A lock-free thread-safe arena based Skiplist impelementation for building memtable.
APACHE-2.0 License
SkipMap
implementation based on ARENA skiplist which helps develop MVCC memtable for LSM-Tree.SkipMap
.Only use heap backend (suppport no_std
)
[dependencies]
skl = "0.18"
Enable memory map backend
[dependencies]
skl = { version = "0.18", features = ["memmap"] }
SkipMap
provide lock-free operations, ensuring efficient concurrent access without the need for explicit locking mechanisms.SkipMap
offer a flexible foundation for key-value database developers. You can easily build your own memtable or durable storage using these structures.CompressionPolicy::High
).SkipMap
. Additionally, bounded iterators are supported, allowing you to traverse only a specified range of elements efficiently.SkipMap
, offering a read-only view of the contents at a specific moment in time. Snapshots provide a consistent view of the data, enabling implementations of transactional semantics and other use cases where data consistency is crucial.Please see examples folder for more details.
Does the on-disk version SkipMap
ensure crash safety or power failure resilience?
No, If you really need a crash safe, power failure resilience, concurrent-safe and durable ordered write-ahead log implementation,
see orderwal
project.
On-disk version SkipMap
does not ensure crash safety or power failure resilience. Hence, it is not recommended to directly
use the SkipMap
as a durable database. It is recommended to use the on-disk version SkipMap
as a final frozen file for quick lookup.
aol
: Yet another generic purpose, append-only write-ahead log implementation.orderwal
: A generic-purpose, atomic, ordered, zero-copy, concurrent-safe, pre-allocate style (memory map) write-ahead-log for developing databases.test
:
cargo test --all-features
miri
(Stack Borrows)
MIRIFLAGS="-Zmiri-strict-provenance -Zmiri-disable-isolation -Zmiri-symbolic-alignment-check" \
RUSTFLAGS = "--cfg all_tests" \
cargo miri test --all-features
miri
(Tree Borrows)
MIRIFLAGS="-Zmiri-strict-provenance -Zmiri-disable-isolation -Zmiri-symbolic-alignment-check -Zmiri-tree-borrows" \
RUSTFLAGS = "--cfg all_tests" \
cargo miri test --all-features
See cross
section in GitHub CI file.
This code is inspired and modified based on Cockroachdb's pebble arenaskl and Dgraph's badger skl code:
https://github.com/cockroachdb/pebble/tree/master/internal/arenaskl
https://github.com/dgraph-io/badger/tree/master/skl
The pebble's arenaskl code is based on Andy Kimball's arenaskl code:
https://github.com/andy-kimball/arenaskl
The arenaskl code is based on the skiplist found in Badger, a Go-based KV store:
https://github.com/dgraph-io/badger/tree/master/skl
The skiplist in Badger is itself based on a C++ skiplist built for Facebook's RocksDB:
https://github.com/facebook/rocksdb/tree/master/memtable
skl
is under the terms of both the MIT license and the
Apache License (Version 2.0).
See LICENSE-APACHE, LICENSE-MIT for details.
Copyright (c) 2022 Al Liu.