streams.js•2.98 kB
"use strict"
var Buffer = require("safer-buffer").Buffer
// NOTE: Due to 'stream' module being pretty large (~100Kb, significant in browser environments),
// we opt to dependency-inject it instead of creating a hard dependency.
module.exports = function (streamModule) {
var Transform = streamModule.Transform
// == Encoder stream =======================================================
function IconvLiteEncoderStream (conv, options) {
this.conv = conv
options = options || {}
options.decodeStrings = false // We accept only strings, so we don't need to decode them.
Transform.call(this, options)
}
IconvLiteEncoderStream.prototype = Object.create(Transform.prototype, {
constructor: { value: IconvLiteEncoderStream }
})
IconvLiteEncoderStream.prototype._transform = function (chunk, encoding, done) {
if (typeof chunk !== "string") {
return done(new Error("Iconv encoding stream needs strings as its input."))
}
try {
var res = this.conv.write(chunk)
if (res && res.length) this.push(res)
done()
} catch (e) {
done(e)
}
}
IconvLiteEncoderStream.prototype._flush = function (done) {
try {
var res = this.conv.end()
if (res && res.length) this.push(res)
done()
} catch (e) {
done(e)
}
}
IconvLiteEncoderStream.prototype.collect = function (cb) {
var chunks = []
this.on("error", cb)
this.on("data", function (chunk) { chunks.push(chunk) })
this.on("end", function () {
cb(null, Buffer.concat(chunks))
})
return this
}
// == Decoder stream =======================================================
function IconvLiteDecoderStream (conv, options) {
this.conv = conv
options = options || {}
options.encoding = this.encoding = "utf8" // We output strings.
Transform.call(this, options)
}
IconvLiteDecoderStream.prototype = Object.create(Transform.prototype, {
constructor: { value: IconvLiteDecoderStream }
})
IconvLiteDecoderStream.prototype._transform = function (chunk, encoding, done) {
if (!Buffer.isBuffer(chunk) && !(chunk instanceof Uint8Array)) { return done(new Error("Iconv decoding stream needs buffers as its input.")) }
try {
var res = this.conv.write(chunk)
if (res && res.length) this.push(res, this.encoding)
done()
} catch (e) {
done(e)
}
}
IconvLiteDecoderStream.prototype._flush = function (done) {
try {
var res = this.conv.end()
if (res && res.length) this.push(res, this.encoding)
done()
} catch (e) {
done(e)
}
}
IconvLiteDecoderStream.prototype.collect = function (cb) {
var res = ""
this.on("error", cb)
this.on("data", function (chunk) { res += chunk })
this.on("end", function () {
cb(null, res)
})
return this
}
return {
IconvLiteEncoderStream: IconvLiteEncoderStream,
IconvLiteDecoderStream: IconvLiteDecoderStream
}
}