tinyset
tinyset
contains a few collections that are optimized to scale
in size well for small numbers of elements, while still scaling
well in time (and size) for numbers of elements. We now have
just a few types that you might care for.
-
[
Set64
] is a set for types that are 64 bits in size or less and areCopy
, intended for essentially integer types. This is our most efficient type, since it can store small sets with just the size of one pointer, with no heap storage. -
[
SetU64
] just holdsu64
items, and is the internal storage of [Set64
]. -
[
SetU32
] just holdsu32
items, and uses a bit less memory than [SetU64
]. -
[
SetUsize
] holdsusize
items, and uses either [SetU64] or [SetU32] internally.
All of these set types will do no heap allocation for small sets of small elements. On 64-bit systems, each set will store up to seven elements with no heap allocation, if the elements are small. The more elements there are, the smaller they need to be.
These sets all differ from the standard sets in that they iterate
over items rather than references to items, because they do not
store values directly in a way that can be referenced. All of the
type-specific sets further differ in that remove
and contains
accept values rather than references.
This crate has a single optional dependency (enabled by default), which
is the rand
crate, used for randomization to avoid DOS collision attacks.
You can speed up your compile by disabling this feature with
tinyset = { version = "0.4", default-features = false }
which will result in using a very simple pseudorandom number generator seeded by the system time.
Benchmarks
To run the benchmark suite, run
cargo bench
This will give you loads of timings and storage requirements for a wide variety of set types.