Commit graph

80 commits

Author SHA1 Message Date
Eelco Dolstra f9613da180 Remove unused variables 2012-07-30 15:43:37 -04:00
Eelco Dolstra 8c79100839 Merge branch 'master' into no-manifests 2012-07-26 15:14:33 -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 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 b7fd2c2822 Use "#pragma once" to prevent repeated header file inclusion 2012-07-18 14:59:03 -04:00
Eelco Dolstra fe241ece29 Merge branch 'master' into no-manifests 2012-07-18 10:47:59 -04:00
Eelco Dolstra ccc52adfb2 Add function queryPathFromHashPart()
To implement binary caches efficiently, Hydra needs to be able to map
the hash part of a store path (e.g. "gbg...zr7") to the full store
path (e.g. "/nix/store/gbg...kzr7-subversion-1.7.5").  (The binary
cache mechanism uses hash parts as a key for looking up store paths to
ensure privacy.)  However, doing a search in the Nix store for
/nix/store/<hash>* is expensive since it requires reading the entire
directory.  queryPathFromHashPart() prevents this by doing a cheap
database lookup.
2012-07-17 18:55:39 -04:00
Eelco Dolstra 09a6321aeb Replace hasSubstitutes() with querySubstitutablePaths()
querySubstitutablePaths() takes a set of paths, so this greatly
reduces daemon <-> client latency.
2012-07-11 17:52:18 -04:00
Eelco Dolstra 58ef4d9a95 Add a function queryValidPaths()
queryValidPaths() combines multiple calls to isValidPath() in one.
This matters when using the Nix daemon because it reduces latency.
For instance, on "nix-env -qas \*" it reduces execution time from 5.7s
to 4.7s (which is indistinguishable from the non-daemon case).
2012-07-11 11:08:47 -04:00
Eelco Dolstra 667d5f1936 Rename queryValidPaths() to queryAllValidPaths() 2012-07-11 10:49:04 -04:00
Eelco Dolstra eb3036da87 Implement querySubstitutablePathInfos() in the daemon
Also removed querySubstitutablePathInfo().
2012-07-11 10:43:24 -04:00
Eelco Dolstra 11800e6198 download-from-binary-cache: parallelise fetching of NAR info files
Getting substitute information using the binary cache substituter has
non-trivial latency overhead.  A package or NixOS system configuration
can have hundreds of dependencies, and in the worst case (when the
local info cache is empty) we have to do a separate HTTP request for
each of these.  If the ping time to the server is t, getting N info
files will take tN seconds; e.g., with a ping time of 0.1s to
nixos.org, sequentially downloading 1000 info files (a typical NixOS
config) will take at least 100 seconds.

To fix this problem, the binary cache substituter can now perform
requests in parallel.  This required changing the substituter
interface to support a function querySubstitutablePathInfos() that
queries multiple paths at the same time, and rewriting queryMissing()
to take advantage of parallelism.  (Due to local caching,
parallelising queryMissing() is sufficient for most use cases, since
it's almost always called before building a derivation and thus fills
the local info cache.)

For example, parallelism speeds up querying all 1056 paths in a
particular NixOS system configuration from 116s to 2.6s.  It works so
well because the eccentricity of the top-level derivation in the
dependency graph is only 9.  So we only need 10 round-trips (when
using an unlimited number of parallel connections) to get everything.

Currently we do a maximum of 150 parallel connections to the server.
Thus it's important that the binary cache server (e.g. nixos.org) has
a high connection limit.  Alternatively we could use HTTP pipelining,
but WWW::Curl doesn't support it and libcurl has a hard-coded limit of
5 requests per pipeline.
2012-07-06 19:08:20 -04:00
Eelco Dolstra 1aba0bf0fa nix-store -r: do substitutions in parallel
I.e. when multiple non-derivation arguments are passed to ‘nix-store
-r’ to be substituted, do them in parallel.
2012-06-27 16:58:15 -04:00
Eelco Dolstra 4bc4da331a Reserve some disk space for the garbage collector
We can't open a SQLite database if the disk is full.  Since this
prevents the garbage collector from running when it's most needed, we
reserve some dummy space that we can free just before doing a garbage
collection.  This actually revives some old code from the Berkeley DB
days.

Fixes #27.
2012-05-29 22:59:12 -04:00
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 194d21f9f6 * Sync with the trunk. 2011-12-16 23:33:01 +00:00
Eelco Dolstra 273b288a7e * importPath() -> importPaths(). Because of buffering of the input
stream it's now necessary for the daemon to process the entire
  sequence of exported paths, rather than letting the client do it.
2011-12-16 22:31:25 +00:00
Shea Levy af2e53fd48 Include all outputs of derivations in the closure of explicitly-passed derivation paths
This required adding a queryOutputDerivationNames function in the store API
2011-11-06 06:28:20 +00:00
Eelco Dolstra 13114daa3e * Ouch. A store upgrade could cause a substituter to be triggered,
causing a deadlock.
2011-09-12 09:07:43 +00:00
Eelco Dolstra b2027f70d9 * Fix a huuuuge security hole in the Nix daemon. It didn't check that
derivations added to the store by clients have "correct" output
  paths (meaning that the output paths are computed by hashing the
  derivation according to a certain algorithm).  This means that a
  malicious user could craft a special .drv file to build *any*
  desired path in the store with any desired contents (so long as the
  path doesn't already exist).  Then the attacker just needs to wait
  for a victim to come along and install the compromised path.

  For instance, if Alice (the attacker) knows that the latest Firefox
  derivation in Nixpkgs produces the path

    /nix/store/1a5nyfd4ajxbyy97r1fslhgrv70gj8a7-firefox-5.0.1

  then (provided this path doesn't already exist) she can craft a .drv
  file that creates that path (i.e., has it as one of its outputs),
  add it to the store using "nix-store --add", and build it with
  "nix-store -r".  So the fake .drv could write a Trojan to the
  Firefox path.  Then, if user Bob (the victim) comes along and does

    $ nix-env -i firefox
    $ firefox

  he executes the Trojan injected by Alice.

  The fix is to have the Nix daemon verify that derivation outputs are
  correct (in addValidPath()).  This required some refactoring to move
  the hash computation code to libstore.
2011-07-20 18:10:47 +00:00
Eelco Dolstra 8062d3af30 * `nix-store --verify --check-contents': don't hold the global GC lock
while checking the contents, since this operation can take a very
  long time to finish.  Also, fill in missing narSize fields in the DB
  while doing this.
2010-12-06 15:29:38 +00:00
Eelco Dolstra e60c962fb8 * Add an operation `nix-store -q --size'. 2010-11-17 12:40:52 +00:00
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 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 3e5e0faf9c * Okay, putting a lock on the temporary directory used by importPath()
doesn't work because the garbage collector doesn't actually look at
  locks.  So r22253 was stupid.  Use addTempRoot() instead.  Also,
  locking the temporary directory in exportPath() was silly because it
  isn't even in the store.
2010-06-21 11:08:09 +00:00
Eelco Dolstra f92c9a0ac5 * Allow unprivileged users to do `nix-store --clear-failed-paths' and
`nix-store --query-failed-paths'.
2010-05-04 10:45:10 +00:00
Eelco Dolstra 6199f9b93e * Added a command `nix-store --clear-failed-paths <PATHS>' to clear
the "failed" status of the given store paths.  The special value `*'
  clears all failed paths.
2010-04-26 12:56:42 +00:00
Eelco Dolstra 2398af13c5 * Add an command `nix-store --query-failed-paths' to list the cached
failed paths (when using the `build-cache-failure' option).
2010-04-26 12:43:42 +00:00
Eelco Dolstra e33f67ff0b * Refactor the upgrade / database initialisation logic a bit. 2010-02-24 16:30:20 +00:00
Eelco Dolstra cfe742cfc5 * A function to query just the database id of a valid path. 2010-02-24 15:07:23 +00:00
Eelco Dolstra a3c63d0d6c * Disable fsync() in SQLite if the fsync-metadata option is set to
false.
* Change the default for `fsync-metadata' to true.
* Disable `fsync-metadata' in `make check'.
2010-02-24 13:12:57 +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 299ff64812 * Put the derivation outputs in the database. This is useful for the
garbage collector.
2010-02-22 11:15:50 +00:00
Eelco Dolstra 1930570ad9 * Foreign key support in SQLite is not a persistent setting, so enable
it at startup.
* Implement negative caching.  Now `make check' passes.
2010-02-19 17:15:22 +00:00
Eelco Dolstra 9c9a88e9e2 * Implement more stuff. 2010-02-19 16:43:25 +00:00
Eelco Dolstra 762cee72cc * Implement registerValidPath(). 2010-02-19 16:04:51 +00:00
Eelco Dolstra 836e5b6f57 * Implemented queryReferrers(). 2010-02-18 16:21:59 +00:00
Eelco Dolstra 77cb9e3fb1 * Implement queryPathInfo(). 2010-02-18 15:52:57 +00:00
Eelco Dolstra 885e22b16e * Implement isValidPath(). 2010-02-18 15:11:08 +00:00
Eelco Dolstra e0305bb7a8 * Some wrapper objects to ensure that SQLite objects are properly
destroyed.
2010-02-18 14:30:42 +00:00
Eelco Dolstra c1a07f9445 * Convert the Nix database to SQLite. 2010-02-18 13:16:59 +00:00
Eelco Dolstra 07ffdc2862 * Added an option "fsync-metadata" to fsync() changes to
/nix/var/nix/db.
* Removed the function writeStringToFile since it does (almost) the
  same thing as writeFile.
2010-01-29 12:22:58 +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 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 6b9f6b0222 * Remove a prototype for a function that no longer exists. 2009-10-22 08:12:38 +00:00
Eelco Dolstra 14bc3ce3d6 * Canonicalise timestamps in the Nix store to 1 (1970-01-01 00:00:01
UTC) rather than 0 (00:00:00).  1 is a better choice because some
  programs use 0 as a special value.  For instance, the Template
  Toolkit uses a timestamp of 0 to denote the non-existence of a file,
  so it barfs on files in the Nix store (see
  template-toolkit-nix-store.patch in Nixpkgs).  Similarly, Maya 2008
  fails to load script directories with a timestamp of 0 and can't be
  patched because it's closed source.

  This will also shut up those "implausibly old time stamp" GNU tar
  warnings.
2009-06-13 16:30:58 +00:00
Eelco Dolstra c7152c8f97 * Don't use the non-standard __gnu_cxx::stdio_filebuf class. 2009-03-28 19:41:53 +00:00
Eelco Dolstra 92f525ecf4 * Negative caching, i.e. caching of build failures. Disabled by
default.  This is mostly useful for Hydra.
2009-03-25 21:05:42 +00:00