proxmox-backup/src/backup/read_chunk.rs

116 lines
3.4 KiB
Rust

use std::future::Future;
use std::pin::Pin;
use std::sync::Arc;
use anyhow::{bail, Error};
use super::crypt_config::{CryptConfig, CryptMode};
use super::data_blob::DataBlob;
use super::datastore::DataStore;
/// The ReadChunk trait allows reading backup data chunks (local or remote)
pub trait ReadChunk {
/// Returns the encoded chunk data
fn read_raw_chunk(&self, digest: &[u8; 32]) -> Result<DataBlob, Error>;
/// Returns the decoded chunk data
fn read_chunk(&self, digest: &[u8; 32]) -> Result<Vec<u8>, Error>;
}
#[derive(Clone)]
pub struct LocalChunkReader {
store: Arc<DataStore>,
crypt_config: Option<Arc<CryptConfig>>,
crypt_mode: CryptMode,
}
impl LocalChunkReader {
pub fn new(store: Arc<DataStore>, crypt_config: Option<Arc<CryptConfig>>, crypt_mode: CryptMode) -> Self {
Self {
store,
crypt_config,
crypt_mode,
}
}
fn ensure_crypt_mode(&self, chunk_mode: CryptMode) -> Result<(), Error> {
match self.crypt_mode {
CryptMode::Encrypt => {
match chunk_mode {
CryptMode::Encrypt => Ok(()),
CryptMode::SignOnly | CryptMode::None => bail!("Index and chunk CryptMode don't match."),
}
},
CryptMode::SignOnly | CryptMode::None => {
match chunk_mode {
CryptMode::Encrypt => bail!("Index and chunk CryptMode don't match."),
CryptMode::SignOnly | CryptMode::None => Ok(()),
}
},
}
}
}
impl ReadChunk for LocalChunkReader {
fn read_raw_chunk(&self, digest: &[u8; 32]) -> Result<DataBlob, Error> {
let chunk = self.store.load_chunk(digest)?;
self.ensure_crypt_mode(chunk.crypt_mode()?)?;
Ok(chunk)
}
fn read_chunk(&self, digest: &[u8; 32]) -> Result<Vec<u8>, Error> {
let chunk = ReadChunk::read_raw_chunk(self, digest)?;
let raw_data = chunk.decode(self.crypt_config.as_ref().map(Arc::as_ref), Some(digest))?;
Ok(raw_data)
}
}
pub trait AsyncReadChunk: Send {
/// Returns the encoded chunk data
fn read_raw_chunk<'a>(
&'a self,
digest: &'a [u8; 32],
) -> Pin<Box<dyn Future<Output = Result<DataBlob, Error>> + Send + 'a>>;
/// Returns the decoded chunk data
fn read_chunk<'a>(
&'a self,
digest: &'a [u8; 32],
) -> Pin<Box<dyn Future<Output = Result<Vec<u8>, Error>> + Send + 'a>>;
}
impl AsyncReadChunk for LocalChunkReader {
fn read_raw_chunk<'a>(
&'a self,
digest: &'a [u8; 32],
) -> Pin<Box<dyn Future<Output = Result<DataBlob, Error>> + Send + 'a>> {
Box::pin(async move{
let (path, _) = self.store.chunk_path(digest);
let raw_data = tokio::fs::read(&path).await?;
let chunk = DataBlob::load_from_reader(&mut &raw_data[..])?;
self.ensure_crypt_mode(chunk.crypt_mode()?)?;
Ok(chunk)
})
}
fn read_chunk<'a>(
&'a self,
digest: &'a [u8; 32],
) -> Pin<Box<dyn Future<Output = Result<Vec<u8>, Error>> + Send + 'a>> {
Box::pin(async move {
let chunk = AsyncReadChunk::read_raw_chunk(self, digest).await?;
let raw_data = chunk.decode(self.crypt_config.as_ref().map(Arc::as_ref), Some(digest))?;
// fixme: verify digest?
Ok(raw_data)
})
}
}