Add file-based transaction support and enhance revert functionality to support large size and number of changesets#9322
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khanaffan wants to merge 11 commits into
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Add file-based transaction support and enhance revert functionality to support large size and number of changesets#9322khanaffan wants to merge 11 commits into
khanaffan wants to merge 11 commits into
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Pull request overview
This PR enhances backend revert functionality to support very large changesets by leveraging native file-based transaction storage, and adds new API surface to control/inspect file-based transaction mode while improving revert cleanup behavior.
Changes:
- Add internal
BriefcaseDbAPIs to enable/disable and query file-based transaction mode (fileBasedTxnslocal value). - Extend
revertAndPushChangesto restore the pre-call file-based txn setting and add configurable failure cleanup viainCaseOfFailure. - Add an integration test that reverts schema+data changesets and verifies the resulting state across two briefcases.
Reviewed changes
Copilot reviewed 5 out of 5 changed files in this pull request and generated 7 comments.
Show a summary per file
| File | Description |
|---|---|
| full-stack-tests/backend/src/integration/TxnManager.test.ts | Adds an integration test covering revertAndPushChanges across two briefcases and validates reverted schema/data state. |
| core/backend/src/IModelDb.ts | Adds file-based txn toggles and updates revertAndPushChanges cleanup/restore logic and failure handling. |
| core/backend/src/BriefcaseManager.ts | Extends RevertChangesArgs with inCaseOfFailure to control cleanup strategy on failure. |
| common/changes/@itwin/core-backend/affank-file-based-txns_2026-05-20-15-09.json | Changelog entry for the revert robustness improvement. |
| common/api/core-backend.api.md | Updates extracted API to include new internal members and the updated RevertChangesArgs shape. |
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Agent-Logs-Url: https://github.com/iTwin/itwinjs-core/sessions/47500152-cc3d-4a11-b090-5fde1b1dda72 Co-authored-by: khanaffan <29756942+khanaffan@users.noreply.github.com>
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rschili
reviewed
May 21, 2026
| throw err; | ||
| } finally { | ||
| this[_nativeDb].abandonChanges(); | ||
| if (!wasFileBasedTxnsEnabled && !nativeDb.hasPendingTxns() && !nativeDb.hasUnsavedChanges()) |
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Suggested change
| if (!wasFileBasedTxnsEnabled && !nativeDb.hasPendingTxns() && !nativeDb.hasUnsavedChanges()) | |
| if (!wasFileBasedTxnsEnabled && !nativeDb.hasPendingTxns() && !nativeDb.hasUnsavedChanges() && this.isOpen) |
rschili
approved these changes
May 21, 2026
soham-bentley
approved these changes
May 22, 2026
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imodel-native: iTwin/imodel-native#1438
Issue
RevertTimelineChanges could not handle large amounts of changes or very large changesets. The limitation is SQLite's inability to store blobs greater than 2 GB in the dgn_Txn table. Reverting anything exceeding 2 GB resulted in a failure when SQLite could not allocate the blob.
Solution
Add support for file-based transaction storage. When enabled, changeset data is written to individual .txn files on disk (LZMA-compressed) rather than stored as blobs in dgn_Txns. Only a small header (signature + uncompressed size + SHA1 checksum) is stored in the Change column.
This is activated automatically when calling RevertTimelineChanges, which enables the fileBasedTxns briefcase-local property and saves each reverted changeset individually with SaveChanges("reverted changeset ").