Commit graph

10 commits

Author SHA1 Message Date
Eelco Dolstra 6193105710 Automatically optimise the Nix store when a new path is added
Auto-optimisation is enabled by default.  It can be turned off by
setting auto-optimise-store to false in nix.conf.
2012-07-23 17:14:15 -04:00
Eelco Dolstra 564fb7d9fa optimiseStore(): Use a content-addressed file store in /nix/store/.links
optimiseStore() now creates persistent, content-addressed hard links
in /nix/store/.links.  For instance, if it encounters a file P with
hash H, it will create a hard link

  P' = /nix/store/.link/<H>

to P if P' doesn't already exist; if P' exist, then P is replaced by a
hard link to P'.  This is better than the previous in-memory map,
because it had the tendency to unnecessarily replace hard links with a
hard link to whatever happened to be the first file with a given hash
it encountered.  It also allows on-the-fly, incremental optimisation.
2012-07-23 17:14:15 -04:00
Eelco Dolstra bd013b6f98 On Linux, make the Nix store really read-only by using the immutable bit
I was bitten one time too many by Python modifying the Nix store by
creating *.pyc files when run as root.  On Linux, we can prevent this
by setting the immutable bit on files and directories (as in ‘chattr
+i’).  This isn't supported by all filesystems, so it's not an error
if setting the bit fails.  The immutable bit is cleared by the garbage
collector before deleting a path.  The only tricky aspect is in
optimiseStore(), since it's forbidden to create hard links to an
immutable file.  Thus optimiseStore() temporarily clears the immutable
bit before creating the link.
2012-02-15 01:31:56 +01:00
Eelco Dolstra a3883cbd28 * Store the size of a store path in the database (to be precise, the
size of the NAR serialisation of the path, i.e., `nix-store --dump
  PATH').  This is useful for Hydra.
2010-11-16 17:11:46 +00:00
Eelco Dolstra 07ca66cf24 * Applied a patch from David Brown to prevent `nix-store --optimise'
from failing on rename() on BtrFS.
2010-06-04 13:56:11 +00:00
Eelco Dolstra c7057fc1f2 * And some more. 2009-09-24 07:39:55 +00:00
Eelco Dolstra d5eab2fc82 * Use foreach in a lot of places. 2009-04-21 11:52:16 +00:00
Eelco Dolstra a8f3b02092 * `nix-store --optimise': handle files with >= 32000 hard links.
(There can easily be more than 32000 occurrences of the empty file.)
2008-06-18 14:13:00 +00:00
Eelco Dolstra a72709afd8 * Some refactoring: put the GC options / results in separate structs.
* The garbage collector now also prints the number of blocks freed.
2008-06-18 09:34:17 +00:00
Eelco Dolstra b0e92f6d47 * Merged the no-bdb branch (-r10900:HEAD
https://svn.nixos.org/repos/nix/nix/branches/no-bdb).
2008-06-09 13:52:45 +00:00