JavaScript/archive/code/node_modules/bl/bl.js at main · iu5git/JavaScript · GitHub

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var DuplexStream = require('readable-stream/duplex')

, util = require('util')

, Buffer = require('safe-buffer').Buffer

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

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.append = function append (buf) {

var i = 0

if (Buffer.isBuffer(buf)) {

this._appendBuffer(buf);

} else 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()

this._appendBuffer(Buffer.from(buf));

}

return this

}

BufferList.prototype._appendBuffer = function appendBuffer (buf) {

this._bufs.push(buf)

this.length += buf.length

}

BufferList.prototype._write = function _write (buf, encoding, callback) {

this._appendBuffer(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) {

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)

bufoff += l

} else {

this._bufs[i].copy(dst, bufoff, start, start + bytes)

bufoff += l

break

}

bytes -= l

if (start)

start = 0

}

// safeguard so that we don't return uninitialized memory

if (dst.length > bufoff) return dst.slice(0, bufoff)

return dst

}

BufferList.prototype.shallowSlice = function shallowSlice (start, end) {

start = start || 0

end = end || this.length

if (start < 0)

start += this.length

if (end < 0)

end += this.length

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 new BufferList(buffers)

}

BufferList.prototype.toString = function toString (encoding, start, end) {

return this.slice(start, end).toString(encoding)

}

BufferList.prototype.consume = function consume (bytes) {

// first, normalize the argument, in accordance with how Buffer does it

bytes = Math.trunc(bytes)

// do nothing if not a positive number

if (Number.isNaN(bytes) || bytes <= 0) return this

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

JavaScript/archive/code/node_modules/bl/bl.js at main · iu5git/JavaScript · GitHub

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