vasilito/RedBear-OS
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Use same logic for read and write in disk wrapper

Browse Source
This commit is contained in:
Jeremy Soller
2022-09-07 10:40:41 -06:00
parent 8d2d4cd62d
commit 0b4f836f2a
1 changed files with 36 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/disk_wrapper.rs
+36 -34
View File
@@ -14,6 +14,11 @@ pub struct DiskWrapper {
seek: u64,
}
enum Buffer<'a> {
Read(&'a mut [u8]),
Write(&'a [u8]),
}
impl DiskWrapper {
pub fn open<P: AsRef<Path>>(path: P) -> Result<Self> {
let disk = OpenOptions::new()
@@ -40,17 +45,20 @@ impl DiskWrapper {
pub fn size(&self) -> u64 {
self.size
}
}
impl Read for DiskWrapper {
//TODO: improve performance by directly using block aligned parts of buf
fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
fn io<'a>(&mut self, buf: &mut Buffer<'a>) -> Result<usize> {
let buf_len = match buf {
Buffer::Read(read) => read.len(),
Buffer::Write(write) => write.len(),
};
let mut i = 0;
while i < buf.len() {
while i < buf_len {
let block_len: u64 = self.block.len().try_into().unwrap();
let block = self.seek / block_len;
let offset: usize = (self.seek % block_len).try_into().unwrap();
let remaining = buf.len().checked_sub(i).unwrap();
let remaining = buf_len.checked_sub(i).unwrap();
let len = cmp::min(
remaining,
self.block.len().checked_sub(offset.try_into().unwrap()).unwrap()
@@ -59,17 +67,36 @@ impl Read for DiskWrapper {
self.disk.seek(SeekFrom::Start(block.checked_mul(block_len).unwrap()))?;
self.disk.read_exact(&mut self.block)?;
buf[i..i.checked_add(len).unwrap()].copy_from_slice(
&self.block[offset..offset.checked_add(len).unwrap()]
);
match buf {
Buffer::Read(read) => {
read[i..i.checked_add(len).unwrap()].copy_from_slice(
&self.block[offset..offset.checked_add(len).unwrap()]
);
},
Buffer::Write(write) => {
self.block[offset..offset.checked_add(len).unwrap()].copy_from_slice(
&write[i..i.checked_add(len).unwrap()]
);
self.disk.seek(SeekFrom::Start(block.checked_mul(block_len).unwrap()))?;
self.disk.write_all(&mut self.block)?;
}
}
i = i.checked_add(len).unwrap();
self.seek = self.seek.checked_add(len.try_into().unwrap()).unwrap();
}
Ok(i)
}
}
impl Read for DiskWrapper {
fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
self.io(&mut Buffer::Read(buf))
}
}
impl Seek for DiskWrapper {
fn seek(&mut self, pos: SeekFrom) -> Result<u64> {
let current: i64 = self.seek.try_into().unwrap();
@@ -90,33 +117,8 @@ impl Seek for DiskWrapper {
}
impl Write for DiskWrapper {
//TODO: improve performance by directly using block aligned parts of buf
fn write(&mut self, buf: &[u8]) -> Result<usize> {
let mut i = 0;
while i < buf.len() {
let block_len: u64 = self.block.len().try_into().unwrap();
let block = self.seek / block_len;
let offset: usize = (self.seek % block_len).try_into().unwrap();
let remaining = buf.len().checked_sub(i).unwrap();
let len = cmp::min(
remaining,
self.block.len().checked_sub(offset.try_into().unwrap()).unwrap()
);
self.disk.seek(SeekFrom::Start(block.checked_mul(block_len).unwrap()))?;
self.disk.read_exact(&mut self.block)?;
self.block[offset..offset.checked_add(len).unwrap()].copy_from_slice(
&buf[i..i.checked_add(len).unwrap()]
);
self.disk.seek(SeekFrom::Start(block.checked_mul(block_len).unwrap()))?;
self.disk.write_all(&mut self.block)?;
i = i.checked_add(len).unwrap();
self.seek = self.seek.checked_add(len.try_into().unwrap()).unwrap();
}
Ok(i)
self.io(&mut Buffer::Write(buf))
}
fn flush(&mut self) -> Result<()> {