Re: [gentoo-dev] RFC: make system-sqlite a global USE flag

[Nirbheek Chauhan]

On Tue, Oct 5, 2010 at 7:41 PM, Donnie Berkholz <dberkholz@g.o> wrote:
> On 15:52 Tue 05 Oct     , "Paweł Hajdan, Jr." wrote:
>> The meaning is identical in all those cases, and I think the number of
>> packages may have hit the threshold for a global flag.
>>
>> However, we already have a very similar global USE flag: sqlite, which
>> makes this a bit more tricky. The difference is very subtle:
>>
>> IUSE="sqlite" means "the sqlite support is optional; -sqlite means no
>> sqlite support"
>>
>> IUSE="system-sqlite" means "we can use the bundled sqlite or the
>> system one; -system-sqlite means we use the bundled one; both settings
>> result in sqlite support"
>>
>> If we'd make system-sqlite a global USE flag, I'd suggest a
>> description like "Use the system-wide dev-db/sqlite instead of bundled
>> copy of sqlite."
>
> I think making this a global flag implicitly endorses building bundled
> code as an OK thing to do. Why is it an option at all, local or
> otherwise?
>

The reason is that with SQLITE_SECURE_DELETE, sqlite zeroes out
portions that have been deleted causing a very noticeable drop in
performance. This may be acceptable for browsers, but is rarely
desirable system-wide. See
https://bugzilla.mozilla.org/show_bug.cgi?id=546162 for details.

To fix this problem sqlite upstream made a specific change allowing a
#pragma to be used to define where secure-delete is required, avoiding
the need to use secure-delete *everywhere*.[1] However, Mozilla
upstream considers the two-line-change[2] an unacceptable level of
maintenance burden, and refused to implement it[3].

I presume Chromium upstream has a similar stance on the issue, hence
making the use-flag necessary for us since we (at least mozilla team)
avoid adding patches that are not upstream yet.

1. https://bugzilla.mozilla.org/show_bug.cgi?id=546162#c8
2. https://bugzilla.mozilla.org/show_bug.cgi?id=546162#c11
3. https://bugzilla.mozilla.org/show_bug.cgi?id=546162#c15
-- 
~Nirbheek Chauhan

Gentoo GNOME+Mozilla Team