diff options
author | Rebecca Turner <me@re-becca.org> | 2018-05-24 23:31:26 +0300 |
---|---|---|
committer | Rebecca Turner <me@re-becca.org> | 2018-05-24 23:31:38 +0300 |
commit | 0483f5c5deaf18c968a128657923103e49f4e67a (patch) | |
tree | 210f154da2f60938471d96a844dcb32cbda09e2a /node_modules/are-we-there-yet/README.md | |
parent | 6c294614d800cb95a49ef1c422fbdde65b0731a2 (diff) |
Flatten dependencies and add dev deps to git
Diffstat (limited to 'node_modules/are-we-there-yet/README.md')
-rw-r--r-- | node_modules/are-we-there-yet/README.md | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/node_modules/are-we-there-yet/README.md b/node_modules/are-we-there-yet/README.md new file mode 100644 index 000000000..7e2b42d86 --- /dev/null +++ b/node_modules/are-we-there-yet/README.md @@ -0,0 +1,195 @@ +are-we-there-yet +---------------- + +Track complex hiearchies 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 rudamentary 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. + +* 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. |