08-27-周三_17-09-29

node_modules/bl/bl.js

@@ -0,0 +1,227 @@
+var DuplexStream = require('readable-stream/duplex')
+  , util         = require('util')
+
+function BufferList (callback) {
+  if (!(this instanceof BufferList))
+    return new BufferList(callback)
+
+  this._bufs  = []
+  this.length = 0
+
+  if (typeof callback == 'function') {
+    this._callback = callback
+
+    var piper = function (err) {
+      if (this._callback) {
+        this._callback(err)
+        this._callback = null
+      }
+    }.bind(this)
+
+    this.on('pipe', function (src) {
+      src.on('error', piper)
+    })
+    this.on('unpipe', function (src) {
+      src.removeListener('error', piper)
+    })
+  }
+  else if (Buffer.isBuffer(callback))
+    this.append(callback)
+  else if (Array.isArray(callback)) {
+    callback.forEach(function (b) {
+      Buffer.isBuffer(b) && this.append(b)
+    }.bind(this))
+  }
+
+  DuplexStream.call(this)
+}
+
+util.inherits(BufferList, DuplexStream)
+
+BufferList.prototype._offset = function (offset) {
+  var tot = 0, i = 0, _t
+  for (; i < this._bufs.length; i++) {
+    _t = tot + this._bufs[i].length
+    if (offset < _t)
+      return [ i, offset - tot ]
+    tot = _t
+  }
+}
+
+BufferList.prototype.append = function (buf) {
+  var isBuffer = Buffer.isBuffer(buf) ||
+                 buf instanceof BufferList
+
+  // coerce number arguments to strings, since Buffer(number) does
+  // uninitialized memory allocation
+  if (typeof buf == 'number')
+    buf = buf.toString()
+
+  if (buf instanceof BufferList) {
+    this._bufs.push.apply(this._bufs, buf._bufs)
+    this.length += buf.length
+  } else {
+    this._bufs.push(isBuffer ? buf : new Buffer(buf))
+    this.length += buf.length
+  }
+
+  return this
+}
+
+BufferList.prototype._write = function (buf, encoding, callback) {
+  this.append(buf)
+  if (callback)
+    callback()
+}
+
+BufferList.prototype._read = function (size) {
+  if (!this.length)
+    return this.push(null)
+  size = Math.min(size, this.length)
+  this.push(this.slice(0, size))
+  this.consume(size)
+}
+
+BufferList.prototype.end = function (chunk) {
+  DuplexStream.prototype.end.call(this, chunk)
+
+  if (this._callback) {
+    this._callback(null, this.slice())
+    this._callback = null
+  }
+}
+
+BufferList.prototype.get = function (index) {
+  return this.slice(index, index + 1)[0]
+}
+
+BufferList.prototype.slice = function (start, end) {
+  return this.copy(null, 0, start, end)
+}
+
+BufferList.prototype.copy = function (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 || new Buffer(0)
+  if (srcEnd <= 0)
+    return dst || new Buffer(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, just return a full concat
+      return Buffer.concat(this._bufs)
+
+    // 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 = new Buffer(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.toString = function (encoding, start, end) {
+  return this.slice(start, end).toString(encoding)
+}
+
+BufferList.prototype.consume = function (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 () {
+  var i = 0
+    , copy = new BufferList()
+
+  for (; i < this._bufs.length; i++)
+    copy.append(this._bufs[i])
+
+  return copy
+}
+
+BufferList.prototype.destroy = function () {
+  this._bufs.length = 0;
+  this.length = 0;
+  this.push(null);
+}
+
+;(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
+  }
+
+  for (var m in methods) {
+    (function (m) {
+      BufferList.prototype[m] = function (offset) {
+        return this.slice(offset, offset + methods[m])[m](0)
+      }
+    }(m))
+  }
+}())
+
+module.exports = BufferList