Trait bitstream_io::read::BitRead[−][src]

pub trait BitRead {
    fn read_bit(&mut self) -> Result<bool>;
    fn read<U>(&mut self, bits: u32) -> Result<U>
    where
        U: Numeric;
    fn read_signed<S>(&mut self, bits: u32) -> Result<S>
    where
        S: SignedNumeric;
    fn skip(&mut self, bits: u32) -> Result<()>;
    fn byte_aligned(&self) -> bool;
    fn byte_align(&mut self);

    fn read_bytes(&mut self, buf: &mut [u8]) -> Result<()> { ... }
    fn read_unary0(&mut self) -> Result<u32> { ... }
    fn read_unary1(&mut self) -> Result<u32> { ... }
}

Expand description

A trait for anything that can read a variable number of potentially un-aligned values from an input stream

Required methods

fn read_bit(&mut self) -> Result<bool>[src]

Reads a single bit from the stream. true indicates 1, false indicates 0

Errors

Passes along any I/O error from the underlying stream.

fn read<U>(&mut self, bits: u32) -> Result<U> where
    U: Numeric,

[src]

Reads an unsigned value from the stream with the given number of bits.

Errors

Passes along any I/O error from the underlying stream. Also returns an error if the output type is too small to hold the requested number of bits.

fn read_signed<S>(&mut self, bits: u32) -> Result<S> where
    S: SignedNumeric,

[src]

Reads a twos-complement signed value from the stream with the given number of bits.

Errors

Passes along any I/O error from the underlying stream. Also returns an error if the output type is too small to hold the requested number of bits.

fn skip(&mut self, bits: u32) -> Result<()>[src]

Skips the given number of bits in the stream. Since this method does not need an accumulator, it may be slightly faster than reading to an empty variable. In addition, since there is no accumulator, there is no upper limit on the number of bits which may be skipped. These bits are still read from the stream, however, and are never skipped via a seek method.

Errors

Passes along any I/O error from the underlying stream.

fn byte_aligned(&self) -> bool[src]

Returns true if the stream is aligned at a whole byte.

fn byte_align(&mut self)[src]

Throws away all unread bit values until the next whole byte. Does nothing if the stream is already aligned.

Provided methods

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

Completely fills the given buffer with whole bytes. If the stream is already byte-aligned, it will map to a faster read_exact call. Otherwise it will read bytes individually in 8-bit increments.

Errors

Passes along any I/O error from the underlying stream.

fn read_unary0(&mut self) -> Result<u32>[src]

Counts the number of 1 bits in the stream until the next 0 bit and returns the amount read. Because this field is variably-sized and may be large, its output is always a u32 type.

Errors

Passes along any I/O error from the underlying stream.

fn read_unary1(&mut self) -> Result<u32>[src]

Counts the number of 0 bits in the stream until the next 1 bit and returns the amount read. Because this field is variably-sized and may be large, its output is always a u32 type.

Errors

Passes along any I/O error from the underlying stream.

Implementors

impl<R: Read, E: Endianness> BitRead for BitReader<R, E>[src]

fn read_bit(&mut self) -> Result<bool>[src]

Examples

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0b10110111];
let mut reader = BitReader::endian(Cursor::new(&data), BigEndian);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), false);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), false);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), true);

use std::io::{Read, Cursor};
use bitstream_io::{LittleEndian, BitReader, BitRead};
let data = [0b10110111];
let mut reader = BitReader::endian(Cursor::new(&data), LittleEndian);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), false);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), true);
assert_eq!(reader.read_bit().unwrap(), false);
assert_eq!(reader.read_bit().unwrap(), true);

fn read<U>(&mut self, bits: u32) -> Result<U> where
    U: Numeric,

[src]

Examples

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0b10110111];
let mut reader = BitReader::endian(Cursor::new(&data), BigEndian);
assert_eq!(reader.read::<u8>(1).unwrap(), 0b1);
assert_eq!(reader.read::<u8>(2).unwrap(), 0b01);
assert_eq!(reader.read::<u8>(5).unwrap(), 0b10111);

use std::io::{Read, Cursor};
use bitstream_io::{LittleEndian, BitReader, BitRead};
let data = [0b10110111];
let mut reader = BitReader::endian(Cursor::new(&data), LittleEndian);
assert_eq!(reader.read::<u8>(1).unwrap(), 0b1);
assert_eq!(reader.read::<u8>(2).unwrap(), 0b11);
assert_eq!(reader.read::<u8>(5).unwrap(), 0b10110);

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0;10];
let mut reader = BitReader::endian(Cursor::new(&data), BigEndian);
assert!(reader.read::<u8>(9).is_err());    // can't read  9 bits to u8
assert!(reader.read::<u16>(17).is_err());  // can't read 17 bits to u16
assert!(reader.read::<u32>(33).is_err());  // can't read 33 bits to u32
assert!(reader.read::<u64>(65).is_err());  // can't read 65 bits to u64

fn read_signed<S>(&mut self, bits: u32) -> Result<S> where
    S: SignedNumeric,

[src]

Examples

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0b10110111];
let mut reader = BitReader::endian(Cursor::new(&data), BigEndian);
assert_eq!(reader.read_signed::<i8>(4).unwrap(), -5);
assert_eq!(reader.read_signed::<i8>(4).unwrap(), 7);

use std::io::{Read, Cursor};
use bitstream_io::{LittleEndian, BitReader, BitRead};
let data = [0b10110111];
let mut reader = BitReader::endian(Cursor::new(&data), LittleEndian);
assert_eq!(reader.read_signed::<i8>(4).unwrap(), 7);
assert_eq!(reader.read_signed::<i8>(4).unwrap(), -5);

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0;10];
let mut r = BitReader::endian(Cursor::new(&data), BigEndian);
assert!(r.read_signed::<i8>(9).is_err());   // can't read 9 bits to i8
assert!(r.read_signed::<i16>(17).is_err()); // can't read 17 bits to i16
assert!(r.read_signed::<i32>(33).is_err()); // can't read 33 bits to i32
assert!(r.read_signed::<i64>(65).is_err()); // can't read 65 bits to i64

fn skip(&mut self, bits: u32) -> Result<()>[src]

Examples

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0b10110111];
let mut reader = BitReader::endian(Cursor::new(&data), BigEndian);
assert!(reader.skip(3).is_ok());
assert_eq!(reader.read::<u8>(5).unwrap(), 0b10111);

use std::io::{Read, Cursor};
use bitstream_io::{LittleEndian, BitReader, BitRead};
let data = [0b10110111];
let mut reader = BitReader::endian(Cursor::new(&data), LittleEndian);
assert!(reader.skip(3).is_ok());
assert_eq!(reader.read::<u8>(5).unwrap(), 0b10110);

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

Example

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = b"foobar";
let mut reader = BitReader::endian(Cursor::new(data), BigEndian);
assert!(reader.skip(24).is_ok());
let mut buf = [0;3];
assert!(reader.read_bytes(&mut buf).is_ok());
assert_eq!(&buf, b"bar");

fn read_unary0(&mut self) -> Result<u32>[src]

Examples

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0b01110111, 0b11111110];
let mut reader = BitReader::endian(Cursor::new(&data), BigEndian);
assert_eq!(reader.read_unary0().unwrap(), 0);
assert_eq!(reader.read_unary0().unwrap(), 3);
assert_eq!(reader.read_unary0().unwrap(), 10);

use std::io::{Read, Cursor};
use bitstream_io::{LittleEndian, BitReader, BitRead};
let data = [0b11101110, 0b01111111];
let mut reader = BitReader::endian(Cursor::new(&data), LittleEndian);
assert_eq!(reader.read_unary0().unwrap(), 0);
assert_eq!(reader.read_unary0().unwrap(), 3);
assert_eq!(reader.read_unary0().unwrap(), 10);

fn read_unary1(&mut self) -> Result<u32>[src]

Examples

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0b10001000, 0b00000001];
let mut reader = BitReader::endian(Cursor::new(&data), BigEndian);
assert_eq!(reader.read_unary1().unwrap(), 0);
assert_eq!(reader.read_unary1().unwrap(), 3);
assert_eq!(reader.read_unary1().unwrap(), 10);

use std::io::{Read, Cursor};
use bitstream_io::{LittleEndian, BitReader, BitRead};
let data = [0b00010001, 0b10000000];
let mut reader = BitReader::endian(Cursor::new(&data), LittleEndian);
assert_eq!(reader.read_unary1().unwrap(), 0);
assert_eq!(reader.read_unary1().unwrap(), 3);
assert_eq!(reader.read_unary1().unwrap(), 10);

fn byte_aligned(&self) -> bool[src]

Example

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0];
let mut reader = BitReader::endian(Cursor::new(&data), BigEndian);
assert_eq!(reader.byte_aligned(), true);
assert!(reader.skip(1).is_ok());
assert_eq!(reader.byte_aligned(), false);
assert!(reader.skip(7).is_ok());
assert_eq!(reader.byte_aligned(), true);

fn byte_align(&mut self)[src]

Example

use std::io::{Read, Cursor};
use bitstream_io::{BigEndian, BitReader, BitRead};
let data = [0x00, 0xFF];
let mut reader = BitReader::endian(Cursor::new(&data), BigEndian);
assert_eq!(reader.read::<u8>(4).unwrap(), 0);
reader.byte_align();
assert_eq!(reader.read::<u8>(8).unwrap(), 0xFF);