Add bounded atomic SQL dump import

[findolor]

Related PRs and issue

• RAI-2650
• Producer grouped SQL change: raindex#2893. This PR adds an upstream import API for the subsequent browser integration; neither PR needs the other to merge.
• Builds on the existing transaction(statements) API from sqlite-web#28.

Motivation

The browser bootstrap currently creates a JS/Rust worker request and SQLite statement for each imported SQL statement. Grouping rows on the producer side reduces transport overhead, but the browser still needs a bounded way to stream SQL into one atomic import without exposing partial data across tabs.

Solution

• Add beginSqlDumpImport, appendSqlDumpChunk, finishSqlDumpImport, and cancelSqlDumpImport to the public wasm API. The database worker owns one BEGIN IMMEDIATE transaction across chunks and commits only after a successful finish; SQL errors, invalid chunks, cancellation, and abandoned sessions roll back.
• Parse SQL incrementally across chunk boundaries, including strings, comments, and trigger bodies. Bound each UTF-8 chunk to 512 KiB and an unfinished statement to 16 MiB. Reject row-returning statements during import to avoid collecting unbounded results.
• Reject connection PRAGMA settings, EXPLAIN, and ATTACH/DETACH before preparation so failures cannot leave connection changes that transaction rollback would not undo. Accept and skip the standard PRAGMA foreign_keys=OFF;/=0 dump header while preserving existing foreign-key enforcement.
• Reject unpaired UTF-16 surrogates before conversion or dispatch. A cached JavaScript regex validates each chunk with one call across the Wasm boundary.
• Run all core import tests against SQLite's memory VFS without silently skipping failed opens, alongside real OPFS browser integration. Cover partial lexical states, triggers, statement limits, rollback, cancellation, and caller-visible leader-loss outcomes.
• Route import actions through the existing leader/follower coordinator. Reject competing queries and transactions while an import is active, limit outstanding import work, and expire abandoned imports after 120 seconds of inactivity on the next request or 30-second watchdog tick. An import response is reported only after the database worker resolves it, so a delayed commit cannot be reported as a follower timeout.
• Document the API and limits; add browser integration tests and an isolated synthetic benchmark.

This PR does not change the producer, the browser bootstrap call site, the dump format, or the published package version. The repository's main-branch release workflow publishes the next patch version after merge.

Checks

• nix develop -c build-submodules
• nix develop -c local-bundle
• nix develop -c rainix-rs-static
• Core WASM tests in Chrome: 123 passed (14 core import tests execute through the memory VFS)
• Public WASM tests in Chrome: 42 passed
• nix develop -c npm test in svelte-test: 170 passed, 4 existing skips
• nix develop -c npm run lint-format-check in svelte-test
• git diff --check

The WASM suites ran under Nix with cargo test --workspace --target wasm32-unknown-unknown and the cached matching wasm-bindgen-test runner. Locally, Chrome is 154 and ChromeDriver is 144; driver build checking was disabled for these runs. The packaged browser integration suite also passed under Playwright Chromium. CI runs the repository's standard test-wasm wrapper on Linux.

In an isolated browser benchmark of 10,000 equal rows, the existing transaction statement array took 59.3 ms and grouped SQL chunk import took 17.1 ms (about 3.5× faster). This measures import only; it excludes download, full dump parsing, indexing, and end-to-end bootstrap. The raindex browser integration should measure those separately.

Review focus: cross-tab serialization, transaction-marker handling, containment of connection state, and rollback behavior when a chunk or finish fails. A leader change before an import response reports an unknown outcome to the caller. Any lost finish response requires checking/resetting the database before retrying; the new test deliberately stalls a DB-worker response to make that path deterministic.

Local Codex review completed three rounds with four reviewers and no OpenCode supplement. The review fixes also close the EXPLAIN PRAGMA bypass and prevent attachment changes from surviving cancellation.

Summary by CodeRabbit

• New Features
  • Added support for importing SQL dumps in chunks, with controls to begin, finish, or cancel an import.
  • Imports validate input and SQL statements, reject unsupported operations, and roll back on errors or after 120 seconds of inactivity. Regular database operations are blocked while an import is active.
• Documentation
  • Added guidance on streaming SQL dumps, import constraints, failure handling, and checking the database before retrying when the commit outcome is unknown.

[linear]

RAI-2650

[findolor]

• Add bounded atomic SQL dump import #35 👈 (View in Graphite)
• main

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

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Run ID: 9e731055-ee09-4891-8b93-5adf6edd7c34

📥 Commits

Reviewing files that changed from the base of the PR and between af0c055 and 4cbc50a.

📒 Files selected for processing (6)

• docs/sql-dump-import.md
• packages/sqlite-web-core/src/coordination.rs
• packages/sqlite-web-core/src/database.rs
• packages/sqlite-web-core/src/messages.rs
• packages/sqlite-web/src/db.rs
• svelte-test/tests/integration/sql-dump-import.test.ts

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Walkthrough

This change adds streamed SQL dump imports to the SQLite database API. It defines import actions and database behavior, routes requests through workers, and adds client methods, documentation, tests, and a benchmark.

Changes

SQL dump import flow

Layer / File(s)	Summary
Import protocol and database execution packages/sqlite-web-core/src/messages.rs, packages/sqlite-web-core/src/database.rs	Adds import action messages and database handling for chunked SQL, transaction markers, session ownership, size limits, rollback, and idle expiry. Database tests cover parsing, execution, and rollback cases.
Worker routing and import expiry packages/sqlite-web-core/src/coordination.rs	Routes import actions through worker and broadcast paths, queues requests, rejects an import when another import is queued, and starts a watchdog after a successful Begin.
Client API and usage validation packages/sqlite-web/src/db.rs, docs/sql-dump-import.md, svelte-test/tests/integration/*, svelte-test/benchmarks/*, svelte-test/vitest.benchmark.config.js	Adds client methods to begin, append, finish, and cancel imports. Documentation describes limits and failure behavior. Integration tests cover import outcomes and concurrent requests; a benchmark compares import paths.

Priority: ➖ Normal

Estimated code review effort: 4 (Complex) | ~45 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant SQLiteWasmDatabase
  participant handle_main_message
  participant DbWorkerState
  participant SQLiteDatabase
  SQLiteWasmDatabase->>handle_main_message: Send import action
  handle_main_message->>DbWorkerState: Forward import job
  DbWorkerState->>SQLiteDatabase: Call import_sql_action
  SQLiteDatabase-->>DbWorkerState: Return import result
  DbWorkerState-->>SQLiteWasmDatabase: Deliver response

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Merge Risk: ⚪ Minimal · up to 4cbc5

The import now accepts standard SQLite dump markers and empty statements, and interrupted follower requests report an unknown outcome without blocking subsequent imports. No actionable merge-blocking risk remains beyond normal checks.

Security Architecture Review

Security architecture risk: 🔵 Low · up to 4cbc5

The import design limits input buffering, prevents dump SQL from controlling transaction boundaries, and commits only on successful completion. No material privilege expansion was established. Recovery after a low-level rollback failure remains unproven, so the assessment is not minimal risk.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The directly affected security scope is the shared browser database and callers using its channel. Supplied SQL can modify that database, and an active import rejects competing operations across its clients. The inspected flow does not establish cross-origin, backend-service, credential, or infrastructure authority.

Security Findings and Attack Paths

• inferred — A same-origin channel participant observing an import session ID can submit matching append, finish, or cancel actions because the protocol carries no authenticated owner identity. However, participants on this channel already had arbitrary SQL access before this PR. This is a trust-model limitation, not an established new privilege escalation or cross-origin attack path.

Trust Boundaries and Controls

• observed — Leader/readiness gates preserve database-worker ownership, while random session IDs reject mismatched actions. SQL-level controls separately prevent transaction-boundary and non-rollbackable connection-state changes. Session matching is not sender authentication.

Resilience and Maintainability Implications

• observed — The client limits outstanding import requests and the database queue rejects an additional queued import. Idle cleanup checks every 30 seconds against a 120-second threshold, subject to browser scheduling. These controls do not bound total SQL execution time or the ordinary-work queue; that queue was already unbounded before this change.

Hardening Proposals

• proposed — Make cleanup confirm SQLite autocommit before admitting subsequent work; otherwise quarantine or recreate the connection and return an uncertain-cleanup error. Fault-injection coverage could validate this recovery invariant without assuming rollback always succeeds.
• proposed — Document that same-origin participants sharing the database channel belong to one trust domain. If future integrations require mutually untrusted callers, introduce authenticated ownership and caller admission controls rather than treating the broadcast session ID as an isolation boundary.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 74 functions across 7 files. (1 skipped: …	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: adding a bounded, atomic SQL dump import API.

Full details: Docstring Coverage

Explanation

Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 74 functions across 7 files. (1 skipped: 1 unsupported.)

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Actionable comments posted: 4

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Inline comments:
Review comments at @packages/sqlite-web-core/src/coordination.rs:
- Around line 564-575: Update the leader-change handling for NewLeader and
LeaderReady to detect when the leader differs from the current one, remove
pending imports from follower_pending, and resolve each with an error indicating
the SQL dump import was rolled back. Locate the pending import tracking
alongside ImportRequest handling in the coordination flow.

Review comments at @packages/sqlite-web-core/src/database.rs:
- Around line 316-318: Update the statement handling around is_sql_trivia_only
and first_sql_keyword_and_tail so a statement containing only SQL trivia and its
terminating semicolon is skipped as a no-op. Preserve keyword parsing for
statements with SQL content.
- Around line 319-329: Update the outer transaction-marker checks around
`state.saw_begin` and `state.saw_commit` to accept valid `BEGIN`
mode/`TRANSACTION` suffixes and `COMMIT` or `END` markers, without requiring
`statement_count` to be zero; still allow only one well-formed marker pair. Add
an import test for a dump beginning with `PRAGMA foreign_keys=OFF;` and `BEGIN
TRANSACTION;` and ending with `COMMIT;`.

Review comments at @packages/sqlite-web-core/src/messages.rs:
- Around line 24-31: Extend test_worker_message_execute_batch_serialization with
wire-format serialization and round-trip assertions for the import-sql-dump and
import-request envelopes, covering SqlImportAction::Begin and the relevant
payload variant; verify the envelope fields and kebab-case kind values match the
JS client.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Advanced

Run ID: f688b48a-7970-414f-aad0-82664e9b2493

📥 Commits

Reviewing files that changed from the base of the PR and between 5d3c9eb and af0c055.

📒 Files selected for processing (8)

• docs/sql-dump-import.md
• packages/sqlite-web-core/src/coordination.rs
• packages/sqlite-web-core/src/database.rs
• packages/sqlite-web-core/src/messages.rs
• packages/sqlite-web/src/db.rs
• svelte-test/benchmarks/sql-dump-import.benchmark.ts
• svelte-test/tests/integration/sql-dump-import.test.ts
• svelte-test/vitest.benchmark.config.js

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[ueco-jb]

The import core is sound. Chunks are scanned correctly across boundaries in every lexical state, trigger bodies are closed by sqlite3_complete, and transaction control statements inside the dump are rejected. The row-returning check runs before sqlite3_step. Every failure path drops import_state after the rollback, so a later finish cannot commit partial data. Other queries, batches and a second begin are rejected while a session is active. One liveness defect remains on the follower path. The other comments cover connection state that the rollback does not undo, input the worker silently changes, and tests that do not prove the claimed behaviour.