| 31 Jul 2025 |
|  Sammy (It/Its) left the room. | 10:11:40 |
| 29 Jul 2025 |
 John Ericson | https://github.com/NixOS/nix/issues/13570 issue I am curious about | 14:58:08 |
 Mic92 | Left a comment. | 15:17:42 |
| John Ericson | thanks! | 15:24:40 |
| John Ericson | didn't think of that angle | 15:24:43 |
| John Ericson | Mic92: any idea where we would get a nice meaty real-world structured attrs derivation? | 20:17:00 |
| John Ericson | I'll need that to test my PR | 20:17:26 |
| John Ericson | nevermind | 20:35:30 |
| John Ericson | firefox.overrideAttrs (_: { __structuredAttrs = true; }) that works | 20:35:44 |
| John Ericson | oh nevermind i grepped wrong, it was already structured attrs! | 20:38:06 |
| John Ericson | Mic92 Sergei Zimmerman (xokdvium) OK yeah firefox parses 4 times slower | 20:39:21 |
 Sergei Zimmerman (xokdvium) | In reply to @Ericson2314:matrix.org
Mic92 Sergei Zimmerman (xokdvium) OK yeah firefox parses 4 times slower So doing the lazy thing is worth it certainly. | 20:40:10 |
| John Ericson | OK! | 20:40:17 |
| John Ericson | Sergei Zimmerman (xokdvium): I wonder if I should use mutable since it is morally pure | 20:41:03 |
| John Ericson | not good for concurrency const | 20:41:13 |
| Mic92 | In reply to @Ericson2314:matrix.org
Mic92: any idea where we would get a nice meaty real-world structured attrs derivation? Anything in stdenv has to be parsed/generated multiple times. Bootstrapping in general takes most of the time in any eval flamegraph I have seen so far. | 20:41:19 |
| John Ericson | but is good for "are we changing it?" const | 20:41:21 |
| Mic92 | So this Code makes parsing 4x slower? https://github.com/NixOS/nix/commit/7f0ff4957e634de8aa2edb3cac5e79375c605148 | 20:46:04 |
| Mic92 | Surprising because the throughput of our current parser is slower than what I expect a JSON parser to be able to pull off. | 20:47:48 |
| Mic92 | * Surprising because the throughput of our current derivation parser is slower than what I expect a JSON parser to be able to pull off. | 20:48:04 |
| John Ericson | Mic92: oh wait tbh I was doing unoptimized builds | 20:51:13 |
| John Ericson | that doesn't mean much | 20:51:19 |
| John Ericson | I opened up https://github.com/NixOS/nix/issues/13573 regardless | 20:57:19 |
| John Ericson | since we can make GC faster by not parsing the entire derivation | 20:57:28 |
| John Ericson | OK optimized before
BM_ParseRealDerivationFile/hello 6814 ns 6791 ns 104081 bytes_per_second=247.735Mi/s
BM_ParseRealDerivationFile/firefox 31529 ns 31420 ns 22281 bytes_per_second=486.429Mi/s
| 21:18:01 |
| John Ericson | BM_ParseRealDerivationFile/hello 6952 ns 6929 ns 102364 bytes_per_second=242.772Mi/s
BM_ParseRealDerivationFile/firefox 71569 ns 71292 ns 9695 bytes_per_second=214.381Mi
| 21:18:27 |
| John Ericson | optimized after | 21:18:29 |
| John Ericson | 4x to 2x | 21:18:39 |
