[thweetkomputer]

Context

Grouped range, rank and count reads take whole-key S and wait for unrelated group writers. Let these projections use key IS and protect only the payload groups they require.

Behavior before and after

Grouped ZRANGE aliases, ZRANK/ZREVRANK, ZCOUNT and ZLEXCOUNT acquire the required group S holds in identity order, revalidate routing and capture one immutable directory for counts and bounds. Rank also protects its member leaf. Ambiguous routing falls back once to key S.

Score counts lock partial boundary pages. Score LIMIT/OFFSET uses resident ranks to skip unrelated pages, including reverse ranges. Mixed-score lexical projections protect every ordered page because there is no lexical directory.

Implementation

Page loaders validate protected group revisions while unrelated roots publish. The common logical view is captured after acquisition, so concurrent changes to preceding cardinality cannot shift a range midway through its read.

Optional OnlineLatencyTrace* diagnostics is the final parameter in the affected storage helpers. Group-lock flags, retry outputs and deferred commit state precede it. Declarations, definitions and callers use the same order; callers that supply diagnostics explicitly supply any preceding default control argument. The dependent PRs apply the same convention to their additional helpers and calls.

Design decisions and alternatives

Retain group holds across waits and IO, with one whole-key fallback when routing cannot be validated. Parameter reordering preserves each argument value and default, including group_locked; it does not treat a diagnostic pointer as a Boolean flag.

Documentation and comments

The grouped-collections architecture describes IS range/rank/count projections and their common-view boundary. Existing ownership and lock-precondition comments remain applicable to the parameter-order cleanup, which does not change that architectural model.

Test plan

The Debug build for this PR passed, followed by 25 focused tests: 24 CTest cases plus the trace lifecycle metrics test. Coverage includes range/rank/count semantics, lock wait/wakeup, member projections, recovery, native replication, dependent commits and latency tracing.

cmake --build build_debug --target lavik lavik_unit_tests lavik_grouped_ordered_write_e2e_test lavik_metrics_e2e_test --parallel 4
ctest --test-dir build_debug --output-on-failure --stop-on-failure -R '^(StorageGroupedReadDeathTest|StorageGroupedReadTest|LatencyIntervalsTest)\.|^StorageWriteBufferResumeTest\.PreparedSameKeyPlansMergeWithoutLosingEitherGraph$|^lavik_grouped_ordered_write_e2e\.GroupedSortedSetWriteE2e\.(MemberReadsLockOnlyRequestedLeaves|RangeReadsKeepOneCutWhileOtherGroupsPublish|ConcurrentGroupsWaitWakeAndRecover|ConcurrentPointCommandsPreserveBothIndexes|MemberScoreProjectionPreservesOrderAndRecovery|MemberRanksSkipUnrelatedPagesAfterRecovery|ScoreBoundsSkipUnrelatedPagesAfterRecovery|ScoreCountsSkipInteriorPagesAfterRecovery|ScoreCountsTrackBoundsMutationsAndRecovery|ScoreOffsetsSkipInteriorPagesAfterRecovery|ScoreOffsetsRespectBoundsAndTiesAcrossPages|BoundedRangeAliasesRanksBoundsAndMixedScoreLex|RangeRemovalFitsSelectedPagesAndRecovers|RandomAndRangeRemovalPreserveSemantics|GeoPointReadsPreserveRepliesAndExecVisibility)$|^lavik_latency_diagnostics_e2e$|^lavik_native_replicaof_e2e$|^lavik_tx_commit_retry_e2e\.dependent$'
build_debug/lavik_metrics_e2e_test build_debug/lavik --gtest_filter=MetricsE2eTest.OnlineLatencyTraceLifecycleAndThreshold

The first latency E2E attempt received HTTP 502 because the environment proxied its loopback metrics request. That case and the remaining dependent-commit case passed with loopback proxy bypass:

NO_PROXY=127.0.0.1,localhost no_proxy=127.0.0.1,localhost ctest --test-dir build_debug --output-on-failure --stop-on-failure -R '^lavik_latency_diagnostics_e2e$|^lavik_tx_commit_retry_e2e\.dependent$'

The complete stack through #441 also built and passed 17 focused tests for Hash/Set intents and sampling, replication TTL fallback, zset batch/selected writes and latency diagnostics:

cmake --build build_debug --target lavik lavik_unit_tests lavik_grouped_ordered_write_e2e_test lavik_grouped_hash_write_e2e_test --parallel 4
NO_PROXY=127.0.0.1,localhost no_proxy=127.0.0.1,localhost ctest --test-dir build_debug --output-on-failure --stop-on-failure -R '^lavik_grouped_hash_write_e2e\.(GroupedHashWriteE2e\.(Intent.*|ConcurrentFinalDeletionRetriesUnderKeyX)|GroupedSetIntentE2e\..*|GroupedHashSetSamplingE2e\..*)$|^lavik_grouped_ordered_write_e2e\.GroupedSortedSetWriteE2e\.(SamplingReadsLockOnlyTheirWindow|BatchWritesOrderAllGroupsAndPublishAtomically|SelectedWritesProtectPredicatesAndAllowMemberReads|PopRevalidatesSelectionAfterReleasingReadLocks)$|^lavik_latency_diagnostics_e2e$'

Formatting checks passed. Each rebased tree was checked against the prior source with only the parameter-order transformation applied.

Risk assessment

The relevant boundaries are routing revalidation, group-lock lifetime, common-view consistency and trace forwarding. The focused tests exercise these paths, including disjoint progress and conflicting writers. Compact values and externally locked transaction callers retain their existing protection; durable formats and wire replies are unchanged.

Rollback plan

Revert the feature and helper-signature changes together with dependent call-site updates. No storage migration is required.

Reviewer guide

Start with TryConcurrentSortedSetRangeRead, then the grouped page loaders and ExecuteGroupedSortedSetLocked. The parameter-order cleanup is a separate commit. This PR is based directly on main.

Follow-up work

PRs #436–#441 extend intent locking to sampling, additional writes and Hash/Set operations. Their callers have been adapted to the final diagnostics parameter and remain independently reviewable against their immediate bases.

[coderabbitai]

Caution

Review failed

The pull request is closed.

• Autofix · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

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Cppcheck (2.22.0)

src/storage/engine/grouped/list.cpp

Cppcheck timed out; analysis of this file is incomplete

src/storage/engine/grouped/ordered_io.cpp

Cppcheck timed out; analysis of this file is incomplete

src/storage/engine/compact_api.cpp

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