commit 637777857f0843545d1a68f2b84e2a957895a59d
author Konstantin Shcheglov <scheglov@google.com> Tue Sep 30 08:59:41 2025 -0700
committer Commit Queue <dart-scoped@luci-project-accounts.iam.gserviceaccount.com> Tue Sep 30 08:59:41 2025 -0700
tree d95a72aaa6dd0c0c4f76a577f2aadbe10f2ecf7e
parent cd26fe29fb639e6e6d1e36e3983a6fe5018d80e9

Fine. Use digest in diagnostics bundle; drop in-memory cache

Introduce `RequirementsManifestDigest` to `LibraryDiagnosticsBundle` and
remove the driver's in-memory diagnostics bundle cache. Bundles are now
always read from the byte store; we first validate using the digest and
only fall back to a full requirements check when needed.

Key changes:
- Replace stored `RequirementsManifest` with:
  - a compact `RequirementsManifestDigest` for fast validation, and
  - the full manifest serialized as raw bytes, decoded on demand.
- Remove `_libraryDiagnosticsCache` and the API-signature validation
  path; reuse is governed by the digest + (rare) full check.
- Persist bundles via `LibraryDiagnosticsBundle.write(...)`.
- Bump `DATA_VERSION` to 569 to reflect the new on-disk layout.

Impact:
- Peak memory drops from 652 MB to 544 MB (−108 MB, −16.6%).
- The fine-deps mode is now within +32 MB (+6.25%) of the 512 MB
  baseline without fine-grained dependencies.
- Typical reuse gets a cheaper “is satisfied” check; full requirement
  deserialization is avoided on the common path.

Compatibility:
- The bundle format changed; older cached entries are invalidated by
  the data version bump. No public API behavior changes.

Rationale:
- Eliminates a large RAM resident cache while preserving fast re-use of
  diagnostics through a stable, order-independent digest.

Change-Id: I3479ca13bc48922ecd8fa351dbe53a0e3390a29e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/452224
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>