proxmox-backup/pbs-client/src/remote_chunk_reader.rs

128 lines
4.0 KiB
Rust

use std::future::Future;
use std::collections::HashMap;
use std::pin::Pin;
use std::sync::{Arc, Mutex};
use anyhow::{bail, Error};
use proxmox_async::runtime::block_on;
use pbs_tools::crypt_config::CryptConfig;
use pbs_api_types::CryptMode;
use pbs_datastore::data_blob::DataBlob;
use pbs_datastore::read_chunk::ReadChunk;
use pbs_datastore::read_chunk::AsyncReadChunk;
use super::BackupReader;
/// Read chunks from remote host using ``BackupReader``
#[derive(Clone)]
pub struct RemoteChunkReader {
client: Arc<BackupReader>,
crypt_config: Option<Arc<CryptConfig>>,
crypt_mode: CryptMode,
cache_hint: Arc<HashMap<[u8; 32], usize>>,
cache: Arc<Mutex<HashMap<[u8; 32], Vec<u8>>>>,
}
impl RemoteChunkReader {
/// Create a new instance.
///
/// Chunks listed in ``cache_hint`` are cached and kept in RAM.
pub fn new(
client: Arc<BackupReader>,
crypt_config: Option<Arc<CryptConfig>>,
crypt_mode: CryptMode,
cache_hint: HashMap<[u8; 32], usize>,
) -> Self {
Self {
client,
crypt_config,
crypt_mode,
cache_hint: Arc::new(cache_hint),
cache: Arc::new(Mutex::new(HashMap::new())),
}
}
/// Downloads raw chunk. This only verifies the (untrusted) CRC32, use
/// DataBlob::verify_unencrypted or DataBlob::decode before storing/processing further.
pub async fn read_raw_chunk(&self, digest: &[u8; 32]) -> Result<DataBlob, Error> {
let mut chunk_data = Vec::with_capacity(4 * 1024 * 1024);
self.client
.download_chunk(digest, &mut chunk_data)
.await?;
let chunk = DataBlob::load_from_reader(&mut &chunk_data[..])?;
match self.crypt_mode {
CryptMode::Encrypt => {
match chunk.crypt_mode()? {
CryptMode::Encrypt => Ok(chunk),
CryptMode::SignOnly | CryptMode::None => bail!("Index and chunk CryptMode don't match."),
}
},
CryptMode::SignOnly | CryptMode::None => {
match chunk.crypt_mode()? {
CryptMode::Encrypt => bail!("Index and chunk CryptMode don't match."),
CryptMode::SignOnly | CryptMode::None => Ok(chunk),
}
},
}
}
}
impl ReadChunk for RemoteChunkReader {
fn read_raw_chunk(&self, digest: &[u8; 32]) -> Result<DataBlob, Error> {
block_on(Self::read_raw_chunk(self, digest))
}
fn read_chunk(&self, digest: &[u8; 32]) -> Result<Vec<u8>, Error> {
if let Some(raw_data) = (*self.cache.lock().unwrap()).get(digest) {
return Ok(raw_data.to_vec());
}
let chunk = ReadChunk::read_raw_chunk(self, digest)?;
let raw_data = chunk.decode(self.crypt_config.as_ref().map(Arc::as_ref), Some(digest))?;
let use_cache = self.cache_hint.contains_key(digest);
if use_cache {
(*self.cache.lock().unwrap()).insert(*digest, raw_data.to_vec());
}
Ok(raw_data)
}
}
impl AsyncReadChunk for RemoteChunkReader {
fn read_raw_chunk<'a>(
&'a self,
digest: &'a [u8; 32],
) -> Pin<Box<dyn Future<Output = Result<DataBlob, Error>> + Send + 'a>> {
Box::pin(Self::read_raw_chunk(self, digest))
}
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 {
if let Some(raw_data) = (*self.cache.lock().unwrap()).get(digest) {
return Ok(raw_data.to_vec());
}
let chunk = Self::read_raw_chunk(self, digest).await?;
let raw_data = chunk.decode(self.crypt_config.as_ref().map(Arc::as_ref), Some(digest))?;
let use_cache = self.cache_hint.contains_key(digest);
if use_cache {
(*self.cache.lock().unwrap()).insert(*digest, raw_data.to_vec());
}
Ok(raw_data)
})
}
}