🔴 Migrate gp-storage FFI from Kùzu (kuzu_*) to LadybugDB (lbug crate)

[web3guru888]

Summary

Migrate gp-storage FFI bindings from Kùzu (kuzu_*) to LadybugDB (lbug_*). KuzuDB was archived in October 2025 — no further security patches or development.

Findings

Affected Files

File	References	Nature
rust/gp-storage/src/ffi.rs	131 refs	CRITICAL: Hand-rolled C FFI — all kuzu_* struct/function names
rust/gp-storage/src/safe.rs	87 refs	CRITICAL: Safe Rust wrappers around FFI
rust/gp-storage/src/lib.rs	3 refs	Module declarations with kuzu-ffi feature gate

Migration Path

LadybugDB is 95%+ API compatible with Kùzu. The C API symbols changed prefix:

• kuzu_database_init() → lbug_database_init()
• kuzu_connection_init() → lbug_connection_init()
• kuzu_query_result_* → lbug_query_result_*
• etc.

Two Options

1. Rename FFI symbols — sed s/kuzu_/lbug_/g on ffi.rs + safe.rs, update link directive. ~1 day.
2. Replace with lbug crate — Drop hand-rolled FFI entirely, use the published lbug = "0.16" crate. More work but cleaner long-term. ~2-3 days.

Recommendation: Option 2 (replace with crate)

• Published crate (lbug) has safe Rust API, no unsafe FFI needed
• Maintained by community — we don't carry FFI maintenance burden
• Future LadybugDB updates are just cargo update
• Breaking change from kuzu's API: ~5% of calls need adjustment (documented in migration report)

Testing

• All 694 existing tests must pass
• Add integration test with LadybugDB persistent database
• Verify Cypher DDL schema from kuzu-schema-design.md works unchanged

References

• Migration report: 2026-05-15-kuzu-to-ladybug-migration.md (634 lines)
• LadybugDB crate: https://crates.io/crates/lbug (v0.16.1, 43K downloads)
• LadybugDB repo: https://github.com/ladybugdb/ladybugdb (1,134 stars)

Estimated Effort

• Option 1 (rename): 1 day
• Option 2 (replace with crate): 2-3 days ← recommended
• Testing: 1 day