Struct ForwardBitWriter 

pub struct ForwardBitWriter { /* private fields */ }

Forward bitstream writer (LSB first).

Used for writing FSE table descriptions, various headers, and other forward-direction bitstream data in Zstandard frames.

Bits are packed into bytes starting from the least significant bit. When a byte is full, it is flushed to the output buffer and the accumulator resets.

Implementations

impl ForwardBitWriter

pub fn new() -> Self

Create a new forward bitstream writer.

pub fn with_capacity(byte_capacity: usize) -> Self

Create a new forward bitstream writer with a capacity hint.

pub fn write_bits(&mut self, value: u32, num_bits: u8)

Write num_bits bits from value (LSB first, up to 25 bits).

The lowest num_bits bits of value are written to the stream. Bits are packed into bytes starting from the least significant bit.

Panics

Panics if num_bits exceeds 25.

pub fn write_bit(&mut self, bit: bool)

Write a single bit (0 or 1).

pub fn finish(self) -> Vec<u8>

Flush remaining bits, padding with zeros to the next byte boundary.

Consumes the writer and returns the accumulated output bytes. If there are any pending bits that do not fill a complete byte, they are padded with zeros in the high bits.

pub fn bit_position(&self) -> usize

Current bit position (total number of bits written so far).

pub fn byte_len(&self) -> usize

Current byte length of the output (not counting partial byte).

pub fn is_empty(&self) -> bool

Whether no bits have been written yet.

pub fn as_bytes(&self) -> &[u8]

Get a reference to the bytes written so far (not including partial byte).

Trait Implementations

impl Default for ForwardBitWriter

fn default() -> Self

Returns the “default value” for a type.