added the bitmap, tests still need to be done

This commit is contained in:
AmauryBrodu 2023-03-29 13:17:21 +02:00
parent 021aac6e6a
commit 52929cef24
2 changed files with 104 additions and 1 deletions

102
src/utility/bitmap.rs Normal file
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@ -0,0 +1,102 @@
pub const BITS_IN_BYTE: usize = 8;
pub const BITS_IN_WORD: usize = 32;
use std::fs::File;
use std::io::{Cursor, Write, Read};
pub struct BitMap {
num_bits: usize,
num_words: usize,
map: Vec<u32>,
}
impl BitMap {
pub fn mark(&mut self, which: usize) {
assert!(which >= 0 && which < self.num_bits);
self.map[which / BITS_IN_WORD] |= 1 << (which % BITS_IN_WORD);
}
pub fn test(&self, which: usize) -> bool {
assert!(which < self.num_bits);
(self.map[which / BITS_IN_WORD] & (1 << (which % BITS_IN_WORD))) != 0
}
pub fn find(&mut self) -> i32 {
for i in 0..self.num_bits {
if !self.test(i) {
self.mark(i);
return i as i32;
}
}
-1
}
pub fn clear(&mut self, which: usize) {
assert!(which < self.num_bits, "index out of range");
let word_idx = which / BITS_IN_WORD;
let bit_idx = which % BITS_IN_WORD;
self.map[word_idx] &= !(1 << bit_idx);
}
pub fn num_clear(&self) -> i32 {
let mut count = 0;
for i in 0..self.num_bits {
if !self.test(i) {
count += 1;
}
}
count
}
pub fn print(&self) {
println!("Bitmap set:");
for i in 0..self.num_bits {
if self.test(i) {
print!("{}, ", i);
}
}
println!();
}
pub fn fetch_from(&mut self, file_path: &str) -> std::io::Result<&Vec<u32>> {
// Ouvre le fichier en mode lecture seule
let mut file = File::open(file_path)?;
// Lit les octets du fichier dans un buffer
let mut buffer = vec![0; self.num_words * std::mem::size_of::<u32>()];
file.read_exact(&mut buffer)?;
// Convertit les octets en vecteur de u32
self.map = vec![0; self.num_words];
for i in 0..self.num_words {
let j = i * std::mem::size_of::<u32>();
let bytes = [
buffer[j], buffer[j+1], buffer[j+2], buffer[j+3]
];
self.map[i] = u32::from_le_bytes(bytes);
}
Ok(&self.map)
}
pub fn write_back(&mut self, file_path: &str) -> std::io::Result<()> {
// Encapsule le vecteur dans un std::io::Cursor pour l'utiliser comme un std::io::Write
let mut cursor = Cursor::new(Vec::<u8>::new());
for u32_val in self.map.as_mut_slice() {
cursor.write_all(&u32_val.to_le_bytes())?;
}
// Ouvre le fichier en mode écriture
let mut file = File::create(file_path)?;
// Écrit les données dans le fichier
file.write_all(&cursor.into_inner())?;
Ok(())
}
}

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@ -1 +1,2 @@
pub mod list;
pub mod list;
pub mod bitmap;