1 unstable release
0.3.1 | Apr 26, 2024 |
---|
#65 in #structures
260 downloads per month
Used in sbwt
445KB
7.5K
SLoC
Simple-sds-sbwt
This is a fork of simple-sds used in the sbwt crate.
Simple succinct data structures
These structures are comparable to those in SDSL in performance and scalability. As the focus is on (relative) simplicity, ugly low-level optimizations are generally avoided.
Implemented functionality
Integer vectors
RawVector
: A bit array that supports reading, writing, and appending 1-64 bits at a time. Implemented on top ofVec<u64>
.RawVectorWriter
: An append-only version ofRawVector
that writes the structure directly to a file.RawVectorMapper
: An immutable memory-mappedRawVector
.
IntVector
: A bit-packed vector of fixed-width integers implemented on top ofRawVector
. Likesdsl::int_vector
but also supports stack functionality.IntVectorWriter
: An append-only version ofIntVector
that writes the structure directly to a file. Like a subset ofsdsl::int_vector_buffer
.IntVectorMapper
: An immutable memory-mappedIntVector
.
WaveletMatrix
: An immutable vector of fixed-width integers. Similar tosdsl::wm_int
.- Supports
rank()
,inverse_select()
,select()
,predecessor()
, andsuccessor()
with each item value. - Iterators over all items and over items with a specified value.
- Implemented using a
BitVector
for each level.
- Supports
Bitvectors
BitVector
: A plain immutable bitvector.- Supports
rank()
,rank_zero()
,select()
,select_zero()
,predecessor()
, andsuccessor()
queries using optional support structures. - Iterators over set bits, unset bits, and all bits.
- Implemented on top of
RawVector
.
- Supports
RLVector
: A run-length encoded bitvector.- Supports
rank()
,rank_zero()
,select()
,select_zero()
,predecessor()
, andsuccessor()
queries. - Iterators over set bits and all bits.
- Space-efficient construction with
RLBuilder
.
- Supports
SparseVector
: An Elias-Fano encoded bitvector.- Supports
rank()
,rank_zero()
,select()
,select_zero()
,predecessor()
, andsuccessor()
queries . - Iterators over set bits and all bits.
- Space-efficient construction with
SparseBuilder
.
- Supports
Planned functionality
Integer vectors
- Mutable memory-mapped vectors.
Bitvectors
- Versions of
predecessor()
andsuccessor()
that return values instead of iterators? - Slice-like functionality based on iterators?
Notes
- The included
.cargo/config.toml
sets the target CPU tonative
. - This crate is designed for the x86_64 architecture with the BMI2 instruction set (Intel Haswell / AMD Excavator or later). Some operations may be slow without the POPCNT, LZCNT, TZCNT, and PDEP instructions.
- 64-bit ARM is also supported.
- Unix-like operating system is required for
mmap()
. - Things may not work if the system is not little-endian or if
usize
is not 64-bit.
Dependencies
~0.4–475KB