Struct dsi_bitstream::impls::BufBitReader

pub struct BufBitReader<E: Endianness, WR: WordRead, RP: ReadParams = DefaultReadParams>
where
    WR::Word: DoubleType,
{ /* private fields */ }

An implementation of BitRead and BitSeek for a WordRead and a WordSeek.

This implementation uses a bit buffer to store bits that are not yet read. The buffer is sized as twice the word size of the underlying WordRead. Typically, the best choice is to have a buffer that is sized as usize, which means that the word of the underlying WordRead should be half of that (i.e., u32 for a 64-bit architecture). However, results will vary depending on the CPU.

The peek word is equal to the bit buffer. The value returned by peek_bits contains at least as many bits as the word size plus one (extended with zeros beyond end of stream).

This implementation is usually faster than BitReader.

The additional type parameter RP is used to select the parameters for the instantanous codes, but the casual user should be happy with the default value. See ReadParams for more details.

Implementations

impl<E: Endianness, WR: WordRead, RP: ReadParams> BufBitReader<E, WR, RP>

where WR::Word: DoubleType,

pub fn new(backend: WR) -> Self

Create a new BufBitReader around a WordRead.

Example

use dsi_bitstream::prelude::*;
let words: [u32; 2] = [0x0043b59f, 0xccf16077];
let word_reader = MemWordReader::new(&words);
let mut buf_bit_reader = <BufBitReader<BE, _>>::new(word_reader);

Trait Implementations

impl<WR: WordRead, RP: ReadParams> BitRead<BigEndian> for BufBitReader<BE, WR, RP>

where WR::Word: DoubleType + UpcastableInto<u64>, <<WR as WordRead>::Word as DoubleType>::DoubleType: CastableInto<u64>,

type Error = <WR as WordRead>::Error

type PeekWord = <<WR as WordRead>::Word as DoubleType>::DoubleType

The type we can read from the stream without advancing.

fn peek_bits(&mut self, n_bits: usize) -> Result<Self::PeekWord, Self::Error>

Peeks at n bits without advancing the stream position. n must be nonzero, and at most PeekWord::BITS.

fn skip_bits(&mut self, n_bits: usize) -> Result<(), Self::Error>

Skip n bits from the stream.

fn read_bits(&mut self, n_bits: usize) -> Result<u64, Self::Error>

Read n bits and return them in the lowest bits.

fn read_unary_param<const USE_TABLE: bool>( &mut self ) -> Result<u64, Self::Error>

Read a unary code.

fn read_unary(&mut self) -> Result<u64, Self::Error>

Read a unary code.

fn skip_unary(&mut self) -> Result<(), Self::Error>

Skip a unary code.

impl<WR: WordRead, RP: ReadParams> BitRead<LittleEndian> for BufBitReader<LE, WR, RP>

where WR::Word: DoubleType + UpcastableInto<u64>, <<WR as WordRead>::Word as DoubleType>::DoubleType: CastableInto<u64>,

type Error = <WR as WordRead>::Error

type PeekWord = <<WR as WordRead>::Word as DoubleType>::DoubleType

The type we can read from the stream without advancing.

fn skip_bits(&mut self, n_bits: usize) -> Result<(), Self::Error>

Skip n bits from the stream.

fn read_bits(&mut self, n_bits: usize) -> Result<u64, Self::Error>

Read n bits and return them in the lowest bits.

fn peek_bits(&mut self, n_bits: usize) -> Result<Self::PeekWord, Self::Error>

Peeks at n bits without advancing the stream position. n must be nonzero, and at most PeekWord::BITS.

fn read_unary_param<const USE_TABLE: bool>( &mut self ) -> Result<u64, Self::Error>

Read a unary code.

fn read_unary(&mut self) -> Result<u64, Self::Error>

Read a unary code.

fn skip_unary(&mut self) -> Result<(), Self::Error>

Skip a unary code.

impl<E: Error, WR: WordRead<Error = E> + WordSeek<Error = E>, RP: ReadParams> BitSeek for BufBitReader<BE, WR, RP>

where WR::Word: DoubleType,

type Error = <WR as WordSeek>::Error

fn get_bit_pos(&mut self) -> Result<u64, Self::Error>

Get the current position in bits from the start of the file.

fn set_bit_pos(&mut self, bit_index: u64) -> Result<(), Self::Error>

Set the current position in bits from the start of the file to bit_pos.

impl<E: Error, WR: WordRead<Error = E> + WordSeek<Error = E>, RP: ReadParams> BitSeek for BufBitReader<LE, WR, RP>

where WR::Word: DoubleType,

type Error = <WR as WordSeek>::Error

fn get_bit_pos(&mut self) -> Result<u64, Self::Error>

Get the current position in bits from the start of the file.

fn set_bit_pos(&mut self, bit_index: u64) -> Result<(), Self::Error>

Set the current position in bits from the start of the file to bit_pos.

impl<E: Endianness, WR: WordRead + Clone, RP: ReadParams> Clone for BufBitReader<E, WR, RP>

where WR::Word: DoubleType,

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<E: Debug + Endianness, WR: Debug + WordRead, RP: Debug + ReadParams> Debug for BufBitReader<E, WR, RP>

where WR::Word: DoubleType,

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<WR: WordRead> DeltaRead<BigEndian> for BufBitReader<BigEndian, WR, DefaultReadParams>

where WR::Word: DoubleType + UpcastableInto<u64>, <WR::Word as DoubleType>::DoubleType: CastableInto<u64>,

fn read_delta(&mut self) -> Result<u64, Self::Error>

fn skip_delta(&mut self) -> Result<(), Self::Error>

impl<WR: WordRead> DeltaRead<LittleEndian> for BufBitReader<LittleEndian, WR, DefaultReadParams>

where WR::Word: DoubleType + UpcastableInto<u64>, <WR::Word as DoubleType>::DoubleType: CastableInto<u64>,

fn read_delta(&mut self) -> Result<u64, Self::Error>

fn skip_delta(&mut self) -> Result<(), Self::Error>

impl<WR: WordRead> GammaRead<BigEndian> for BufBitReader<BigEndian, WR, DefaultReadParams>

where WR::Word: DoubleType + UpcastableInto<u64>, <WR::Word as DoubleType>::DoubleType: CastableInto<u64>,

fn read_gamma(&mut self) -> Result<u64, Self::Error>

fn skip_gamma(&mut self) -> Result<(), Self::Error>

impl<WR: WordRead> GammaRead<LittleEndian> for BufBitReader<LittleEndian, WR, DefaultReadParams>

where WR::Word: DoubleType + UpcastableInto<u64>, <WR::Word as DoubleType>::DoubleType: CastableInto<u64>,

fn read_gamma(&mut self) -> Result<u64, Self::Error>

fn skip_gamma(&mut self) -> Result<(), Self::Error>

impl<WR: WordRead> ZetaRead<BigEndian> for BufBitReader<BigEndian, WR, DefaultReadParams>

where WR::Word: DoubleType + UpcastableInto<u64>, <WR::Word as DoubleType>::DoubleType: CastableInto<u64>,

fn read_zeta(&mut self, k: u64) -> Result<u64, Self::Error>

fn skip_zeta(&mut self, k: u64) -> Result<(), Self::Error>

fn read_zeta3(&mut self) -> Result<u64, Self::Error>

fn skip_zeta3(&mut self) -> Result<(), Self::Error>

impl<WR: WordRead> ZetaRead<LittleEndian> for BufBitReader<LittleEndian, WR, DefaultReadParams>

where WR::Word: DoubleType + UpcastableInto<u64>, <WR::Word as DoubleType>::DoubleType: CastableInto<u64>,

fn read_zeta(&mut self, k: u64) -> Result<u64, Self::Error>

fn skip_zeta(&mut self, k: u64) -> Result<(), Self::Error>

fn read_zeta3(&mut self) -> Result<u64, Self::Error>

fn skip_zeta3(&mut self) -> Result<(), Self::Error>