Re: Fast access git-rev-list output: some OS knowledge required

From: Marco Costalba <mcostalba@gmail.com>
Date: Dec 9, 2006, 12:15 UTC
Message-ID: <e5bfff550612090415i26af8ea5q383889e951659d7e@mail.gmail.com>
In-Reply-To: <f2b55d220612081210u6ec3e95ciec6665a6b5e6a827@mail.gmail.com>

On 12/8/06, Michael K. Edwards <medwards.linux@gmail.com> wrote:

> There is a very handy solution to this problem called "tmpfs".  It
> should already be mounted at /tmp.  Put tmp.txt there and your problem
> will go away.
>

Thanks Michael,

It seems to work! patch pushed.

 Marco

P.S: I've looked again to Shawn idea (and code) of linking qgit against libgit.a but I found these two difficult points:

- traverse_commit_list(&revs, show_commit, show_object) is blocking,
i.e. the GUI will stop responding for few seconds while traversing the
list. This is easily and transparently solved by the OS scheduler if
an external process is used for git-rev-list. To solve this in qgit I
have two ways: 1) call QEventLoop() once in a while from inside
show_commit()/ show_object() to process pending events  2) Use a
separate thread (QThread class). The first idea is not nice, the
second opens a whole a new set of problems and it's a big amount of
not trivial new code to add.

-  traverse_commit_list() having an internal state it's not
re-entrant. git-rev-list it's used to load main view data but also
file history in another tab, and the two calls _could_ be ran
concurrently. With external process I simply run two instances of
DataLoader class and consequently two external git-rev-list processes,