forked from zhurui/management
103 lines
2.7 KiB
Markdown
103 lines
2.7 KiB
Markdown
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# multipipe
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A better `Stream#pipe` that creates duplex streams and lets you handle errors in one place.
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[](http://travis-ci.org/segmentio/multipipe)
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## Example
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```js
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var pipe = require('multipipe');
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// pipe streams
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var stream = pipe(streamA, streamB, streamC);
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// centralized error handling
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stream.on('error', fn);
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// creates a new stream
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source.pipe(stream).pipe(dest);
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// optional callback on finish or error
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pipe(streamA, streamB, streamC, function(err){
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// ...
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});
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```
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## Duplex streams
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Write to the pipe and you'll really write to the first stream, read from the pipe and you'll read from the last stream.
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```js
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var stream = pipe(a, b, c);
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source
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.pipe(stream)
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.pipe(destination);
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```
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In this example the flow of data is:
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* source ->
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* a ->
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* b ->
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* c ->
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* destination
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## Error handling
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Each `pipe` forwards the errors the streams it wraps emit, so you have one central place to handle errors:
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```js
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var stream = pipe(a, b, c);
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stream.on('error', function(err){
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// called three times
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});
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a.emit('error', new Error);
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b.emit('error', new Error);
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c.emit('error', new Error);
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```
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## API
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### pipe(stream, ...)
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Pass a variable number of streams and each will be piped to the next one.
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A stream will be returned that wraps passed in streams in a way that errors will be forwarded and you can write to and/or read from it.
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Pass a function as last argument to be called on `error` or `finish` of the last stream.
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## Installation
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```bash
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$ npm install multipipe
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```
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## License
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The MIT License (MIT)
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Copyright (c) 2014 Segment.io Inc. <friends@segment.io>
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Copyright (c) 2014 Julian Gruber <julian@juliangruber.com>
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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THE SOFTWARE.
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