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

• 2022-06-20: Version 0.3.1
  • Accept StorableRef instead of references to Storable in more places
    • Allow passing StorableRef instead of reference to Storable as key to method Txn::get_owned (which was already allowed for Txn::get)
    • More generic implementation of StorableRef for tuples (e.g. (&i32, &String) in addition to (&i32, &str)), which enhances usability in some cases
• 2022-05-26: Version 0.3.0
  • Storing owned types differently
    • Removed implementation of Storable for certain smart pointers such as Vec<u8> and String
    • New traits BorrowStorable and StorableRef which handle storing tuples in a more efficient way (without unnecessary cloning/copying)
  • Improved documentation in module storable
  • Minor style change: Renamed type arg from X to T for generic structs in owning_pointer

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