lepu-test-platform-web/node_modules/duplexer/index.js

88 lines
1.8 KiB
JavaScript

var Stream = require("stream")
var writeMethods = ["write", "end", "destroy"]
var readMethods = ["resume", "pause"]
var readEvents = ["data", "close"]
var slice = Array.prototype.slice
module.exports = duplex
function forEach (arr, fn) {
if (arr.forEach) {
return arr.forEach(fn)
}
for (var i = 0; i < arr.length; i++) {
fn(arr[i], i)
}
}
function duplex(writer, reader) {
var stream = new Stream()
var ended = false
forEach(writeMethods, proxyWriter)
forEach(readMethods, proxyReader)
forEach(readEvents, proxyStream)
reader.on("end", handleEnd)
writer.on("drain", function() {
stream.emit("drain")
})
writer.on("error", reemit)
reader.on("error", reemit)
stream.writable = writer.writable
stream.readable = reader.readable
return stream
function proxyWriter(methodName) {
stream[methodName] = method
function method() {
return writer[methodName].apply(writer, arguments)
}
}
function proxyReader(methodName) {
stream[methodName] = method
function method() {
stream.emit(methodName)
var func = reader[methodName]
if (func) {
return func.apply(reader, arguments)
}
reader.emit(methodName)
}
}
function proxyStream(methodName) {
reader.on(methodName, reemit)
function reemit() {
var args = slice.call(arguments)
args.unshift(methodName)
stream.emit.apply(stream, args)
}
}
function handleEnd() {
if (ended) {
return
}
ended = true
var args = slice.call(arguments)
args.unshift("end")
stream.emit.apply(stream, args)
}
function reemit(err) {
stream.emit("error", err)
}
}