--- /dev/null
+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 piper (err) {
+ if (this._callback) {
+ this._callback(err)
+ this._callback = null
+ }
+ }.bind(this)
+
+ this.on('pipe', function onPipe (src) {
+ src.on('error', piper)
+ })
+ this.on('unpipe', function onUnpipe (src) {
+ src.removeListener('error', piper)
+ })
+ } else {
+ this.append(callback)
+ }
+
+ DuplexStream.call(this)
+}
+
+
+util.inherits(BufferList, DuplexStream)
+
+
+BufferList.prototype._offset = function _offset (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 append (buf) {
+ var i = 0
+ , newBuf
+
+ if (Array.isArray(buf)) {
+ for (; i < buf.length; i++)
+ this.append(buf[i])
+ } else if (buf instanceof BufferList) {
+ // unwrap argument into individual BufferLists
+ for (; i < buf._bufs.length; i++)
+ this.append(buf._bufs[i])
+ } else if (buf != null) {
+ // coerce number arguments to strings, since Buffer(number) does
+ // uninitialized memory allocation
+ if (typeof buf == 'number')
+ buf = buf.toString()
+
+ newBuf = Buffer.isBuffer(buf) ? buf : new Buffer(buf)
+ this._bufs.push(newBuf)
+ this.length += newBuf.length
+ }
+
+ return this
+}
+
+
+BufferList.prototype._write = function _write (buf, encoding, callback) {
+ this.append(buf)
+
+ if (typeof callback == 'function')
+ callback()
+}
+
+
+BufferList.prototype._read = function _read (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 end (chunk) {
+ DuplexStream.prototype.end.call(this, chunk)
+
+ if (this._callback) {
+ this._callback(null, this.slice())
+ this._callback = null
+ }
+}
+
+
+BufferList.prototype.get = function get (index) {
+ return this.slice(index, index + 1)[0]
+}
+
+
+BufferList.prototype.slice = function slice (start, end) {
+ 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 || 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 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 = new BufferList()
+
+ for (; i < this._bufs.length; i++)
+ copy.append(this._bufs[i])
+
+ return copy
+}
+
+
+BufferList.prototype.destroy = function destroy () {
+ 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
Code Review / simantics / district.git / blobdiff