Bruce Leidl
7f3b3aa409
Many many changes. The major themes of the refactor were to move the x86 specific code into a separate 'arch' package and make the main initialization and run loop much simpler to understand. The second big change was to improve how errors are handled by making them more 'local' so that packages define their own errors most of the time.
94 lines
3.0 KiB
Rust
94 lines
3.0 KiB
Rust
use std::{io, error, fmt, result, cmp};
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use std::fs::File;
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use std::os::linux::fs::MetadataExt;
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use std::io::{SeekFrom, Seek};
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use crate::system;
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mod realmfs;
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mod raw;
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mod memory;
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pub use raw::RawDiskImage;
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pub use realmfs::RealmFSImage;
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use std::path::PathBuf;
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const SECTOR_SIZE: usize = 512;
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#[derive(Debug,PartialEq)]
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pub enum OpenType {
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ReadOnly,
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ReadWrite,
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MemoryOverlay,
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}
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pub trait DiskImage: Sync+Send {
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fn open(&mut self) -> Result<()>;
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fn read_only(&self) -> bool;
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fn sector_count(&self) -> u64;
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fn disk_file(&mut self) -> Result<&mut File>;
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fn seek_to_sector(&mut self, sector: u64) -> Result<()> {
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if sector > self.sector_count() {
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return Err(Error::BadSectorOffset(sector));
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}
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let offset = SeekFrom::Start(sector * SECTOR_SIZE as u64);
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let file = self.disk_file()?;
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file.seek(offset)
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.map_err(Error::DiskSeek)?;
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Ok(())
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}
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fn write_sectors(&mut self, start_sector: u64, buffer: &[u8]) -> Result<()>;
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fn read_sectors(&mut self, start_sector: u64, buffer: &mut [u8]) -> Result<()>;
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fn flush(&mut self) -> Result<()> { Ok(()) }
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fn disk_image_id(&self) -> &[u8];
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}
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fn generate_disk_image_id(disk_file: &File) -> Vec<u8> {
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const VIRTIO_BLK_ID_BYTES: usize = 20;
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let meta = match disk_file.metadata() {
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Ok(meta) => meta,
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Err(_) => return vec![0u8; VIRTIO_BLK_ID_BYTES]
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};
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let dev_id = format!("{}{}{}", meta.st_dev(), meta.st_rdev(), meta.st_ino());
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let bytes = dev_id.as_bytes();
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let len = cmp::min(bytes.len(), VIRTIO_BLK_ID_BYTES);
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Vec::from(&bytes[..len])
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}
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pub type Result<T> = result::Result<T, Error>;
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#[derive(Debug)]
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pub enum Error {
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ReadOnly,
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ImageDoesntExit(PathBuf),
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DiskOpen(PathBuf,io::Error),
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DiskOpenTooShort(PathBuf),
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DiskRead(io::Error),
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DiskWrite(io::Error),
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DiskSeek(io::Error),
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BadSectorOffset(u64),
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MemoryOverlayCreate(system::Error),
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NotOpen,
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}
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impl error::Error for Error {}
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impl fmt::Display for Error {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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use Error::*;
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match self {
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ReadOnly => write!(f, "attempted write to read-only device"),
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ImageDoesntExit(path) => write!(f, "disk image {} does not exist", path.display()),
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DiskOpen(path, err) => write!(f, "failed to open disk image {}: {}", path.display(), err),
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DiskOpenTooShort(path) => write!(f, "failed to open disk image {} because file is too short", path.display()),
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DiskRead(err) => write!(f, "error reading from disk image: {}", err),
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DiskWrite(err) => write!(f, "error writing to disk image: {}", err),
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DiskSeek(err) => write!(f, "error seeking to offset on disk image: {}", err),
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BadSectorOffset(sector) => write!(f, "attempt to access invalid sector offset {}", sector),
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MemoryOverlayCreate(err) => write!(f, "failed to create memory overlay: {}", err),
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NotOpen => write!(f, "disk not open"),
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}
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}
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} |