forked from zhurui/management
108 lines
2.5 KiB
JavaScript
108 lines
2.5 KiB
JavaScript
module.exports = FileWriter
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var fs = require('graceful-fs')
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var Writer = require('./writer.js')
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var inherits = require('inherits')
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var EOF = {}
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inherits(FileWriter, Writer)
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function FileWriter (props) {
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var self = this
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if (!(self instanceof FileWriter)) {
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throw new Error('FileWriter must be called as constructor.')
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}
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// should already be established as a File type
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if (props.type !== 'File' || !props.File) {
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throw new Error('Non-file type ' + props.type)
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}
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self._buffer = []
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self._bytesWritten = 0
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Writer.call(this, props)
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}
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FileWriter.prototype._create = function () {
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var self = this
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if (self._stream) return
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var so = {}
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if (self.props.flags) so.flags = self.props.flags
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so.mode = Writer.filemode
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if (self._old && self._old.blksize) so.bufferSize = self._old.blksize
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self._stream = fs.createWriteStream(self._path, so)
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self._stream.on('open', function () {
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// console.error("FW open", self._buffer, self._path)
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self.ready = true
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self._buffer.forEach(function (c) {
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if (c === EOF) self._stream.end()
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else self._stream.write(c)
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})
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self.emit('ready')
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// give this a kick just in case it needs it.
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self.emit('drain')
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})
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self._stream.on('error', function (er) { self.emit('error', er) })
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self._stream.on('drain', function () { self.emit('drain') })
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self._stream.on('close', function () {
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// console.error('\n\nFW Stream Close', self._path, self.size)
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self._finish()
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})
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}
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FileWriter.prototype.write = function (c) {
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var self = this
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self._bytesWritten += c.length
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if (!self.ready) {
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if (!Buffer.isBuffer(c) && typeof c !== 'string') {
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throw new Error('invalid write data')
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}
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self._buffer.push(c)
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return false
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}
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var ret = self._stream.write(c)
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// console.error('\t-- fw wrote, _stream says', ret, self._stream._queue.length)
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// allow 2 buffered writes, because otherwise there's just too
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// much stop and go bs.
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if (ret === false && self._stream._queue) {
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return self._stream._queue.length <= 2
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} else {
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return ret
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}
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}
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FileWriter.prototype.end = function (c) {
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var self = this
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if (c) self.write(c)
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if (!self.ready) {
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self._buffer.push(EOF)
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return false
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}
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return self._stream.end()
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}
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FileWriter.prototype._finish = function () {
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var self = this
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if (typeof self.size === 'number' && self._bytesWritten !== self.size) {
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self.error(
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'Did not get expected byte count.\n' +
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'expect: ' + self.size + '\n' +
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'actual: ' + self._bytesWritten)
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}
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Writer.prototype._finish.call(self)
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}
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