Struct sparse_bitfield::Bitfield

pub struct Bitfield {
    pub pages: Pager,
    // some fields omitted
}

Bitfield instance.

Fields

pages: Pager

A memory-pager instance.

Methods

impl Bitfield

pub fn new(page_size: usize) -> Self

Create a new instance.

Panics

The page size must be a multiple of 2, and bigger than 0.

pub fn from_file(     file: &mut File,     page_size: usize,     offset: Option<usize> ) -> Result<Self, Error>

Create a new instance from a File.

pub fn set(&mut self, index: usize, value: bool) -> Change

Set a bit to true or false. Returns a boolean indicating if the value was changed.

pub fn get(&mut self, index: usize) -> bool

Get the value of a bit.

pub fn get_byte(&self, index: usize) -> u8

Get a byte from our internal buffers.

pub fn set_byte(&mut self, index: usize, byte: u8) -> Change

Set a byte to the right value inside our internal buffers.

pub fn page_size(&self) -> usize

Get the memory page size in bytes.

pub fn len(&self) -> usize

Get the amount of bits in the bitfield.

Examples

let mut bits = Bitfield::new(1024);
assert_eq!(bits.len(), 0);
bits.set(0, true);
assert_eq!(bits.len(), 8);
bits.set(1, true);
assert_eq!(bits.len(), 8);
bits.set(9, false);
assert_eq!(bits.len(), 16);

pub fn byte_len(&self) -> usize

Get the amount of bytes in the bitfield.

Examples

let mut bits = Bitfield::new(1024);
assert_eq!(bits.byte_len(), 0);
bits.set(0, true);
assert_eq!(bits.byte_len(), 1);
bits.set(1, true);
assert_eq!(bits.byte_len(), 1);
bits.set(9, false);
assert_eq!(bits.byte_len(), 2);

pub fn page_len(&self) -> usize

Get the amount of memory pages in the bitfield.

Examples

let mut bits = Bitfield::new(1024);
assert_eq!(bits.page_len(), 0);
bits.set(0, true);
assert_eq!(bits.page_len(), 1);
bits.set(1, true);
assert_eq!(bits.page_len(), 1);
bits.set(2, false);
assert_eq!(bits.page_len(), 1);
bits.set(1024 * 8 + 1, true);
assert_eq!(bits.page_len(), 2);

pub fn is_empty(&self) -> bool

Returns true if no bits are stored.

Examples

let mut bits = Bitfield::new(1024);
assert!(bits.is_empty());
bits.set(0, true);
assert!(!bits.is_empty());

Important traits for Iter<'a>

impl<'a> Iterator for Iter<'a> type Item = bool;

pub fn iter(&mut self) -> Iter

Create an Iterator that iterates over all pages.

Trait Implementations

impl Debug for Bitfield

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

Formats the value using the given formatter.

impl Default for Bitfield

Create a new instance with a page_size of 1kb.

fn default() -> Self

Returns the "default value" for a type.