Commit graph

9044 commits

Author SHA1 Message Date
Maximilian Bosch
559fd7ffe7
nix flake check: improve error message if overlay is not a lambda (#8582)
* nix flake check: improve error message if overlay is not a lambda

Suppose you have an overlay like this

    {
      inputs = { /* ... */ };
      outputs = { flake-utils, ... }: flake-utils.lib.eachDefaultSystem
        (system: {
          overlays.default = final: prev: {

          };
        });
    }

then `nix flake check` (correctly) fails because `overlays` are supposed
to have the structure `overlays.<name> = final: prev: exp`. However, the
error-message is a little bit counter-intuitive:

    error: overlay does not take an argument named 'final'

While one might guess where the error actually comes from because the
trace above says `… while checking the overlay 'overlays.x86_64-linux'`
this is still pretty confusing because it complains about an argument
not being named `final` even though that's evidently the case.

With this change, the error-message actually makes it clear what's
wrong:

    [ma27@carsten:~/Projects/nix/tmp]$ nix flake check --extra-experimental-features 'nix-command flakes' path:$(pwd)
    error:
           … while checking flake output 'overlays'

             at /nix/store/clgblnxx003hyrq8qkz5ab6kgqkck6qc-source/flake.nix:4:5:

                3|   outputs = { ... }: {
                4|     overlays.x86_64-linux.snens = final: prev: {
                 |     ^
                5|       kek = throw "snens";

           … while checking the overlay 'overlays.x86_64-linux'

             at /nix/store/clgblnxx003hyrq8qkz5ab6kgqkck6qc-source/flake.nix:4:5:

                3|   outputs = { ... }: {
                4|     overlays.x86_64-linux.snens = final: prev: {
                 |     ^
                5|       kek = throw "snens";

           error: overlay is not a lambda, but a set instead
2023-06-27 14:58:29 +02:00
Eelco Dolstra
8e770dac9f
Merge pull request #8576 from obsidiansystems/findPath-cleanup
Use a struct not `std::pair` for `SearchPathElem`
2023-06-26 12:37:06 +02:00
Théophane Hufschmitt
60f06a1714
Merge pull request #5385 from Enzime/add/dirty-rev
Add `dirtyRev` and `dirtyShortRev` to `fetchGit`
2023-06-24 14:55:31 +02:00
Michael Hoang
a7b49086c7 Add dirtyRev and dirtyShortRev to fetchGit
Fixes #4682
2023-06-24 14:17:25 +10:00
John Ericson
484290a9e0 Use a struct not std::pair for SearchPathElem
I got very confused trying to keep all the `first` and `second` straight
reading the code, *especially* as there is also another `(boolean,
string)` pair type also being used.

Named fields is much better.

There are other cleanups that we can do (for example, the existing
TODO), but we can do them later. Doing them now would just make this
harder to review.
2023-06-23 12:01:10 -04:00
Robert Hensing
fd4f03b8fd
Merge pull request #8519 from fricklerhandwerk/reword-trusted-users
reword documentation on trusted users and substituters
2023-06-23 13:08:46 +02:00
Eelco Dolstra
8350f06d6c
Merge pull request #8574 from inclyc/nixd/remove-unused-token
libexpr: remove unused token `ATTRPATH` in token declaration
2023-06-23 12:02:40 +02:00
Yingchi Long
9d8c4ac446 libexpr: remove unused token ATTRPATH in token declaration 2023-06-23 13:35:41 +08:00
John Ericson
97df060588 Better document build failure exit codes
- Improved API docs from comment

- Exit codes are for `nix-build`, not just `nix-store --release`

- Make note in tests so the magic numbers are not surprising

Picking up where #8387 left off.
2023-06-22 14:29:45 -04:00
Yingchi Long
1400fde144 libexpr: extend Value::print to allow limited depth 2023-06-22 18:28:30 +08:00
Yingchi Long
c48277c1c1 libexpr: add tests for nix::Value::print 2023-06-22 18:28:30 +08:00
John Ericson
48fe0ed554
Merge pull request #8374 from obsidiansystems/improve-path-setting
Split `OptionalPathSetting` from `PathSetting`
2023-06-21 15:40:43 -04:00
Valentin Gagarin
e91d19db5f
be more serious about security risks with trusted users 2023-06-20 12:23:53 +02:00
Eelco Dolstra
b1352700c4
Merge pull request #8552 from edolstra/fix-eagain
GC server: Clear O_NONBLOCK on the right file descriptor
2023-06-20 12:12:53 +02:00
Ben Radford
6ae35534b7
Support opening local store with database on read-only filesystem (#8356)
Previously it was not possible to open a local store when its database is on a read-only filesystem. Obviously a store on a read-only filesystem cannot be modified, but it would still be useful to be able to query it.

This change adds a new read-only setting to LocalStore. When set to true, Nix will skip operations that fail when the database is on a read-only filesystem (acquiring big-lock, schema migration, etc), and the store database will be opened in immutable mode.

Co-authored-by: Ben Radford <benradf@users.noreply.github.com>
Co-authored-by: cidkidnix <cidkidnix@protonmail.com>
Co-authored-by: Dylan Green <67574902+cidkidnix@users.noreply.github.com>
Co-authored-by: John Ericson <git@JohnEricson.me>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-06-20 11:34:09 +02:00
Eelco Dolstra
a6a75ecad8 GC server: Clear O_NONBLOCK on the right file descriptor
The bug fix in 6d30f9e6fe erroneously
cleared O_NONBLOCK on the server rather than client FD (leaving both
in an incorrect state).

Fixes #8551.
2023-06-20 11:19:14 +02:00
John Ericson
3859cf6b21 Remove unused #include from local-derivation-goal.cc
These were never needed for this file, and date back to before this was
split from `derivation-goal.cc`.
2023-06-19 12:18:04 -04:00
John Ericson
9f69b7dee9 Create worker_proto::{Read,Write}Conn
Pass this around instead of `Source &` and `Sink &` directly. This will
give us something to put the protocol version on once the time comes.

To do this ergonomically, we need to expose `RemoteStore::Connection`,
so do that too. Give it some more API docs while we are at it.
2023-06-19 12:08:23 -04:00
John Ericson
4e8b495ad7 Likewise namespace and enum struct-ify ServeCommand
The motivation is exactly the same as for the last commit. In addition,
this anticipates us formally defining separate serialisers for the serve
protocol.
2023-06-19 12:08:23 -04:00
John Ericson
95eae0c002 Put worker protocol items inside a WorkerProto struct
See API docs on that struct for why. The pasing as as template argument
doesn't yet happen in that commit, but will instead happen in later
commit.

Also make `WorkerOp` (now `Op`) and enum struct. This led us to catch
that two operations were not handled!

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-06-19 12:08:23 -04:00
John Ericson
469d06f9bc Split out worker protocol template definitions from declarations
This is generally a fine practice: Putting implementations in headers
makes them harder to read and slows compilation. Unfortunately it is
necessary for templates, but we can ameliorate that by putting them in a
separate header. Only files which need to instantiate those templates
will need to include the header with the implementation; the rest can
just include the declaration.

This is now documenting in the contributing guide.

Also, it just happens that these polymorphic serializers are the
protocol agnostic ones. (Worker and serve protocol have the same logic
for these container types.) This means by doing this general template
cleanup, we are also getting a head start on better indicating which
code is protocol-specific and which code is shared between protocols.
2023-06-19 11:45:59 -04:00
Eelco Dolstra
f5e620bf2b
Merge pull request #8483 from edolstra/save-root
restoreMountNamespace(): Restore the original root directory
2023-06-19 12:54:05 +02:00
Eelco Dolstra
8f6255b86a
Merge pull request #8524 from amjoseph-nixpkgs/pr/doc/linkify-allowed-uris
src/libexpr/eval.hh: add link for allowed-uris option
2023-06-19 06:59:07 +02:00
John Ericson
c404623a1d
Clean up a few things related to profiles (#8526)
- Greatly expand API docs

- Clean up code in misc ways

  - Instead of a complicated single loop on generations, do different
    operations in successive subsequent steps.

  - Avoid `ref` in one place where `&` is fine

  - Just return path instead of mutating an argument in `makeName`

Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-06-19 04:04:59 +00:00
Adam Joseph
6b06e97bde src/libexpr/eval.hh: add link for allowed-uris option
This commit adds a link to the documentation for `--option
allowed-uris` where that option is mentioned while describing
`restrict-eval`.
2023-06-18 23:36:32 -04:00
John Ericson
d2ce2e89b1 Split OptionalPathSetting from PathSetting
Rather than doing `allowEmpty` as boolean, have separate types and use
`std::optional`. This makes it harder to forget the possibility of an
empty path.

The `build-hook` setting was categorized as a `PathSetting`, but
actually it was split into arguments. No good! Now, it is
`Setting<Strings>` which actually reflects what it means and how it is
used.

Because of the subtyping, we now also have support for
`Setting<std::optional<String>>` in general. I imagine this can be used
to clean up many more settings also.
2023-06-18 23:31:18 -04:00
John Ericson
c8825e9d8c Create nlohmann serializers for std::optional and use
This is somewhat tricky.
2023-06-18 23:31:10 -04:00
Eelco Dolstra
e503eadafc
Merge pull request #8477 from edolstra/tarball-flake-redirects
Tarball flake improvements
2023-06-16 18:03:50 +02:00
Valentin Gagarin
f695a74751
Update src/libstore/globals.hh 2023-06-16 17:58:01 +02:00
Valentin Gagarin
baef05e6fe
fix typo
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-06-16 14:37:08 +02:00
Valentin Gagarin
126eea48e3
do not refer to trusted-users another time 2023-06-16 14:36:53 +02:00
Valentin Gagarin
1a8ca85d48
use "store URLs" consistently 2023-06-16 14:34:11 +02:00
Valentin Gagarin
4a33d5fe35
fix link text
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
2023-06-16 14:33:31 +02:00
Eelco Dolstra
713836112c
Merge pull request #8517 from hercules-ci/fix-build-hook-error-for-lib-users
Fix build hook error for libstore library users
2023-06-16 13:20:50 +02:00
Théophane Hufschmitt
b2247ef4f6 Don't assume the type of string::size_type
The code accidentally conflated `std::string::size_type` and `long unsigned int`.
This was fine on 64bits machines where they are apparently the same in
practice, but not on 32bits. Fix that by using `std::string::size_type`
everywhere.
2023-06-15 21:24:14 +02:00
Valentin Gagarin
2ceacce484
Update src/libstore/globals.hh 2023-06-15 15:57:54 +02:00
Robert Hensing
d2696cdd1e Fix build hook error for libstore library users
A library shouldn't require changes to the caller's argument handling,
especially if it doesn't have to, and indeed we don't have to.

This changes the lookup order to prioritize the hardcoded path to nix
if it exists. The static executable still finds itself through /proc
and the like.
2023-06-15 14:32:00 +02:00
John Ericson
e1fa48f17c
Update src/nix/daemon.cc
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-06-15 07:41:37 -04:00
Adam Joseph
098fbf6273 src/libexpr/eval.hh: fix typo
The option name is `allowed-uris`, not `allowed-uri`.
2023-06-14 21:47:58 -07:00
Valentin Gagarin
b7d47e1d22
fix wording 2023-06-15 04:58:07 +02:00
Valentin Gagarin
e09b40e0d0 reword documentation on trusted users and substituters
this is to make it slightly easier to scan over
2023-06-15 02:19:13 +02:00
John Ericson
ca9f544160
Merge pull request #8516 from wentasah/remove-registerprimop
Remove RegisterPrimOp constructor without support for documentation
2023-06-15 01:13:46 +02:00
Valentin Gagarin
a1cf16563f
Fixup description of substituters (#8291)
Introduce what substituters "are" in the configuration option entry.
Remove arbitrary line breaks for easier editing in the future.
Link glossary some more.

Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: John Ericson <git@JohnEricson.me>
2023-06-14 20:49:58 +00:00
Michal Sojka
a0c4d58549 Remove RegisterPrimOp constructor without support for documentation
The remaining constructor RegisterPrimOp::RegisterPrimOp(Info && info)
allows specifying the documentation in .args and .doc members of the
Info structure.

Commit 8ec1ba0210 removed all uses of the removed constructor in the
nix binary. Here, we remove the constructor completely as well as its
use in a plugin test. According to #8515, we didn't promis to maintain
compatibility with external plugins.

Fixes #8515
2023-06-14 22:37:52 +02:00
John Ericson
05eb06a1de
Merge pull request #8490 from flox/stdin_handling
fix: Do not apply default installables when using --stdin
2023-06-14 20:41:22 +02:00
John Ericson
e377746842
Merge pull request #8491 from wentasah/builtins-doc
Document several undocumented builtin functions
2023-06-14 20:32:37 +02:00
Daniel Asaturov
468add5aa0
Remove dead code (#8504)
`filesystem.cc` is the only place where `createSymlink()` is used with three arguments:
in the definition of `replaceSymlink()` with three parameters that _is not used at all_.

Closes #8495
2023-06-14 14:09:11 -04:00
John Ericson
ff905cb796
Merge pull request #4803 from ShamrockLee/nix-channel-list-generations
Add `nix-channel --list-generations`
2023-06-14 18:30:35 +02:00
John Ericson
61a3e1f2e2
Merge pull request #4282 from tweag/fix-ca-hash-rewriting
fix the hash rewriting for ca-derivations
2023-06-14 18:25:00 +02:00
Michal Sojka
c6d7c4f9ec Document fromTOML, hasContext and getContext builtins
Until now, these functions were completely missing in the Nix manual.

Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-06-13 21:53:03 +02:00
Eelco Dolstra
1ad3328c5e Allow tarball URLs to redirect to a lockable immutable URL
Previously, for tarball flakes, we recorded the original URL of the
tarball flake, rather than the URL to which it ultimately
redirects. Thus, a flake URL like
http://example.org/patchelf-latest.tar that redirects to
http://example.org/patchelf-<revision>.tar was not really usable. We
couldn't record the redirected URL, because sites like GitHub redirect
to CDN URLs that we can't rely on to be stable.

So now we use the redirected URL only if the server returns the
`x-nix-is-immutable` or `x-amz-meta-nix-is-immutable` headers in its
response.
2023-06-13 14:17:45 +02:00
Eelco Dolstra
3402b650cd Add a generic check for rev attribute mismatches 2023-06-13 14:13:50 +02:00
Tom Bereknyei
0e3849dc65 test: add test for non-defaulting for stding installable input 2023-06-12 08:40:17 -04:00
Eelco Dolstra
87c66f6b0f Don't include uds-remote-store.md from a header file
Closes #8484.
2023-06-12 11:10:55 +02:00
Michal Sojka
8ec1ba0210 Register all PrimOps via the Info structure
This will allow documenting them (in later commits).

Note that we keep the old constructor even if it is no longer used by
Nix code, because it is used in tests/plugins/plugintest.cc, which
suggests that it might be used by some external plugin.
2023-06-11 21:40:43 +02:00
Tom Bereknyei
08089fdd32 fix: Do not apply default installables when using --stdin 2023-06-11 13:33:38 -04:00
Eelco Dolstra
e54538c461 restoreMountNamespace(): Restore the original root directory
This is necessary when we're in a chroot environment, where the
process root is not the same as the root of the mount namespace
(e.g. in nixos-enter).

Fixes #7602.
2023-06-09 16:09:29 +02:00
Eelco Dolstra
381a32981b
Merge branch 'master' into angerman/mac-fix-recursive-nix 2023-06-09 13:06:47 +02:00
Andrea Bedini
3c78920f73
Parse TOML timestamps (#8120)
Currently `fromTOML` throws an exception when encountering a timestamp
since the Nix language lacks a way to represent them.

This patch changes this beaviour and makes `fromTOML` parse timestamps as
attrsets of the format

  { _type = "timestamp"; value = "1979-05-27T07:32:00Z"; }

This is guarded by an experimental feature flag to leave room for iterating on the representation.
2023-06-09 11:53:18 +02:00
Eelco Dolstra
b56319a139
Merge pull request #8391 from aneeshusa/remove-wrong-default-value-in-docs-for-hashed-mirrors
Remove old default from docs for `hashed-mirrors`
2023-06-06 12:54:28 +02:00
Eelco Dolstra
864ab1a7ac
Merge pull request #8438 from zhaofengli/armv5tel-linux32
Also set the PER_LINUX32 personality flag on armv5tel-linux
2023-06-06 12:47:16 +02:00
Eelco Dolstra
51b3576855
Merge pull request #8456 from emilytrau/include-select
Add missing <sys/select.h> include
2023-06-06 12:45:51 +02:00
Eelco Dolstra
f5c6b29940 Fix SourcePath::resolveSymlinks()
This fixes handling of symlinks that start with '..', and symlink
targets that contain symlinks themselves.
2023-06-06 11:24:10 +02:00
Emily Trau
b37dd43db4 Add missing <sys/select.h> include
`select()` may not be ambiently available for use on every platform
2023-06-05 20:18:24 -07:00
figsoda
b64450ed4e Fix code block formatting in man page 2023-06-04 14:50:47 -04:00
Alexander Bantyev
a15b2c01c0
Document manual migration for use-xdg-base-directories (#8044)
* Document manual migration for use-xdg-base-directories

As there's currently no automatic migration for use-xdg-base-directories
option, add instructions for manual migration to the option's
description.

Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
2023-06-02 15:38:17 +00:00
Zhaofeng Li
48632e6139 Also set the PER_LINUX32 personality flag on armv5tel-linux 2023-06-02 03:04:13 -06:00
Shamrock Lee
b292177eec Add nix-channel --list-generations
Add support to --list-generations
as another way to say
nix-env --profile /nix/var/nix/profiles/per-user/$USER/channels --list-generations
the way we did for nix-channel --rollback [generation id]
2023-06-02 10:12:35 +02:00
Eelco Dolstra
9a5b9c588f
Merge pull request #8421 from fricklerhandwerk/doc-replaceStrings
update documentation according to release notes
2023-05-31 12:10:32 +02:00
Valentin Gagarin
738c0d5064
Merge pull request #8318 from fricklerhandwerk/doc-currentTime
document `builtins.currentTime`
2023-05-31 03:15:54 +02:00
Valentin Gagarin
9afd525e18 update documentation according to release notes 2023-05-30 22:58:15 +02:00
Robert Hensing
bed2fe2312
Merge pull request #8398 from polykernel/perf/lazy-eval-replacements-replacestrings
primops: lazy evaluation of replaceStrings replacements
2023-05-30 22:49:42 +02:00
Eelco Dolstra
ecae62020b
Merge pull request #8406 from NixOS/fix-ca-attrs-false
Restore Nix 2.3 behaviour for {__impure,__contentAddressed} = false
2023-05-30 11:59:14 +02:00
Eelco Dolstra
61ddfa154b
Merge pull request #8399 from tweag/fix-chrooted-stores-error-path
Properly report build errors on chrooted stores
2023-05-27 17:55:57 +02:00
Eelco Dolstra
e4aebccf20 Restore Nix 2.3 behaviour for {__impure,__contentAddressed} = false
Fixes #8405.
2023-05-27 17:53:30 +02:00
Yorick van Pelt
2c462486fe
create pathAccessible, use it to infer default dirs 2023-05-26 15:36:47 +02:00
Yorick van Pelt
a6c78ba367
getDefaultNixPath: ignore EPERM 2023-05-26 15:36:46 +02:00
Yorick van Pelt
b7cde90c6b
Call getDefaultSSLCertFile() only when none is specified
This does pathExists on various paths, which crashes on EPERM in the
macOS sandbox.
2023-05-26 15:36:45 +02:00
Silvan Mosberger
be48907470
ci: Always run with sandbox, even on Darwin
And fix a test failure in the sandbox due to /home
existing on Darwin but not being accessible in the sandbox since it's a
symlink to /System/Volumes/Data/home, see
https://github.com/NixOS/nix/actions/runs/4205378453/jobs/7297384658#step:6:2127:

    C++ exception with description "error: getting status of /home/schnitzel/darmstadt/pommes: Operation not permitted" thrown in the test body.

On Linux this wasn't a problem because there /home doesn't exist in the sandbox
2023-05-26 15:36:44 +02:00
polykernel
a382919d7d
primops: lazy evaluation of replaceStrings replacements
The primop `builtins.replaceStrings` currently always strictly evaluates the
replacement strings, however time and space are wasted for their computation
if the corresponding pattern do not occur in the input string. This commit
makes the evaluation of the replacement strings lazy by deferring their
evaluation to when the corresponding pattern are matched and memoize the result
for efficient retrieval on subsequent matches.

The testcases for replaceStrings was updated to check for lazy evaluation
of the replacements. A note was also added in the release notes to
document the behavior change.
2023-05-25 18:35:23 -04:00
Théophane Hufschmitt
d16a1994fb Properly report build errors on chrooted stores
When encountering a build error, Nix moves the output paths out of the
chroot into their final location (for “easier debugging of build
failures”). However this was broken for chroot stores as it was moving
it to the _logical_ location, not the _physical_ one.

Fix it by moving to the physical (_real_) location.

Fix https://github.com/NixOS/nix/issues/8395
2023-05-25 16:38:29 +02:00
Aneesh Agrawal
c694f1a2f3 Remove old default from docs for hashed-mirrors
The `hashed-mirrors` option did use to have this default value,
but it was removed and re-added with an empty default value.
As the autogenerated docs show the (actual) default values from code,
remove this incorrect reference from the docs.

I was updating my nix.conf settings after a few years and noticed this.
2023-05-24 11:05:40 -04:00
Théophane Hufschmitt
34e1b464f0 Normalize the hash-rewriting process when building derivations 2023-05-24 14:11:50 +02:00
Théophane Hufschmitt
a917fb0d53 Use a RewritingSink in derivation goal
Possibly this will make it stream
2023-05-24 14:11:50 +02:00
Théophane Hufschmitt
3ebe1341ab Make RewritingSink accept a map of rewrites
Giving it the same semantics as `rewriteStrings`.
Also add some tests for it
2023-05-24 14:11:50 +02:00
oxalica
303858afad Fix typo in error message of too long store path 2023-05-24 01:24:28 +08:00
Peter Becich
a420ccc6a8
nix flake check: skip derivations for foreign systems (#7759)
`nix flake show` now skips derivations for foreign systems: https://github.com/NixOS/nix/pull/6988

This commit borrows from that to implement the same behavior for `nix flake check`.

See "nix flake check breaks on IFD in multi-platform flake" https://github.com/NixOS/nix/issues/4265
2023-05-23 06:59:44 +02:00
Théophane Hufschmitt
494a09c6df
Merge pull request #8377 from layus/fix-ssl-cert-mount
Make mounting ssl cert file optional
2023-05-22 14:06:57 +02:00
Théophane Hufschmitt
673fe85976
Merge pull request #8365 from obsidiansystems/proto-structs
Revert "Revert "Use template structs instead of phantoms""
2023-05-22 09:34:34 +02:00
Guillaume Maudoux
b14fea6fff Shortcircuit for empty caFile 2023-05-19 23:30:35 +02:00
Guillaume Maudoux
36b7e30c11 Make mounting ssl cert file optional 2023-05-19 22:47:40 +02:00
Eelco Dolstra
3305fd0cb1
Merge pull request #8354 from KasyanDiGris/git-fetcher-ask-credentials
Ask for git credentials in fetcher
2023-05-19 13:40:43 +02:00
Eelco Dolstra
34381d5747
Merge pull request #8215 from obsidiansystems/general-repair-path
Support `repairPath` on most stores.
2023-05-19 13:39:48 +02:00
Eelco Dolstra
e31d9b910d
Merge pull request #7312 from layus/fixed-output-system-cert
Allow system certs access to fixed-output derivations
2023-05-19 13:05:16 +02:00
Robert Hensing
b1c34c0ee8
Merge pull request #8366 from obsidiansystems/worker-proto-forward-decl-types
Don't use `store-api.hh` in `worker-protocol.hh`
2023-05-18 14:33:52 +02:00
Konstantin Vukolov
31ffd0c1fe Remove unused 2023-05-18 13:26:23 +03:00
Konstantin Vukolov
4c4ae887b8 Add option isInteractive 2023-05-18 13:18:34 +03:00
John Ericson
9923403d90 Don't use store-api.hh in worker-protocol.hh
Using abstract types like can help cut down on compilation time, both
from scratch, and especially incremental builds during development. The
idea is that `worker-protocol.hh` can declare all the (de)serializers, but
only again abstract types; when code needs to use some (de)serializers, it can
include headers just for the data types it needs to (de)serialize.

`store-api.hh` in particular is a bit of a sledgehammer, and the data
types we want to serialize have their own headers.
2023-05-18 00:20:24 -04:00
John Ericson
cb5052d98f Revert "Revert "Use template structs instead of phantoms""
This is the more typically way to do [Argument-dependent
lookup](https://en.cppreference.com/w/cpp/language/adl)-leveraging
generic serializers in C++. It makes the relationship between the `read`
and `write` methods more clear and rigorous, and also looks more
familiar to users coming from other languages that do not have C++'s
libertine ad-hoc overloading.

I am returning to this because during the review in
https://github.com/NixOS/nix/pull/6223, it came up as something that
would make the code easier to read --- easier today hopefully already,
but definitely easier if we were have multiple codified protocols with
code sharing between them as that PR seeks to accomplish.

If I recall correctly, the main criticism of this the first time around
(in 2020) was that having to specify the type when writing, e.g.
`WorkerProto<MyType>::write`, was too verbose and cumbersome. This is
now addressed with the `workerProtoWrite` wrapper function.

This method is also the way `nlohmann::json`, which we have used for a
number of years now, does its serializers, for what its worth.

This reverts commit 45a0ed82f0. That
commit in turn reverted 9ab07e99f5.
2023-05-17 22:44:47 -04:00
John Ericson
b9e5ce4a27 Upgrade downstreamPlaceholder to a type with methods
This gets us ready for dynamic derivation dependencies (part of RFC 92).
2023-05-17 17:41:16 -04:00