tools/android/loading Support "report" tasks in the Clovis frontend

tools/android/loading/cloud/frontend/README.md

 # Appengine Frontend for Clovis
 
 [TOC]
 
 ## Usage
 
 Visit the application URL in your browser, and upload a JSON dictionary with the
 following keys:
 
--   `action` (string): the action to perform. Only `trace` is supported.
+-   `action` (string): the action to perform. Only `trace` and `report` are
+    supported.
 -   `action_params` (dictionary): the parameters associated to the action.
     See below for more details.
 -   `backend_params` (dictionary): the parameters configuring the backend for
     this task. See below for more details.
 
 ### Parameters for `backend_params`
 
 -   `instance_count` (int): Number of Compute Engine instances that will be
     started for this task.
 -   `storage_bucket` (string): Name of the storage bucket used by the backend
     instances. Backend code and data must have been previously deployed to this
     bucket using the `deploy.sh` [script][4].
 -   `tag` (string, optional): tag internally used to associate tasks to backend
     ComputeEngine instances. This parameter should not be set in general, as it
     is mostly exposed for development purposes. If this parameter is not
     specified, a unique tag will be generated.
 -   `timeout_hours` (int, optional): if workers are still alive after this
     delay, they will be forcibly killed, to avoid wasting Compute Engine
     resources. Defaults to `5`.
 
 ### Parameters for the `trace` action
 
 -   `urls` (list of strings): the list of URLs to process.
 -   `repeat_count` (integer, optional): the number of traces to be generated
     for each URL. Defaults to 1.
 -   `emulate_device` (string, optional): the device to emulate (e.g. `Nexus 4`).
 -   `emulate_network` (string, optional): the network to emulate.
 
+### Parameters for the `report` action
+
+-   `urls` (list of strings): the list of URLs to process.

[blundell, 2016/05/11 10:35:39]

I would think we'll also want a mode where you just point to a trace directory
and it processes all the URLs underneath. WDYT?

[droger, 2016/05/11 11:16:27]

Very good point.
This was my initial idea too, but then I decided to go by URLs, because it
seemed much more difficult to implement (see below).

If we do it per directory, then it's also not clear whether we would want that
in addition to the URL mode. Maybe the directory mode would be enough.


The reason why I chose URLs instead of directory is because it is much simpler
to split the work into small tasks (splitting a list of URLs is easy).

If I wanted to take a directory as input, I would need either to:

-reconstruct the list of URLs in the frontend, which means that the frontend
would need to load and call into things LoadingTraceDatabase, which seems a bit
complex (I liked the idea of keeping the frontend relatively dumb, and also
would require some refactoring of the directory structure so that appengine can
reference this code).

- or split the work across another dimension. The most obvious being to find all
the loading trace database files (just by doing a prefix match, and without
loading them), and create one task per file. The downside of this approach is
that these tasks will be rather large.

We can definitely discuss more about this.

+
 ## Development
 
 ### Design overview
 
 -   Appengine configuration:
     -   `app.yaml` defines the handlers. There is a static handler for all URLs
     in the `static/` directory, and all other URLs are handled by the
     `clovis_frontend.py` script.
     -   `queue.yaml` defines the task queues associated with the application. In
         particular, the `clovis-queue` is a pull-queue where tasks are added by
@@ skipping 49 matching lines @@
 # Install dependencies in the lib/ directory.
 pip install -r requirements.txt -t lib
 # Deploy.
 gcloud preview app deploy app.yaml
 ```
 
 [1]: https://cloud.google.com/sdk
 [2]: https://cloud.google.com/appengine/docs/python/taskqueue
 [3]: https://cloud.google.com/appengine/docs/python/config/queue
 [4]: ../backend/README.md#Deploy-the-code