mmtkvdb

mmtkvdb is a crate for Rust which provides a memory-mapped key-value database. It uses LMDB and links with an existing liblmdb on the system.

Safety

Because of how memory-mapped I/O is being used and also because of certain assumptions of the underlying LMDB API, opening environments and databases requires unsafe Rust (i.e. the programmer must ensure that certain preconditions are met that cannot be enforced by the compiler to avoid undefined behavior). If you aim to program in safe Rust only, this Rust library is not suitable for you.

API Documentation

For documentation on how to use this crate, refer to the example in src/lib.rs.

License

See contained LICENSE file (MIT License).

Changelog

• 2023-03-07: Version 0.13.0
  • Added various cursor methods to Txn trait, which allow moving cursors without retrieving data
  • Removed deprecated implementation of Storable for () (use NoKey and/or NoValue instead of ())
• 2023-03-06: Version 0.12.1
  • Removed dependencies on unstable Rust features
  • Introduced NoKey and NoValue unit structs to replace () as type for databases which have no key or no value, respectively (this deprecates the implementation of Storable for ())
  • Added method which deletes all entries in database
  • New method TxnRw::on_commit allows registering a closure that will be executed on Txn::commit before the transaction is actually committed

For older changes, refer to the CHANGELOG.md file.