123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869 |
- # minipass-pipeline
- Create a pipeline of streams using Minipass.
- Calls `.pipe()` on all the streams in the list. Returns a stream where
- writes got to the first pipe in the chain, and reads are from the last.
- Errors are proxied along the chain and emitted on the Pipeline stream.
- ## USAGE
- ```js
- const Pipeline = require('minipass-pipeline')
- // the list of streams to pipeline together,
- // a bit like `input | transform | output` in bash
- const p = new Pipeline(input, transform, output)
- p.write('foo') // writes to input
- p.on('data', chunk => doSomething()) // reads from output stream
- // less contrived example (but still pretty contrived)...
- const decode = new bunzipDecoder()
- const unpack = tar.extract({ cwd: 'target-dir' })
- const tbz = new Pipeline(decode, unpack)
- fs.createReadStream('archive.tbz').pipe(tbz)
- // specify any minipass options if you like, as the first argument
- // it'll only try to pipeline event emitters with a .pipe() method
- const p = new Pipeline({ objectMode: true }, input, transform, output)
- // If you don't know the things to pipe in right away, that's fine.
- // use p.push(stream) to add to the end, or p.unshift(stream) to the front
- const databaseDecoderStreamDoohickey = (connectionInfo) => {
- const p = new Pipeline()
- logIntoDatabase(connectionInfo).then(connection => {
- initializeDecoderRing(connectionInfo).then(decoderRing => {
- p.push(connection, decoderRing)
- getUpstreamSource(upstream => {
- p.unshift(upstream)
- })
- })
- })
- // return to caller right away
- // emitted data will be upstream -> connection -> decoderRing pipeline
- return p
- }
- ```
- Pipeline is a [minipass](http://npm.im/minipass) stream, so it's as
- synchronous as the streams it wraps. It will buffer data until there is a
- reader, but no longer, so make sure to attach your listeners before you
- pipe it somewhere else.
- ## `new Pipeline(opts = {}, ...streams)`
- Create a new Pipeline with the specified Minipass options and any streams
- provided.
- ## `pipeline.push(stream, ...)`
- Attach one or more streams to the pipeline at the end (read) side of the
- pipe chain.
- ## `pipeline.unshift(stream, ...)`
- Attach one or more streams to the pipeline at the start (write) side of the
- pipe chain.
|