James Matlik
54 lines
1.4 KiB
Rust
54 lines
1.4 KiB
Rust
use std::fs::{File, OpenOptions};
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use std::io::{Read, Seek, SeekFrom, Write};
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use std::path::Path;
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use syscall::error::{Error, Result, EIO};
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use crate::disk::Disk;
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use crate::BLOCK_SIZE;
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macro_rules! try_disk {
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($expr:expr) => {
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match $expr {
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Ok(val) => val,
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Err(err) => {
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eprintln!("Disk I/O Error: {}", err);
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return Err(Error::new(EIO));
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}
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}
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};
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}
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pub struct DiskSparse {
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pub file: File,
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pub max_size: u64,
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}
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impl DiskSparse {
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pub fn create<P: AsRef<Path>>(path: P, max_size: u64) -> Result<DiskSparse> {
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let file = try_disk!(OpenOptions::new()
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.read(true)
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.write(true)
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.create(true)
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.open(path));
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Ok(DiskSparse { file, max_size })
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}
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}
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impl Disk for DiskSparse {
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unsafe fn read_at(&mut self, block: u64, buffer: &mut [u8]) -> Result<usize> {
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try_disk!(self.file.seek(SeekFrom::Start(block * BLOCK_SIZE)));
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let count = try_disk!(self.file.read(buffer));
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Ok(count)
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}
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unsafe fn write_at(&mut self, block: u64, buffer: &[u8]) -> Result<usize> {
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try_disk!(self.file.seek(SeekFrom::Start(block * BLOCK_SIZE)));
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let count = try_disk!(self.file.write(buffer));
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Ok(count)
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}
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fn size(&mut self) -> Result<u64> {
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Ok(self.max_size)
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}
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}
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