forked from lix-project/lix
6644b6099b
This exploits the hermetic nature of flake evaluation to speed up
repeated evaluations of a flake output attribute.
For example (doing 'nix build' on an already present package):
$ time nix build nixpkgs:firefox
real 0m1.497s
user 0m1.160s
sys 0m0.139s
$ time nix build nixpkgs:firefox
real 0m0.052s
user 0m0.038s
sys 0m0.007s
The cache is ~/.cache/nix/eval-cache-v1.sqlite, which has entries like
INSERT INTO Attributes VALUES(
X'92a907d4efe933af2a46959b082cdff176aa5bfeb47a98fabd234809a67ab195',
'packages.firefox',
1,
'/nix/store/pbalzf8x19hckr8cwdv62rd6g0lqgc38-firefox-67.0.drv /nix/store/g6q0gx0v6xvdnizp8lrcw7c4gdkzana0-firefox-67.0 out');
where the hash 92a9... is a fingerprint over the flake store path and
the contents of the lockfile. Because flakes are evaluated in pure
mode, this uniquely identifies the evaluation result.
|
||
|---|---|---|
| .. | ||
| flake | ||
| primops | ||
| attr-path.cc | ||
| attr-path.hh | ||
| attr-set.cc | ||
| attr-set.hh | ||
| common-eval-args.cc | ||
| common-eval-args.hh | ||
| eval-inline.hh | ||
| eval.cc | ||
| eval.hh | ||
| get-drvs.cc | ||
| get-drvs.hh | ||
| json-to-value.cc | ||
| json-to-value.hh | ||
| lexer.l | ||
| local.mk | ||
| names.cc | ||
| names.hh | ||
| nix-expr.pc.in | ||
| nixexpr.cc | ||
| nixexpr.hh | ||
| parser.y | ||
| primops.cc | ||
| primops.hh | ||
| symbol-table.hh | ||
| value-to-json.cc | ||
| value-to-json.hh | ||
| value-to-xml.cc | ||
| value-to-xml.hh | ||
| value.hh | ||