Commit graph

2963 commits

Author SHA1 Message Date
Eelco Dolstra 767101824a Avoid concatenating lists of one string 2012-08-13 15:10:29 -04:00
Eelco Dolstra e5c589d271 Don't allocate empty lists
This saves about 4 MB when evaluating a NixOS system configuration.
2012-08-13 15:02:09 -04:00
Eelco Dolstra 3e89ef597c Optimise concatenating a list to an empty list
More precisely, in concatLists, if all lists except one are empty,
then just return the non-empty list.  This reduces the number of list
element allocations by 32% when evaluating a NixOS system
configuration.
2012-08-13 14:58:54 -04:00
Eelco Dolstra 9c2d63084b Add a primop ‘elemAt’ to get an element from a list 2012-08-13 13:46:42 -04:00
Eelco Dolstra 198d0338be Add a primop ‘concatLists’
This can serve as a generic efficient list builder.  For instance, the
function ‘catAttrs’ in Nixpkgs can be rewritten from

  attr: l: fold (s: l: if hasAttr attr s then [(getAttr attr s)] ++ l else l) [] l

to

  attr: l: builtins.concatLists (map (s: if hasAttr attr s then [(getAttr attr s)] else []) l)

Statistics before:

  time elapsed: 1.08683
  size of a value: 24
  environments allocated: 1384376 (35809568 bytes)
  list elements: 6946783 (55574264 bytes)
  list concatenations: 37434
  values allocated: 1760440 (42250560 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18273
  number of thunks: 1297673
  number of thunks avoided: 1380759
  number of attr lookups: 430802
  number of primop calls: 628912
  number of function calls: 1333544

Statistics after (including new catAttrs):

  time elapsed: 0.959854
  size of a value: 24
  environments allocated: 1010198 (26829296 bytes)
  list elements: 1984878 (15879024 bytes)
  list concatenations: 30488
  values allocated: 1589760 (38154240 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18274
  number of thunks: 1040925
  number of thunks avoided: 1038428
  number of attr lookups: 438419
  number of primop calls: 474844
  number of function calls: 959366
2012-08-13 01:53:10 -04:00
Eelco Dolstra b9e5b908ed Provide an efficient implementation of ‘elem’
The one in Nixpkgs is O(n^2), this one is O(n).  Big reduction in the
number of list allocations.

Statistics before (on a NixOS system config):

  time elapsed: 1.17982
  size of a value: 24
  environments allocated: 1543334 (39624560 bytes)
  list elements: 9612638 (76901104 bytes)
  list concatenations: 37434
  values allocated: 1854933 (44518392 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18272
  number of thunks: 1392467
  number of thunks avoided: 1507311
  number of attr lookups: 430801
  number of primop calls: 691600
  number of function calls: 1492502

Statistics after:

  time elapsed: 1.08683
  size of a value: 24
  environments allocated: 1384376 (35809568 bytes)
  list elements: 6946783 (55574264 bytes)
  list concatenations: 37434
  values allocated: 1760440 (42250560 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18273
  number of thunks: 1297673
  number of thunks avoided: 1380759
  number of attr lookups: 430802
  number of primop calls: 628912
  number of function calls: 1333544
2012-08-13 01:05:35 -04:00
Eelco Dolstra 4ccd48ce24 Add a "filter" primop
Evaluation of a NixOS configuration spends quite a lot of time in the
"filter" function in Nixpkgs.  As implemented in Nixpkgs, this is a
O(n^2) operation, so it's a good candidate for providing a more
efficient (i.e. primop) implementation.  Using it gives a ~10% speed
increase and a significant reduction in the number of evaluations.

Statistics before (on a NixOS system config):

  time elapsed: 1.3258
  size of a value: 24
  environments allocated: 1980939 (50127080 bytes)
  list elements: 14679308 (117434464 bytes)
  list concatenations: 50828
  values allocated: 2098938 (50374512 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18271
  number of thunks: 1645752
  number of thunks avoided: 1921196
  number of attr lookups: 430798
  number of primop calls: 838807
  number of function calls: 1930107

Statistics after:

  time elapsed: 1.17982
  size of a value: 24
  environments allocated: 1543334 (39624560 bytes)
  list elements: 9612638 (76901104 bytes)
  list concatenations: 37434
  values allocated: 1854933 (44518392 bytes)
  attribute sets allocated: 392040
  right-biased unions: 186334
  values copied in right-biased unions: 591137
  symbols in symbol table: 18272
  number of thunks: 1392467
  number of thunks avoided: 1507311
  number of attr lookups: 430801
  number of primop calls: 691600
  number of function calls: 1492502
2012-08-13 00:28:08 -04:00
Eelco Dolstra 62f72eb9e1 Add some more evaluations stats 2012-08-12 23:41:48 -04:00
Eelco Dolstra e82767910c Add some basic profiling support to the evaluator
Setting the environment variable NIX_COUNT_CALLS to 1 enables some
basic profiling in the evaluator.  It will count calls to functions
and primops as well as evaluations of attributes.

For example, to see where evaluation of a NixOS configuration spends
its time:

$ NIX_SHOW_STATS=1 NIX_COUNT_CALLS=1 ./src/nix-instantiate/nix-instantiate '<nixos>' -A system --readonly-mode
...
calls to 39 primops:
    239532 head
    233962 tail
    191252 hasAttr
...
calls to 1595 functions:
    224157 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:19'
    221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:14'
    221767 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/lists.nix:17:10'
...
evaluations of 7088 attributes:
    167377 undefined position
    132459 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:119:41'
     47322 `/nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs/pkgs/lib/attrsets.nix:13:21'
...
2012-08-12 23:29:28 -04:00
Eelco Dolstra 325d1cfebf Don't warn about maximum link count exceeded on 0-byte files 2012-08-07 16:22:54 -04:00
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 b6c989b801 Fix race condition when two processes create a hard link to a file in .links
This is a problem because one process may set the immutable bit before
the second process has created its link.

Addressed random Hydra failures such as:

error: cannot rename `/nix/store/.tmp-link-17397-1804289383' to
`/nix/store/rsvzm574rlfip3830ac7kmaa028bzl6h-nixos-0.1pre-git/upstart-interface-version':
Operation not permitted
2012-08-05 21:41:44 -04:00
Eelco Dolstra 108e14bb18 Fix race condition when two processes create the same link in /nix/store/.links 2012-08-05 18:17:55 -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 9c2decaa19 Merge branch 'master' into no-manifests 2012-08-01 18:03:49 -04:00
Eelco Dolstra 5170c5691a nix-channel: Use binary caches advertised by channels
Channels can now advertise a binary cache by creating a file
<channel-url>/binary-cache-url.  The channel unpacker puts these in
its "binary-caches" subdirectory.  Thus, the URLS of the binary caches
for the channels added by root appear in
/nix/var/nix/profiles/per-user/eelco/channels/binary-caches/*.  The
binary cache substituter reads these and adds them to the list of
binary caches.
2012-08-01 17:56:11 -04:00
Eelco Dolstra 79bba3782c Doh 2012-08-01 17:21:47 -04:00
Eelco Dolstra ca94b38371 nix-env: Ignore manifest.nix when recursing into ~/.nix-defexpr
Channels are implemented using a profile now, and profiles contain a
manifest.nix file.  This should be ignored to prevent bogus packages
from showing up in nix-env.
2012-08-01 17:17:07 -04:00
Eelco Dolstra 46f852cda0 Use a GNU tar flag to shut up warnings about implausibly old timestamp 2012-08-01 16:42:51 -04:00
Eelco Dolstra afa7e01878 Inline unpack-channel.sh 2012-08-01 16:34:17 -04:00
Eelco Dolstra 234ce610e0 Doh 2012-08-01 16:09:47 -04:00
Eelco Dolstra 7b10562370 Make ‘nix-store --optimise’ interruptible 2012-08-01 16:06:49 -04:00
Eelco Dolstra 8a25d787d7 download-from-binary-cache: Remove duplicate URLs 2012-08-01 11:33:15 -04:00
Eelco Dolstra c770a2422a Report substituter errors to clients of the Nix daemon 2012-08-01 11:19:24 -04:00
Eelco Dolstra 4d1b64f118 Allow daemon users to override ‘binary-caches’
For security reasons, daemon users can only specify caches that appear
in the ‘binary-caches’ and ‘trusted-binary-caches’ options in
nix.conf.
2012-07-31 18:56:22 -04:00
Eelco Dolstra eb7849e3a2 Prevent an injection attack in passing untrusted options to substituters 2012-07-31 18:50:32 -04:00
Eelco Dolstra 90d9c58d4d Pass all --option flags to the daemon 2012-07-31 18:19:44 -04:00
Eelco Dolstra 89a8207029 Add an option ‘build-fallback’ (equivalent to the --fallback flag) 2012-07-31 17:56:02 -04:00
Eelco Dolstra 157170059d Manual: Remove reference to non-existent -I option 2012-07-30 22:29:42 -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 d50d7a2874 Whitespace 2012-07-30 17:13:25 -04:00
Eelco Dolstra 9cd63d2244 Do some validation of URLs 2012-07-30 17:09:36 -04:00
Eelco Dolstra f3eb29c653 Fix the test 2012-07-30 17:09:13 -04:00
Eelco Dolstra 9de6d10d11 Get rid of $NIX_BINARY_CACHES
You can use ‘--option binary-caches URLs’ instead.
2012-07-30 16:39:31 -04:00
Eelco Dolstra ab42bf1dab nix-install-package: Support binary caches
The .nixpkg file format is extended to optionally include the URL of a
binary cache, which will be used in preference to the manifest URL
(which can be set to a non-existent value).
2012-07-30 16:11:02 -04:00
Eelco Dolstra d059bf48e4 Pass configuration settings to the substituters
Previously substituters could read nix.conf themselves, but this
didn't take --option flags into account.
2012-07-30 16:09:54 -04:00
Eelco Dolstra f9613da180 Remove unused variables 2012-07-30 15:43:37 -04:00
Eelco Dolstra 6183cf2f19 Fix whitespace 2012-07-30 15:42:18 -04:00
Eelco Dolstra f15083c10a Document the --option flag
Pointed out by Daniel Santa Cruz on IRC.
2012-07-29 14:37:40 -04:00
Eelco Dolstra 66a3ac6a56 Allow a binary cache to declare that it doesn't support "nix-env -qas"
Querying all substitutable paths via "nix-env -qas" is potentially
hard on a server, since it involves sending thousands of HEAD
requests.  So a binary cache must now have a meta-info file named
"nix-cache-info" that specifies whether the server wants this.  It
also specifies the store prefix so that we don't send useless queries
to a binary cache for a different store prefix.
2012-07-27 18:16:05 -04:00
Eelco Dolstra 6ecf4f13f6 Use "set -x" in the tests to see where a test fails 2012-07-27 14:33:01 -04:00
Eelco Dolstra e6ab52cdd1 Test "nix-env -qas" with the binary cache substituter 2012-07-27 14:15:03 -04:00
Eelco Dolstra 73acb8b836 Let build.cc verify the expected hash of a substituter's output
Since SubstitutionGoal::finished() in build.cc computes the hash
anyway, we can prevent the inefficiency of computing the hash twice by
letting the substituter tell Nix about the expected hash, which can
then verify it.
2012-07-27 12:16:02 -04:00
Eelco Dolstra fbf59d95f6 Remove more tabs 2012-07-27 10:56:33 -04:00
Eelco Dolstra 3a8f841612 download-using-manifests: Don't use nix-prefetch-url
Instead call curl directly and pipe it into ‘nix-store --restore’.
This saves I/O and prevents creating garbage in the Nix store.
2012-07-27 10:47:36 -04:00
Eelco Dolstra b4ea83249b Remove trailing whitespace / tabs 2012-07-27 09:59:18 -04:00
Eelco Dolstra 7f8e805c8e download-from-binary-cache: Only use the default cache for /nix/store 2012-07-27 09:57:42 -04:00