clearing search bar with a large database is slow

[mixxxbot]

Reported by: Be-ing
Date: 2016-10-20T02:18:32Z
Status: Fix Released
Importance: Medium
Launchpad Issue: lp1635087

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From http://www.mixxx.org/forums/viewtopic.php?p=29623#p29623:
"I've learned to NEVER click the X button in the library search. It wants to re-sort the world every time. I give the field focus, hit ctrl-A to select all the text, and start typing."

Confirmed by another user here: http://mixxx.org/forums/viewtopic.php?p=30520#p30520

[mixxxbot]

Commented by: rryan
Date: 2016-11-28T01:31:07Z

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Looks like clearing via the X is equivalent to changing the search query 5 times:

Debug [Main]: WSearchLineEdit::onSearchTextCleared
Debug [Main]: WSearchLineEdit::slotTextChanged ""
Debug [Main]: WSearchLineEdit::triggerSearch ""
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 2 ms 293
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 2 ms 293
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 2 ms 293
Debug [Main]: WSearchLineEdit::triggerSearch ""
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 3 ms 293
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 3 ms 293

Other than a few minor differences the code paths are identical (e.g. restoring the vertical bar position) so we can probably fix this by making it search for "" just once.

Odd that the workaround works, because it's functionally equivalent except for:

• QLineEdit::clear()

• WTrackTableView::restoreVScrollVarPosition() [1]

Compare the WTrackTableView::onSearchCleared vs. WTrackTableView::onSearch

[1] https://github.com/mixxxdj/mixxx/blob/master/src/widget/wtracktableview.cpp#L981

[mixxxbot]

Commented by: rryan
Date: 2016-11-28T01:32:16Z

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Oops, everything from "Odd that the workaround works, because it's functionally equivalent except for:" and below was an old draft.

[mixxxbot]

Commented by: uklotzde
Date: 2018-12-17T19:11:39Z

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Instead of immediately triggering a search that returns all tracks of the (probably huge) library the debouncing timer should be engaged when clearing the search edit. This is an easy fix and would establish a consistent behaviour.

[mixxxbot]

Commented by: uklotzde
Date: 2018-12-17T19:21:25Z

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#1947

[mixxxbot]

Commented by: daschuer
Date: 2018-12-17T20:24:50Z

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The PR cann't fix the route cause of this bug. But it is also not the right bug to track the root cause so let's close it.

[mixxxbot]

Commented by: uklotzde
Date: 2018-12-17T21:34:29Z

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Of course, it doesn't fix the bug. It just establishes a consistent behaviour. With the configurable debouncing timeout in 2.2 it actually becomes useful.

Clearing the box without starting the debouncing timer is not an option, because then the contents of the view might stay inconsistent forever.

The issue will finally be resolved once we no longer fetch the whole result set eagerly from the database.

[mixxxbot]

Issue closed with status Fix Released.