Spent some time closing off the Dynamo-Browse shortlist. I think I’ve got most of the big ticket items addressed. Here’s a brief update on each one:
Fix the activity indicator that is sometimes not clearing when a long running task is finished.
How long running tasks are dealt with has been completely overhauled. The previous implementation had many opportunities for race conditions, which was probably the cause of the activity indicator showing up when nothing was happening. I rewrote this using a dedicated goroutine for handling these tasks, and the event bus for sending events to the other areas of the app, including the UI layer. Updates and status changes are handled with mutexes and channels, and it just feels like better code as well.
It will need some further testing, especially in real world use against a real DynamoDB database. We’ll see if this bug rears its unpleasant head once more.
Fix a bug in which executing a query expression with just the sort key does nothing. I suspect this has something to do with the query planner somehow getting confused if the sort key is used but the partition key is not.
Turns out that this was actually a problem with the “has prefix” operator. It was incorrectly determining that an expression of the form
sort_key ^= "string" with no partition key could be executed as a query instead of a scan. Adding a check to see if the partition key also existed in the expression fixed the problem.
Also made a number of other changes to the query expression. Added the ability to use indexed references, like
that["thing"]. This has been a long time coming so it’s good to see it implemented. Unfortuntly this only works reliably when a single level is used, so
this will result in an error. The cause of this is a bug in the Go SDK I’m using to produce the query expressions that are run against the database. If this becomes a problem I look at this again.
I also realised that
false were not treated as boolean literals, so I fixed that as well.
Finally, the query planner now consider GSIs when it’s working out how to run a query expression. If the expression can be a query over a GSI, it will be executed as one. Given the types of queries I need to run, I’ll be finding this feature useful.
Fix a bug where
set default-limitsreturns a bad value.
This was a pretty simple string conversion bug.
Add a way to describe the table, i.e. show keys, indices, etc. This should also be made available to scripts. Add a way to “goto” a particular row, that is select rows just by entering the value of the partition and optionally the sort key.
These I did not do. The reason is that they’ll make good candidates for scripts and it would be a good test to see if they can be written as one. I think the “goto” feature would be easy enough. I added the ability to get information about the current table in the script, and also for scripts to add new key bindings, so I don’t force any issues here.
The table description would be trickier. There’s currently no real way to display a large block of text (except the status bar, but even there it’s a little awkward). So a full featured description might be difficult. But the information is there, at least to a degree, so maybe something showing the basics would work.
Anyway, the plan now is to use this version for a while to test it out. Then cut a release and update the documentation. That’s a large enough task in and of itself, but I’d really like to get this finished so I can move onto something else.