From 2127e196322d8c21124dcd15d28fe43b9f8b8ddb Mon Sep 17 00:00:00 2001 From: krakenrf <> Date: Thu, 27 Oct 2022 12:26:32 +0100 Subject: node --- middleware/node_modules/delayed-stream/Readme.md | 141 +++++++++++++++++++++++ 1 file changed, 141 insertions(+) create mode 100644 middleware/node_modules/delayed-stream/Readme.md (limited to 'middleware/node_modules/delayed-stream/Readme.md') diff --git a/middleware/node_modules/delayed-stream/Readme.md b/middleware/node_modules/delayed-stream/Readme.md new file mode 100644 index 0000000..aca36f9 --- /dev/null +++ b/middleware/node_modules/delayed-stream/Readme.md @@ -0,0 +1,141 @@ +# delayed-stream + +Buffers events from a stream until you are ready to handle them. + +## Installation + +``` bash +npm install delayed-stream +``` + +## Usage + +The following example shows how to write a http echo server that delays its +response by 1000 ms. + +``` javascript +var DelayedStream = require('delayed-stream'); +var http = require('http'); + +http.createServer(function(req, res) { + var delayed = DelayedStream.create(req); + + setTimeout(function() { + res.writeHead(200); + delayed.pipe(res); + }, 1000); +}); +``` + +If you are not using `Stream#pipe`, you can also manually release the buffered +events by calling `delayedStream.resume()`: + +``` javascript +var delayed = DelayedStream.create(req); + +setTimeout(function() { + // Emit all buffered events and resume underlaying source + delayed.resume(); +}, 1000); +``` + +## Implementation + +In order to use this meta stream properly, here are a few things you should +know about the implementation. + +### Event Buffering / Proxying + +All events of the `source` stream are hijacked by overwriting the `source.emit` +method. Until node implements a catch-all event listener, this is the only way. + +However, delayed-stream still continues to emit all events it captures on the +`source`, regardless of whether you have released the delayed stream yet or +not. + +Upon creation, delayed-stream captures all `source` events and stores them in +an internal event buffer. Once `delayedStream.release()` is called, all +buffered events are emitted on the `delayedStream`, and the event buffer is +cleared. After that, delayed-stream merely acts as a proxy for the underlaying +source. + +### Error handling + +Error events on `source` are buffered / proxied just like any other events. +However, `delayedStream.create` attaches a no-op `'error'` listener to the +`source`. This way you only have to handle errors on the `delayedStream` +object, rather than in two places. + +### Buffer limits + +delayed-stream provides a `maxDataSize` property that can be used to limit +the amount of data being buffered. In order to protect you from bad `source` +streams that don't react to `source.pause()`, this feature is enabled by +default. + +## API + +### DelayedStream.create(source, [options]) + +Returns a new `delayedStream`. Available options are: + +* `pauseStream` +* `maxDataSize` + +The description for those properties can be found below. + +### delayedStream.source + +The `source` stream managed by this object. This is useful if you are +passing your `delayedStream` around, and you still want to access properties +on the `source` object. + +### delayedStream.pauseStream = true + +Whether to pause the underlaying `source` when calling +`DelayedStream.create()`. Modifying this property afterwards has no effect. + +### delayedStream.maxDataSize = 1024 * 1024 + +The amount of data to buffer before emitting an `error`. + +If the underlaying source is emitting `Buffer` objects, the `maxDataSize` +refers to bytes. + +If the underlaying source is emitting JavaScript strings, the size refers to +characters. + +If you know what you are doing, you can set this property to `Infinity` to +disable this feature. You can also modify this property during runtime. + +### delayedStream.dataSize = 0 + +The amount of data buffered so far. + +### delayedStream.readable + +An ECMA5 getter that returns the value of `source.readable`. + +### delayedStream.resume() + +If the `delayedStream` has not been released so far, `delayedStream.release()` +is called. + +In either case, `source.resume()` is called. + +### delayedStream.pause() + +Calls `source.pause()`. + +### delayedStream.pipe(dest) + +Calls `delayedStream.resume()` and then proxies the arguments to `source.pipe`. + +### delayedStream.release() + +Emits and clears all events that have been buffered up so far. This does not +resume the underlaying source, use `delayedStream.resume()` instead. + +## License + +delayed-stream is licensed under the MIT license. -- cgit v1.2.3