write_u16_le
def write_u16_le(mut buf: List[UInt8], v: UInt16)roaring.portable
Shared constants and little-endian byte helpers for the Roaring "portable" serialization format (RoaringFormatSpec) — used by both the 32-bit container layer and the Bitmap32/Bitmap64 assemblers.
Format recap (see https://github.com/RoaringBitmap/RoaringFormatSpec):
- No run containers: 4-byte LE cookie
SERIAL_COOKIE_NO_RUNCONTAINER(12346), 4-byte LE container count N, N x (2-byte LE key, 2-byte LE cardinality-1), N x 4-byte LE offset (always present), then container bodies back to back. - Has run containers: 4-byte LE value combining cookie
SERIAL_COOKIE(12347) in the low 16 bits and (N-1) in the high 16 bits, a ceil(N/8)-byte bitset marking which containers are run containers, N x (2-byte LE key, 2-byte LE cardinality-1), then N x 4-byte LE offset UNLESS N <NO_OFFSET_THRESHOLD(in which case offsets are omitted), then container bodies.
Container promotion: an array container holds up to ARRAY_MAX_CARDINALITY
(4096) sorted UInt16 values (2 bytes each); above that it becomes a bitset
container (fixed BITSET_BYTES = 8192 bytes = 65536 bits). A run container
stores a 2-byte run count followed by that many (2-byte LE start, 2-byte LE
length-1) pairs, and is used only when run_optimize() finds it smaller.
Functions
write_u32_le
def write_u32_le(mut buf: List[UInt8], v: UInt32)write_u64_le
def write_u64_le(mut buf: List[UInt8], v: UInt64)read_u16_le
def read_u16_le[origin: Origin[mut=origin.mut], //](data: Span[UInt8, origin], pos: Int) -> UInt16read_u32_le
def read_u32_le[origin: Origin[mut=origin.mut], //](data: Span[UInt8, origin], pos: Int) -> UInt32read_u64_le
def read_u64_le[origin: Origin[mut=origin.mut], //](data: Span[UInt8, origin], pos: Int) -> UInt64Aliases
comptime SERIAL_COOKIE_NO_RUNCONTAINER = UInt32(12346)comptime SERIAL_COOKIE = UInt32(12347)comptime NO_OFFSET_THRESHOLD = Int(4)comptime ARRAY_MAX_CARDINALITY = Int(4096)comptime BITSET_WORDS = Int(1024)comptime BITSET_BYTES = Int(8192)