97 lines
2.8 KiB
Rust
97 lines
2.8 KiB
Rust
//! ISO sector reader — file-backed SectorReader for Blu-ray ISO images.
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//!
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//! An ISO is a flat image of 2048-byte sectors. Sector N starts at byte offset N * 2048.
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//! Used by DiscStream::open_iso() and Disc::scan_image().
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use crate::error::{Error, Result};
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use crate::sector::SectorReader;
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use std::fs::File;
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use std::io::{Read, Seek, SeekFrom};
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use std::path::Path;
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const SECTOR_SIZE: u64 = 2048;
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/// File-backed sector reader for ISO images.
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pub struct IsoSectorReader {
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file: File,
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capacity: u32,
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}
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impl IsoSectorReader {
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pub fn open(path: &str) -> std::io::Result<Self> {
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let file = File::open(Path::new(path))
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.map_err(|e| std::io::Error::new(e.kind(), format!("iso://{path}: {e}")))?;
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let size = file.metadata()?.len();
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let sectors = size / SECTOR_SIZE;
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if sectors > u32::MAX as u64 {
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return Err(crate::error::Error::IsoTooLarge {
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path: path.to_string(),
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}
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.into());
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}
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let capacity = sectors as u32;
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Ok(Self { file, capacity })
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}
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pub fn capacity(&self) -> u32 {
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self.capacity
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}
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}
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impl SectorReader for IsoSectorReader {
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fn read_sectors(&mut self, lba: u32, count: u16, buf: &mut [u8]) -> Result<usize> {
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let bytes = count as usize * SECTOR_SIZE as usize;
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self.file
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.seek(SeekFrom::Start(lba as u64 * SECTOR_SIZE))
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.map_err(|e| Error::IoError { source: e })?;
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self.file
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.read_exact(&mut buf[..bytes])
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.map_err(|e| Error::IoError { source: e })?;
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Ok(bytes)
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn iso_reader_read_sectors() {
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let mut data = vec![0u8; 4 * SECTOR_SIZE as usize];
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for i in 0..4u8 {
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let offset = i as usize * SECTOR_SIZE as usize;
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data[offset] = i + 1;
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data[offset + 2047] = i + 100;
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}
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let dir = std::env::temp_dir().join("freemkv_test_iso_read");
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std::fs::write(&dir, &data).unwrap();
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let mut reader = IsoSectorReader::open(dir.to_str().unwrap()).unwrap();
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assert_eq!(reader.capacity(), 4);
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let mut buf = [0u8; 2048];
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reader.read_sectors(0, 1, &mut buf).unwrap();
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assert_eq!(buf[0], 1);
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assert_eq!(buf[2047], 100);
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reader.read_sectors(2, 1, &mut buf).unwrap();
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assert_eq!(buf[0], 3);
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assert_eq!(buf[2047], 102);
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std::fs::remove_file(&dir).ok();
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}
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#[test]
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fn iso_reader_capacity() {
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let data = vec![0u8; 10 * SECTOR_SIZE as usize];
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let dir = std::env::temp_dir().join("freemkv_test_iso_cap");
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std::fs::write(&dir, &data).unwrap();
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let reader = IsoSectorReader::open(dir.to_str().unwrap()).unwrap();
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assert_eq!(reader.capacity(), 10);
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std::fs::remove_file(&dir).ok();
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}
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}
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