Re: [Tracker] Integratin Tracker and Apple Spotlight

[Frank Lahm <franklahm gmail com>]

Hi Martyn,

2012/7/2 Martyn Russell <martyn lanedo com>:
> > Most use cases will be indexing and searching shored storage spaces
> > (volumes, shares) which are accessed by multiple users. Netatalk
> > creates distinct UNIX processes for every user session on the server,
> > running with the priviliges of the users UNIX account.
> >
> > Can someone please give me a hint if and now this can be done with
> > Tracker? From what I've researched as of now (mostly checking the
> > available Tracker query API), Tracker is built around the assumption
> > of one Tracker instance per user. So I always just assumed that well,
> > let that user be root and index whatever I configure.
>
>
> That's one way, though I wouldn't advise using root for that sort of thing
> but a dedicated user instead (perhaps in teh same group)?

Yes, possibly once I've gotten my head around dbus and tracker. ;)
Until then I resorted to start a dbus session and tracker via a small
shell script:
---8<---
#!/bin/sh
eval `dbus-launch --sh-syntax
--config-file=/usr/local/netatalk/etc/dbus-session.conf`
echo "D-Bus per-session daemon address is: $DBUS_SESSION_BUS_ADDRESS"
nohup /usr/lib/tracker/trackerd &
---8<---

I've put a <listen> directive with a TCP address (127.0.0.1:12345) in
the dbus-session.conf so DBUS_SESSION_BUS_ADDRESS is a known value
which I can export to my a shell where I play with tracker-search and
putenv() to the environment of the relevant Netatalk process (afpd)
which will call tracker-sparql C API stuff.

Btw, we're now facing the interesting problem of translating Apple's
Spotlight query syntax to SPARQL. An example for a more complex
Spotlight query:

((true) && (((kMDItemResolutionHeightDPI < 72) && (_kMDItemGroupId =
13) && InRange(kMDItemContentModificationDate,360453600.000000,363132000.000000))))
&& ((* = "pic*"cdw || kMDItemTextContent = "pic*"cdw))

That's a search for a picture (_kMDItemGroupId 13) with a string "pic"
a the beginning of any metadata attribute or filename, changed within
the last 30 days (kMDItemContentModificationDate) and a resolution
smaller then 72 dpi.

We're looking for interested persons or companies who might be
interested in doing paid work on this. In case you're interested
please contact me off-list. Thanks!

-f