mirror of
https://gitee.com/onvia/ccc-tnt-psd2ui
synced 2024-12-27 12:07:45 +00:00
209 lines
6.4 KiB
Markdown
209 lines
6.4 KiB
Markdown
are-we-there-yet
|
|
----------------
|
|
|
|
Track complex hierarchies of asynchronous task completion statuses. This is
|
|
intended to give you a way of recording and reporting the progress of the big
|
|
recursive fan-out and gather type workflows that are so common in async.
|
|
|
|
What you do with this completion data is up to you, but the most common use case is to
|
|
feed it to one of the many progress bar modules.
|
|
|
|
Most progress bar modules include a rudimentary version of this, but my
|
|
needs were more complex.
|
|
|
|
Usage
|
|
=====
|
|
|
|
```javascript
|
|
var TrackerGroup = require("are-we-there-yet").TrackerGroup
|
|
|
|
var top = new TrackerGroup("program")
|
|
|
|
var single = top.newItem("one thing", 100)
|
|
single.completeWork(20)
|
|
|
|
console.log(top.completed()) // 0.2
|
|
|
|
fs.stat("file", function(er, stat) {
|
|
if (er) throw er
|
|
var stream = top.newStream("file", stat.size)
|
|
console.log(top.completed()) // now 0.1 as single is 50% of the job and is 20% complete
|
|
// and 50% * 20% == 10%
|
|
fs.createReadStream("file").pipe(stream).on("data", function (chunk) {
|
|
// do stuff with chunk
|
|
})
|
|
top.on("change", function (name) {
|
|
// called each time a chunk is read from "file"
|
|
// top.completed() will start at 0.1 and fill up to 0.6 as the file is read
|
|
})
|
|
})
|
|
```
|
|
|
|
Shared Methods
|
|
==============
|
|
|
|
* var completed = tracker.completed()
|
|
|
|
Implemented in: `Tracker`, `TrackerGroup`, `TrackerStream`
|
|
|
|
Returns the ratio of completed work to work to be done. Range of 0 to 1.
|
|
|
|
* tracker.finish()
|
|
|
|
Implemented in: `Tracker`, `TrackerGroup`
|
|
|
|
Marks the tracker as completed. With a TrackerGroup this marks all of its
|
|
components as completed.
|
|
|
|
Marks all of the components of this tracker as finished, which in turn means
|
|
that `tracker.completed()` for this will now be 1.
|
|
|
|
This will result in one or more `change` events being emitted.
|
|
|
|
Events
|
|
======
|
|
|
|
All tracker objects emit `change` events with the following arguments:
|
|
|
|
```
|
|
function (name, completed, tracker)
|
|
```
|
|
|
|
`name` is the name of the tracker that originally emitted the event,
|
|
or if it didn't have one, the first containing tracker group that had one.
|
|
|
|
`completed` is the percent complete (as returned by `tracker.completed()` method).
|
|
|
|
`tracker` is the tracker object that you are listening for events on.
|
|
|
|
TrackerGroup
|
|
============
|
|
|
|
* var tracker = new TrackerGroup(**name**)
|
|
|
|
* **name** *(optional)* - The name of this tracker group, used in change
|
|
notifications if the component updating didn't have a name. Defaults to undefined.
|
|
|
|
Creates a new empty tracker aggregation group. These are trackers whose
|
|
completion status is determined by the completion status of other trackers added to this aggregation group.
|
|
|
|
Ex.
|
|
|
|
```javascript
|
|
var tracker = new TrackerGroup("parent")
|
|
var foo = tracker.newItem("firstChild", 100)
|
|
var bar = tracker.newItem("secondChild", 100)
|
|
|
|
foo.finish()
|
|
console.log(tracker.completed()) // 0.5
|
|
bar.finish()
|
|
console.log(tracker.completed()) // 1
|
|
```
|
|
|
|
* tracker.addUnit(**otherTracker**, **weight**)
|
|
|
|
* **otherTracker** - Any of the other are-we-there-yet tracker objects
|
|
* **weight** *(optional)* - The weight to give the tracker, defaults to 1.
|
|
|
|
Adds the **otherTracker** to this aggregation group. The weight determines
|
|
how long you expect this tracker to take to complete in proportion to other
|
|
units. So for instance, if you add one tracker with a weight of 1 and
|
|
another with a weight of 2, you're saying the second will take twice as long
|
|
to complete as the first. As such, the first will account for 33% of the
|
|
completion of this tracker and the second will account for the other 67%.
|
|
|
|
Returns **otherTracker**.
|
|
|
|
* var subGroup = tracker.newGroup(**name**, **weight**)
|
|
|
|
The above is exactly equivalent to:
|
|
|
|
```javascript
|
|
var subGroup = tracker.addUnit(new TrackerGroup(name), weight)
|
|
```
|
|
|
|
* var subItem = tracker.newItem(**name**, **todo**, **weight**)
|
|
|
|
The above is exactly equivalent to:
|
|
|
|
```javascript
|
|
var subItem = tracker.addUnit(new Tracker(name, todo), weight)
|
|
```
|
|
|
|
* var subStream = tracker.newStream(**name**, **todo**, **weight**)
|
|
|
|
The above is exactly equivalent to:
|
|
|
|
```javascript
|
|
var subStream = tracker.addUnit(new TrackerStream(name, todo), weight)
|
|
```
|
|
|
|
* console.log( tracker.debug() )
|
|
|
|
Returns a tree showing the completion of this tracker group and all of its
|
|
children, including recursively entering all of the children.
|
|
|
|
Tracker
|
|
=======
|
|
|
|
* var tracker = new Tracker(**name**, **todo**)
|
|
|
|
* **name** *(optional)* The name of this counter to report in change
|
|
events. Defaults to undefined.
|
|
* **todo** *(optional)* The amount of work todo (a number). Defaults to 0.
|
|
|
|
Ordinarily these are constructed as a part of a tracker group (via
|
|
`newItem`).
|
|
|
|
* var completed = tracker.completed()
|
|
|
|
Returns the ratio of completed work to work to be done. Range of 0 to 1. If
|
|
total work to be done is 0 then it will return 0.
|
|
|
|
* tracker.addWork(**todo**)
|
|
|
|
* **todo** A number to add to the amount of work to be done.
|
|
|
|
Increases the amount of work to be done, thus decreasing the completion
|
|
percentage. Triggers a `change` event.
|
|
|
|
* tracker.completeWork(**completed**)
|
|
|
|
* **completed** A number to add to the work complete
|
|
|
|
Increase the amount of work complete, thus increasing the completion percentage.
|
|
Will never increase the work completed past the amount of work todo. That is,
|
|
percentages > 100% are not allowed. Triggers a `change` event.
|
|
|
|
* tracker.finish()
|
|
|
|
Marks this tracker as finished, tracker.completed() will now be 1. Triggers
|
|
a `change` event.
|
|
|
|
TrackerStream
|
|
=============
|
|
|
|
* var tracker = new TrackerStream(**name**, **size**, **options**)
|
|
|
|
* **name** *(optional)* The name of this counter to report in change
|
|
events. Defaults to undefined.
|
|
* **size** *(optional)* The number of bytes being sent through this stream.
|
|
* **options** *(optional)* A hash of stream options
|
|
|
|
The tracker stream object is a pass through stream that updates an internal
|
|
tracker object each time a block passes through. It's intended to track
|
|
downloads, file extraction and other related activities. You use it by piping
|
|
your data source into it and then using it as your data source.
|
|
|
|
If your data has a length attribute then that's used as the amount of work
|
|
completed when the chunk is passed through. If it does not (eg, object
|
|
streams) then each chunk counts as completing 1 unit of work, so your size
|
|
should be the total number of objects being streamed.
|
|
|
|
* tracker.addWork(**todo**)
|
|
|
|
* **todo** Increase the expected overall size by **todo** bytes.
|
|
|
|
Increases the amount of work to be done, thus decreasing the completion
|
|
percentage. Triggers a `change` event.
|