Stop delegating to `HttpBinaryCacheStore::upsertFile` and instead
handle compression in the S3 store's `upsertFile` override, then call
our own `upload()` method. This separation is necessary for future
multipart upload support.
Introduce protected `upload` method overloads in `HttpBinaryCacheStore`
that handle the actual upload after compression has been applied. This
separates compression concerns (in `upsertFile`) from upload mechanics
(in `upload`).
Two overloads are provided:
1. `upload(path, RestartableSource &, sizeHint, mimeType, contentEncoding)`
2. `upload(path, CompressedSource &, mimeType)`
Introduce a `CompressedSource` class in libutil's `serialise.hh` that
compresses a `RestartableSource` and owns the compressed data. This is a
general-purpose utility that can be used anywhere compressed data needs
to be treated as a source.
Make uploads run in constant memory. Also change the callbacks to be
noexcept, since we really don't want to be unwinding the stack in the
curl thread. That will definitely corrupt that stack and make nix/curl
crash in very bad ways.
Fix a race condition where interrupting a download (via Ctrl-C) during a
retry attempt could cause a crash. When `enqueueItem()` throws because the
download thread is shutting down, the exception would propagate without
setting `done=true`, causing the `TransferItem` destructor to invoke the
callback a second time.
This triggered an assertion failure in `Callback::rethrow()` with:
`Assertion '!prev' failed` and the error message `cannot enqueue download
request because the download thread is shutting down`.
The fix catches the exception from `enqueueItem()` and calls `fail()` to
properly complete the transfer, ensuring the callback is invoked exactly
once.
Implement `uploadPart()` for uploading individual parts in S3 multipart
uploads:
- Constructs URL with `?partNumber=N&uploadId=ID` query parameters
- Uploads chunk data with `application/octet-stream` mime type
- Extracts and returns `ETag` from response
This is a good default (the methods that allow for an arbitrary choice
of source accessor are generally preferable both to implement and to
use). And it also pays its way by allowing us to delete *both* the
`DummyStore` and `LocalStore` implementations.
Introduces `scanForReferencesDeep` to provide per-file granularity when
scanning for store path references, enabling better diagnostics for
cycle detection and `nix why-depends --precise`.
Implement `abortMultipartUpload()` for cleaning up incomplete multipart
uploads on error:
- Constructs URL with `?uploadId=ID` query parameter
- Issues `DELETE` request to abort the multipart upload
The `showBytes()` function was redundant with `renderSize()` as the
latter automatically selects the appropriate unit (KiB, MiB, GiB, etc.)
based on the value, whereas `showBytes()` always formatted as MiB
regardless of size.
Co-authored-by: Bernardo Meurer Costa <beme@anthropic.com>
In particular
- Remove `get`, it is redundant with `valueAt` and the `get` in
`util.hh`.
- Remove `nullableValueAt`. It is morally just the function composition
`getNullable . valueAt`, not an orthogonal combinator like the others.
- `optionalValueAt` return a pointer, not `std::optional`. This also
expresses optionality, but without creating a needless copy. This
brings it in line with the other combinators which also return
references.
- Delete `valueAt` and `optionalValueAt` taking the map by value, as we
did for `get` in 408c09a120, which
prevents bugs / unnecessary copies.
`adl_serializer<DerivationOptions::OutputChecks>::from_json` was the one
use of `getNullable`. I give it a little static function for the
ultimate creation of a `std::optional` it does need to do (after
switching it to using `getNullable . valueAt`. That could go in
`json-utils.hh` eventually, but I didn't bother for now since only one
things needs it.
Co-authored-by: Sergei Zimmerman <sergei@zimmerman.foo>
S3 buckets support object versioning to prevent unexpected changes,
but Nix previously lacked the ability to fetch specific versions of
S3 objects. This adds support for a `versionId` query parameter in S3
URLs, enabling users to pin to specific object versions:
```
s3://bucket/key?region=us-east-1&versionId=abc123
```
Move HttpBinaryCacheStore class from .cc file to header to enable
inheritance by S3BinaryCacheStore. Create S3BinaryCacheStore class that
overrides upsertFile() to implement multipart upload logic.
