filesys.rs : decompname & find_dir

src/filesys/filesys.rs

@@ -1,6 +1,103 @@
+use super::directory;
 
+pub const DIRECTORY_SECTOR: i32 = 1;
+
+/// decompose the name of the first directory
+/// of the path given in argument, as well as the remainder of the path.
+/// if we call decompname("/bin/new/halt", head, tail), we get "bin" in head and "/new/halt" in tail
+/// returns true if everything goes ok, otherwise, return false.
+/// head and tail MUST be large enough to contain the resulting strings
+///
+/// ### parameters
+///
+/// - **orig_path** the pathname we want to decompose
+/// - **head** the first element in the path (for instance "bin")
+/// - **tail** the remainder of the string (for instance "/new/halt")
+pub fn decomp_name(origin_path: String, head: &mut String, tail: &mut String) -> bool {
+    let mut working_path = origin_path;
+
+    // remove the leading "/" if any
+    if working_path.get(0..1).unwrap_or_else(|| "").eq("/") {
+        working_path = (&working_path[1..]).to_string();
+    }
+
+    if working_path.contains("/") {
+        let index = working_path.find("/").expect("shouldn't happen");
+        *head = working_path[..index].to_string();
+        *tail = working_path[index..].to_string();
+        return true;
+    } else {
+        *head = "".to_string();
+        *tail = origin_path;
+        return false;
+    }
+}
+
+/// this function takes a complete pathname and returns
+/// the disc sector of the fileheader of the directory.
+/// return -1 in case of error
+///
+/// IMPORTANT WARNING : name is modified : after the execution, name
+/// contains only the name of the file
+/// (e.g. if we called find_dir("/bin/halt") then name is "halt" after the execution,
+/// the function returns the sector number of the directory "/bin").
+///
+/// Actually, this function does not support complete pathnames
+/// This is one of the objectives of the file system assignment
+///
+/// ### parameters
+///
+/// - **name** is the complete name (relatively to the root directory).
+///            its content will be modified!
+pub fn find_dir(name: &mut String) -> i32 {
+    let directory = directory::init_directory(config.num_dir_entries);
+    directory.fetch_from(filesys::get_dir_file());
+
+    let mut sector = DIRECTORY_SECTOR;
+    let mut dirname = String::from("");
+    let mut reminder = String::from("");
+
+    while decomp_name(name.to_string(), &mut dirname, &mut reminder) {
+        *name = reminder;
+
+        // Get the sector of the file/directory corresponding to 'name'
+        sector = directory.find(dirname);
+        if sector < 0 {
+            return -1; // This file/directory does not exist
+        }
+
+        let file = openfile::init_open_file(sector);
+        if file.get_file_header().is_dir() {
+            directory.fetch_from(&file);
+        } else {
+            return -1;
+        }
+    }
+    *name = reminder;
+
+    sector
+}
 
 pub struct Filesys {
-    pub free_map_file : Open_File, //Bit map of free disk blocks, represented as a file
+    pub free_map_file: Open_file, //Bit map of free disk blocks, represented as a file
-    pub directory_file : Open_file //"Root" directory -- list of file names, represented as a file
+    pub directory_file: Open_file, //"Root" directory -- list of file names, represented as a file
-}
+}
+
+impl Filesys {
+    /// Initialize the file system.
+    /// If format = true, the disk has nothing on it,
+    /// and we need to initialize the disk to contain an empty directory,
+    /// and a bitmap of free sectors (with almost but not all of the sectors marked as free).  
+    ///
+    ///	If format = false, we just have to open the files
+    ///	representing the bitmap and the directory.
+    ///
+    /// ### parameters
+    ///
+    ///	- **format** should we initialize the disk?
+    pub fn init_filesys(format: bool) -> Filesys {
+        if format {
+            let free_map = bitmap::init_bitmap();
+        }
+    }
+}

src/filesys/fsmisc.rs

@@ -1,19 +1,23 @@
-use std::{fs::File, io::{Seek, SeekFrom, Read}};
+use std::{
+    fs::File,
+    io::{Read, Seek, SeekFrom},
+};
 
 use super::filesys;
 
 pub const TRANSFER_SIZE: usize = 10;
 
 /// copy the contents of the UNIX file "from" to the Nachos file "to"
-/// 
+///
 /// `panic!` when the file from doesn't exist
-/// 
+///
+/// ### parameters
+///
 /// - **from** file UNIX
 /// - **to** BurritOS file
-pub fn copy(from : &str, to : &str) {
+pub fn copy(from: &str, to: &str) {
-
     let file_from_opt = File::options().read(true).open(from);
-    let mut file_from : File;
+    let mut file_from: File;
     match file_from_opt {
         Err(e) => {
             panic!("Copy: couldn't open Unix file {}", from);
@@ -35,7 +39,9 @@ pub fn copy(from : &str, to : &str) {
 
     let mut buffer = [0; TRANSFER_SIZE];
     loop {
-        let amount_read = file_from.read(&mut buffer).expect("copy : couldn't read the UNIX file");
+        let amount_read = file_from
+            .read(&mut buffer)
+            .expect("copy : couldn't read the UNIX file");
         open_file.write(&buffer[..amount_read]);
 
         if amount_read != TRANSFER_SIZE {
@@ -45,11 +51,13 @@ pub fn copy(from : &str, to : &str) {
 }
 
 /// Print the contents of the Nachos file "name".
-/// 
+///
 /// `panic!` when the file name doewn't exist
-/// 
+///
+/// ### parameters
+///
 /// - **name** of the BurritOS file
-pub fn print(name : &str) {
+pub fn print(name: &str) {
     let open_file = filesys::open(name);
 
     let mut buffer = [0; TRANSFER_SIZE];
@@ -63,4 +71,4 @@ pub fn print(name : &str) {
             break;
         }
     }
-}
+}

src/filesys/mod.rs

@@ -1,2 +1,3 @@
+pub mod directory;
+pub mod filesys;
 pub mod fsmisc;
-pub mod filesys;