Write dump information and dump progress bar to stderr when verbose m…

[guvra]

When -v option is provided, display information about the dump, as well as a progress bar.

[guvra]

Fixes #111

[guvra]

@staabm is the current implementation ok for your use case?

[staabm]

thanks for working on my feature request. I will have some time in the following days to look into the change and test it .

I will report back

[guvra]

After testing it with a big database, I found out that the setInfoHook function provided by mysqldump-php is triggered after the table was dumped, not before.

So when a table name is displayed in the progress bar, it's not actually dumping this table, it's dumping the next table...

[staabm]

thanks again for working on it.

I tried it on a bigger schema, and have the following feedback:
I wonder whether we could use a undetermined progress bar and print progress every X thousand rows.
in my case with millions of rows in a single table it still looks like no progress is going on.

it might also make sense to look into redraw-parameters, as the symfony console per default redraws every 100ms, which is waaay too fast for our progress. I think once every second or similar would be plenty.

https://symfony.com/doc/current/components/console/helpers/progressbar.html#bar-settings

// this redraws the screen every 100 iterations, but sets additional limits:
// don't redraw slower than 200ms (0.2) or faster than 100ms (0.1)
$progressBar->setRedrawFrequency(100);
$progressBar->maxSecondsBetweenRedraws(0.2);
$progressBar->minSecondsBetweenRedraws(0.1);

[guvra]

thanks again for working on it.

I tried it on a bigger schema, and have the following feedback: I wonder whether we could use a undetermined progress bar and print progress every X thousand rows. in my case with millions of rows in a single table it still looks like no progress is going on.

I don't think it's possible with the current implementation of the cli 😞
The dumper is executed in the same process as the cli, so when mysqldump-php is dumping a table, the whole process is blocked, and the progress bar cannot be updated.
It can only be updated when the hook from setInfoHook is triggered (once per table).

it might also make sense to look into redraw-parameters, as the symfony console per default redraws every 100ms, which is waaay too fast for our progress. I think once every second or similar would be plenty.

Does it redraw anything when mysqldump-php is dumping a table though?
It looks like the progress bar is redrawn only when the bar progresses (so once per table at most).

[staabm]

I don't think it's possible with the current implementation of the cli 😞
The dumper is executed in the same process as the cli, so when mysqldump-php is dumping a table, the whole process is blocked, and the progress bar cannot be updated.
It can only be updated when the hook from setInfoHook is triggered (once per table).

I see. maybe its good enough for now 👍

Does it redraw anything when mysqldump-php is dumping a table though?
It looks like the progress bar is redrawn only when the bar progresses (so once per table at most).

I didn't check how often it re-renders. I judged from the symfony progress bar docs. but as you say.. when the process is blocked we will for sure not doing it too often :)

[staabm]

The dumper is executed in the same process as the cli, so when mysqldump-php is dumping a table, the whole process is blocked, and the progress bar cannot be updated.
It can only be updated when the hook from setInfoHook is triggered (once per table).

I left an idea in https://github.com/druidfi/mysqldump-php/pull/38/files#r1505546205 regarding printing progress while a table is dumped

[staabm]

just tested this again locally. it feels like it updates every second now, which is awesome.

thank you

[guvra]

just tested this again locally. it feels like it updates every second now, which is awesome.

thank you

Yes, the min progress timer is set to 0.1s, but if the progress bar is stuck on a specific step, it upgrades every 1 second.

[staabm]

what do you think about a thousands separator?

in my case the numbers get rather long and harder to read:

Dump progress
  57/405 [===>------------------------]  14% - my_table (101748356 rows) - 26 mins, 1 sec - 35.5 MiB

[guvra]

With a space character as the separator of course 😃