Commit graph

4 commits

Author SHA1 Message Date
regnat 9355ecd543 Add a new Cmd type working on RealisedPaths
Where a `RealisedPath` is a store path with its history, meaning either
an opaque path for stuff that has been directly added to the store, or a
`Realisation` for stuff that has been built by a derivation

This is a low-level refactoring that doesn't bring anything by itself
(except a few dozen extra lines of code :/ ), but raising the
abstraction level a bit is important on a number of levels:

- Commands like `nix build` have to query for the realisations after the
  build is finished which is fragile (see
  27905f12e4a7207450abe37c9ed78e31603b67e1 for example). Having them
  oprate directly at the realisation level would avoid that
- Others like `nix copy` currently operate directly on (built) store
  paths, but need a bit more information as they will need to register
  the realisations on the remote side
2021-01-28 09:38:44 +01:00
regnat bab1cda0e6 Use the hash modulo in the derivation outputs
Rather than storing the derivation outputs as `drvPath!outputName` internally,
store them as `drvHashModulo!outputName` (or `outputHash!outputName` for
fixed-output derivations).

This makes the storage slightly more opaque, but enables an earlier
cutoff in cases where a fixed-output dependency changes (but keeps the
same output hash) − same as what we already do for input-addressed
derivations.
2020-12-11 21:17:23 +01:00
regnat 8914e01e37 Store the realisations as JSON in the binary cache
Fix #4332
2020-12-11 21:05:09 +01:00
regnat 58cdab64ac Store metadata about drv outputs realisations
For each known realisation, store:
- its output
- its output path

This comes with a set of needed changes:

- New `realisations` module declaring the types needed for describing
  these mappings
- New `Store::registerDrvOutput` method registering all the needed informations
  about a derivation output (also replaces `LocalStore::linkDeriverToPath`)
- new `Store::queryRealisation` method to retrieve the informations for a
  derivations

This introcudes some redundancy on the remote-store side between
`wopQueryDerivationOutputMap` and `wopQueryRealisation`.
However we might need to keep both (regardless of backwards compat)
because we sometimes need to get some infos for all the outputs of a
derivation (where `wopQueryDerivationOutputMap` is handy), but all the
stores can't implement it − because listing all the outputs of a
derivation isn't really possible for binary caches where the server
doesn't allow to list a directory.
2020-12-11 20:41:32 +01:00