Use DirEntry#size (#9)

* Fix off by one line error

* Change create_file and create_dir to return DirEntry

* Implement DirEntry#size

* Use filesize to copy file

* Add example of long text

* Replace sleep after write in FS by wait in ATA

dsk/tmp/alice.txt

@@ -0,0 +1,92 @@
+ALICE'S ADVENTURES IN WONDERLAND
+
+Lewis Carroll
+
+
+CHAPTER I. Down the Rabbit-Hole
+
+Alice was beginning to get very tired of sitting by her sister on the
+bank, and of having nothing to do: once or twice she had peeped into the
+book her sister was reading, but it had no pictures or conversations in
+it, 'and what is the use of a book,' thought Alice 'without pictures or
+conversations?'
+
+So she was considering in her own mind (as well as she could, for the
+hot day made her feel very sleepy and stupid), whether the pleasure
+of making a daisy-chain would be worth the trouble of getting up and
+picking the daisies, when suddenly a White Rabbit with pink eyes ran
+close by her.
+
+There was nothing so VERY remarkable in that; nor did Alice think it so
+VERY much out of the way to hear the Rabbit say to itself, 'Oh dear!
+Oh dear! I shall be late!' (when she thought it over afterwards, it
+occurred to her that she ought to have wondered at this, but at the time
+it all seemed quite natural); but when the Rabbit actually TOOK A WATCH
+OUT OF ITS WAISTCOAT-POCKET, and looked at it, and then hurried on,
+Alice started to her feet, for it flashed across her mind that she had
+never before seen a rabbit with either a waistcoat-pocket, or a watch
+to take out of it, and burning with curiosity, she ran across the field
+after it, and fortunately was just in time to see it pop down a large
+rabbit-hole under the hedge.
+
+In another moment down went Alice after it, never once considering how
+in the world she was to get out again.
+
+The rabbit-hole went straight on like a tunnel for some way, and then
+dipped suddenly down, so suddenly that Alice had not a moment to think
+about stopping herself before she found herself falling down a very deep
+well.
+
+Either the well was very deep, or she fell very slowly, for she had
+plenty of time as she went down to look about her and to wonder what was
+going to happen next. First, she tried to look down and make out what
+she was coming to, but it was too dark to see anything; then she
+looked at the sides of the well, and noticed that they were filled with
+cupboards and book-shelves; here and there she saw maps and pictures
+hung upon pegs. She took down a jar from one of the shelves as
+she passed; it was labelled 'ORANGE MARMALADE', but to her great
+disappointment it was empty: she did not like to drop the jar for fear
+of killing somebody, so managed to put it into one of the cupboards as
+she fell past it.
+
+'Well!' thought Alice to herself, 'after such a fall as this, I shall
+think nothing of tumbling down stairs! How brave they'll all think me at
+home! Why, I wouldn't say anything about it, even if I fell off the top
+of the house!' (Which was very likely true.)
+
+Down, down, down. Would the fall NEVER come to an end! 'I wonder how
+many miles I've fallen by this time?' she said aloud. 'I must be getting
+somewhere near the centre of the earth. Let me see: that would be four
+thousand miles down, I think--' (for, you see, Alice had learnt several
+things of this sort in her lessons in the schoolroom, and though this
+was not a VERY good opportunity for showing off her knowledge, as there
+was no one to listen to her, still it was good practice to say it over)
+'--yes, that's about the right distance--but then I wonder what Latitude
+or Longitude I've got to?' (Alice had no idea what Latitude was, or
+Longitude either, but thought they were nice grand words to say.)
+
+Presently she began again. 'I wonder if I shall fall right THROUGH the
+earth! How funny it'll seem to come out among the people that walk with
+their heads downward! The Antipathies, I think--' (she was rather glad
+there WAS no one listening, this time, as it didn't sound at all the
+right word) '--but I shall have to ask them what the name of the country
+is, you know. Please, Ma'am, is this New Zealand or Australia?' (and
+she tried to curtsey as she spoke--fancy CURTSEYING as you're falling
+through the air! Do you think you could manage it?) 'And what an
+ignorant little girl she'll think me for asking! No, it'll never do to
+ask: perhaps I shall see it written up somewhere.'
+
+Down, down, down. There was nothing else to do, so Alice soon began
+talking again. 'Dinah'll miss me very much to-night, I should think!'
+(Dinah was the cat.) 'I hope they'll remember her saucer of milk at
+tea-time. Dinah my dear! I wish you were down here with me! There are no
+mice in the air, I'm afraid, but you might catch a bat, and that's very
+like a mouse, you know. But do cats eat bats, I wonder?' And here Alice
+began to get rather sleepy, and went on saying to herself, in a dreamy
+sort of way, 'Do cats eat bats? Do cats eat bats?' and sometimes, 'Do
+bats eat cats?' for, you see, as she couldn't answer either question,
+it didn't much matter which way she put it. She felt that she was dozing
+off, and had just begun to dream that she was walking hand in hand with
+Dinah, and saying to her very earnestly, 'Now, Dinah, tell me the truth:
+did you ever eat a bat?' when suddenly, thump! thump! down she came upon
+a heap of sticks and dry leaves, and the fall was over.

src/kernel/ata.rs

@@ -220,6 +220,8 @@ impl Bus {
             data.set_bits(8..16, buf[i * 2 + 1] as u16);
             self.write_data(data);
         }
+
+        while self.is_busy() {}
     }
 }
 

src/kernel/fs.rs

@@ -28,9 +28,12 @@ pub fn filename(pathname: &str) -> &str {
     &pathname[i..n] 
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Clone)]
 pub struct File {
-    addr: u32
+    name: String,
+    addr: u32,
+    size: u32,
+    dir: Dir, // TODO: Replace with `parent: Some(Dir)` and also add it to `Dir`
 }
 
 impl File {
@@ -39,7 +42,7 @@ impl File {
         let filename = filename(pathname);
         if let Some(dir) = Dir::open(dirname) {
             if let Some(dir_entry) = dir.create_file(filename) {
-                return Some(Self { addr: dir_entry.addr });
+                return Some(dir_entry.to_file());
             }
         }
         None
@@ -51,13 +54,17 @@ impl File {
         if let Some(dir) = Dir::open(dirname) {
             if let Some(dir_entry) = dir.find(filename) {
                 if dir_entry.is_file() {
-                    return Some(Self { addr: dir_entry.addr });
+                    return Some(dir_entry.to_file());
                 }
             }
         }
         None
     }
 
+    pub fn size(&self) -> usize {
+        self.size as usize
+    }
+
     pub fn read(&self, buf: &mut [u8]) -> usize {
         let buf_len = buf.len();
         let mut addr = self.addr;
@@ -67,10 +74,7 @@ impl File {
             let data = block.data();
             let data_len = data.len();
             for j in 0..data_len {
-                if i == buf_len {
-                    return i;
-                }
-                if data[j] == 0 { // TODO: Use filesize
+                if i == buf_len || i == self.size() {
                     return i;
                 }
                 buf[i] = data[j];
@@ -84,8 +88,8 @@ impl File {
     }
 
     pub fn read_to_string(&self) -> String {
-        let mut buf: Vec<u8> = Vec::new();
-        buf.resize(2048, 0); // TODO: Use filesize
+        let mut buf: Vec<u8> = Vec::with_capacity(self.size());
+        buf.resize(self.size(), 0);
         let bytes = self.read(&mut buf);
         buf.resize(bytes, 0);
         String::from_utf8(buf).unwrap()
@@ -131,6 +135,8 @@ impl File {
             block.set_next(addr);
             block.write();
         }
+        self.size = i as u32;
+        self.dir.update_entry_size(&self.name, self.size);
         Ok(())
     }
 
@@ -176,7 +182,6 @@ impl Block {
         let bus = 1; // TODO
         let dsk = 0; // TODO
         kernel::ata::write(bus, dsk, self.addr, &self.buf);
-        kernel::sleep::sleep(0.01);
     }
 
     pub fn alloc() -> Option<Self> {
@@ -285,18 +290,19 @@ impl BlockBitmap {
     }
 }
 
-#[derive(Debug)]
+#[derive(Clone)]
 pub struct DirEntry {
+    dir: Dir,
     kind: FileType,
     addr: u32,
     size: u32,
     name: String,
 }
 
 impl DirEntry {
-    pub fn new(kind: FileType, addr: u32, size: u32, name: &str) -> Self {
+    pub fn new(dir: Dir, kind: FileType, addr: u32, size: u32, name: &str) -> Self {
         let name = String::from(name);
-        Self { kind, addr, size, name }
+        Self { dir, kind, addr, size, name }
     }
 
     pub fn is_dir(&self) -> bool {
@@ -316,14 +322,21 @@ impl DirEntry {
     }
 
     pub fn to_dir(&self) -> Dir {
+        assert!(self.kind == FileType::Dir);
         Dir { addr: self.addr }
     }
 
+    pub fn to_file(&self) -> File {
+        assert!(self.kind == FileType::File);
+        File { name: self.name.clone(), addr: self.addr, size: self.size, dir: self.dir }
+    }
+
     pub fn len(&self) -> usize {
         1 + 4 + 4 + 1 + self.name.len()
     }
 }
 
+#[derive(Clone, Copy)]
 pub struct Dir {
     addr: u32,
 }
@@ -428,7 +441,7 @@ impl Dir {
         }
         read_dir.block.write();
 
-        Some(DirEntry::new(kind, entry_addr, entry_size, name))
+        Some(DirEntry::new(self.clone(), kind, entry_addr, entry_size, name))
     }
 
     // Deleting an entry is done by setting the entry address to 0
@@ -462,8 +475,25 @@ impl Dir {
         Err(())
     }
 
+    fn update_entry_size(&mut self, name: &str, size: u32) {
+        let mut read_dir = self.read();
+        for entry in &mut read_dir {
+            if entry.name == name {
+                let data = read_dir.block.data_mut();
+                let i = read_dir.data_offset - entry.len();
+                data[i + 5] = size.get_bits(24..32) as u8;
+                data[i + 6] = size.get_bits(16..24) as u8;
+                data[i + 7] = size.get_bits(8..16) as u8;
+                data[i + 8] = size.get_bits(0..8) as u8;
+                read_dir.block.write();
+                break;
+            }
+        }
+    }
+
     pub fn read(&self) -> ReadDir {
         ReadDir {
+            dir: self.clone(),
             block: Block::read(self.addr),
             data_offset: 0,
         }
@@ -481,6 +511,7 @@ impl Dir {
 }
 
 pub struct ReadDir {
+    dir: Dir,
     block: Block,
     data_offset: usize,
 }
@@ -537,7 +568,7 @@ impl Iterator for ReadDir {
                     continue;
                 }
 
-                return Some(DirEntry::new(entry_kind, entry_addr, entry_size, &entry_name));
+                return Some(DirEntry::new(self.dir, entry_kind, entry_addr, entry_size, &entry_name));
             }
 
             match self.block.next() {

src/main.rs

@@ -27,6 +27,7 @@ fn main(boot_info: &'static BootInfo) -> ! {
     include_file("/ini/boot.sh", include_str!("../dsk/ini/boot.sh"));
     include_file("/ini/banner.txt", include_str!("../dsk/ini/banner.txt"));
     include_file("/ini/passwords.csv", include_str!("../dsk/ini/passwords.csv"));
+    include_file("/tmp/alice.txt", include_str!("../dsk/tmp/alice.txt"));
     loop {
         user::shell::main(&["shell", "/ini/boot.sh"]);
     }

src/user/copy.rs

@@ -1,3 +1,4 @@
+use alloc::vec::Vec;
 use crate::{print, kernel, user};
 
 pub fn main(args: &[&str]) -> user::shell::ExitCode {
@@ -15,7 +16,9 @@ pub fn main(args: &[&str]) -> user::shell::ExitCode {
 
     if let Some(file_from) = kernel::fs::File::open(from) {
         if let Some(mut file_to) = kernel::fs::File::create(to) {
-            let mut buf = [0u8; 2048];
+            let filesize = file_from.size();
+            let mut buf = Vec::with_capacity(filesize);
+            buf.resize(filesize, 0);
             file_from.read(&mut buf);
             match file_to.write(&buf) {
                 Ok(()) => {

src/user/editor.rs

@@ -44,17 +44,18 @@ impl Editor {
         Self { file, pathname, lines, offset }
     }
 
-    pub fn save(&self) -> user::shell::ExitCode {
-        if self.file.is_some() {
-            let mut contents = String::new();
-            let n = self.lines.len();
-            for i in 0..n {
-                contents.push_str(&self.lines[i]);
-                if i < n - 1 {
-                    contents.push('\n');
-                }
+    pub fn save(&mut self) -> user::shell::ExitCode {
+        let mut contents = String::new();
+        let n = self.lines.len();
+        for i in 0..n {
+            contents.push_str(&self.lines[i]);
+            if i < n - 1 {
+                contents.push('\n');
             }
-            self.file.unwrap().write(&contents.as_bytes()).unwrap();
+        }
+
+        if let Some(file) = &mut self.file {
+            file.write(&contents.as_bytes()).unwrap();
             user::shell::ExitCode::CommandSuccessful
         } else {
             print!("Could not write to '{}'\n", self.pathname);