Replay Sound

Replay game

Replaying game

This is what you recorded.

Game replayed.

Of course, all of these then go into the event log.

Would you like to... see it again on instant replay?

Our plan would be to record every function call with parameters in a log then later be able to replay them.

At this point we've seen how to handle static data, how to capture and replay user interaction and even a generic mechanism to record and replay the interaction with the environment.

Record global variables, or record only a subset of all calls.

They may capture sensitive information, which should not go to developers.

That is, mouse clicks and keystrokes, but also facilities to replay at higher levels.

You can replay the same sound again by clicking this button or using the File menu, Replay Sound.

It's one standard deviation in the distribution of sample means.

For programs that take text based commands, recording and replaying input is fairly easy to realize.

And the creator very considerately offered a replay for her mom.

If the search button is moved from down here to up here, then again replaying the event log based on absolute coordinates will click in the wrong position.

Here, in fact, is the state of all the demo that I just gave.

During the capture all input from the user, that is mouse clicks, keystrokes, and similar events, are recorded in the log file.

The question is whether it would be possible to record and replay this interaction as a whole.

However, as it comes to reproducing graphical user interaction it becomes hard to decide what of events to record and replay.

We use function calls to access user interaction or generally anything that comes form the environment.

This mechanism, in general, allows to record arbitrary interaction between program parts, as well as arbitrary interaction between the program and its environment.

You read a program that is outside of the webpage one would now go and store the saved commands content permanently, say in a file for recording and for replaying.

Now when you're replaying, and in particular, when you are replaying something from a web page, it may be that there are delays, and the drop down menu will not appear on time.

At this point we have seen how to reproduce static data simply by shipping the files over as the data is required by the program.

You have a captured replay tool that interposes itself between the user and the program and stores all events coming from the user in an event log such that they can be later replayed.

Then you'd be clicking somewhere completely different when replaying the recorded events, which stipulate that after half a second you'd click in this very position.

Another strategy we used in Reddit a lot is we would take before doing a big deployment, we would capture the last 10,000 requests or so, and we would store those, and we'd re played them against our new app servers or in development.

If you enter a password, for instance, on a webpage, and this is recorded, this can even become a security issue.

This of course is also true for rearrangements as long as the identifiers of the GUI elements stay the same, we'll still be able to replay earlier logs even though many details, in terms of the rendering, have changed.

If we turn this into a string that looks exactly like a function call, then we can pass this to the Python eval function, which takes a string and interprets it as code.

In particular, one could store the list of calls in a file such that it can be reproduced at any time, handle structured elements properly, that is, lists and maps, record, and possibly replay, return values too.

In all of this, changes in size, changes in language, changes in speed, or changes in the program itself are all obstacles for record, replay, reproduction of graphical user elements.