Struct DecoderBuffer 

pub struct DecoderBuffer<'a> { /* private fields */ }

Available on crate feature decoder only.

Input buffer for reading compressed Draco data.

DecoderBuffer provides sequential byte and bit-level access to compressed data. It supports both byte-aligned reads (integers, floats, strings) and bit-level reads for entropy-coded data.

Example

use draco_core::DecoderBuffer;

let data = &[0x44, 0x52, 0x41, 0x43, 0x4F]; // "DRACO" header
let mut buffer = DecoderBuffer::new(data);

assert_eq!(buffer.decode_u8().unwrap(), 0x44);
assert_eq!(buffer.remaining_size(), 4);

Implementations

impl<'a> DecoderBuffer<'a>

pub fn new(data: &'a [u8]) -> Self

Creates a new DecoderBuffer from a byte slice.

pub fn set_version(&mut self, major: u8, minor: u8)

Sets the Draco bitstream version for version-dependent decoding.

pub fn version_major(&self) -> u8

Returns the major version number.

pub fn version_minor(&self) -> u8

Returns the minor version number.

pub fn bitstream_version(&self) -> u16

Returns the packed 0xMMmm bitstream version for ordered comparisons.

pub fn position(&self) -> usize

Returns the current read position in bytes.

pub fn set_position(&mut self, pos: usize) -> Result<(), DracoError>

Sets the read position.

Errors

Returns DracoError::BufferError if:

• Bit decoding is currently active
• Position is beyond the buffer length

pub fn remaining_size(&self) -> usize

Returns the number of bytes remaining in the buffer.

pub fn peek_bytes(&self, len: usize) -> Vec<u8>

Peeks at the next len bytes without advancing the position.

pub fn start_bit_decoding( &mut self, decode_size: bool, ) -> Result<u64, DracoError>

Starts bit-level decoding mode.

When decode_size is true, reads the bit sequence size from the buffer. Returns the size in bytes.

Errors

Returns DracoError::BufferError if bit decoding is already active.

pub fn end_bit_decoding(&mut self)

Ends bit-level decoding mode and advances the byte position.

pub fn decode_least_significant_bits32( &mut self, nbits: u32, ) -> Result<u32, DracoError>

Decodes nbits least significant bits as a u32.

Errors

Returns DracoError::BufferError if bit decoding is not active or end of stream.

pub fn decode_least_significant_bits32_fast( &mut self, nbits: u32, ) -> Result<u32, DracoError>

Optimized version for hot paths - reads multiple bytes at once.

pub fn decode<T: Copy + Pod>(&mut self) -> Result<T, DracoError>

Decodes a value of type T using raw memory copy.

Errors

Returns DracoError::BufferError if:

• Bit decoding is active
• Not enough bytes remaining

pub fn decode_u8(&mut self) -> Result<u8, DracoError>

Decodes a single byte.

pub fn decode_u16(&mut self) -> Result<u16, DracoError>

Decodes a little-endian u16.

pub fn decode_u32(&mut self) -> Result<u32, DracoError>

Decodes a little-endian u32.

pub fn decode_u64(&mut self) -> Result<u64, DracoError>

Decodes a little-endian u64.

pub fn decode_f32(&mut self) -> Result<f32, DracoError>

Decodes a little-endian f32.

pub fn decode_f64(&mut self) -> Result<f64, DracoError>

Decodes a little-endian f64.

pub fn decode_string(&mut self) -> Result<String, DracoError>

Decodes a null-terminated string.

pub fn decode_bytes(&mut self, out: &mut [u8]) -> Result<(), DracoError>

Decodes bytes into the provided buffer.

Errors

Returns DracoError::BufferError if not enough bytes remaining.

pub fn decode_varint(&mut self) -> Result<u64, DracoError>

Decodes a variable-length unsigned integer (varint).

pub fn decode_varint_signed_i32(&mut self) -> Result<i32, DracoError>

Decodes a Draco-compatible signed varint.

Uses unsigned varint encoding with ConvertSymbolToSignedInt transformation.

pub fn remaining_data(&self) -> &'a [u8]

Returns a slice of the remaining data without advancing.

pub fn advance(&mut self, n: usize)

Advances the position by n bytes without reading.

pub fn try_advance(&mut self, n: usize) -> Result<(), DracoError>

Advances the position by n bytes without reading.

Errors

Returns DracoError::BufferError if the requested advance would move beyond the end of the input buffer.

pub fn decode_slice(&mut self, size: usize) -> Result<&'a [u8], DracoError>

Decodes and returns a slice of the specified size.

Errors

Returns DracoError::BufferError if not enough bytes remaining.