Re: Wiki, information on database back ends.
Dan White wrote: The current imapd.conf hints at the available data types for each cyrus database. Depending on the option, the following database types are available (in 2.3.16): (...snip...) I don't know why the (rpm) upgrade script chose skiplist as an intermediate format, rather than flat. Perhaps skiplist hasn't changed much between major versions, and offers a speed benefit. Actually the RPM packages patch up lib/imapoptions to default to skiplist for all databases. The script choosing skiplist as the default format to convert databases to is nothing but a choice that makes a default export/import much faster because the script does not actually have to export/import (it merely has to detect/determine/compare/continue). As far as skiplist, that seems to be a proprietary format. skiplist: ? http://git.cyrusimap.org/cyrus-imapd/tree/lib/cyrusdb_skiplist.c is the implementation of http://en.wikipedia.org/wiki/Skip_list inspired by ftp://ftp.cs.umd.edu/pub/skipLists/skiplists.pdf. I fail to see how exactly this could lead to the conclusion it may be proprietary software. Kind regards, -- Jeroen van Meeuwen Senior Engineer, Kolab Systems AG e: vanmeeu...@kolabsys.com t: +316 42 801 403 w: http://www.kolabsys.com pgp: 9342 BF08
Re: Wiki, information on database back ends.
On 15/09/10 21:19 +0200, Jeroen van Meeuwen (Kolab Systems) wrote: As far as skiplist, that seems to be a proprietary format. skiplist: ? http://git.cyrusimap.org/cyrus-imapd/tree/lib/cyrusdb_skiplist.c is the implementation of http://en.wikipedia.org/wiki/Skip_list inspired by ftp://ftp.cs.umd.edu/pub/skipLists/skiplists.pdf. I fail to see how exactly this could lead to the conclusion it may be proprietary software. Not proprietary software, but a proprietary database format, in that it's specific to Cyrus, as opposed to something like Berekely, where there's external documentation. I'm not trying to make a judgement, just trying to answer the question what is skiplist?, which due to my own ignorance I can't answer. -- Dan White
Re: Wiki, information on database back ends.
Patrick Goetz wrote: On 09/14/2010 02:24 PM, Patrick Goetz wrote: This raises a number of questions, though: I forgot to add: 4. The Redhat script uses a file called /usr/share/cyrus-imapd/rpm/db.cfg Presumably this is specific to the redhat package, since I can't find a db.cfg file associated with my 2.1.16 cyrus server, or is my version just too old and behind the times? This file is also written out by the same script. The location of the script (the mentioning of 'rpm/' in the path) is completely arbitrary (for all the script cares the file lives in /boot/). Kind regards, -- Jeroen van Meeuwen Senior Engineer, Kolab Systems AG e: vanmeeu...@kolabsys.com t: +316 42 801 403 w: http://www.kolabsys.com pgp: 9342 BF08
Re: Wiki, information on database back ends.
On 09/14/2010 04:06 PM, Jeroen van Meeuwen (Kolab Systems) wrote:
This file is also written out by the same script. The location of the script
(the mentioning of 'rpm/' in the path) is completely arbitrary (for all the
script cares the file lives in /boot/).
Small correction: created while compiling; from the comments in the
script and the actual lines of code the file appears in:
# The format of current db files is determined using the 'file' command
# with a magic file added for skiplist db, the new format is read from
# a config file usually in /usr/share/cyrus-imapd/rpm/db.cfg, which is
# created while compiling. After converting, the db.cfg file is
...
db_cfg=${data_dir}/db.cfg
db_current=${imap_prefix}/rpm/db.cfg.current
db_cache=${imap_prefix}/rpm/db.cfg.cache
# source default db backend config
. $db_cfg
Re: Wiki, information on database back ends.
Patrick Goetz wrote: On 09/14/2010 02:35 PM, Dave McMurtrie wrote: On 09/14/2010 03:24 PM, Patrick Goetz wrote: The flip side of this is that you are now welcome and encouraged to change that. I'd be happy to write up some stuff as soon as I have answers to some of my questions (i.e. as soon as I have something to write about). I added some basic information to the FAQ in the Questions about features section to attempt to answer your database backends question. It doesn't fully answer your question, but it's a start. I've spent quite a bit of time looking at cyrus 2.3.16 source code this summer, and it sure would have been helpful if the coders had taken 30 seconds or a minute to write a few comments for each function. Just sayin There aren't a ton of style guidelines for the Cyrus codebase other than http://www.cyrusimap.org/mediawiki/index.php/Cyrus_IMAP_Hacking Specifically, I'm not aware of anything that tells a developer to add a comment for each function. Since we're aiming to attract more developers to the project, I'm planning to soon open this topic up for further discussion with the core developers. Now that you've studied the code, if we can get core developer agreement on having a standard comment blurb for each function, would you be interested in submitting patches to include these comments? Thanks, Dave
Re: Wiki, information on database back ends.
On Tue, Sep 14, 2010 at 03:04:33PM -0500, Patrick Goetz wrote: On 09/14/2010 02:35 PM, Dave McMurtrie wrote: On 09/14/2010 03:24 PM, Patrick Goetz wrote: The flip side of this is that you are now welcome and encouraged to change that. I'd be happy to write up some stuff as soon as I have answers to some of my questions (i.e. as soon as I have something to write about). I've spent quite a bit of time looking at cyrus 2.3.16 source code this summer, and it sure would have been helpful if the coders had taken 30 seconds or a minute to write a few comments for each function. Just sayin Tell me about it. Though I have to warn you, a LOT has changed in what will become 2.4. I'm trying to document it better Bron.
