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