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use crate::disk::inode::Inode;
use std::ffi::{OsStr, OsString};
use std::os::unix::ffi::OsStrExt;
pub trait Block: Default + Clone {}
#[repr(C)]
#[derive(Clone)]
pub struct DataBlock(pub(crate) [u8; 4096]);
impl Default for DataBlock {
fn default() -> Self {
Self([0; 4096])
}
}
impl Block for DataBlock {}
#[repr(C)]
#[derive(Clone)]
pub struct InodeBlock {
pub(crate) inodes: [Inode; 32],
}
impl Default for InodeBlock {
fn default() -> Self {
Self {
inodes: [
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
Inode::empty(),
],
}
}
}
impl Block for InodeBlock {}
#[repr(C)]
#[derive(Clone)]
pub struct DirectoryEntry {
pub inode: u32,
pub record_len: u16,
pub name_len: u8,
pub file_type: u8,
pub name: [u8; 256],
}
impl DirectoryEntry {
pub(crate) fn name(&self) -> OsString {
let name = &self.name[0..self.name_len as usize];
OsStr::from_bytes(name).to_os_string()
}
}
impl Default for DirectoryEntry {
fn default() -> Self {
Self {
inode: 0,
record_len: 0,
name_len: 0,
file_type: 0x0,
name: [0; 256],
}
}
}
#[repr(C)]
#[derive(Clone)]
pub struct DirectoryBlock {
pub entries: [DirectoryEntry; 15],
pub occupancy: [u8; 2],
reserved: [u8; 134],
}
impl Default for DirectoryBlock {
fn default() -> Self {
Self {
entries: [
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
DirectoryEntry::default(),
],
occupancy: [0x80, 0x00], // 0b1000_0000
reserved: [0xFF; 134],
}
}
}
impl DirectoryBlock {
#[allow(unused)]
pub(crate) fn is_full(&self) -> bool {
self.occupancy[0] == 0xFF && self.occupancy[1] == 0xFF
}
pub(crate) fn query(&self, mut index: usize) -> bool {
if index < 7 {
// 0-6, first u8
index = index + 1;
self.occupancy[0] & (1 << (7 - index)) as u8 != 0
} else if index < 15 {
// 7-14, second u8
index = index - 7;
self.occupancy[1] & (1 << (7 - index)) as u8 != 0
} else {
false
}
}
pub(crate) fn allocate(&mut self, mut index: usize) -> bool {
if index < 7 {
index = index + 1;
let mask = (1 << (7 - index)) as u8;
if self.occupancy[0] & mask != 0 {
false
} else {
self.occupancy[0] |= mask;
true
}
} else {
index = index - 7;
let mask = (1 << (7 - index)) as u8;
if self.occupancy[1] & mask != 0 {
false
} else {
self.occupancy[1] |= mask;
true
}
}
}
// pub(crate) fn allocate(&mut self) -> Option<usize> {
// if self.occupancy[0] != 0xFF {
// let leading_ones = self.occupancy[0].leading_ones();
// self.occupancy[0] |= (1 << (7 - leading_ones)) as u8;
// Some(leading_ones as usize)
// } else if self.occupancy[1] != 0xFF {
// let leading_ones = self.occupancy[1].leading_ones();
// self.occupancy[1] |= (1 << (7 - leading_ones)) as u8;
// Some(7 + leading_ones as usize)
// } else {
// None
// }
// }
pub(crate) fn deallocate(&mut self, mut index: usize) {
if index < 7 {
index = index + 1;
self.occupancy[0] &= !((1 << (7 - index)) as u8);
} else if index < 15 {
// 7-14, second u8
index = index - 7;
self.occupancy[1] &= !((1 << (7 - index)) as u8);
}
}
}
impl Block for DirectoryBlock {}
#[repr(C)]
#[derive(Clone)]
pub struct IndirectBlock {
pub entries: [u32; 1024],
}
impl Default for IndirectBlock {
fn default() -> Self {
Self { entries: [0; 1024] }
}
}
impl Block for IndirectBlock {}
#[repr(C)]
#[derive(Clone)]
pub struct DoubleIndirectBlock {
pub indirect: [u32; 1024],
}
impl Default for DoubleIndirectBlock {
fn default() -> Self {
Self {
indirect: [0; 1024],
}
}
}
impl Block for DoubleIndirectBlock {}
#[repr(C)]
#[derive(Clone)]
pub struct TripleIndirectBlock {
pub double_indirect: [u32; 1024],
}
impl Default for TripleIndirectBlock {
fn default() -> Self {
Self {
double_indirect: [0; 1024],
}
}
}
impl Block for TripleIndirectBlock {}
|
