RUBY-3712 Expose atClusterTime in snapshot sessions#3035
Merged
comandeo-mongo merged 1 commit intomongodb:masterfrom May 4, 2026
Merged
RUBY-3712 Expose atClusterTime in snapshot sessions#3035comandeo-mongo merged 1 commit intomongodb:masterfrom
comandeo-mongo merged 1 commit intomongodb:masterfrom
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Add a public, read-only snapshot_timestamp accessor on Mongo::Session and a :snapshot_time option to Client#start_session, so applications can both inspect and pre-seed the atClusterTime used by snapshot reads. The setter is idempotent: snapshotTime is established at most once per session, either from the option at construction or from the first server response. Update the unified test runner with a getSnapshotTime operation and entity-reference resolution for snapshotTime in sessionOptions, and refresh the YAML fixtures from the spec repo.
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Pull request overview
Exposes snapshot session atClusterTime (“snapshot time”) through Mongo::Session#snapshot_timestamp and adds unified-test-format support for getSnapshotTime plus fixture updates to validate pre-seeding snapshot time into new snapshot sessions.
Changes:
- Add
snapshot_timesession option validation and initialize@snapshot_timestampfrom it; makesnapshot_timestamppublicly readable and the writer idempotent. - Unified test runner: resolve
sessionOptions.snapshotTimeentity references and add agetSnapshotTimeoperation handler. - Refresh snapshot sessions unified YAML fixtures to cover “pre-seeded snapshotTime” scenarios across multiple operations.
Reviewed changes
Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.
Show a summary per file
| File | Description |
|---|---|
| spec/spec_tests/data/sessions_unified/snapshot-sessions.yml | Adds unified spec cases validating getSnapshotTime + snapshotTime pre-seeding behavior. |
| spec/runners/unified/test.rb | Builds session options with snapshotTime entity-reference resolution. |
| spec/runners/unified/support_operations.rb | Implements getSnapshotTime unified operation mapping. |
| spec/mongo/session_spec.rb | Adds unit tests for snapshot_time validation and timestamp exposure/idempotence. |
| lib/mongo/session.rb | Adds snapshot_time validation, stores initial snapshot timestamp, exposes snapshot_timestamp and makes writer idempotent. |
| lib/mongo/operation/shared/executable.rb | Simplifies snapshot timestamp capture to always attempt assignment for snapshot sessions. |
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| def snapshot_timestamp=(value) | ||
| @snapshot_timestamp ||= value | ||
| end |
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| if session.snapshot? && !session.snapshot_timestamp | ||
| if session.snapshot? | ||
| session.snapshot_timestamp = result.snapshot_timestamp |
| let(:options) { { snapshot: true, snapshot_time: initial_timestamp } } | ||
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| it 'is a no-op once a snapshot timestamp is set' do | ||
| session.snapshot_timestamp = later_timestamp |
jamis
approved these changes
Apr 30, 2026
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Adds the ability to read and pre-seed the snapshot timestamp on a snapshot session, per the snapshot-sessions spec and the unified-test-format addition for
getSnapshotTime.Changes
Mongo::Session#snapshot_timestampis now public and returns the BSON::Timestamp captured for the session, ornilfor a non-snapshot session and for snapshot sessions that haven't yet performed a read.Client#start_session(snapshot: true, snapshot_time: ts)accepts a pre-set snapshot time. Validates that:snapshot_timerequires:snapshot: trueand that the value is aBSON::Timestamp.@snapshot_timestamp ||= value), enforcing the spec's "snapshotTime must be read-only" rationale at the source of truth rather than at one call site. Removed the now-redundant guard inexecutable.rb.getSnapshotTimeoperation handler and entity-reference resolution forsnapshotTimeinsessionOptions, per unified-test-format.md §getSnapshotTime.snapshot-sessions.ymlfixtures from the spec repo.Test plan
bundle exec rubocopclean on all changed filesMONGODB_URI=... bundle exec rspec spec/spec_tests/sessions_unified_spec.rb spec/mongo/session_spec.rb spec/integration/snapshot_query_examples_spec.rb— 78 examples, 0 failures, 7 pre-existing pending:snapshot_timewithout:snapshot, non-Timestamp value) that aren't expressible in the unified test formatsnapshot_time) all passJira
RUBY-3712 (split from DRIVERS-2782)