Commit graph

1344 commits

Author SHA1 Message Date
pennae
8775be3393 store Symbols in a table as well, like positions
this slightly increases the amount of memory used for any given symbol, but this
increase is more than made up for if the symbol is referenced more than once in
the EvalState that holds it. on average every symbol should be referenced at
least twice (once to introduce a binding, once to use it), so we expect no
increase in memory on average.

symbol tables are limited to 2³² entries like position tables, and similar
arguments apply to why overflow is not likely: 2³² symbols would require as many
string instances (at 24 bytes each) and map entries (at 24 bytes or more each,
assuming that the map holds on average at most one item per bucket as the docs
say). a full symbol table would require at least 192GB of memory just for
symbols, which is well out of reach. (an ofborg eval of nixpks today creates
less than a million symbols!)
2022-04-21 21:56:31 +02:00
pennae
00a3280232 don't use Symbol in Pos to represent a path
PosTable deduplicates origin information, so using symbols for paths is no
longer necessary. moving away from path Symbols also reduces the usage of
symbols for things that are not keys in attribute sets, which will become
important in the future when we turn symbols into indices as well.
2022-04-21 21:46:10 +02:00
pennae
6526d1676b replace most Pos objects/ptrs with indexes into a position table
Pos objects are somewhat wasteful as they duplicate the origin file name and
input type for each object. on files that produce more than one Pos when parsed
this a sizeable waste of memory (one pointer per Pos). the same goes for
ptr<Pos> on 64 bit machines: parsing enough source to require 8 bytes to locate
a position would need at least 8GB of input and 64GB of expression memory. it's
not likely that we'll hit that any time soon, so we can use a uint32_t index to
locate positions instead.
2022-04-21 21:46:06 +02:00
Eelco Dolstra
3b9d31b88c Rename fmt test -> hilte 2022-04-21 13:00:50 +02:00
Eelco Dolstra
f1eee873ea Fix fmt test 2022-04-21 13:00:24 +02:00
Eelco Dolstra
f05e1f6fbb Move hiliteMatches into a separate header
This is mostly so that we don't #include <regex> everywhere (which
adds quite a bit of compilation time).
2022-04-21 12:06:29 +02:00
Théophane Hufschmitt
9345b4e9ca
Merge pull request #3720 from obsidiansystems/fix-url-format
Avoid `fmt` when constructor already does it
2022-04-20 20:01:37 +02:00
John Ericson
3c220442ff Merge remote-tracking branch 'upstream/master' into fix-url-format 2022-04-20 16:53:16 +00:00
Yorick van Pelt
ebf2fd76b1
Add custom to_json and from_json functions for ExperimentalFeature
nix show-config --json was serializing experimental features as ints.
nlohmann::json will automatically use these definitions to serialize
and deserialize ExperimentalFeatures.

Strictly, we don't use the from_json instance yet, it's provided for
completeness and hopefully future use.
2022-04-20 15:41:01 +02:00
Eelco Dolstra
51712bf012
Merge pull request #6128 from ncfavier/fix-completion
Shell completion improvements
2022-04-19 13:45:33 +02:00
John Ericson
75b62e5260 Avoid fmt when constructor already does it
There is a correctnes issue here, but #3724 will fix that. This is just
a cleanup for brevity's sake.
2022-04-19 01:44:11 +00:00
Eelco Dolstra
092f6d2e7a
Merge pull request #6380 from thufschmitt/fix-double-slahsh-in-uri
Allow empty path segments in urls
2022-04-11 11:15:14 +02:00
Théophane Hufschmitt
646af7325d
Merge pull request #6376 from Uthar/master
don't assume that rev is a SHA1 hash
2022-04-08 17:56:27 +02:00
Théophane Hufschmitt
f3d3587ab3 Allow empty path segments in urls
Valid per https://datatracker.ietf.org/doc/html/rfc3986#section-3.3 (and
also somewhat frequently happening for local paths)
2022-04-08 16:09:49 +02:00
Eelco Dolstra
8bd9ebf52c Error: Remove unused sname() method 2022-04-08 11:31:51 +02:00
Eelco Dolstra
168ef9f3ab Remove unused Error.name field 2022-04-08 11:31:51 +02:00
Kasper Gałkowski
2c2fd4946f don't assume that rev is a SHA1 hash
This was a problem when writing a fetcher that uses e.g. sha256 hashes
for revisions. This doesn't actually do anything new, but allows for
creating such fetchers in the future (perhaps when support for Git's
SHA256 object format gains more popularity).
2022-04-07 19:49:47 +02:00
Eelco Dolstra
8b1e328d5d
Merge pull request #6348 from cole-h/fix-restoring-mount-namespace
libutil: Fix restoring mount namespace
2022-04-07 18:15:33 +02:00
Eelco Dolstra
c0ad86f681
Merge pull request #6366 from danpls/base64-reserve
libutil: Reserve memory when en/decoding base64
2022-04-05 23:20:33 +02:00
Daniel Pauls
513652d594 tokenizeString: Fix semantic mistake
`string_view::find_first_not_of(...)` and
`string_view::find_first_of(...)` return `string_view::npos` on error
not `string::npos`.
2022-04-05 22:33:03 +02:00
Daniel Pauls
1fa0393479 libutil: Reserve memory when en/decoding base64
The size of the output when encoding to and decoding from base64 is
(roughly) known so we can allocate it in advance to prevent
reallocation.
2022-04-05 21:30:50 +02:00
Cole Helbling
56009b2639 libutil: don't save cwd fd, use path instead
Saving the cwd fd didn't actually work well -- prior to this commit, the
following would happen:

    : ~/w/vc/nix ; doas outputs/out/bin/nix --experimental-features 'nix-command flakes' run nixpkgs#coreutils -- --coreutils-prog=pwd
    pwd: couldn't find directory entry in ‘../../../..’ with matching i-node
    : ~/w/vc/nix ; doas outputs/out/bin/nix --experimental-features 'nix-command flakes' develop -c pwd
    pwd: couldn't find directory entry in ‘../../../..’ with matching i-node
2022-04-04 10:28:08 -07:00
Cole Helbling
10b9c1b2b2 libutil: save cwd fd in restoreMountNamespace
This doesn't work very well (maybe I'm misunderstanding the desired
implementation):

    : ~/w/vc/nix ; doas outputs/out/bin/nix --experimental-features 'nix-command flakes' develop -c pwd
    pwd: couldn't find directory entry in ‘../../../..’ with matching i-node
2022-04-04 10:28:00 -07:00
Cole Helbling
f89b0f7846 libutil: try restoring the cwd from fdSavedCwd 2022-04-04 08:33:59 -07:00
Cole Helbling
e135d223f6 libutil: save fd to cwd instead of cwd itself 2022-04-04 08:32:45 -07:00
Cole Helbling
e5b70d47aa libutil: cleanup savedCwd logic
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
2022-04-04 08:20:11 -07:00
Cole Helbling
2a45cf54e4 libutil: Properly guard self-allocating getcwd on GNU
It's a GNU extension, as pointed out by pennae.
2022-04-01 12:20:34 -07:00
Cole Helbling
7f5caaa7c0 libutil: Don't use std::filesystem
Just in case making libutil depend on std::filesystem is unacceptable,
here is the non-filesystem approach.
2022-04-01 10:24:31 -07:00
aszlig
435848cef1 libutil: Fix restoring mount namespace
I regularly pass around simple scripts by using nix-shell as the script
interpreter, eg. like this:

    #!/usr/bin/env nix-shell
    #!nix-shell -p dd_rescue coreutils bash -i bash

While this works most of the time, I recently had one occasion where it
would not and the above would result in the following:

    $ sudo ./myscript.sh
    bash: ./myscript.sh: No such file or directory

Note the "sudo" here, because this error only occurs if we're root.

The reason for the latter is because running Nix as root means that we
can directly access the store, which makes sure we use a filesystem
namespace to make the store writable. XXX - REWORD!

So when stracing the process, I stumbled on the following sequence:

    openat(AT_FDCWD, "/proc/self/ns/mnt", O_RDONLY) = 3
    unshare(CLONE_NEWNS)                            = 0
    ... later ...
    getcwd("/the/real/cwd", 4096)                   = 14
    setns(3, CLONE_NEWNS)                           = 0
    getcwd("/", 4096)                               = 2

In the whole strace output there are no calls to chdir() whatsoever, so
I decided to look into the kernel source to see what else could change
directories and found this[1]:

    /* Update the pwd and root */
    set_fs_pwd(fs, &root);
    set_fs_root(fs, &root);

The set_fs_pwd() call is roughly equivalent to a chdir() syscall and
this is called when the setns() syscall is invoked[2].

[1]: b14ffae378/fs/namespace.c (L4659)
[2]: b14ffae378/kernel/nsproxy.c (L346)
2022-04-01 09:30:52 -07:00
Eelco Dolstra
c9a29d0d92
Merge pull request #6227 from NixOS/impure-derivations-ng
Impure derivations
2022-03-31 19:58:35 +02:00
Eelco Dolstra
5cd72598fe Add support for impure derivations
Impure derivations are derivations that can produce a different result
every time they're built. Example:

  stdenv.mkDerivation {
    name = "impure";
    __impure = true; # marks this derivation as impure
    outputHashAlgo = "sha256";
    outputHashMode = "recursive";
    buildCommand = "date > $out";
  };

Some important characteristics:

* This requires the 'impure-derivations' experimental feature.

* Impure derivations are not "cached". Thus, running "nix-build" on
  the example above multiple times will cause a rebuild every time.

* They are implemented similar to CA derivations, i.e. the output is
  moved to a content-addressed path in the store. The difference is
  that we don't register a realisation in the Nix database.

* Pure derivations are not allowed to depend on impure derivations. In
  the future fixed-output derivations will be allowed to depend on
  impure derivations, thus forming an "impurity barrier" in the
  dependency graph.

* When sandboxing is enabled, impure derivations can access the
  network in the same way as fixed-output derivations. In relaxed
  sandboxing mode, they can access the local filesystem.
2022-03-31 13:43:20 +02:00
Eelco Dolstra
0fe8849914
Merge pull request #6337 from danpls/fix-to-json-repl
libexpr: Throw the correct error in toJSON
2022-03-31 11:33:16 +02:00
Eelco Dolstra
28309352d9 replaceEnv(): Pass newEnv by reference 2022-03-31 10:39:53 +02:00
Daniel Pauls
629edd43ba libutil: Change return value of addTrace to void
The return value of BaseError::addTrace(...) is never used and
error-prone as subclasses calling it will return a BaseError instead of
the subclass.
This commit changes its return value to be void.
2022-03-30 18:37:32 +02:00
Maximilian Bosch
c85467a1b6
Revert "TarArchive: Small refactoring"
This reverts commit 50a35860ee.

With this change Nix fails to open bzip2 logfiles that were created from
builds with no stdout/stderr.
2022-03-24 22:30:46 +01:00
Eelco Dolstra
f902f3c2cb Add experimental feature 'fetch-closure' 2022-03-24 21:33:33 +01:00
Eelco Dolstra
a53c1dc96d
Merge pull request #6245 from trofi/fix-nix-store-gc-limit-auto-optimise-store
nix store gc: account for auto-optimised store
2022-03-16 09:19:57 +01:00
Maximilian Bosch
34e20c164c
libfetchers/path: set lastModified to path's mtime
When importing e.g. a local `nixpkgs` in a flake to test a change like

    {
      inputs.nixpkgs.url = path:/home/ma27/Projects/nixpkgs;
      outputs = /* ... */
    }

then the input is missing a `lastModified`-field that's e.g. used in
`nixpkgs.lib.nixosSystem`. Due to the missing `lastMoified`-field, the
mtime is set to 19700101:

    result -> /nix/store/b7dg1lmmsill2rsgyv2w7b6cnmixkvc1-nixos-system-nixos-22.05.19700101.dirty

With this change, the `path`-fetcher now sets a `lastModified` attribute
to the `mtime` just like it's the case in the `tarball`-fetcher already.
When building NixOS systems with `nixpkgs` being a `path`-input and this
patch, the output-path now looks like this:

    result -> /nix/store/ld2qf9c1s98dxmiwcaq5vn9k5ylzrm1s-nixos-system-nixos-22.05.20220217.dirty
2022-03-15 12:32:11 +01:00
Sergei Trofimovich
6b1872312f nix store gc: account for auto-optimised store
Before the change on a system with `auto-optimise-store = true`:

    $ nix store gc --verbose --max 1

deleted all the paths instead of one path (we requested 1 byte limit).

It happens because every file in `auto-optimise-store = true` has at
least 2 links: file itself and a link in /nix/store/.links/ directory.

The change conservatively assumes that any file that has one (as before)
or two links (assume auto-potimise mode) will free space.

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>
2022-03-13 07:24:48 +00:00
Eelco Dolstra
31a392dfe2 Merge pull request #5865 from pennae/memory-friendliness
be more memory friendly
2022-03-11 11:52:39 +01:00
pennae
8e2eaaaf69 make Finally more local
no need for function<> with c++17 deduction. this saves allocations and virtual
calls, but has the same semantics otherwise. not going through function has the
side effect of giving compilers more insight into the cleanup code, so we need a
few local warning disables.
2022-03-09 00:16:50 +01:00
pennae
47baa9d43c make Pos smaller
reduces peak hep memory use on eval of our test system from 264.4MB to 242.3MB,
possibly also a slight performance boost.

theoretically memory use could be cut down by another eight bytes per Pos on
average by turning it into a tuple containing an index into a global base
position table with row and column offsets, but that doesn't seem worth the
effort at this point.
2022-03-08 23:30:18 +01:00
Eelco Dolstra
30ddd37873 Merge branch 'cli-suggestions' of https://github.com/thufschmitt/nix 2022-03-07 19:47:45 +01:00
regnat
dcf4f77fac Merge or-suggestions.hh into suggestions.hh
No real need for keeping a separate header for such a simple class.

This requires changing a bit `OrSuggestions<T>::operator*` to not throw
an `Error` to prevent a cyclic dependency. But since this error is only
thrown on programmer error, we can replace the whole method by a direct
call to `std::get` which will raise its own assertion if needs be.
2022-03-07 17:49:02 +01:00
Naïm Favier
55c6906701
Perform tilde expansion when completing flake fragments
Allows completing `nix build ~/flake#<Tab>`.
We can implement expansion for `~user` later if needed.
Not using wordexp(3) since that expands way too much.
2022-03-07 12:01:54 +01:00
Naïm Favier
5461ff532d
Make completeDir follow symlinks
Allows completing `nix why-depends /run/cur<Tab>` to /run/current-system
2022-03-07 12:01:54 +01:00
Naïm Favier
a6d7cd4183
Ensure the completion marker is not processed beyond completion
I was surprised to see an error mentioning ___COMPLETE___ when trying to
complete a flag argument that had no completer implemented
2022-03-07 12:01:54 +01:00
regnat
313bbc07a8 Implement operator<< for Suggestions
That way there’s no need to explicitely convert it to a string when
printing it
2022-03-07 10:09:10 +01:00
regnat
fd45d85b41 Move OrSuggestions to its own header
Prevents a recursive inclusion
2022-03-07 10:09:10 +01:00
regnat
98e361ad4c Also display suggestions for the commands using the eval cache
Make `nix build .#nix-armv8l-linux` work for example
2022-03-07 10:09:10 +01:00