[pacman-dev] So many HOOK puns could go here!

[Allan McRae]

On 06/07/13 04:20, Andrew Gregory wrote:
> On 07/06/13 at 01:08am, Allan McRae wrote:
>>
>>
>> Looking at the ini parsing patch yesterday motivated me to get hooks
>> implemented.  But first we need to completely flesh out the details.
>> This is too complex of a change to make up as we go along.
>>
>> >From the mention of the previous patch, you should be able to figure out
>> the format I am pushing...
>>
>> Look here:
>> https://wiki.archlinux.org/index.php/User:Allan/Pacman_Hooks
>>
>>
>> Questions to answer:
>>
>> 1) Should hooks have a defined suffix.
>> PRO: Avoids .pac{save,new} conflicts
>> CON: There should be none (adjustments made in /etc)
>>
> 
> I would vote for a suffix just as a precaution.

OK.  Bikeshedding time!   I have added the requirement of a ".hook" suffix.

>>
>> 2) Complete list of when hooks can be run.  Current list:
>>
>> PreRemove
>> PostRemove
>> PreInstall
>> PostInstall
>> Transaction
>>
>> I guess we should add Pre/Post suffix to Transaction for generality.
>> Any more needed?
>>
>>
>> 3) Trigger.  In the wiki I have "File" and "Package" to specify
>> triggers, allowing wildcards.  These can be suffixed with
>> Install/Upgrade/Removal.  Note that any operation can be triggered by
>> using e.g "PackageInstall = *".   Does that seem general enough?
>>
> 
> There is some redundancy here.  Do we need Install/Remove/Upgrade in
> both the "when" and the trigger?

No we don't...  I was over thinking details without seeing the big
picture.  Removed.

>>
>> 4) Should File hooks run immediately after the file or at the end of the
>> package.   At the end of the package fits in with out current install
>> scripts ad so would be easier to implement.  Can anyone think of a
>> situation with directly after the file is preferable?
>>
> 
> I think all of the "when"s should mean the same thing whether the
> trigger is a file or a package.  If we discover we need hooks that run
> immediately after a file is modified we should add a separate "when"
> for that.

OK - I am doubting we will need that given no-one has mentioned the need
with only our install scriptlets available.

>>
>> 5) How should we handle packages installing a new hook?   e.g. In Arch,
>> texinfo will carry the install-info hook.  I think it will still need a
>> post_install script to add all the info files installed before texinfo
>> was to the info directory, but then the hook install should be
>> recognised and act on any packages installed after that.  Reasonable?
>>
> 
> I think hooks have to be immediately recognized as you describe.
> Otherwise, it seems like it would be difficult to ever transition from
> using an install script to a hook.
> 
>>
>> 6) Any other comments?
>>
> 
> Hooks have the potential to replace install scripts altogether; is
> that the intent or do you just want to supplement them?

They will not replace install scripts altogether, but should replace
those that appear multiple times.

Allan