Commit graph

220 commits

Author SHA1 Message Date
Guillaume Maudoux 43331d6344 detail memory roots 2019-03-10 00:56:09 +01:00
Daiderd Jordan 070823baa4
Store: expose the protocol version used by a store 2018-09-02 12:54:29 +02:00
Eelco Dolstra 81ea8bd5ce
Simplify the callback mechanism 2018-05-30 13:34:37 +02:00
Eelco Dolstra d34fa2bcc3
Fix #1921 2018-04-13 15:42:35 +02:00
Eelco Dolstra 48662d151b
Reduce substitution memory consumption
copyStorePath() now pipes the output of srcStore->narFromPath()
directly into dstStore->addToStore(). The sink used by the former is
converted into a source usable by the latter using
boost::coroutine2. This is based on [1].

This reduces the maximum resident size of

  $ nix build --store ~/my-nix/ /nix/store/b0zlxla7dmy1iwc3g459rjznx59797xy-binutils-2.28.1 --substituters file:///tmp/binary-cache-xz/ --no-require-sigs

from 418592 KiB to 53416 KiB. (The previous commit also reduced the
runtime from ~4.2s to ~3.4s, not sure why.) A further improvement will
be to download files into a Sink.

[1] https://github.com/NixOS/nix/compare/master...Mathnerd314:dump-fix-coroutine#diff-dcbcac55a634031f9cc73707da6e4b18

Issue #1969.
2018-03-16 20:35:59 +01:00
Eelco Dolstra 9bcb4d2dd9 Fix hang in build-remote 2018-02-12 22:48:55 +01:00
Eelco Dolstra c287d73121
Rename 1.12 -> 2.0
Following discussion with Shea and Graham. It's a big enough change
from the last release. Also, from a semver perspective, 2.0 makes more
sense because we did remove some interfaces (like nix-pull/nix-push).
2018-01-31 18:58:45 +01:00
Eelco Dolstra 91a1987607
signed-binary-caches -> require-sigs
Unlike signed-binary-caches (which could only be '*' or ''),
require-sigs is a proper Boolean option. The default is true.
2017-11-20 17:44:07 +01:00
Eelco Dolstra 308ecf6361
Show the pid of temporary roots 2017-09-14 15:02:52 +02:00
Eelco Dolstra da1e4fdfb5
nix-store -q --roots / --gc --print-roots: Print temporary / in-memory roots
For example,

  $ nix-store -q --roots /nix/store/7phd2sav7068nivgvmj2vpm3v47fd27l-patchelf-0.8pre845_0315148
  {temp:1}

denotes that the path is only being kept alive by a temporary root
(i.e. /nix/var/nix/temproots/). Similarly,

  $ nix-store --gc --print-roots
  ...
  {memory:9} -> /nix/store/094gpjn9f15ip17wzxhma4r51nvsj17p-curl-7.53.1

shows that curl is being used by some process.
2017-09-14 14:38:36 +02:00
Eelco Dolstra 0b606aad46
Add automatic garbage collection
Nix can now automatically run the garbage collector during builds or
while adding paths to the store. The option "min-free = <bytes>"
specifies that Nix should run the garbage collector whenever free
space in the Nix store drops below <bytes>. It will then delete
garbage until "max-free" bytes are available.

Garbage collection during builds is asynchronous; running builds are
not paused and new builds are not blocked. However, there also is a
synchronous GC run prior to the first build/substitution.

Currently, no old GC roots are deleted (as in "nix-collect-garbage
-d").
2017-09-05 20:43:42 +02:00
Eelco Dolstra b932ea58ec
GC: Don't delete own temproots file
Since file locks are per-process rather than per-file-descriptor, the
garbage collector would always acquire a lock on its own temproots
file and conclude that it's stale.
2017-09-05 20:39:57 +02:00
Eelco Dolstra b4ed97e3a3
nix optimise-store: Show how much space has been freed 2017-08-16 20:56:03 +02:00
Eelco Dolstra fcca702a96
Replace a few bool flags with enums
Functions like copyClosure() had 3 bool arguments, which creates a
severe risk of mixing up arguments.

Also, implement copyClosure() using copyPaths().
2017-07-03 11:38:08 +02:00
Eelco Dolstra 1860070548
Merge branch 'rework-options' of https://github.com/copumpkin/nix 2017-04-13 16:15:51 +02:00
Eelco Dolstra 2040240e23
Add a Config class to simplify adding configuration settings
The typical use is to inherit Config and add Setting<T> members:

  class MyClass : private Config
  {
    Setting<int> foo{this, 123, "foo", "the number of foos to use"};
    Setting<std::string> bar{this, "blabla", "bar", "the name of the bar"};

    MyClass() : Config(readConfigFile("/etc/my-app.conf"))
    {
      std::cout << foo << "\n"; // will print 123 unless overriden
    }
  };

Currently, this is used by Store and its subclasses for store
parameters. You now get a warning if you specify a non-existant store
parameter in a store URI.
2017-04-13 16:03:31 +02:00
Eelco Dolstra 105f8ffc98
Minor cleanup
Also, possible fix for #1310 on 32-bit systems.
2017-04-10 11:27:33 +02:00
Eelco Dolstra c5b83d8913
copyPaths(): Use queryValidPaths() to reduce SSH latency 2017-03-16 13:50:01 +01:00
Eelco Dolstra 0afeb7f51e
Store: Add a method for getting build logs
This allows various Store implementations to provide different ways to
get build logs. For example, BinaryCacheStore can get the build logs
from the binary cache.

Also, remove the log-servers option since we can use substituters for
this.
2017-03-15 16:48:29 +01:00
Eelco Dolstra 215b70f51e
Revert "Get rid of unicode quotes (#1140)"
This reverts commit f78126bfd6. There
really is no need for such a massive change...
2016-11-26 00:38:01 +01:00
Guillaume Maudoux f78126bfd6 Get rid of unicode quotes (#1140) 2016-11-25 15:48:27 +01:00
Eelco Dolstra fdbbcc4492 Remove addPathToAccessor 2016-10-21 18:09:30 +02:00
Eelco Dolstra 542ae5c8f8 BinaryCacheStore: Optionally write a NAR listing
The store parameter "write-nar-listing=1" will cause BinaryCacheStore
to write a file ‘<store-hash>.ls.xz’ for each ‘<store-hash>.narinfo’
added to the binary cache. This file contains an XZ-compressed JSON
file describing the contents of the NAR, excluding the contents of
regular files.

E.g.

  {
    "version": 1,
    "root": {
      "type": "directory",
      "entries": {
        "lib": {
          "type": "directory",
          "entries": {
            "Mcrt1.o": {
              "type": "regular",
              "size": 1288
            },
            "Scrt1.o": {
              "type": "regular",
              "size": 3920
            },
          }
        }
      }
      ...
    }
  }

(The actual file has no indentation.)

This is intended to speed up the NixOS channels programs index
generator [1], since fetching gazillions of large NARs from
cache.nixos.org is currently a bottleneck for updating the regular
(non-small) channel.

[1] https://github.com/NixOS/nixos-channel-scripts/blob/master/generate-programs-index.cc
2016-10-21 16:50:28 +02:00
Eelco Dolstra 75989bdca7 Make computeFSClosure() single-threaded again
The fact that queryPathInfo() is synchronous meant that we needed a
thread for every concurrent binary cache lookup, even though they end
up being handled by the same download thread. Requiring hundreds of
threads is not a good idea. So now there is an asynchronous version of
queryPathInfo() that takes a callback function to process the
result. Similarly, enqueueDownload() now takes a callback rather than
returning a future.

Thus, a command like

  nix path-info --store https://cache.nixos.org/ -r /nix/store/slljrzwmpygy1daay14kjszsr9xix063-nixos-16.09beta231.dccf8c5

that returns 4941 paths now takes 1.87s using only 2 threads (the main
thread and the downloader thread). (This is with a prewarmed
CloudFront.)
2016-09-16 18:54:14 +02:00
Eelco Dolstra d961c29c9c Mark content-addressed paths in the Nix database and in .narinfo
This allows such paths to be imported without signatures.
2016-08-10 18:05:35 +02:00
Eelco Dolstra d64e0c1b64 Make derivationFromPath work on diverted stores 2016-06-02 18:43:36 +02:00
Eelco Dolstra a24f2c9b84 nix run: Mount the Nix store in a private namespace
This is a convenience command to allow users who are not privileged to
create /nix/store to use Nix with regular binary caches. For example,

  $ NIX_REMOTE="local?state=$HOME/nix/var&real=/$HOME/nix/store" nix run firefox bashInteractive

will download Firefox and bash from cache.nixos.org, then start a
shell in which $HOME/nix/store is mounted on /nix/store.
2016-06-02 16:51:43 +02:00
Eelco Dolstra 4494000e04 LocalStore: Allow the physical and logical store directories to differ
This is primarily to subsume the functionality of the
copy-from-other-stores substituter. For example, in the NixOS
installer, we can now do (assuming we're in the target chroot, and the
Nix store of the installation CD is bind-mounted on /tmp/nix):

  $ nix-build ... --option substituters 'local?state=/tmp/nix/var&real=/tmp/nix/store'

However, unlike copy-from-other-stores, this also allows write access
to such a store. One application might be fetching substitutes for
/nix/store in a situation where the user doesn't have sufficient
privileges to create /nix, e.g.:

  $ NIX_REMOTE="local?state=/home/alice/nix/var&real=/home/alice/nix/store" nix-build ...
2016-06-02 16:02:48 +02:00
Eelco Dolstra 812c0dfbe2 Allow setting the state directory as a store parameter
E.g. "local?store=/tmp/store&state=/tmp/var".
2016-06-02 16:02:48 +02:00
Eelco Dolstra 7850d3d279 Make the store directory a member variable of Store 2016-06-01 16:24:17 +02:00
Eelco Dolstra c2d27d30cf nix-copy-closure / build-remote.pl: Disable signature checking
This restores the Nix 1.11 behaviour.
2016-05-31 11:48:05 +02:00
Eelco Dolstra 57d33013ce Check signatures before downloading the substitute 2016-05-30 15:18:12 +02:00
Eelco Dolstra 3593c8285d Re-implement binary cache signature checking
This is now done in LocalStore::addToStore(), rather than in the
binary cache substituter (which no longer exists).
2016-05-30 15:18:12 +02:00
Eelco Dolstra 538a64e8c3 Add a Store::addToStore() variant that accepts a NAR
As a side effect, this ensures that signatures are propagated when
copying paths between stores.

Also refactored import/export to make use of this.
2016-05-04 16:15:54 +02:00
Eelco Dolstra f435f82475 Remove OpenSSL-based signing 2016-05-04 11:01:48 +02:00
Eelco Dolstra 95d20dfde9 Allow parameters in store URIs
This is to allow store-specific configuration,
e.g. s3://my-cache?compression=bzip2&secret-key=/path/to/key.
2016-04-29 16:26:16 +02:00
Eelco Dolstra aa3bc3d5dc Eliminate the substituter mechanism
Substitution is now simply a Store -> Store copy operation, most
typically from BinaryCacheStore to LocalStore.
2016-04-29 13:57:08 +02:00
Eelco Dolstra e0204f8d46 Move path info caching from BinaryCacheStore to Store
Caching path info is generally useful. For instance, it speeds up "nix
path-info -rS /run/current-system" (i.e. showing the closure sizes of
all paths in the closure of the current system) from 5.6s to 0.15s.

This also eliminates some APIs like Store::queryDeriver() and
Store::queryReferences().
2016-04-19 18:52:53 +02:00
Eelco Dolstra 8cffec8485 Remove failed build caching
This feature was implemented for Hydra, but Hydra no longer uses it.
2016-04-08 18:19:04 +02:00
Eelco Dolstra f398949b40 Make LocalStore thread-safe
Necessary for multi-threaded commands like "nix verify-paths".
2016-04-08 18:07:13 +02:00
Eelco Dolstra e39999ed48 Sign locally-built paths
Locally-built paths are now signed automatically using the secret keys
specified by the ‘secret-key-files’ option.
2016-04-07 15:16:57 +02:00
Eelco Dolstra d0f5719c2a Add "nix copy-sigs" command
This imports signatures from one store into another. E.g.

  $ nix copy-sigs -r /run/current-system -s https://cache.nixos.org/
  imported 595 signatures
2016-04-05 16:39:23 +02:00
Eelco Dolstra 9cee600c88 LocalStore: Keep track of ultimately trusted paths
These are content-addressed paths or outputs of locally performed
builds. They are trusted even if they don't have signatures, so "nix
verify-paths" won't complain about them.
2016-03-30 17:35:48 +02:00
Eelco Dolstra 3d119f0a3b Improve the SQLite wrapper API
In particular, this eliminates a bunch of boilerplate code.
2016-03-30 15:50:45 +02:00
Eelco Dolstra d9c5e3bbf0 Factour out SQLite handling 2016-03-30 13:27:25 +02:00
Eelco Dolstra bcc9943cee importPaths(): Optionally add NARs to binary cache accessor
This enables an optimisation in hydra-queue-runner, preventing a
download of a NAR it just uploaded to the cache when reading files
like hydra-build-products.
2016-02-26 15:20:10 +01:00
Eelco Dolstra 1042c10fd0 Add NAR / Store accessor abstraction
This is primary to allow hydra-queue-runner to extract files like
"nix-support/hydra-build-products" from NARs in binary caches.
2016-02-25 17:43:19 +01:00
Eelco Dolstra 28e7e29abd Eliminate reserveSpace flag 2016-02-24 17:44:55 +01:00
Eelco Dolstra c8f4d89a34 Expose the export magic value and move LocalStore::queryReferences to Store 2016-02-15 15:01:26 +01:00
Eelco Dolstra fa7cd5369b StoreAPI -> Store
Calling a class an API is a bit redundant...
2016-02-04 14:48:42 +01:00
Eelco Dolstra c10c61449f Eliminate the "store" global variable
Also, move a few free-standing functions into StoreAPI and Derivation.

Also, introduce a non-nullable smart pointer, ref<T>, which is just a
wrapper around std::shared_ptr ensuring that the pointer is never
null. (For reference-counted values, this is better than passing a
"T&", because the latter doesn't maintain the refcount. Usually, the
caller will have a shared_ptr keeping the value alive, but that's not
always the case, e.g., when passing a reference to a std::thread via
std::bind.)
2016-02-04 14:28:26 +01:00
Eelco Dolstra 9e7c1a4bbd Use the daemon when we don't have write access to the Nix database 2016-01-31 10:28:48 +01:00
Eelco Dolstra 4ba6bc184c Shut up clang warnings 2015-09-18 01:22:35 +02:00
Eelco Dolstra 1511aa9f48 Allow remote builds without sending the derivation closure
Previously, to build a derivation remotely, we had to copy the entire
closure of the .drv file to the remote machine, even though we only
need the top-level derivation. This is very wasteful: the closure can
contain thousands of store paths, and in some Hydra use cases, include
source paths that are very large (e.g. Git/Mercurial checkouts).

So now there is a new operation, StoreAPI::buildDerivation(), that
performs a build from an in-memory representation of a derivation
(BasicDerivation) rather than from a on-disk .drv file. The only files
that need to be in the Nix store are the sources of the derivation
(drv.inputSrcs), and the needed output paths of the dependencies (as
described by drv.inputDrvs). "nix-store --serve" exposes this
interface.

Note that this is a privileged operation, because you can construct a
derivation that builds any store path whatsoever. Fixing this will
require changing the hashing scheme (i.e., the output paths should be
computed from the other fields in BasicDerivation, allowing them to be
verified without access to other derivations). However, this would be
quite nice because it would allow .drv-free building (e.g. "nix-env
-i" wouldn't have to write any .drv files to disk).

Fixes #173.
2015-07-17 17:57:40 +02:00
Eelco Dolstra 7ea6ecf855 addToStore(): Take explicit name argument 2015-03-25 17:06:12 +01:00
Eelco Dolstra 1256ab3b44 Clean up temp roots in a more C++ way 2014-11-19 17:07:29 +01:00
Ludovic Courtès 8fb8c26b6d Add an 'optimiseStore' remote procedure call. 2014-09-01 23:53:26 +02:00
Eelco Dolstra 54a34119f3 Use std::unordered_set 2014-05-26 17:53:17 +02:00
Eelco Dolstra 84813af5b9 nix-store --optimise: Remove bogus statistics 2014-05-15 11:33:46 +02:00
Wout Mertens 3b9ea8452f Shortcut store files before lstat
readdir() already returns the inode numbers, so we don't need to call
lstat to know if a file was already linked or not.
2014-05-15 09:02:22 +02:00
Wout Mertens d73ffc552f Use the inodes given by readdir directly 2014-05-14 22:52:10 +02:00
Wout Mertens e974f20c98 Preload linked hashes to speed up lookups
By preloading all inodes in the /nix/store/.links directory, we can
quickly determine of a hardlinked file was already linked to the hashed
links.
This is tolerant of removing the .links directory, it will simply
recalculate all hashes in the store.
2014-05-13 23:10:06 +02:00
Eelco Dolstra 1aa19b24b2 Add a flag ‘--check’ to verify build determinism
The flag ‘--check’ to ‘nix-store -r’ or ‘nix-build’ will cause Nix to
redo the build of a derivation whose output paths are already valid.
If the new output differs from the original output, an error is
printed.  This makes it easier to test if a build is deterministic.
(Obviously this cannot catch all sources of non-determinism, but it
catches the most common one, namely the current time.)

For example:

  $ nix-build '<nixpkgs>' -A patchelf
  ...
  $ nix-build '<nixpkgs>' -A patchelf --check
  error: derivation `/nix/store/1ipvxsdnbhl1rw6siz6x92s7sc8nwkkb-patchelf-0.6' may not be deterministic: hash mismatch in output `/nix/store/4pc1dmw5xkwmc6q3gdc9i5nbjl4dkjpp-patchelf-0.6.drv'

The --check build fails if not all outputs are valid.  Thus the first
call to nix-build is necessary to ensure that all outputs are valid.

The current outputs are left untouched: the new outputs are either put
in a chroot or diverted to a different location in the store using
hash rewriting.
2014-02-18 01:01:14 +01:00
Eelco Dolstra a478e8a7bb Remove nix-setuid-helper
AFAIK, nobody uses it, it's not maintained, and it has no tests.
2013-11-14 11:57:37 +01:00
Eelco Dolstra a737f51fd9 Retry all SQLite operations
To deal with SQLITE_PROTOCOL, we also need to retry read-only
operations.
2013-10-16 15:58:20 +02:00
Ivan Kozik 34bb806f74 Fix typos, especially those that end up in the Nix manual 2013-08-26 11:15:22 +02:00
Eelco Dolstra 22144afa8d Don't keep "disabled" substituters running
For instance, it's pointless to keep copy-from-other-stores running if
there are no other stores, or download-using-manifests if there are no
manifests.  This also speeds things up because we don't send queries
to those substituters.
2013-06-20 11:55:15 +02:00
Eelco Dolstra 1b6ee8f4c7 Allow hard links between the outputs of a derivation 2013-06-13 17:29:56 +02:00
Eelco Dolstra 5959c591a0 Process stderr from substituters while doing have/info queries 2013-06-07 15:02:14 +02:00
Eelco Dolstra c5f9d0d080 Buffer reads from the substituter
This greatly reduces the number of system calls.
2013-06-07 14:00:23 +02:00
Eelco Dolstra bdd4646338 Revert "Prevent config.h from being clobbered"
This reverts commit 28bba8c44f.
2013-03-08 01:24:59 +01:00
Eelco Dolstra 28bba8c44f Prevent config.h from being clobbered 2013-03-07 23:55:55 +01:00
Eelco Dolstra b008674e46 Refactoring: Split off the non-recursive canonicalisePathMetaData()
Also, change the file mode before changing the owner.  This prevents a
slight time window in which a setuid binary would be setuid root.
2013-02-27 16:42:19 +01:00
Eelco Dolstra 5526a282b5 Security: Don't allow builders to change permissions on files they don't own
It turns out that in multi-user Nix, a builder may be able to do

  ln /etc/shadow $out/foo

Afterwards, canonicalisePathMetaData() will be applied to $out/foo,
causing /etc/shadow's mode to be set to 444 (readable by everybody but
writable by nobody).  That's obviously Very Bad.

Fortunately, this fails in NixOS's default configuration because
/nix/store is a bind mount, so "ln" will fail with "Invalid
cross-device link".  It also fails if hard-link restrictions are
enabled, so a workaround is:

  echo 1 > /proc/sys/fs/protected_hardlinks

The solution is to check that all files in $out are owned by the build
user.  This means that innocuous operations like "ln
${pkgs.foo}/some-file $out/" are now rejected, but that already failed
in chroot builds anyway.
2013-02-26 02:30:19 +01:00
Eelco Dolstra def5160b61 Clear any immutable bits in the Nix store
Doing this once makes subsequent operations like garbage collecting
more efficient since we don't have to call makeMutable() first.
2013-01-03 12:59:23 +01:00
Eelco Dolstra 2754a07ead nix-store -q --roots: Respect the gc-keep-outputs/gc-keep-derivations settings
So if a path is not garbage solely because it's reachable from a root
due to the gc-keep-outputs or gc-keep-derivations settings, ‘nix-store
-q --roots’ now shows that root.
2012-12-20 18:41:44 +01:00
Eelco Dolstra 06f62defe6 Yet another rewrite of the garbage collector
But this time it's *obviously* correct!  No more segfaults due to
infinite recursions for sure, etc.

Also, move directories to /nix/store/trash instead of renaming them to
/nix/store/bla-gc-<pid>.  Then we can just delete /nix/store/trash at
the end.
2012-12-20 17:32:15 +01:00
Eelco Dolstra ea89df2b76 Use vfork() instead of fork() if available
Hopefully this reduces the chance of hitting ‘unable to fork: Cannot
allocate memory’ errors.  vfork() is used for everything except
starting builders.
2012-11-09 18:00:33 +01:00
Eelco Dolstra 0a7084567f Add a ‘--repair’ flag to nix-instantiate
This allows repairing corrupted derivations and other source files.
2012-10-03 15:09:18 -04:00
Eelco Dolstra a3f205b249 When repairing a derivation, check and repair the entire output closure
If we find a corrupted path in the output closure, we rebuild the
derivation that produced that particular path.
2012-10-03 10:38:09 -04:00
Eelco Dolstra 2001895f3d Add a --repair flag to ‘nix-store -r’ to repair derivation outputs
With this flag, if any valid derivation output is missing or corrupt,
it will be recreated by using a substitute if available, or by
rebuilding the derivation.  The latter may use hash rewriting if
chroots are not available.
2012-10-02 17:13:46 -04:00
Eelco Dolstra 8e3a7bd712 nix-store --verify: Add an option ‘--repair’ to repair all missing/corrupt paths
Also, return a non-zero exit code if errors remain after
verifying/repairing.
2012-10-02 15:12:56 -04:00
Eelco Dolstra 9958bd6992 Add operation ‘nix-store --repair-path’
This operation allows fixing corrupted or accidentally deleted store
paths by redownloading them using substituters, if available.

Since the corrupted path cannot be replaced atomically, there is a
very small time window (one system call) during which neither the old
(corrupted) nor the new (repaired) contents are available.  So
repairing should be used with some care on critical packages like
Glibc.
2012-10-02 14:08:59 -04:00
Eelco Dolstra b9124a5c33 Support having /nix/store as a read-only bind mount
It turns out that the immutable bit doesn't work all that well.  A
better way is to make the entire Nix store a read-only bind mount,
i.e. by doing

  $ mount --bind /nix/store /nix/store
  $ mount -o remount,ro,bind /nix/store

(This would typically done in an early boot script, before anything
from /nix/store is used.)

Since Nix needs to be able to write to the Nix store, it now detects
if /nix/store is a read-only bind mount and then makes it writable in
a private mount namespace.
2012-09-19 15:45:29 -04:00
Eelco Dolstra e6e495649c Vacuum the SQLite DB after running the garbage collector 2012-09-13 14:33:41 -04:00
Eelco Dolstra e94806d030 Merge branch 'master' into no-manifests 2012-08-27 11:09:07 -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 c770a2422a Report substituter errors to clients of the Nix daemon 2012-08-01 11:19:24 -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 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