Commit Graph
6 Commits
Author SHA1 Message Date
Sergei Zimmerman 88517c324f libexpr: slim down attrsets by 8 bytes on 64 bit systems
It's pretty bad that Bindings effectively wasted whole 8
bytes (4 for capacity and + 4 for alignment padding) to
store something it doesn't actually need. BindingsBuilder
allows the capacity to be checked at construction time,
after which the Bindings does not get mutated aside from
the ugly case of builtins, which doesn't get built all
at once.

For `nix search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello`
this shaves off around 53MB allocations out of 2GB used
for attrsets in total:

<     "bytes": 2001170768,
---
>     "bytes": 1947398072,

<     "Bindings": 16,
---
>     "Bindings": 8,

Nix PR: https://github.com/NixOS/nix/pull/13919

Change-Id: I939c5ac545f5abbca048370dcf4936346339d75c
2025-09-12 19:23:38 +03:00
Sergei ZimmermanandEmily 2898b9e7dc libexpr: Canonicalize TOML timestamps for toml11 > 4.0
This addresses several changes from toml11 4.0 bump in
nixpkgs [1].

1. Added more regression tests for timestamp formats.
   Special attention needs to be paid to the precision
   of the subsecond range for local-time. Prior versions select the closest
   (upwards) multiple of 3 with a hard cap of 9 digits.

2. Normalize local datetime and offset datetime to always
   use the uppercase separator `T`. This is actually the issue
   surfaced in [2]. This canonicalization is basically a requirement
   by (a certain reading) of rfc3339 section 5.6 [3].

3. If using toml11 >= 4.0 also keep the old behavior wrt
   to the number of digits used for subsecond part of the local-time.

[1]: https://www.github.com/NixOS/nixpkgs/pull/331649
[2]: https://www.github.com/NixOS/nix/issues/11441
[3]: https://datatracker.ietf.org/doc/html/rfc3339

(cherry picked from commit dc769d72cb8ad22a0f89768682b5499a9d2b3d8b)
Upstream-PR: https://github.com/NixOS/nix/pull/13741
Change-Id: Iac4fbe5108be79be585e9670fa42dfd11f3c5e89
2025-08-16 13:39:20 +01:00
Sergei ZimmermanandEmily 19d9a87c2f libexpr: Use table.size() instead of unnecessary loop
(cherry picked from commit d8fc55a46e0c09241131097dbf1d6fa09e0a9808)
Upstream-PR: https://github.com/NixOS/nix/pull/13741
Change-Id: I8a11e21ae3bff3a885e13fbab74e1deb162a34cf
2025-08-16 01:20:12 +01:00
Sergei ZimmermanandEmily 5badc1bc8a libexpr: Use recursive lambda instead of std::function
There's no reason to use a std::function for recursive lambdas
since there are polymorphic lambdas.

(cherry picked from commit a80a5c4dba0d944fab8f5ed57a343869ae96bf16)
Upstream-PR: https://github.com/NixOS/nix/pull/13741
Change-Id: I593bd04597e2ae000374ca1eca4d8928e986c0b5
2025-08-16 01:20:12 +01:00
Sergei ZimmermanandEmily 2ca5670ec3 libexpr: Remove extra trailing semicolons (NFC)
This looks really weird after the reformat.

(cherry picked from commit df4e55ffc13c413e270af134227115a20a2341ba)
Upstream-PR: https://github.com/NixOS/nix/pull/13741
Change-Id: I8de92d58620cc4545a31d8b7d533d2f1e9f4f233
2025-08-16 01:14:07 +01:00
Sergei ZimmermanandEmily b2e48aac5c tests/functional/lang: Add more tests for TOML timestamps
Current test suite doesn't cover the subsecond formatting at
all and toml11 is quite finicky with that. We should at the very
least test its behavior to avoid silent breakages on updates.

(cherry picked from commit 7ed0229d1abd4414144c7af396842462ce6fc1eb)
Upstream-PR: https://github.com/NixOS/nix/pull/13741
Change-Id: I6a6a696433b168072d6ad2585dce8a3c10ccbc39
2025-08-15 01:11:52 +01:00