73 lines
2.0 KiB
Rust
73 lines
2.0 KiB
Rust
use std::{
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fs::{File, OpenOptions},
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io::{Read, Seek, SeekFrom, Write},
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mem,
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path::Path,
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};
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#[derive(Debug)]
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pub struct TieredStorageFile(pub File);
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impl TieredStorageFile {
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pub fn new_readonly(file_path: impl AsRef<Path>) -> Self {
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Self(
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OpenOptions::new()
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.read(true)
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.create(false)
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.open(&file_path)
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.unwrap_or_else(|e| {
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panic!(
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"[TieredStorageError] Unable to open {:?} as read-only: {:?}",
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file_path.as_ref().display(),
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e
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);
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}),
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)
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}
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pub fn new_writable(file_path: impl AsRef<Path>) -> Result<Self, std::io::Error> {
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Ok(Self(
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OpenOptions::new()
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.create_new(true)
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.write(true)
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.open(file_path)?,
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))
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}
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pub fn write_type<T>(&self, value: &T) -> Result<usize, std::io::Error> {
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let ptr = value as *const _ as *const u8;
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let slice = unsafe { std::slice::from_raw_parts(ptr, mem::size_of::<T>()) };
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(&self.0).write_all(slice)?;
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Ok(std::mem::size_of::<T>())
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}
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pub fn read_type<T>(&self, value: &mut T) -> Result<(), std::io::Error> {
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let ptr = value as *mut _ as *mut u8;
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let slice = unsafe { std::slice::from_raw_parts_mut(ptr, mem::size_of::<T>()) };
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(&self.0).read_exact(slice)?;
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Ok(())
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}
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pub fn seek(&self, offset: u64) -> Result<u64, std::io::Error> {
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(&self.0).seek(SeekFrom::Start(offset))
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}
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pub fn seek_from_end(&self, offset: i64) -> Result<u64, std::io::Error> {
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(&self.0).seek(SeekFrom::End(offset))
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}
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pub fn write_bytes(&self, bytes: &[u8]) -> Result<usize, std::io::Error> {
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(&self.0).write_all(bytes)?;
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Ok(bytes.len())
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}
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pub fn read_bytes(&self, buffer: &mut [u8]) -> Result<(), std::io::Error> {
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(&self.0).read_exact(buffer)?;
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Ok(())
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}
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}
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