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#[macro_use]
extern crate error_chain;
extern crate integer_encoding;
use std::io::prelude::*;
use std::path::Path;
use std::fs::File;
use integer_encoding::FixedInt;
mod errors {
// Create the Error, ErrorKind, ResultExt, and Result types
error_chain! {
foreign_links { Fmt(::std::fmt::Error);
Io(::std::io::Error) #[cfg(unix)]; }
}
}
pub use errors::*;
// Abstract access to SLEEP content
pub trait SleepStorage {
fn get_magic(&self) -> u32;
fn get_algorithm(&self) -> Option<String>;
fn get_entry_size(&self) -> u16;
fn read(&self, index: u64) -> Result<&[u8]>;
fn write(&self, index: u64, data: &[u8]) -> Result<()>;
fn length(&self) -> Result<u64>;
}
#[derive(Debug)]
pub struct SleepFile {
file: File,
magic: u32,
entry_size: u16,
algorithm_name: Option<String>,
}
impl SleepFile {
// TODO: 'from' File trait
pub fn open(path: &Path, writable: bool) -> Result<SleepFile> {
// TODO: use writable here
let mut f = File::open(path)?;
let mut header = [0; 32];
f.read_exact(&mut header)?;
let version: u8 = header[4];
if version != 0 {
return Err("Invalid SLEEP header: version must be 0".into());
}
let algo_len: u8 = header[8];
if algo_len > 24 {
return Err("Invalid SLEEP header: can't have algo_len > 24".into());
}
let algorithm_name = if algo_len == 0 { None } else {
Some(String::from_utf8_lossy(&header[8..(8+(algo_len as usize))]).into_owned())
};
// TODO: endian-ness of u16 entry_size
Ok(SleepFile {
file: f,
magic: FixedInt::decode_fixed(&header[0..4]),
entry_size: FixedInt::decode_fixed(&header[6..8]),
algorithm_name: algorithm_name,
})
}
/*
pub fn create(path: Path, magic: u32, entry_size: u16, algo: &str) -> Result<SleepFile> {
let mut sf = SleepFile {
};
}
*/
}
impl SleepStorage for SleepFile {
fn get_magic(&self) -> u32 { self.magic }
fn get_algorithm(&self) -> Option<String> { self.algorithm_name.clone() }
fn get_entry_size(&self) -> u16 { self.entry_size }
fn read(&self, index: u64) -> Result<&[u8]> {
unimplemented!()
//Err("unimplemented")
}
fn write(&self, index: u64, data: &[u8]) -> Result<()> {
Ok(())
}
fn length(&self) -> Result<u64> {
let length = self.file.metadata()?.len();
// TODO: assert that length >= 32
// TODO: assert that (length - 32) % self.entry_size == 0
return Ok((length - 32) / (self.entry_size as u64))
}
}
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