Struct 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.

For additional flexibility, this structures implements std::io::Read. Note that because of coherence rules it is not possible to implement std::io::Read for a generic BitRead.

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);

pub fn into_inner(self) -> Result<WR, Infallible>

Return the backend, consuming this 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 read_bits(&mut self, n_bits: usize) -> Result<u64, Self::Error>

Read n bits and return them in the lowest bits.

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

Read a unary code.

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

Skip n bits from the stream.

fn copy_to<F: Endianness, W: BitWrite<F>>( &mut self, bit_write: &mut W, n: u64, ) -> Result<(), CopyError<Self::Error, W::Error>>

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

Read n bits and return them in the lowest bits.

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

Read a unary code.

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

Skip n bits from the stream.

fn copy_to<F: Endianness, W: BitWrite<F>>( &mut self, bit_write: &mut W, n: u64, ) -> Result<(), CopyError<Self::Error, W::Error>>

impl<E: Error + Send + Sync + 'static, 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 bit_pos(&mut self) -> Result<u64, Self::Error>

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

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

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

impl<E: Error + Send + Sync + 'static, 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 bit_pos(&mut self) -> Result<u64, Self::Error>

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

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

Set the current position in bits from the start of the stream 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: Endianness, WR, RP: ReadParams> CopyType for BufBitReader<E, WR, RP>

where WR::Word: DoubleType, WR: MemSize + WordRead, <<WR as WordRead>::Word as DoubleType>::DoubleType: MemSize, usize: MemSize, PhantomData<(E, RP)>: MemSize,

type Copy = False

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>

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>

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>

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>

impl<E: Endianness, WR, RP: ReadParams> MemDbgImpl for BufBitReader<E, WR, RP>

where WR::Word: DoubleType, WR: MemDbgImpl + WordRead, <<WR as WordRead>::Word as DoubleType>::DoubleType: MemDbgImpl, usize: MemDbgImpl, PhantomData<(E, RP)>: MemDbgImpl,

fn _mem_dbg_rec_on( &self, _memdbg_writer: &mut impl Write, _memdbg_total_size: usize, _memdbg_max_depth: usize, _memdbg_prefix: &mut String, _memdbg_is_last: bool, _memdbg_flags: DbgFlags, ) -> Result

fn _mem_dbg_depth_on( &self, writer: &mut impl Write, total_size: usize, max_depth: usize, prefix: &mut String, field_name: Option<&str>, is_last: bool, padded_size: usize, flags: DbgFlags, ) -> Result<(), Error>

impl<E: Endianness, WR, RP: ReadParams> MemSize for BufBitReader<E, WR, RP>

where WR::Word: DoubleType, WR: MemSize + WordRead, <<WR as WordRead>::Word as DoubleType>::DoubleType: MemSize, usize: MemSize, PhantomData<(E, RP)>: MemSize,

fn mem_size(&self, _memsize_flags: SizeFlags) -> usize

Returns the (recursively computed) overall memory size of the structure in bytes.

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

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

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

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

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

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

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: usize) -> Result<u64, Self::Error>

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

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