[pbs-devel] [PATCH v2 backup-qemu 4/5] use AsyncIndexReader for read_image_at
Stefan Reiter
s.reiter at proxmox.com
Wed Jul 22 15:56:24 CEST 2020
Replaces the removed BufferedFixedReader and makes the API fully async
(not block_in_place or block_on which could break with many requests at
once).
A tokio::sync::Mutex needs to be used for exclusive access, since a
regular one would not work with async/await calls.
Signed-off-by: Stefan Reiter <s.reiter at proxmox.com>
---
src/restore.rs | 21 ++++++++++-----------
1 file changed, 10 insertions(+), 11 deletions(-)
diff --git a/src/restore.rs b/src/restore.rs
index 3e37066..2be0295 100644
--- a/src/restore.rs
+++ b/src/restore.rs
@@ -1,13 +1,14 @@
use std::sync::{Arc, Mutex};
use std::collections::HashMap;
-use std::io::{Read, Seek, SeekFrom};
+use std::io::SeekFrom;
use std::convert::TryInto;
use anyhow::{format_err, bail, Error};
use once_cell::sync::OnceCell;
use tokio::runtime::Runtime;
+use tokio::prelude::*;
-use proxmox_backup::tools::runtime::{get_runtime_with_builder, block_in_place};
+use proxmox_backup::tools::runtime::get_runtime_with_builder;
use proxmox_backup::backup::*;
use proxmox_backup::client::{HttpClient, HttpClientOptions, BackupReader, RemoteChunkReader};
@@ -16,7 +17,7 @@ use crate::registry::Registry;
use crate::capi_types::DataPointer;
struct ImageAccessInfo {
- reader: Arc<Mutex<BufferedFixedReader<RemoteChunkReader>>>,
+ reader: Arc<tokio::sync::Mutex<AsyncIndexReader<RemoteChunkReader, FixedIndexReader>>>,
_archive_name: String,
archive_size: u64,
}
@@ -231,12 +232,12 @@ impl RestoreTask {
let index = client.download_fixed_index(&manifest, &archive_name).await?;
let archive_size = index.index_bytes();
- let reader = BufferedFixedReader::new(index, chunk_reader);
+ let reader = AsyncIndexReader::new(index, chunk_reader);
let info = ImageAccessInfo {
archive_size,
_archive_name: archive_name, /// useful to debug
- reader: Arc::new(Mutex::new(reader)),
+ reader: Arc::new(tokio::sync::Mutex::new(reader)),
};
(*self.image_registry.lock().unwrap()).register(info)
@@ -260,12 +261,10 @@ impl RestoreTask {
bail!("read index {} out of bounds {}", offset, image_size);
}
- let bytes = block_in_place(|| {
- let mut reader = reader.lock().unwrap();
- reader.seek(SeekFrom::Start(offset))?;
- let buf: &mut [u8] = unsafe { std::slice::from_raw_parts_mut(data.0 as *mut u8, size as usize)};
- reader.read(buf)
- })?;
+ let mut reader = reader.lock().await;
+ reader.seek(SeekFrom::Start(offset)).await?;
+ let buf: &mut [u8] = unsafe { std::slice::from_raw_parts_mut(data.0 as *mut u8, size as usize)};
+ let bytes = reader.read(buf).await?;
Ok(bytes.try_into()?)
}
--
2.20.1
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