1 // Basically just a wrapper around an fs.ReadStream
3 module.exports = FileReader
5 var fs = require('graceful-fs')
6 var inherits = require('inherits')
7 var Reader = require('./reader.js')
9 var CLOSE = {CLOSE: true}
11 inherits(FileReader, Reader)
13 function FileReader (props) {
14 // console.error(" FR create", props.path, props.size, new Error().stack)
16 if (!(self instanceof FileReader)) {
17 throw new Error('FileReader must be called as constructor.')
20 // should already be established as a File type
21 // XXX Todo: preserve hardlinks by tracking dev+inode+nlink,
22 // with a HardLinkReader class.
23 if (!((props.type === 'Link' && props.Link) ||
24 (props.type === 'File' && props.File))) {
25 throw new Error('Non-file type ' + props.type)
29 self._bytesEmitted = 0
30 Reader.call(self, props)
33 FileReader.prototype._getStream = function () {
35 var stream = self._stream = fs.createReadStream(self._path, self.props)
37 if (self.props.blksize) {
38 stream.bufferSize = self.props.blksize
41 stream.on('open', self.emit.bind(self, 'open'))
43 stream.on('data', function (c) {
44 // console.error('\t\t%d %s', c.length, self.basename)
45 self._bytesEmitted += c.length
46 // no point saving empty chunks
49 } else if (self._paused || self._buffer.length) {
52 } else self.emit('data', c)
55 stream.on('end', function () {
56 if (self._paused || self._buffer.length) {
57 // console.error('FR Buffering End', self._path)
58 self._buffer.push(EOF)
64 if (self._bytesEmitted !== self.props.size) {
65 self.error("Didn't get expected byte count\n" +
66 'expect: ' + self.props.size + '\n' +
67 'actual: ' + self._bytesEmitted)
71 stream.on('close', function () {
72 if (self._paused || self._buffer.length) {
73 // console.error('FR Buffering Close', self._path)
74 self._buffer.push(CLOSE)
77 // console.error('FR close 1', self._path)
82 stream.on('error', function (e) {
89 FileReader.prototype._read = function () {
91 // console.error('FR _read', self._path)
93 // console.error('FR _read paused', self._path)
98 // console.error('FR _getStream calling', self._path)
99 return self._getStream()
102 // clear out the buffer, if there is one.
103 if (self._buffer.length) {
104 // console.error('FR _read has buffer', self._buffer.length, self._path)
105 var buf = self._buffer
106 for (var i = 0, l = buf.length; i < l; i++) {
109 // console.error('FR Read emitting buffered end', self._path)
111 } else if (c === CLOSE) {
112 // console.error('FR Read emitting buffered close', self._path)
115 // console.error('FR Read emitting buffered data', self._path)
120 // console.error('FR Read Re-pausing at '+i, self._path)
121 self._buffer = buf.slice(i)
125 self._buffer.length = 0
127 // console.error("FR _read done")
128 // that's about all there is to it.
131 FileReader.prototype.pause = function (who) {
133 // console.error('FR Pause', self._path)
134 if (self._paused) return
137 if (self._stream) self._stream.pause()
138 self.emit('pause', who)
141 FileReader.prototype.resume = function (who) {
143 // console.error('FR Resume', self._path)
144 if (!self._paused) return
146 self.emit('resume', who)
148 if (self._stream) self._stream.resume()