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2023-02-02 r/5827 fix(tvix/cli): keep tracking full paths in known_pathsVincent Ambo3-42/+84
We need to distinguish explicitly between the paths used for the scanner, and the paths that populate the derivation inputs. The full paths must be accessible from the result of the refscanner to populate drv fields correctly. This was previously hidden by debug changes that masked actual IO operations with no-ops. Change-Id: I037af6e6bbe2b573034d695f8779bee1b56bc125 Reviewed-on: https://cl.tvl.fyi/c/depot/+/8022 Reviewed-by: flokli <flokli@flokli.de> Tested-by: BuildkiteCI
2023-02-02 r/5826 feat(tvix/cli): cache imported paths in NixCompatIOVincent Ambo1-2/+20
Creates a cache of imported literal files (e.g. `./default-builder.sh`) which avoids shelling out to Nix for each instance of the same file. Note that a better way to tackle this is to create memoizable thunks for these expressions in the compiler, but we are lacking a little bit of infrastructure for that at the moment. Change-Id: Ibc062b20d81e97dd3986e734d225a744e1779fe7 Reviewed-on: https://cl.tvl.fyi/c/depot/+/8015 Tested-by: BuildkiteCI Reviewed-by: flokli <flokli@flokli.de>
2023-02-02 r/5825 refactor(tvix/cli): use Wu-Manber string scanning for drv referencesVincent Ambo7-61/+64
Switch out the string-scanning algorithm used in the reference scanner. The construction of aho-corasick automata made up the vast majority of runtime when evaluating nixpkgs previously. While the actual scanning with a constructed automaton is relatively fast, we almost never scan for the same set of strings twice and the cost is not worth it. An algorithm that better matches our needs is the Wu-Manber multiple string match algorithm, which works efficiently on *long* and *random* strings of the *same length*, which describes store paths (up to their hash component). This switches the refscanner crate to a Rust implementation[0][1] of this algorithm. This has several implications: 1. This crate does not provide a way to scan streams. I'm not sure if this is an inherent problem with the algorithm (probably not, but it would need buffering). Either way, related functions and tests (which were actually unused) have been removed. 2. All strings need to be of the same length. For this reason, we truncate the known paths after their hash part (they are still unique, of course). 3. Passing an empty set of matches, or a match that is shorter than the length of a store path, causes the crate to panic. We safeguard against this by completely skipping the refscanning if there are no known paths (i.e. when evaluating the first derivation of an eval), and by bailing out of scanning a string that is shorter than a store path. On the upside, this reduces overall runtime to less 1/5 of what it was before when evaluating `pkgs.stdenv.drvPath`. [0]: Frankly, it's a random, research-grade MIT-licensed crate that I found on Github: https://github.com/jneem/wu-manber [1]: We probably want to rewrite or at least fork the above crate, and add things like a three-byte wide scanner. Evaluating large portions of nixpkgs can easily lead to more than 65k derivations being scanned for. Change-Id: I08926778e1e5d5a87fc9ac26e0437aed8bbd9eb0 Reviewed-on: https://cl.tvl.fyi/c/depot/+/8017 Tested-by: BuildkiteCI Reviewed-by: flokli <flokli@flokli.de>
2023-02-02 r/5824 docs(tvix): add more information to READMEVincent Ambo1-8/+48
The README was very sparse before and we've actually had people email us (as it says to contact us) just to ask what Tvix *is*. This should answer some questions! Change-Id: I0f248cb060eccfe086468afed1d648652b35dfd1 Reviewed-on: https://cl.tvl.fyi/c/depot/+/8018 Tested-by: BuildkiteCI Autosubmit: tazjin <tazjin@tvl.su> Reviewed-by: flokli <flokli@flokli.de>
2023-02-02 r/5823 fix(tvix/eval): unsafeDiscardStringContext is a no-opVincent Ambo1-4/+2
... not just a TODO. Most use-cases of unsafeDiscardStringContext are for cases where a string is processed in some ways and no longer contains a "physical" reference, but still has its context attached in C++ Nix. We don't need to do this. This does diverge in behaviour in use-cases related to build scheduling, but that whole behaviour will be different in Tvix. Change-Id: I4056d4c09f62d44d6bd52b791db03fe5556672b5 Reviewed-on: https://cl.tvl.fyi/c/depot/+/8016 Reviewed-by: flokli <flokli@flokli.de> Autosubmit: tazjin <tazjin@tvl.su> Tested-by: BuildkiteCI
2023-02-02 r/5822 refactor(tvix/eval): import_cache can be a HashMapVincent Ambo1-2/+2
... instead of a BTreeMap, as we do not need ordering guarantees here. HashMaps are noticeably faster here (especially as we've been sorting essentially random data!). Change-Id: Ie92d74286df9f763c04c9b226ef1066ee8484c13 Reviewed-on: https://cl.tvl.fyi/c/depot/+/8014 Reviewed-by: flokli <flokli@flokli.de> Tested-by: BuildkiteCI Autosubmit: tazjin <tazjin@tvl.su>
2023-02-02 r/5821 chore(tvix/eval): elaborate on internal types in Value::type_ofVincent Ambo1-6/+8
This aids in debugging quite substantially. Change-Id: Ic43232aa6165ae1c3db7ac2701938e1dfeeb418c Reviewed-on: https://cl.tvl.fyi/c/depot/+/8013 Tested-by: BuildkiteCI Reviewed-by: flokli <flokli@flokli.de> Autosubmit: tazjin <tazjin@tvl.su>
2023-02-01 r/5820 chore(corp/tvixbolt): update Cargo.lockFlorian Klink1-52/+52
Change-Id: Ie6bb2df16f79f7d977a7e95187a6b81e3ac0108f Reviewed-on: https://cl.tvl.fyi/c/depot/+/8011 Reviewed-by: tazjin <tazjin@tvl.su> Autosubmit: flokli <flokli@flokli.de> Tested-by: BuildkiteCI
2023-02-01 r/5819 chore(tvix): update Cargo.lockFlorian Klink2-477/+502
Change-Id: I08b2dc2393819c4f0d3871fe05bdbd29e89a6d75 Reviewed-on: https://cl.tvl.fyi/c/depot/+/8010 Tested-by: BuildkiteCI Autosubmit: flokli <flokli@flokli.de> Reviewed-by: tazjin <tazjin@tvl.su>
2023-02-01 r/5818 fix(tvix): add dummy target to attach extra-step toVincent Ambo1-6/+10
Change-Id: I594a6652e2efe7aa6e35c7cdd84fc3097660614f Reviewed-on: https://cl.tvl.fyi/c/depot/+/8009 Reviewed-by: flokli <flokli@flokli.de> Tested-by: BuildkiteCI Autosubmit: tazjin <tazjin@tvl.su>
2023-02-01 r/5817 fix(ops/buildkite): set default_branch explicitlyFlorian Klink1-12/+15
It looks like this needs to be set for the tvix pipeline to succeed. It was set to `canon` for `tvl-kit` (not sure if manually, or some autodetection previously did it for us that's not present anymore). Anyways, this sets it to how it's set in the web interface, to hopefully fix it. Change-Id: Ic3eb60e3f421fa949a84dcdaa928823ff45f679a Reviewed-on: https://cl.tvl.fyi/c/depot/+/8008 Reviewed-by: tazjin <tazjin@tvl.su> Tested-by: BuildkiteCI Autosubmit: flokli <flokli@flokli.de>
2023-02-01 r/5816