nixos/nix

mirror of https://github.com/NixOS/nix.git synced 2025-11-08 19:46:02 +01:00

Nix, the purely functional package manager

c-plus-plus declarative-language functional-programming nix package-manager

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Sergei Zimmerman 6138bc3de3 libexpr: Structural sharing of attrsets This changes the implementation of Bindings to allow for a more space-efficient implementation of attribute set merges. This is accomplished by "layering" over the "base" Bindings. The top "layer" is naturally the right-hand-side of the update operator //. Such an implementation leads to significantly better memory usage on something like nixpkgs: nix-env --query --available --out-path --file ../nixpkgs --eval-system x86_64-linux > /dev/null Comparison against `2b0fd88324` for x86_64-linux on nixpkgs f06c7c3b6f5074dbffcf02542fb86af3a5526afa: \| metric \| mean_before \| mean_after \| mean_diff \| mean_%_change \| p_value \| t_stat \| \| - \| - \| - \| - \| - \| - \| - \| \| cpuTime \| 21.1520 \| 21.3414 \| 0.1894 \| 0.7784 \| 0.3190 \| 1.0219 \| \| envs.bytes \| 461451951.6190 \| 461451951.6190 \| - \| - \| - \| - \| \| envs.elements \| 34344544.8571 \| 34344544.8571 \| - \| - \| - \| - \| \| envs.number \| 23336949.0952 \| 23336949.0952 \| - \| - \| - \| - \| \| gc.cycles \| 7.5238 \| 7.2857 \| -0.2381 \| -4.6825 \| 0.0565 \| -2.0244 \| \| gc.heapSize \| 1777848124.9524 \| 1252162023.6190 \| -525686101.3333 \| -29.9472 \| 0.0000 \| -8.7041 \| \| gc.totalBytes \| 3102787383.6190 \| 2498431578.6667 \| -604355804.9524 \| -19.7704 \| 0.0000 \| -9.3502 \| \| list.bytes \| 59928225.9048 \| 59928225.9048 \| - \| - \| - \| - \| \| list.concats \| 1240028.2857 \| 1240028.2857 \| - \| - \| - \| - \| \| list.elements \| 7491028.2381 \| 7491028.2381 \| - \| - \| - \| - \| \| nrAvoided \| 28165342.2381 \| 28165342.2381 \| - \| - \| - \| - \| \| nrExprs \| 1577412.9524 \| 1577412.9524 \| - \| - \| - \| - \| \| nrFunctionCalls \| 20970743.4286 \| 20970743.4286 \| - \| - \| - \| - \| \| nrLookups \| 10867306.0952 \| 10867306.0952 \| - \| - \| - \| - \| \| nrOpUpdateValuesCopied \| 61206062.0000 \| 25748169.5238 \| -35457892.4762 \| -58.8145 \| 0.0000 \| -8.9189 \| \| nrOpUpdates \| 2167097.4286 \| 2167097.4286 \| - \| - \| - \| - \| \| nrPrimOpCalls \| 12337423.4286 \| 12337423.4286 \| - \| - \| - \| - \| \| nrThunks \| 29361806.7619 \| 29361806.7619 \| - \| - \| - \| - \| \| sets.bytes \| 1393822818.6667 \| 897587655.2381 \| -496235163.4286 \| -36.7168 \| 0.0000 \| -9.1115 \| \| sets.elements \| 84504465.3333 \| 48270845.9524 \| -36233619.3810 \| -43.8698 \| 0.0000 \| -8.9181 \| \| sets.number \| 5218921.6667 \| 5218921.6667 \| - \| - \| - \| - \| \| sizes.Attr \| 16.0000 \| 16.0000 \| - \| - \| - \| - \| \| sizes.Bindings \| 8.0000 \| 24.0000 \| 16.0000 \| 200.0000 \| - \| inf \| \| sizes.Env \| 8.0000 \| 8.0000 \| - \| - \| - \| - \| \| sizes.Value \| 16.0000 \| 16.0000 \| - \| - \| - \| - \| \| symbols.bytes \| 1368494.0952 \| 1368494.0952 \| - \| - \| - \| - \| \| symbols.number \| 109147.1905 \| 109147.1905 \| - \| - \| - \| - \| \| time.cpu \| 21.1520 \| 21.3414 \| 0.1894 \| 0.7784 \| 0.3190 \| 1.0219 \| \| time.gc \| 1.6011 \| 0.8508 \| -0.7503 \| -37.1507 \| 0.0017 \| -3.6328 \| \| time.gcFraction \| 0.0849 \| 0.0399 \| -0.0450 \| -37.4504 \| 0.0035 \| -3.3116 \| \| values.bytes \| 615968144.7619 \| 615968144.7619 \| - \| - \| - \| - \| \| values.number \| 38498009.0476 \| 38498009.0476 \| - \| - \| - \| - \| Overall this does slow down the evaluator slightly (no more than ~10% in most cases), but this seems like a very decent tradeoff for shaving off 33% of memory usage.		2025-09-17 23:54:45 +03:00
.github	build(deps): bump actions/labeler from 5 to 6	2025-09-08 22:00:58 +00:00
ci/gha	flake: Apply nixfmt 1.0.0	2025-08-18 20:29:45 +03:00
contrib	function-trace: always show the trace	2019-09-18 23:23:21 +02:00
doc/manual	nix flake check: Skip substitutable derivations	2025-09-15 21:31:03 +02:00
maintainers	Update work meeting time in README	2025-08-26 00:50:12 +02:00
misc	add rc.d script for the nix-daemon	2025-08-08 09:09:58 +02:00
nix-meson-build-support	nix-meson-build-support/common nix_soversion: fixup removal of 'pre'	2025-09-16 18:31:40 +08:00
packaging	packaging: Drop legacy apple sdk pattern	2025-09-13 01:07:42 +03:00
scripts	add freebsd multi-user installer	2025-08-08 09:10:35 +02:00
src	libexpr: Structural sharing of attrsets	2025-09-17 23:54:45 +03:00
tests	Revert "tests/nixos: Fix daemon store reference in authorization test"	2025-09-17 22:05:26 +03:00
.clang-format	Update clang-format with fixing namespace coments, and separate definition blocks	2025-07-18 12:46:51 -04:00
.clang-tidy	Add .clang-tidy	2024-02-01 01:01:39 +01:00
.dir-locals.el	.dir-locals.el: Set c-block-comment-prefix	2020-07-10 11:21:06 +02:00
.editorconfig	No global eval settings in `libnixexpr`	2024-06-24 12:15:16 -04:00
.git-blame-ignore-revs	git-blame-ignore-revs: Add nixfmt 1.0.0 reformat	2025-08-18 20:30:54 +03:00
.gitignore	Overriding gtest with gmock	2025-05-31 07:41:27 -07:00
.mergify.yml	Update mergify.yml	2025-08-25 10:28:47 +02:00
.shellcheckrc	housekeeping: shellcheck for tests/functional/ca/build-cache.sh	2024-06-12 17:41:16 -04:00
.version	Bump version	2025-08-25 10:27:46 +02:00
CITATION.cff	chore: PhD thesis as reference in `CITATION.cff`	2024-05-18 20:05:22 +02:00
CONTRIBUTING.md	Update developer facing links to nix.dev	2025-07-25 10:59:44 +02:00
COPYING	COPYING: update to latest lgpl-2.1.txt (fixes #13758 )	2025-09-18 00:45:01 +08:00
default.nix	Format .nix files	2025-01-24 17:04:02 +01:00
docker.nix	Merge pull request #13524 from gmarti/fix_cacertificate	2025-08-28 23:28:53 +03:00
flake.lock	flake: Update nixpkgs	2025-08-27 02:23:05 +03:00
flake.nix	flake: nixpkgs: nixos-unstable -> nixos-25.05-small	2025-08-18 20:04:57 +03:00
HACKING.md	Rename `doc/manual{src -> source}`	2024-10-14 11:21:24 -04:00
meson.build	meson: Get rid of multiline array formatting hack	2025-08-07 02:57:02 +03:00
meson.format	flake: Add meson formatter	2025-06-11 22:08:03 +00:00
meson.options	add derivation parser benchmark	2025-07-29 16:51:55 +02:00
README.md	fix(docs): update Matrix channel links	2025-05-04 12:17:48 +02:00
shell.nix	Remove url literals	2022-01-24 13:28:21 +01:00

README.md

Nix

Nix is a powerful package manager for Linux and other Unix systems that makes package management reliable and reproducible. Please refer to the Nix manual for more details.

Installation and first steps

Visit nix.dev for installation instructions and beginner tutorials.

Full reference documentation can be found in the Nix manual.

Building and developing

Follow instructions in the Nix reference manual to set up a development environment and build Nix from source.

Contributing

Check the contributing guide if you want to get involved with developing Nix.

Additional resources

Nix was created by Eelco Dolstra and developed as the subject of his PhD thesis The Purely Functional Software Deployment Model, published 2006. Today, a world-wide developer community contributes to Nix and the ecosystem that has grown around it.

The Nix, Nixpkgs, NixOS Community on nixos.org
Official documentation on nix.dev
Nixpkgs is the largest, most up-to-date free software repository in the world
NixOS is a Linux distribution that can be configured fully declaratively
Discourse
Matrix: #users:nixos.org for user support and #nix-dev:nixos.org for development

License

Nix is released under the LGPL v2.1.