commented the bitmap + init_bitmap + init_file_hdr
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@ -20,6 +20,19 @@ pub struct FileHdr {
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impl FileHdr {
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pub fn init_file_hdr() -> FileHdr {
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FileHdr {
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is_dir: 0,
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num_bytes: 0,
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num_sectors: 0,
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data_sectors: Vec::new(),
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num_header_sectors: 0,
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header_sectors: [0;MAX_HEADER_SECTORS as usize],
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}
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}
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pub fn allocate(&mut self, mut free_map: BitMap, file_size: i32) -> bool {
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self.num_bytes = file_size;
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if file_size > MAX_FILE_LENGTH {
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@ -87,6 +100,11 @@ impl FileHdr {
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//TODO: fetchFrom WriteBack
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pub fn byte_to_sector(&self,offset: i32) -> i32 {
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return self.data_sectors[ (offset / SECTOR_SIZE) as usize];
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}
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@ -4,6 +4,8 @@ pub const BITS_IN_WORD: usize = 32;
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use std::fs::File;
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use std::io::{Cursor, Write, Read};
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use crate::simulator::disk::SECTOR_SIZE;
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pub struct BitMap {
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num_bits: usize,
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num_words: usize,
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@ -12,16 +14,44 @@ pub struct BitMap {
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impl BitMap {
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/// Initialize a bitmap with "nitems" bits, so that every bit is clear.
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/// it can be added somewhere on a list.
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///
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/// ### Parameters
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/// - **nitems** is the number of bits in the bitmap.
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///----------------------------------------------------------------------
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pub fn init_bitmap(&self, n_items: usize) -> BitMap {
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let mut tmp: Vec<u32>;
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BitMap{
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num_bits: n_items,
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num_words: (n_items + SECTOR_SIZE as usize -1) / SECTOR_SIZE as usize,
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map: tmp,
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};
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*self
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}
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/// Set the "nth" bit in a bitmap.
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/// ### Parameters
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/// - **which** is the number of the bit to be set.
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pub fn mark(&mut self, which: usize) {
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assert!(which >= 0 && which < self.num_bits);
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self.map[which / BITS_IN_WORD] |= 1 << (which % BITS_IN_WORD);
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}
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/// return true if the "nth" bit is set.
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///
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/// ### Paramenters
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/// - **which** is the number of the bit to be tested.
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pub fn test(&self, which: usize) -> bool {
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assert!(which < self.num_bits);
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(self.map[which / BITS_IN_WORD] & (1 << (which % BITS_IN_WORD))) != 0
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}
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/// Return the number of the first bit which is clear.
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/// As a side effect, set the bit (mark it as in use).
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/// (In other words, find and allocate a bit.)
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/// If no bits are clear, return ERROR
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pub fn find(&mut self) -> i32 {
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for i in 0..self.num_bits {
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if !self.test(i) {
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@ -32,6 +62,9 @@ impl BitMap {
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-1
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}
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/// Clear the "nth" bit in a bitmap.
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/// ### Parameters
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/// - **which** is the number of the bit to be cleared.
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pub fn clear(&mut self, which: usize) {
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assert!(which < self.num_bits, "index out of range");
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@ -40,6 +73,8 @@ impl BitMap {
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self.map[word_idx] &= !(1 << bit_idx);
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}
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/// Return the number of clear bits in the bitmap.
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/// (In other words, how many bits are unallocated?)
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pub fn num_clear(&self) -> i32 {
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let mut count = 0;
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for i in 0..self.num_bits {
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@ -50,6 +85,9 @@ impl BitMap {
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count
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}
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/// Print the contents of the bitmap, for debugging.
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/// Could be done in a number of ways, but we just print the #'s of
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/// all the bits that are set in the bitmap.
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pub fn print(&self) {
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println!("Bitmap set:");
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for i in 0..self.num_bits {
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@ -60,8 +98,10 @@ impl BitMap {
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println!();
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}
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///Initialize the contents of a bitmap from a Nachos file.
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///
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/// ### Parameters
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/// - **file** is the place to read the bitmap from
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pub fn fetch_from(&mut self, file_path: &str) -> std::io::Result<&Vec<u32>> {
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// Ouvre le fichier en mode lecture seule
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let mut file = File::open(file_path)?;
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@ -83,6 +123,10 @@ impl BitMap {
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Ok(&self.map)
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}
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/// Store the contents of a bitmap to a Nachos file.
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///
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/// ### Paramenters
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/// - **file** is the place to write the bitmap to
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pub fn write_back(&mut self, file_path: &str) -> std::io::Result<()> {
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// Encapsule le vecteur dans un std::io::Cursor pour l'utiliser comme un std::io::Write
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let mut cursor = Cursor::new(Vec::<u8>::new());
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@ -98,5 +142,4 @@ impl BitMap {
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Ok(())
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}
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}
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