Commit graph

259 commits

Author SHA1 Message Date
Eelco Dolstra
d025142f52 Handle amount of disk space saved by hard linking being negative
Fixes bogus messages like "currently hard linking saves
17592186044416.00 MiB".
2012-08-05 21:45:27 -04:00
Eelco Dolstra
6763084ae5 Count bytes freed deleting unused links 2012-08-01 22:43:03 -04:00
Eelco Dolstra
01d56c1eec Drop the block count in the garbage collector 2012-08-01 22:34:46 -04:00
Eelco Dolstra
967d066d8e nix-store --gc: Make ‘--max-freed 0’ do the right thing
That is, delete almost nothing (it will still remove unused links from
/nix/store/.links).
2012-08-01 19:14:58 -04:00
Eelco Dolstra
1df702d347 removeUnusedLinks(): Print stats on disk space saved by hard linking 2012-08-01 19:01:50 -04:00
Eelco Dolstra
97421eb5ec Refactor settings processing
Put all Nix configuration flags in a Settings object.
2012-07-30 19:55:41 -04:00
Eelco Dolstra
680ab6f83d Garbage collect unused links in /nix/store/.links
Incremental optimisation requires creating links in /nix/store/.links
to all files in the store.  However, this means that if we delete a
store path, no files are actually deleted because links in
/nix/store/.links still exists.  So we need to check /nix/store/.links
for files with a link count of 1 and delete them.
2012-07-23 17:14:16 -04:00
Eelco Dolstra
1132dd27ea Fix obscure race condition in GC root creation
This should fix rare Hydra errors of the form:

error: symlinking `/nix/var/nix/gcroots/per-user/hydra/hydra-roots/7sfhs5fdmjxm8sqgcpd0pgcsmz1kq0l0-nixos-iso-0.1pre33785-33795' to `/nix/store/7sfhs5fdmjxm8sqgcpd0pgcsmz1kq0l0-nixos-iso-0.1pre33785-33795': File exists
2012-04-16 18:47:01 +02:00
Eelco Dolstra
446b827bae Mac OS X fix 2012-03-26 23:18:36 +02:00
Eelco Dolstra
480dda0e42 Delete non-directory valid paths right away
It's unlikely that rename() is faster than unlink() on a regular file
or symlink, so don't bother.
2012-03-26 20:56:30 +02:00
Eelco Dolstra
117670be57 Make the garbage collector more concurrent
Make the garbage collector more concurrent by deleting valid paths
outside the region where we're holding the global GC lock.  This
should greatly reduce the time during which new builds are blocked,
since the deletion accounts for the vast majority of the time spent in
the GC.

To ensure that this is safe, the valid paths are invalidated and
renamed to some arbitrary path while we're holding the lock.  This
ensures that we when we finally delete the path, it's not a (newly)
valid or locked path.
2012-03-26 20:43:33 +02:00
Eelco Dolstra
8be1979f1a Remove the --max-links GC option
We don't need this anymore now that current filesystems support more
than 32,000 files in a directory.
2012-03-26 20:00:02 +02:00
Eelco Dolstra
bd50c01972 Ensure that Perl processes delete their entry in the temproots directory
By moving the destructor object to libstore.so, it's also run when
download-using-manifests and nix-prefetch-url exit.  This prevents
them from cluttering /nix/var/nix/temproots with stale files.
2012-03-13 17:07:49 +01:00
Eelco Dolstra
35355fc1fc Set the close-on-exec flag on file descriptors 2012-03-05 20:29:00 +01:00
Eelco Dolstra
58ac7a17a4 Don't use deletePath() to delete a single file 2012-02-15 00:28:01 +01:00
Eelco Dolstra
d5a5a83ad4 Use data() instead of c_str() where appropriate 2012-02-09 18:27:45 +01:00
Eelco Dolstra
6f5e3326ce * Move topoSortPaths() out of gc.cc. 2011-12-30 15:02:50 +00:00
Eelco Dolstra
b1004f40f7 * Reject a build if there is a cycle among the outputs. This is
necessary because existing code assumes that the references graph is
  acyclic.
2011-12-30 14:47:14 +00:00
Eelco Dolstra
524fa8a4f1 * Oops. 2011-12-22 16:27:03 +00:00
Eelco Dolstra
b33da599c5 * In the garbage collector, delete invalid paths before deleting
unreachable paths.  This matters when using --max-freed etc.:
  unreachable paths could become reachable again, so it's nicer to
  keep them if there is "real" garbage to be deleted.  Also, don't use
  readDirectory() but read the Nix store and delete invalid paths in
  parallel.  This reduces GC latency on very large Nix stores.
2011-12-22 15:55:53 +00:00
Eelco Dolstra
58d974336c * Drop unnecessary call to canonPath() (nixStore is already canonical). 2011-12-22 14:33:34 +00:00
Eelco Dolstra
93227ff65c * Eliminate all uses of the global variable ‘store’ from libstore.
This should also fix:

    nix-instantiate: ./../boost/shared_ptr.hpp:254: T* boost::shared_ptr<T>::operator->() const [with T = nix::StoreAPI]: Assertion `px != 0' failed.

  which was caused by hashDerivationModulo() calling the ‘store’
  object (during store upgrades) before openStore() assigned it.
2011-08-31 21:11:50 +00:00
Eelco Dolstra
64fd29855a * Wrap deleteFromStore() in a transaction. Otherwise there might be a
race with other processes that add new referrers to a path,
  resulting in the garbage collector crashing with "foreign key
  constraint failed".  (Nix/4)
* Make --gc --print-dead etc. interruptible.
2010-10-14 15:55:51 +00:00
Eelco Dolstra
e2e168f7c2 `nix-store --verify' improvements:
* If a path has disappeared, check its referrers first, and don't try
  to invalidate paths that have valid referrers.  Otherwise we get a
  foreign key constraint violation.
* Read the whole Nix store directory instead of statting each valid
  path, which is slower.
* Acquire the global GC lock.
2010-08-31 11:47:31 +00:00
Eelco Dolstra
80e722278c * When using the build hook, distinguish between the stderr of the
hook script proper, and the stdout/stderr of the builder.  Only the
  latter should be saved in /nix/var/log/nix/drvs.
* Allow the verbosity to be set through an option.
* Added a flag --quiet to lower the verbosity level.
2010-08-30 14:53:03 +00:00
Eelco Dolstra
20acd43c25 * Disable the GC reachability check for now (when creating new roots),
as it's hopelessly inefficient.
2010-08-30 14:11:57 +00:00
Eelco Dolstra
44f6e6de77 * Set gc-keep-outputs' or gc-keep-derivations' to false with
`--delete --ignore-liveness'.
2010-03-08 21:31:42 +00:00
Eelco Dolstra
c4d388add4 * Get derivation outputs from the database instead of the .drv file,
which requires more I/O.
2010-02-22 12:44:36 +00:00
Eelco Dolstra
103cfee056 * Revert r19650 (implement gc-keep-outputs by looking for derivations
with the same name as the output) and instead use the
  DerivationOutputs table in the database, which is the correct way to
  to do things.
2010-02-22 11:44:17 +00:00
Eelco Dolstra
4bbbe25802 * Remove most Cygwin-specific code. Cygwin 1.7 implements advisory
POSIX locks, and simulates Unix-style file deletion semantics
  sufficiently.  Note that this means that Nix won't work on Cygwin
  1.5 anymore.
2010-02-02 15:28:36 +00:00
Eelco Dolstra
5388944e8d * Make the garbage collector do the right thing when `gc-keep-outputs'
is enabled by not depending on the deriver.
2010-01-25 16:04:32 +00:00
Eelco Dolstra
f9e766db98 * Randomise the order in which we delete entries to make the collector
less biased towards deleting paths that come alphabetically first
  (e.g. /nix/store/000...).  This matters when using --max-freed etc.
2009-11-24 09:53:18 +00:00
Eelco Dolstra
ca50c83fbb 2009-11-23 21:21:29 +00:00
Eelco Dolstra
ae6bf87273 * `nix-store --gc --print-roots': also print the path of the actual
root symlink, not just its target.  E.g.:

  /nix/var/nix/profiles/system-99-link -> /nix/store/76kwf88657nq7wgk1hx3l1z5q91zb9wd-system
2009-11-23 17:23:12 +00:00
Eelco Dolstra
c364d5d1e3 * Made the garbage collector a lot faster. It no longer computes the
complete set of live and dead paths before starting the actual
  deletion, but determines liveness on demand.  I.e. for any path in
  the store, it first tries to delete all the referrers, and then the
  path itself.  This means that the collector can start deleting paths
  almost immediately.
2009-11-23 16:34:24 +00:00
Eelco Dolstra
8824d60fe5 * Remove the --use-atime / --max-atime garbage collector flags. Many
(Linux) machines no longer maintain the atime because it's too
  expensive, and on the machines where --use-atime is useful (like the
  buildfarm), reading the atimes on the entire Nix store takes way too
  much time to make it practical.
2009-11-20 17:12:38 +00:00
Eelco Dolstra
d5eab2fc82 * Use foreach in a lot of places. 2009-04-21 11:52:16 +00:00
Eelco Dolstra
5dd8fb2069 * Don't use ULLONG_MAX in maxFreed - use 0 to mean "no limit".
18446744073709551615ULL breaks on GCC 3.3.6 (`integer constant is
  too large for "long" type').
2009-03-26 11:02:07 +00:00
Eelco Dolstra
92cb7c4dfe * Put chroots in the Nix store. This ensures that we can create hard
links to the inputs.
2008-12-12 17:14:57 +00:00
Eelco Dolstra
0008b0006d * Simplify deleting .lock files in /nix/store: just don't delete them
if they belong a path that's currently being built.  This gets rid
  of some Cygwin-specific code.
2008-12-12 17:03:18 +00:00
Eelco Dolstra
f32fef1b07 * GC option `--max-atime' that specifies an upper limit to the last
accessed time of paths that may be deleted.  Anything more recently
  used won't be deleted.  The time is specified in time_t,
  e.g. seconds since 1970-01-01 00:00:00 UTC; use `date +%s' to
  convert to time_t from the command line. 

  Example: to delete everything that hasn't been used in the last two
  months:

  $ nix-store --gc -v --max-atime $(date +%s -d "2 months ago")
2008-09-17 14:52:35 +00:00
Eelco Dolstra
4af2fdba6d * Typo. 2008-09-17 13:00:55 +00:00
Eelco Dolstra
c987061aa4 * Some refactoring. Better output with `-v' for --use-atime. 2008-09-17 12:54:07 +00:00
Eelco Dolstra
7ab68961e4 * Garbage collector: added an option `--use-atime' to delete paths in
order of ascending last access time.  This is useful in conjunction
  with --max-freed or --max-links to prefer deleting non-recently used
  garbage, which is good (especially in the build farm) since garbage
  may become live again.

  The code could easily be modified to accept other criteria for
  ordering garbage by changing the comparison operator used by the
  priority queue in collectGarbage().
2008-09-17 10:02:55 +00:00
Eelco Dolstra
c03b729319 * Increase the sleep periods a bit to make the test less likely to
fail on slow machines.  Of course it would be better if this test
  wasn't timing dependent...
2008-08-14 09:26:30 +00:00
Eelco Dolstra
d3aa183beb * Garbage collector: option `--max-freed' to stop after at least N
bytes have been freed, `--max-links' to stop when the Nix store
  directory has fewer than N hard links (the latter being important
  for very large Nix stores on filesystems with a 32000 subdirectories
  limit).
2008-06-18 14:20:16 +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
94fd46fa1c * Note. 2008-06-14 16:02:31 +00:00
Eelco Dolstra
826b271d9a * Garbage collector: don't do a complete topological sort of the Nix
store under the reference relation, since that means that the
  garbage collector will need a long time to start deleting paths.
  Instead just delete the referrers of a path first.
2008-06-13 18:25:24 +00:00
Eelco Dolstra
30c9f909b2 * Print some progress info during the early GC stages. 2008-06-13 17:21:20 +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
Eelco Dolstra
633518628f * nix-env -e: support uninstalling by path, so that one can say
$ nix-env -e $(which firefox)

  or

    $ nix-env -e /nix/store/nywzlygrkfcgz7dfmhm5xixlx1l0m60v-pan-0.132

* nix-env -i: if an argument contains a slash anywhere, treat it as a
  path and follow it through symlinks into the Nix store.  This allows
  things like

    $ nix-build -A firefox
    $ nix-env -i ./result

* nix-env -q/-i/-e: don't complain when the `*' selector doesn't match
  anything.  In particular, `nix-env -q \*' doesn't fail anymore on an
  empty profile.
2007-11-29 16:18:24 +00:00
Eelco Dolstra
149e273023 * Don't need gc.hh. 2007-11-15 15:07:27 +00:00
Michael Raskin
6fc60e2060 Added possibility to specify garbage collection levels for store paths; so packages can share intermediate results of compilation and GC will collect it automatically while never touching tarballs, for example. 2007-11-15 03:47:12 +00:00
Eelco Dolstra
e0d7e47862 * PathLocks::lockPaths: don't allow reacquiring a lock we already
hold.
2007-08-28 09:39:03 +00:00
Eelco Dolstra
9e975458b4 * Get rid of the substitutes database table (NIX-47). Instead, if we
need any info on substitutable paths, we just call the substituters
  (such as download-using-manifests.pl) directly.  This means that
  it's no longer necessary for nix-pull to register substitutes or for
  nix-channel to clear them, which makes those operations much faster
  (NIX-95).  Also, we don't have to worry about keeping nix-pull
  manifests (in /nix/var/nix/manifests) and the database in sync with
  each other.

  The downside is that there is some overhead in calling an external
  program to get the substitutes info.  For instance, "nix-env -qas"
  takes a bit longer.

  Abolishing the substitutes table also makes the logic in
  local-store.cc simpler, as we don't need to store info for invalid
  paths.  On the downside, you cannot do things like "nix-store -qR"
  on a substitutable but invalid path (but nobody did that anyway).

* Never catch interrupts (the Interrupted exception).
2007-08-12 00:29:28 +00:00
Eelco Dolstra
6d1a1191b0 * Support queryDeriver() in multi-user installations. 2007-06-12 16:53:44 +00:00
Eelco Dolstra
9bff7ad728 * Check against creation of GC roots in the store. Those roots don't
work, because findRoots() stops when it encounters a symlink to the
  store.  And of course the store is supposed to be read-only.
2007-06-11 11:36:22 +00:00
Eelco Dolstra
b2b6cf3fc8 * Undocumented option `gc-check-reachability' to allow reachability
checking to be turned off on machines with way too many roots.
2007-03-19 09:16:47 +00:00
Eelco Dolstra
9da367b7d5 * `nix-store -qR' and friends: print the paths sorted topologically
under the references relation.  This is useful for commands that
  want to copy paths to another Nix store in the right order.
2007-02-21 22:45:10 +00:00
Eelco Dolstra
8f67b35886 * Make the garbage collector more resilient to certain consistency
errors: in-use paths now cause a warning, not a fatal error.
2007-01-14 16:24:49 +00:00
Eelco Dolstra
62b0497c0f * Better message. 2006-12-05 16:17:01 +00:00
Eelco Dolstra
a9c4f66cfb * Allow unprivileged users to run the garbage collector and to do
`nix-store --delete'.  But unprivileged users are not allowed to
  ignore liveness.
* `nix-store --delete --ignore-liveness': ignore the runtime roots as
  well.
2006-12-05 02:18:46 +00:00
Eelco Dolstra
29cf434a35 * The determination of the root set should be made by the privileged
process, so forward the operation.
* Spam the user about GC misconfigurations (NIX-71).
* findRoots: skip all roots that are unreadable - the warnings with
  which we spam the user should be enough.
2006-12-05 01:31:45 +00:00
Eelco Dolstra
8623256f48 * findRoots: return a map from the symlink (outside of the store) to
the store path (inside the store).
2006-12-05 00:48:36 +00:00
Eelco Dolstra
d27a73b1a9 * In addPermRoot, check that the root that we just registered can be
found by the garbage collector.  This addresses NIX-71 and is a
  particular concern in multi-user stores.
2006-12-05 00:34:42 +00:00
Eelco Dolstra
74033a844f * Add indirect root registration to the protocol so that unprivileged
processes can register indirect roots.  Of course, there is still
  the problem that the garbage collector can only read the targets of
  the indirect roots when it's running as root...
2006-12-04 23:29:16 +00:00
Eelco Dolstra
e25fad691a * Move addTempRoot() to the store API, and add another function
syncWithGC() to allow clients to register GC roots without needing
  write access to the global roots directory or the GC lock.
2006-12-02 16:41:36 +00:00
Eelco Dolstra
9c9cdb06d0 * Remove SwitchToOriginalUser, we're not going to need it anymore. 2006-12-02 14:34:14 +00:00
Eelco Dolstra
e2ef5e07fd * Refactoring. There is now an abstract interface class StoreAPI
containing functions that operate on the Nix store.  One
  implementation is LocalStore, which operates on the Nix store
  directly.  The next step, to enable secure multi-user Nix, is to
  create a different implementation RemoteStore that talks to a
  privileged daemon process that uses LocalStore to perform the actual
  operations.
2006-11-30 17:43:04 +00:00
Eelco Dolstra
c6a97e3b74 * Doh! Path sizes need to be computed recursively of course.
(NIX-70)
2006-11-24 20:24:14 +00:00
Eelco Dolstra
5c38c863bd * Fix a huge gaping hole in nix-env w.r.t. the garbage collector.
Nix-env failed to call addPermRoot(), which is necessary to safely
  add a new root.  So if nix-env started after and finished before the
  garbage collector, the user environment (plus all other new stuff)
  it built might be garbage collected, leading to a dangling symlink
  chain in ~/.nix-profile...

* Be more explicit if we block on the GC lock ("waiting for the big
  garbage collector lock...").

* Don't loop trying to create a new generation.  It's not necessary
  anymore since profiles are locked nowadays.
2006-09-14 22:30:33 +00:00
Eelco Dolstra
75068e7d75 * Use a proper namespace.
* Optimise header file usage a bit.
* Compile the parser as C++.
2006-09-04 21:06:23 +00:00
Eelco Dolstra
4250b641d8 * `nix-store --gc --print-dead': print the total size of the store
objects that would be freed.
2006-08-11 20:26:49 +00:00
Eelco Dolstra
92f7dfa5b7 * Don't assume that paths returned by the runtime root finder are
valid.
2006-08-11 20:15:20 +00:00
Eelco Dolstra
a4273156c4 * Use $(libexecdir) to find find-runtime-roots.pl. 2006-07-20 13:21:37 +00:00
Eelco Dolstra
ee2cf45d76 * Use debug(). 2006-07-20 12:19:55 +00:00
Eelco Dolstra
c15f544356 * Call find-runtime-roots.pl from the garbage collector to prevent
running applications etc. from being garbage collected.
2006-07-20 12:17:25 +00:00
Eelco Dolstra
dbf6d7e783 * Concurrent GC on Cygwin. 2006-06-20 17:48:10 +00:00
Eelco Dolstra
58b4198ed8 * Disable the concurrent garbage collector on Cygwin for now. 2006-05-29 20:46:51 +00:00
Eelco Dolstra
9d72bf8835 * 64-bit compatibility fixes (for problems revealed by building on an Athlon
64 running 64-bit SUSE).  A patched ATerm library is required to run Nix
  succesfully.
2006-05-11 02:19:43 +00:00
Eelco Dolstra
c8bfb11b34 * `nix-env (-i|-u) --dry-run' now shows exactly which missing paths
will be built or substituted.
2006-03-06 11:21:15 +00:00
Eelco Dolstra
f96d2dea26 * Added a flag --ignore-liveness' to nix-store --delete'. It
deletes a path even if it is reachable from a root.  However, it
  won't delete a path that still has referrers (since that would
  violate store invariants).

  Don't try this at home.  It's a useful hack for recovering from
  certain situations in a somewhat clean way (e.g., holes in closures
  due to disk corruption).
2005-12-23 21:36:44 +00:00
Eelco Dolstra
4b9e7f59ca * Revived the old "nix-store --delete" operation that deletes the
specified paths from the Nix store.  However, this operation is
  safe: it refuses to delete anything that the garbage collector
  wouldn't delete.
2005-12-23 21:08:42 +00:00
Eelco Dolstra
530b27df1e * `nix-store --gc' prints out the number of bytes freed on stdout
(even when it is interrupted by a signal).
2005-12-15 21:11:39 +00:00
Eelco Dolstra
ab5c6bb3a3 * Change referer' to referrer' throughout. In particular, the
nix-store query options `--referer' and `--referer-closure' have
  been changed to `--referrer' and `--referrer-closure' (but the old
  ones are still accepted for compatibility).
2005-12-13 21:04:48 +00:00
Eelco Dolstra
109cde6706 * Ignore (with a warning) invalid garbage collector roots. 2005-05-10 14:56:10 +00:00
Eelco Dolstra
298dd487bb * When finding live paths, the deriver need not be valid. 2005-03-25 14:31:12 +00:00
Eelco Dolstra
c6178f0b03 * Create missing log and temproots directories automatically (reported
by Rob).
2005-03-24 17:46:38 +00:00
Eelco Dolstra
8a3a96dd5b * Switch to the calling user context for some more operations in a
setuid installation.
2005-02-17 13:55:18 +00:00
Eelco Dolstra
a04a5de8f7 * Implement the `gc-keep-derivations' global configuretion flag. 2005-02-14 14:16:56 +00:00
Eelco Dolstra
6a8ef36fe6 * Global configuration option `env-keep-derivations' to store pointer
to derivations in user environments.  Nice for developers (since it
  prevents build-time-only dependencies from being GC'ed, in
  conjunction with `gc-keep-outputs').  Turned off by default.
2005-02-14 13:07:09 +00:00
Eelco Dolstra
3d74274b37 * Updated `nix-store --verify' to the new schema. 2005-02-08 13:23:55 +00:00
Eelco Dolstra
fbc434ee4c * `nix-store -qb' to query derivation environment bindings. Useful
for finding build-time dependencies (possibly after a build).  E.g.,

    $ nix-store -qb aterm $(nix-store -qd $(which strc))
    /nix/store/jw7c7s65n1gwhxpn35j9rgcci6ilzxym-aterm-2.3.1

* Arguments to nix-store can be files within store objects, e.g.,
  /nix/store/jw7c...-aterm-2.3.1/bin/baffle.

* Idem for garbage collector roots.
2005-02-07 14:32:44 +00:00
Eelco Dolstra
a37338815d * A GC setting `gc-keep-outputs' to specify whether output paths of
derivations should be kept.
2005-02-01 22:07:48 +00:00
Eelco Dolstra
65b6c8ab4c * Move root finding from nix-collect-garbage' to nix-store --gc'.
This was necessary becase root finding must be done after
  acquisition of the global GC lock.

  This makes `nix-collect-garbage' obsolete; it is now just a wrapper
  around `nix-store --gc'.

* Automatically remove stale GC roots (i.e., indirect GC roots that
  point to non-existent paths).
2005-02-01 15:05:32 +00:00
Eelco Dolstra
630ae0c9d7 * nix-build: use an indirection scheme to make it easier for users to
get rid of GC roots.  Nix-build places a symlink `result' in the
  current directory.  Previously, removing that symlink would not
  remove the store path being linked to as a GC root.  Now, the GC
  root created by nix-build is actually a symlink in
  `/nix/var/nix/gcroots/auto' to `result'.  So if that symlink is
  removed the GC root automatically becomes invalid (since it can no
  longer be resolved).  The root itself is not automatically removed -
  the garbage collector should delete dangling roots.
2005-02-01 13:48:46 +00:00
Eelco Dolstra
dcc37c236c * nix-store, nix-instantiate: added an option `--add-root' to
immediately add the result as a permanent GC root.  This is the only
  way to prevent a race with the garbage collector.  For instance, the
  old style

    ln -s $(nix-store -r $(nix-instantiate foo.nix)) \
      /nix/var/nix/gcroots/result

  has two time windows in which the garbage collector can interfere
  (by GC'ing the derivation and the output, respectively).  On the
  other hand,

    nix-store --add-root /nix/var/nix/gcroots/result -r \
      $(nix-instantiate --add-root /nix/var/nix/gcroots/drv \
        foo.nix)

  is safe.

* nix-build: use `--add-root' to prevent GC races.
2005-02-01 12:36:25 +00:00
Eelco Dolstra
32fa82a56a * Acquire a global GC lock to prevent new temporary root files from
being created after the garbage collector has read the temproots
  directory.  This blocks the creation of new processes, but the
  garbage collector could periodically release the GC lock to allow
  them to run.
2005-01-31 22:23:49 +00:00
Eelco Dolstra
89c9bc11ab * Add a test for a more subtle race: a process starting after the
temporary root files have been read but creating outputs before the
  store directory has been read.
2005-01-31 22:01:55 +00:00
Eelco Dolstra
207bdcbe86 * Automatically remove temporary root files. 2005-01-31 21:20:59 +00:00
Eelco Dolstra
252c9c91ab * Topologically sort paths under the references relation to ensure
that they are deleted in an order that maintains the closure
  invariant.
* Presence of a path in a temporary roots file does not imply that all
  paths in its closure are also present, so add the closure.
2005-01-31 14:00:43 +00:00
Eelco Dolstra
33c5d23b81 * Don't delete active lock files. 2005-01-31 12:19:53 +00:00
Eelco Dolstra
1328aa3307 * Start of concurrent garbage collection. Processes write temporary
roots to a per-process temporary file in /nix/var/nix/temproots
  while holding a write lock on that file.  The garbage collector
  acquires read locks on all those files, thus blocking further
  progress in other Nix processes, and reads the sets of temporary
  roots.
2005-01-31 10:27:25 +00:00
Eelco Dolstra
c505702265 * Fix and simplify the garbage collector (it's still not concurrent,
though).  In particular it's now much easier to register a GC root.
  Just place a symlink to whatever store path it is that you want to
  keep in /nix/var/nix/gcroots.
2005-01-27 15:21:29 +00:00
Eelco Dolstra
96de272b48 * Renamed normalise.cc' -> build.cc', `storeexprs.cc' ->
`derivations.cc', etc.
* Store the SHA-256 content hash of store paths in the database after
  they have been built/added.  This is so that we can check whether
  the store has been messed with (a la `rpm --verify').
* When registering path validity, verify that the closure property
  holds.
2005-01-19 16:39:47 +00:00
Eelco Dolstra
863dcff6c5 * Started removing closure store expressions, i.e., the explicit
representation of closures as ATerms in the Nix store.  Instead, the
  file system pointer graph is now stored in the Nix database.  This
  has many advantages:

  - It greatly simplifies the implementation (we can drop the notion
    of `successors', and so on).

  - It makes registering roots for the garbage collector much easier.
    Instead of specifying the closure expression as a root, you can
    simply specify the store path that must be retained as a root.
    This could not be done previously, since there was no way to find
    the closure store expression containing a given store path.
    
  - Better traceability: it is now possible to query what paths are
    referenced by a path, and what paths refer to a path.
2005-01-19 11:16:11 +00:00
Eelco Dolstra
eb233e728f * `--min-age' flag in nix-store and nix-collect-garbage to only delete
unreachable paths that haven't been used for N hours.  For instance,
  `nix-collect-garbage --min-age 168' only deletes paths that haven't
  been accessed in the last week.

  This is useful for instance in the build farm where many derivations
  can be shared between consecutive builds, and we wouldn't want a
  garbage collect to throw them all away.  We could of course register
  them as roots, but then we'd to unregister them at some point, which
  would be a pain to manage.  The `--min-age' flag gives us a sort of
  MRU caching scheme.

  BUG: this really shouldn't be in gc.cc since that violates
  mechanism/policy separation.
2004-08-25 16:54:08 +00:00
Eelco Dolstra
818047881e * Put the garbage collector in nix-store: operation `--gc',
suboperations `--print-live', `--print-dead', and `--delete'.  The
  roots are not determined by nix-store; they are read from standard
  input.  This is to make it easy to customise what the roots are.

  The collector now no longer fails when store expressions are missing
  (which legally happens when using substitutes).  It never tries to
  fetch paths through substitutes.

  TODO: acquire a global lock on the store while garbage collecting.
  
* Removed `nix-store --delete'.
2004-08-25 11:43:49 +00:00