bufs[0].length) {
+      bytes -= this._bufs[0].length
+      this.length -= this._bufs[0].length
+      this._bufs.shift()
+    } else {
+      this._bufs[0] = this._bufs[0].slice(bytes)
+      this.length -= bytes
+      break
+    }
+  }
+  return this
+}
+
+
+BufferList.prototype.duplicate = function duplicate () {
+  var i = 0
+    , copy = this._new()
+
+  for (; i < this._bufs.length; i++)
+    copy.append(this._bufs[i])
+
+  return copy
+}
+
+BufferList.prototype.append = function append (buf) {
+  var i = 0
+
+  if (buf == null) {
+    return this
+  }
+
+  if (buf.buffer) {
+    // append a view of the underlying ArrayBuffer
+    this._appendBuffer(Buffer.from(buf.buffer, buf.byteOffset, buf.byteLength))
+  } else if (Array.isArray(buf)) {
+    for (; i < buf.length; i++)
+      this.append(buf[i])
+  } else if (this._isBufferList(buf)) {
+    // unwrap argument into individual BufferLists
+    for (; i < buf._bufs.length; i++)
+      this.append(buf._bufs[i])
+  } else {
+    // coerce number arguments to strings, since Buffer(number) does
+    // uninitialized memory allocation
+    if (typeof buf == 'number')
+      buf = buf.toString()
+
+    this._appendBuffer(Buffer.from(buf))
+  }
+
+  return this
+}
+
+BufferList.prototype._appendBuffer = function appendBuffer (buf) {
+  this._bufs.push(buf)
+  this.length += buf.length
+}
+
+BufferList.prototype.indexOf = function (search, offset, encoding) {
+  if (encoding === undefined && typeof offset === 'string') {
+    encoding = offset
+    offset = undefined
+  }
+  if (typeof search === 'function' || Array.isArray(search)) {
+    throw new TypeError('The "value" argument must be one of type string, Buffer, BufferList, or Uint8Array.')
+  } else if (typeof search === 'number') {
+    search = Buffer.from([search])
+  } else if (typeof search === 'string') {
+    search = Buffer.from(search, encoding)
+  } else if (this._isBufferList(search)) {
+    search = search.slice()
+  } else if (Array.isArray(search.buffer)) {
+    search = Buffer.from(search.buffer, search.byteOffset, search.byteLength)
+  } else if (!Buffer.isBuffer(search)) {
+    search = Buffer.from(search)
+  }
+
+  offset = Number(offset || 0)
+  if (isNaN(offset)) {
+    offset = 0
+  }
+
+  if (offset < 0) {
+    offset = this.length + offset
+  }
+
+  if (offset < 0) {
+    offset = 0
+  }
+
+  if (search.length === 0) {
+    return offset > this.length ? this.length : offset
+  }
+
+  var blOffset = this._offset(offset)
+  var blIndex = blOffset[0] // index of which internal buffer we're working on
+  var buffOffset = blOffset[1] // offset of the internal buffer we're working on
+
+  // scan over each buffer
+  for (blIndex; blIndex < this._bufs.length; blIndex++) {
+    var buff = this._bufs[blIndex]
+    while (buffOffset < buff.length) {
+      var availableWindow = buff.length - buffOffset
+      if (availableWindow >= search.length) {
+        var nativeSearchResult = buff.indexOf(search, buffOffset)
+        if (nativeSearchResult !== -1) {
+          return this._reverseOffset([blIndex, nativeSearchResult])
+        }
+        buffOffset = buff.length - search.length + 1 // end of native search window
+      } else {
+        var revOffset = this._reverseOffset([blIndex, buffOffset])
+        if (this._match(revOffset, search)) {
+          return revOffset
+        }
+        buffOffset++
+      }
+    }
+    buffOffset = 0
+  }
+  return -1
+}
+
+BufferList.prototype._match = function (offset, search) {
+  if (this.length - offset < search.length) {
+    return false
+  }
+  for (var searchOffset = 0; searchOffset < search.length; searchOffset++) {
+    if (this.get(offset + searchOffset) !== search[searchOffset]) {
+      return false
+    }
+  }
+  return true
+}
+
+;(function () {
+  var methods = {
+      'readDoubleBE' : 8
+    , 'readDoubleLE' : 8
+    , 'readFloatBE'  : 4
+    , 'readFloatLE'  : 4
+    , 'readInt32BE'  : 4
+    , 'readInt32LE'  : 4
+    , 'readUInt32BE' : 4
+    , 'readUInt32LE' : 4
+    , 'readInt16BE'  : 2
+    , 'readInt16LE'  : 2
+    , 'readUInt16BE' : 2
+    , 'readUInt16LE' : 2
+    , 'readInt8'     : 1
+    , 'readUInt8'    : 1
+    , 'readIntBE'    : null
+    , 'readIntLE'    : null
+    , 'readUIntBE'   : null
+    , 'readUIntLE'   : null
+  }
+
+  for (var m in methods) {
+    (function (m) {
+      if (methods[m] === null) {
+        BufferList.prototype[m] = function (offset, byteLength) {
+          return this.slice(offset, offset + byteLength)[m](0, byteLength)
+        }
+      } else {
+        BufferList.prototype[m] = function (offset) {
+          return this.slice(offset, offset + methods[m])[m](0)
+        }
+      }
+    }(m))
+  }
+}())
+
+// Used internally by the class and also as an indicator of this object being
+// a `BufferList`. It's not possible to use `instanceof BufferList` in a browser
+// environment because there could be multiple different copies of the
+// BufferList class and some `BufferList`s might be `BufferList`s.
+BufferList.prototype._isBufferList = function _isBufferList (b) {
+  return b instanceof BufferList || BufferList.isBufferList(b)
+}
+
+BufferList.isBufferList = function isBufferList (b) {
+  return b != null && b[symbol]
+}
+
+module.exports = BufferList