forked from lix-project/lix
26a8b220eb
we don't have to create an ostream sentry object for every character of a JSON string we write. format a bunch of characters and flush them to the stream all at once instead. this doesn't affect small numbers of string characters, but larger numbers of total JSON string characters written gain a lot. at 1MB of total string written we gain almost 30%, at 16MB it's almost a factor of 3x. large numbers of JSON string characters do occur naturally in a nixos system evaluation to generate documentation (though this is now somewhat mitigated by caching the largest part of nixos option docs). benchmarked with hyperfine 'nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) {e})"' --warmup 1 -L e 1,4,256,4096,65536 before: Benchmark 1: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 1)" Time (mean ± σ): 12.5 ms ± 0.2 ms [User: 9.2 ms, System: 4.0 ms] Range (min … max): 11.9 ms … 13.1 ms 223 runs Benchmark 2: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 4)" Time (mean ± σ): 12.5 ms ± 0.2 ms [User: 9.3 ms, System: 3.8 ms] Range (min … max): 11.9 ms … 13.2 ms 220 runs Benchmark 3: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 256)" Time (mean ± σ): 13.2 ms ± 0.3 ms [User: 9.8 ms, System: 4.0 ms] Range (min … max): 12.6 ms … 14.3 ms 205 runs Benchmark 4: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 4096)" Time (mean ± σ): 24.0 ms ± 0.4 ms [User: 19.4 ms, System: 5.2 ms] Range (min … max): 22.7 ms … 25.8 ms 119 runs Benchmark 5: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 65536)" Time (mean ± σ): 196.0 ms ± 3.7 ms [User: 171.2 ms, System: 25.8 ms] Range (min … max): 190.6 ms … 201.5 ms 14 runs after: Benchmark 1: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 1)" Time (mean ± σ): 12.4 ms ± 0.3 ms [User: 9.1 ms, System: 4.0 ms] Range (min … max): 11.7 ms … 13.3 ms 204 runs Benchmark 2: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 4)" Time (mean ± σ): 12.4 ms ± 0.2 ms [User: 9.2 ms, System: 3.9 ms] Range (min … max): 11.8 ms … 13.0 ms 214 runs Benchmark 3: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 256)" Time (mean ± σ): 12.6 ms ± 0.2 ms [User: 9.5 ms, System: 3.8 ms] Range (min … max): 12.1 ms … 13.3 ms 209 runs Benchmark 4: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 4096)" Time (mean ± σ): 15.9 ms ± 0.2 ms [User: 11.4 ms, System: 5.1 ms] Range (min … max): 15.2 ms … 16.4 ms 171 runs Benchmark 5: nix eval --raw --expr "let s = __concatStringsSep \"\" (__genList (_: \"c\") 256); in __toJSON (__genList (_: s) 65536)" Time (mean ± σ): 69.0 ms ± 0.9 ms [User: 44.3 ms, System: 25.3 ms] Range (min … max): 67.2 ms … 70.9 ms 42 runs |
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.github | ||
config | ||
contrib | ||
doc/manual | ||
m4 | ||
maintainers | ||
misc | ||
mk | ||
nix-rust | ||
perl | ||
scripts | ||
src | ||
tests | ||
.dir-locals.el | ||
.editorconfig | ||
.gitignore | ||
.version | ||
boehmgc-coroutine-sp-fallback.diff | ||
bootstrap.sh | ||
configure.ac | ||
COPYING | ||
default.nix | ||
docker.nix | ||
flake.lock | ||
flake.nix | ||
local.mk | ||
Makefile | ||
Makefile.config.in | ||
precompiled-headers.h | ||
README.md | ||
shell.nix |
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
On Linux and macOS the easiest way to install Nix is to run the following shell command (as a user other than root):
$ curl -L https://nixos.org/nix/install | sh
Information on additional installation methods is available on the Nix download page.
Building And Developing
See our Hacking guide in our manual for instruction on how to build nix from source with nix-build or how to get a development environment.
Additional Resources
- Nix manual
- Nix jobsets on hydra.nixos.org
- NixOS Discourse
- Matrix - #nix:nixos.org
- IRC - #nixos on libera.chat
License
Nix is released under the LGPL v2.1.