From: Stefan Reiter <s.reiter@proxmox.com>
To: Wolfgang Bumiller <w.bumiller@proxmox.com>
Cc: pbs-devel@lists.proxmox.com
Subject: Re: [pbs-devel] [PATCH v2 pxar 01/20] decoder/aio: add contents() and content_size() calls
Date: Thu, 25 Mar 2021 10:23:59 +0100 [thread overview]
Message-ID: <b181367c-1871-2b1f-5f8a-90b3485b3ef4@proxmox.com> (raw)
In-Reply-To: <20210325090836.r662otu4kyc4mokp@wobu-vie.proxmox.com>
On 3/25/21 10:08 AM, Wolfgang Bumiller wrote:
> On Wed, Mar 24, 2021 at 04:18:08PM +0100, Stefan Reiter wrote:
>> Returns a decoder::Contents without a wrapper type, since in this case
>> we don't want to hide the SeqRead implementation (as done in
>> decoder::sync). For conviencience also implement AsyncRead if "tokio-io"
>> is enabled.
>>
>> Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
>> ---
>>
>> proxmox-backup requires a dependency bump on this!
>>
>> v2:
>> * make contents() call available without tokio-io feature
>> * drop peek() implementation
>>
>> src/decoder/aio.rs | 36 +++++++++++++++++++++++++++++++++++-
>> 1 file changed, 35 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/decoder/aio.rs b/src/decoder/aio.rs
>> index 82030b0..ee4d51f 100644
>> --- a/src/decoder/aio.rs
>> +++ b/src/decoder/aio.rs
>> @@ -5,7 +5,7 @@ use std::io;
>> #[cfg(feature = "tokio-fs")]
>> use std::path::Path;
>>
>> -use crate::decoder::{self, SeqRead};
>> +use crate::decoder::{self, Contents, SeqRead};
>> use crate::Entry;
>>
>> /// Asynchronous `pxar` decoder.
>> @@ -56,6 +56,16 @@ impl<T: SeqRead> Decoder<T> {
>> self.inner.next_do().await.transpose()
>> }
>>
>> + /// Get a reader for the contents of the current entry, if the entry has contents.
>> + pub fn contents(&mut self) -> Option<Contents<T>> {
>> + self.inner.content_reader()
>> + }
>> +
>> + /// Get the size of the current contents, if the entry has contents.
>> + pub fn content_size(&self) -> Option<u64> {
>> + self.inner.content_size()
>> + }
>> +
>> /// Include goodbye tables in iteration.
>> pub fn enable_goodbye_entries(&mut self, on: bool) {
>> self.inner.with_goodbye_tables = on;
>> @@ -67,6 +77,7 @@ mod tok {
>> use std::io;
>> use std::pin::Pin;
>> use std::task::{Context, Poll};
>> + use crate::decoder::{Contents, SeqRead};
>>
>> /// Read adapter for `futures::io::AsyncRead`
>> pub struct TokioReader<T> {
>> @@ -93,6 +104,29 @@ mod tok {
>> }
>> }
>> }
>> +
>> + impl<'a, T: crate::decoder::SeqRead> tokio::io::AsyncRead for Contents<'a, T> {
>> + fn poll_read(
>> + self: Pin<&mut Self>,
>> + cx: &mut Context<'_>,
>> + buf: &mut tokio::io::ReadBuf<'_>,
>> + ) -> Poll<io::Result<()>> {
>> + unsafe {
>> + // Safety: poll_seq_read will *probably* only write to the buffer, so we don't
>> + // initialize it first, instead we treat is a &[u8] immediately and uphold the
>> + // ReadBuf invariants in the conditional below.
>> + let write_buf =
>> + &mut *(buf.unfilled_mut() as *mut [std::mem::MaybeUninit<u8>] as *mut [u8]);
>> + let result = self.poll_seq_read(cx, write_buf);
>> + if let Poll::Ready(Ok(n)) = result {
>> + // if we've written data, advance both initialized and filled bytes cursor
>> + buf.assume_init(buf.filled().len() + n);
>> + buf.advance(n);
>
> The differences here look fishy. The docs about `assume_init()` say it
> marks the "first `n` *unfilled* bytes`, so IMO both calls should use
> just `n` as they both start from the beginning of the unfilled range?
>
Hm, you're right:
https://docs.rs/tokio/1.4.0/src/tokio/io/read_buf.rs.html#240
That doc is a bit confusing IMO...
>> + }
>> + result.map(|_| Ok(()))
>> + }
>> + }
>> + }
>> }
>>
>> #[cfg(feature = "tokio-io")]
>> --
>> 2.20.1
next prev parent reply other threads:[~2021-03-25 9:24 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 15:18 [pbs-devel] [PATCH v2 00/20] Single file restore for VM images Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 pxar 01/20] decoder/aio: add contents() and content_size() calls Stefan Reiter
2021-03-25 9:08 ` Wolfgang Bumiller
2021-03-25 9:23 ` Stefan Reiter [this message]
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 02/20] vsock_client: remove wrong comment Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 03/20] vsock_client: remove some &mut restrictions and rustfmt Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 04/20] vsock_client: support authorization header Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 05/20] proxmox_client_tools: move common key related functions to key_source.rs Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 06/20] file-restore: add binary and basic commands Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 07/20] file-restore: allow specifying output-format Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 08/20] server/rest: extract auth to seperate module Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 09/20] server/rest: add ApiAuth trait to make user auth generic Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 10/20] file-restore-daemon: add binary with virtio-vsock API server Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 11/20] file-restore-daemon: add watchdog module Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 12/20] file-restore-daemon: add disk module Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 13/20] add tools/cpio encoding module Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 14/20] file-restore: add qemu-helper setuid binary Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 15/20] file-restore: add basic VM/block device support Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 16/20] debian/client: add postinst hook to rebuild file-restore initramfs Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 17/20] file-restore(-daemon): implement list API Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 18/20] pxar/extract: add sequential variant to extract_sub_dir Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 19/20] tools/zip: add zip_directory helper Stefan Reiter
2021-03-24 15:18 ` [pbs-devel] [PATCH v2 proxmox-backup 20/20] file-restore: add 'extract' command for VM file restore Stefan Reiter
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