345932 - download manager "clean up" button does not "clean up"

Status: RESOLVED FIXED

(Toolkit :: Downloads API, defect)

Description

[Joseph R. Kiniry]

User-Agent:       Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8.0.4) Gecko/20060508 Firefox/1.5.0.4
Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8.0.4) Gecko/20060508 Firefox/1.5.0.4

My Firefox install became progressively slower and slower over time, especially when triggering a download handled by the built-in download manager.  I suspected a non-linear complexity problem in the download manager, thus tried to trigger a "clean up" of my >100 downloads listed.  

At any point in time, when pushed, this button does one of two things: (a) a full-Firefox pause, Firefox consumes mucho CPU, then no change to the download list, or (b) a full-Firefox pause, Firefox consumes mucho CPU, then at least one download on the list disappears.  Even after repeatedly pushing "remove" on various downloads (each action of which takes ~5 seconds), pushing "Clean Up" still has the same behavior.  Thus, I am left with hundreds of downloads in the download manager, a "Clean Up" button that does not "Clean Up", and terrifically slow download performance.  

Perhaps there is a badly chosen hard-coded limit in "Clean Up"s implemementation?  Perhaps the "Clean Up" algorithm is not only incorrect, but should be linear in the number of items in the download manager list?

Reproducible: Always

Steps to Reproduce:
1. download 100s of random items with the download manager
2. attempt to "Clean Up"
3. wash, rinse, repeat

Actual Results:  
"Clean Up" has no effect on the download manager list though Firefox consumes serious resources for several seconds.

Expected Results:  
"Clean Up" should always remove all items in the download manager list, period.

Comment 1

[Jake Olefsky]

WFM in 2.0RC1

Comment 2

[mark]

FF Windows 2.0.0.3 : I have experienced this problem in the last several versions of 2.0. Clean Up button does nothing; slow response to Remove for an individual entry; and selecting Clear Private Data with Download History selected has zero effect.

Comment 3

[Carsten Book [:Tomcat]]

mark, do you see this also in the 2.0.0.4 Release ? Can you reproduce this in Firefox safe mode or with a new profile ?

Comment 4

[mark]

I'm actually running 1.5.0.12 now because of the slow response to downloads with 2.0. I don't know when I will have time to try to reinstall 2.0.0.4.

Comment 5

[Samuel Sidler (old account; do not CC)]

Joseph, how about you? Are you seeing this with Firefox 2.0.0.4 or later with a new profile or in safe mode?

http://kb.mozillazine.org/Profile_Manager
http://kb.mozillazine.org/Safe_Mode

Comment 6

[Joseph R. Kiniry]

I have not witnessed this bug in 2.0.0.4 thus far.

Comment 7

[Shawn Wilsher :sdwilsh]

I'm willing to bet this had to do with the rdf back-end and poor performance.  Should have been fixed by Bug 380250 on trunk.

Comment 8

[sam]

I just did a ~200 file 'flashgot launched' download (200 small ~10KB html files) with Firefox 14.0.1 and experienced a similar problem.  Although only doing 4 requests in parallel, all downloads are added to the list at once.  Browser almost grinds to a halt, and it took quite a while just to clear the list of 200 downloads.  I'm guessing there is either some N^2 slow code in there, or more likely it is writing out the DB and doing fsync after removing each item from the list.  So I guess it's doing 200 full DB writes and fsync, slowly.

I'm sort of willing to try and fix it, but I'm totally ignorant of mozilla code...

Comment 9

[sam]

Maybe if someone will point me at the download manager list code, I'll take a look.

Comment 10

[Samuel Sidler (:ss)]

This bug is already marked FIXED, because it was fixed over 5 years ago. You should file a new bug with the problems you've been experiencing. It could be a regression or an edge case.