tmfalloc-0.1.1 has been yanked.

TMFAlloc: Transactional Mapped File Allocator for Rust

Transactional memory-mapped file allocator inspired by POST++. May be useful as fixed-schema client or embedded application data cache/storage, etc.

Features

File-backed memory-mapped storage.
Implements std::alloc::Allocator trait, so usual std::collections::\* (except Hash\*), std::boxed::Box, etc. containers could be stored in and retreived from the file.
Single writer/multiple reader in multi-threaded code.
Write transactions exploit memory page protection and copy-on-write log file.
Every concrete storage has user-defined Root generic structure instance to store all the application-specific collections.
Storage file is flock-protected, so simultaneous processes access is possible.
Allocates the least but fittable free block with the least address among all equally-sized blocks.
Average allocation and deallocation cost is O(log(number of free blocks)) (plus possible file operations costs).
Allows allocation arena expansion.

Only Linux platforms are supported at the moment.
Storage Holder does not endure process fork.
unsafe-saturated, so highly experimental.
Explicit memory mapping address selection on storage initialization is recommended.
Memory allocation quantum is 32 or 64 bytes on, respectively, 32 or 64-bit architectures.

tests::page_boundary: Test two adjastent pages border handling with 8-byte word write.
tests::read_recovery: Fix and test broken transaction detection and rollback after flock in Holder::read() and Holder::write() to allow parallel writing process to crash.
Memory areas overlapping detection test example in the crate's documentation.

Concurrent threads access tests to detect race conditions.
Allocator::shrink and grow methods.
64 bytes allocation quantum may be too much. Two RBTrees holding free blocks may be too slow. Any suggestions on how to improve this?
Window$ support.
Main file page mlock-ing instead of log file immediate fsync in signal handler to increase write throughput and decrease latency.
Test multi-process concurrent read and exclusive write access.

Vladimir Voznesenskiy <vvoznesensky@yandex.ru>. Looking for interesting Rust job.

Comments, suggestions, bug reports, pull requests, praises and reasonable curses are welcome.