Commit graph

30 commits

Author SHA1 Message Date
Eelco Dolstra
450c358e20 * Maintain a database table (`derivers') that maps output paths to the
derivation that produced them.
* `nix-store -qd PATH' prints out the derivation that produced a path.
2005-02-07 13:40:40 +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
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
a24b78e9f1 * Maintain the references/referers relation also for derivations.
This simplifies garbage collection and `nix-store --query
  --requisites' since we no longer need to treat derivations
  specially.

* Better maintaining of the invariants, e.g., setReferences() can only
  be called on a valid/substitutable path.
2005-01-25 21:28:25 +00:00
Eelco Dolstra
2a2756b856 * Simplification: registerSubstitutes -> registerSubstitute. We no
longer need the former since there we no longer have the
  substitutes-rev table (which triggered a O(n^2) cost in updating
  them).
2005-01-25 20:27:40 +00:00
Eelco Dolstra
066da4ab85 * Really fix the substitute mechanism, i.e., ensure the closure
invariant by registering references through the manifest.
* Added a test for nix-pull.
2005-01-25 17:08:52 +00:00
Eelco Dolstra
52bf9b86bb * In nix-store: added query `--referers-closure' that returns the
closure of the referers relation rather than the references
  relation, i.e., the set of all paths that directly or indirectly
  refer to the given path.  Note that contrary to the references
  closure this set is not fixed; it can change as paths are added to
  or removed from the store.
2005-01-25 11:18:03 +00:00
Eelco Dolstra
80faa2f98a * In nix-store: change --build' back to --realise'. Also brought
back the query flag `--force-realise'.
* Fixed some of the tests.
2005-01-25 10:55:33 +00:00
Eelco Dolstra
e0f4e587c3 * Nix-store queries --references' and referers' to query the pointer
graph.  That is, `nix-store --query --references PATH' shows the set
  of paths referenced by PATH, and `nix-store --query --referers PATH'
  shows the set of paths referencing PATH.
2005-01-19 16:59:56 +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
ef5f254a55 * `nix-store --build' now builds its arguments in parallel instead of
sequentially (within the limits set by `--jobs').  This should
  greatly improve the utilisation of the build farm when doing Nixpkgs
  builds.
2005-01-19 15:02:02 +00:00
Eelco Dolstra
06c77bf7a8 * Change extension .store' to .drv'.
* Re-enable `nix-store --query --requisites'.
2005-01-19 14:36:00 +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
fa9259f5f5 * Simplify the substitute mechanism:
- Drop the store expression.  So now a substitute is just a
    command-line invocation (a program name + arguments).  If you
    register a substitute you are responsible for registering the
    expression that built it (if any) as a root of the garbage
    collector.
  - Drop the substitutes-rev DB table.
2004-12-20 13:43:32 +00:00
Eelco Dolstra
dcc433de47 * Operation `--delete-generations' to delete generations of a
profile.  Arguments are either generation number, or `old' to delete
  all non-current generations.  Typical use:

  $ nix-env --delete-generations old
  $ nix-collect-garbage

* istringstream -> string2Int.
2004-09-10 13:32:08 +00:00
Eelco Dolstra
5c443b6550 * Main the `substitutes-rev' table again, but now in a way that
doesn't take \Theta(n^2) space/time complexity.
2004-08-31 16:13:10 +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
fdec72c6cc * `nix-collect-garbage' now actually performs a garbage collection, it
doesn't just print the set of paths that should be deleted.  So
  there is no more need to pipe the result into `nix-store --delete'
  (which doesn't even exist anymore).
2004-08-25 15:39:13 +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
Eelco Dolstra
91dc023665 * Added a switch `--fallback'. From the manual:
Whenever Nix attempts to realise a derivation for which a closure is
  already known, but this closure cannot be realised, fall back on
  normalising the derivation.

  The most common scenario in which this is useful is when we have
  registered substitutes in order to perform binary distribution from,
  say, a network repository.  If the repository is down, the
  realisation of the derivation will fail.  When this option is
  specified, Nix will build the derivation instead.  Thus, binary
  installation falls back on a source installation.  This option is
  not the default since it is generally not desirable for a transient
  failure in obtaining the substitutes to lead to a full build from
  source (with the related consumption of resources).
2004-06-28 10:42:57 +00:00
Eelco Dolstra
2db9748221 * Remove debug output. 2004-06-21 10:01:17 +00:00
Eelco Dolstra
daf0a923c7 * Wrap calls to registerSubstitute() in a single transaction to
improve throughput.
* Don't build the `substitute-rev' table for now, since it caused
  Theta(N^2) time and log file consumption when adding N substitutes.
  Maybe we can do without it.
2004-06-21 07:38:17 +00:00
Eelco Dolstra
112ee89501 * Re-enable support for substitutes in the normaliser.
* A better substitute mechanism.

  Instead of generating a store expression for each store path for
  which we have a substitute, we can have a single store expression
  that builds a generic program that is invoked to build the desired
  store path, which is passed as an argument.

  This means that operations like `nix-pull' only produce O(1) files
  instead of O(N) files in the store when registering N substitutes.
  (It consumes O(N) database storage, of course, but that's not a
  performance problem).

* Added a test for the substitute mechanism.
  
* `nix-store --substitute' reads the substitutes from standard input,
  instead of from the command line.  This prevents us from running
  into the kernel's limit on command line length.
2004-06-20 19:17:54 +00:00
Eelco Dolstra
76c0e85929 * The environment variable NIX_ROOT can now be set to execute Nix in a
chroot() environment.
* A operation `--validpath' to register path validity.  Useful for
  bootstrapping in a pure Nix environment.
* Safety checks: ensure that files involved in store operations are in
  the store.
2004-02-14 21:44:18 +00:00
Eelco Dolstra
46a71c857c * Option --force-realise' in nix-store --query'. 2004-01-09 14:18:28 +00:00
Eelco Dolstra
078e20885e * Help text for all (non-script) programs, so no more:
$ nix-instantiate --help
error: unknown flag `--help`
Try `nix-instantiate --help' for more information.

:-)
2003-12-01 15:55:05 +00:00
Eelco Dolstra
9898746ef3 * nix-env: a tool to manage user environments.
* Replace all directory reading code by a generic readDirectory()
  function.
2003-11-19 17:27:16 +00:00
Eelco Dolstra
dfc9c64ead * "Fix expression" -> "Nix expression".
* More refactoring.
2003-11-18 12:06:07 +00:00
Renamed from src/nix-store/nix.cc (Browse further)