64 lines
1.5 KiB
JavaScript
64 lines
1.5 KiB
JavaScript
//filter will reemit the data if cb(err,pass) pass is truthy
|
|
|
|
// reduce is more tricky
|
|
// maybe we want to group the reductions or emit progress updates occasionally
|
|
// the most basic reduce just emits one 'data' event after it has recieved 'end'
|
|
|
|
|
|
var through = require('through')
|
|
var Decoder = require('string_decoder').StringDecoder
|
|
|
|
module.exports = split
|
|
|
|
//TODO pass in a function to map across the lines.
|
|
|
|
function split (matcher, mapper, options) {
|
|
var decoder = new Decoder()
|
|
var soFar = ''
|
|
var maxLength = options && options.maxLength;
|
|
if('function' === typeof matcher)
|
|
mapper = matcher, matcher = null
|
|
if (!matcher)
|
|
matcher = /\r?\n/
|
|
|
|
function emit(stream, piece) {
|
|
if(mapper) {
|
|
try {
|
|
piece = mapper(piece)
|
|
}
|
|
catch (err) {
|
|
return stream.emit('error', err)
|
|
}
|
|
if('undefined' !== typeof piece)
|
|
stream.queue(piece)
|
|
}
|
|
else
|
|
stream.queue(piece)
|
|
}
|
|
|
|
function next (stream, buffer) {
|
|
var pieces = ((soFar != null ? soFar : '') + buffer).split(matcher)
|
|
soFar = pieces.pop()
|
|
|
|
if (maxLength && soFar.length > maxLength)
|
|
stream.emit('error', new Error('maximum buffer reached'))
|
|
|
|
for (var i = 0; i < pieces.length; i++) {
|
|
var piece = pieces[i]
|
|
emit(stream, piece)
|
|
}
|
|
}
|
|
|
|
return through(function (b) {
|
|
next(this, decoder.write(b))
|
|
},
|
|
function () {
|
|
if(decoder.end)
|
|
next(this, decoder.end())
|
|
if(soFar != null)
|
|
emit(this, soFar)
|
|
this.queue(null)
|
|
})
|
|
}
|
|
|