From: Wolfgang Bumiller <w.bumiller@proxmox.com>
To: Stefan Reiter <s.reiter@proxmox.com>
Cc: pbs-devel@lists.proxmox.com
Subject: Re: [pbs-devel] [PATCH pxar 01/22] decoder/aio: add contents() and content_size() calls
Date: Wed, 17 Feb 2021 08:56:54 +0100 [thread overview]
Message-ID: <20210217075654.yokzlgbb3anix6mi@olga.proxmox.com> (raw)
In-Reply-To: <20210216170710.31767-2-s.reiter@proxmox.com>
On Tue, Feb 16, 2021 at 06:06:49PM +0100, Stefan Reiter wrote:
> Returns a tokio AsyncRead implementation for its "Contents" to keep with
> the aio theme.
>
> Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
> ---
> src/decoder/aio.rs | 43 ++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 42 insertions(+), 1 deletion(-)
>
> diff --git a/src/decoder/aio.rs b/src/decoder/aio.rs
> index 82030b0..5cc6694 100644
> --- a/src/decoder/aio.rs
> +++ b/src/decoder/aio.rs
> @@ -56,6 +56,18 @@ 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.
> + /// Only available for feature "tokio-io", since it returns an AsyncRead reader.
> + #[cfg(feature = "tokio-io")]
^ Don't do this.
We basically have our own async I/O "entry point" with the SeqRead
trait, and if you want to use it with another I/O runtime (say async-std
or w/e futures or w/e else there is), you want to be able to use
`Contents` there as well and just wrap it an alternative to the
provided `TokioReader` manually.
So just leave `Contents` as a public just-`SeqRead` type.
> + pub fn contents(&mut self) -> Option<Contents<T>> {
> + self.inner.content_reader().map(|inner| Contents { inner })
> + }
> +
> + /// 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;
> @@ -93,7 +105,36 @@ mod tok {
> }
> }
> }
> +
> + pub struct Contents<'a, T: crate::decoder::SeqRead> {
> + pub(crate) inner: crate::decoder::Contents<'a, T>,
^ no need for the `pub(crate)` then when you move it up
> + }
> +
> + 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 only write to the buffer, so we don't need to
> + // initialize it first, we can treat is a &[u8] immediately as long as we uphold
> + // the ReadBuf invariants in the conditional below
^ This comment is actually wrong. `poll_seq_read` will do whatever the
heck the implementer of the trait decides to do ;-)
Personally, I really don't mind doing this *anyway* until a definitive
"solution" actually lands in the *standard* library. Because if someone
f's up a read impl even if it causes wild codegen bugs with tentacles then...
sorry not sorry.
> + let write_buf =
> + &mut *(buf.unfilled_mut() as *mut [std::mem::MaybeUninit<u8>] as *mut [u8]);
> + let result = self
> + .map_unchecked_mut(|this| &mut this.inner as &mut dyn crate::decoder::SeqRead)
> + .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);
> + }
> + result.map(|_| Ok(()))
> + }
> + }
> + }
> }
>
> #[cfg(feature = "tokio-io")]
> -use tok::TokioReader;
> +use tok::{Contents, TokioReader};
^ Needs a `pub` otherwise the type *can* exist as the return type of a
function, but users have no way to actually *type out* the type...
next prev parent reply other threads:[~2021-02-17 7:57 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-16 17:06 [pbs-devel] [PATCH 00/22] Single file restore for VM images Stefan Reiter
2021-02-16 17:06 ` [pbs-devel] [PATCH pxar 01/22] decoder/aio: add contents() and content_size() calls Stefan Reiter
2021-02-17 7:56 ` Wolfgang Bumiller [this message]
2021-02-16 17:06 ` [pbs-devel] [PATCH pxar 02/22] decoder: add peek() Stefan Reiter
2021-02-17 8:20 ` Wolfgang Bumiller
2021-02-17 8:38 ` Stefan Reiter
2021-02-16 17:06 ` [pbs-devel] [PATCH proxmox-restore-vm-data 03/22] initial commit Stefan Reiter
2021-03-15 18:35 ` [pbs-devel] applied: " Thomas Lamprecht
2021-03-16 15:33 ` Stefan Reiter
2021-02-16 17:06 ` [pbs-devel] [PATCH proxmox-backup 04/22] api2/admin/datastore: refactor list_dir_content in catalog_reader Stefan Reiter
2021-02-17 7:50 ` [pbs-devel] applied: " Thomas Lamprecht
2021-02-16 17:06 ` [pbs-devel] [PATCH proxmox-backup 05/22] api2/admin/datastore: accept "/" as path for root Stefan Reiter
2021-02-17 7:50 ` [pbs-devel] applied: " Thomas Lamprecht
2021-02-16 17:06 ` [pbs-devel] [PATCH proxmox-backup 06/22] api2/admin/datastore: refactor create_zip into pxar/extract Stefan Reiter
2021-02-17 7:50 ` [pbs-devel] applied: " Thomas Lamprecht
2021-02-16 17:06 ` [pbs-devel] [PATCH proxmox-backup 07/22] pxar/extract: add extract_sub_dir Stefan Reiter
2021-02-17 7:51 ` [pbs-devel] applied: " Thomas Lamprecht
2021-02-16 17:06 ` [pbs-devel] [PATCH proxmox-backup 08/22] pxar/extract: add sequential variants to create_zip, extract_sub_dir Stefan Reiter
2021-02-16 17:06 ` [pbs-devel] [PATCH proxmox-backup 09/22] client: extract common functions to proxmox_client_tools module Stefan Reiter
2021-02-17 6:49 ` Dietmar Maurer
2021-02-17 7:58 ` Stefan Reiter
2021-02-17 8:50 ` Dietmar Maurer
2021-02-17 9:47 ` Stefan Reiter
2021-02-17 10:12 ` Dietmar Maurer
2021-02-17 9:13 ` [pbs-devel] applied: " Dietmar Maurer
2021-02-16 17:06 ` [pbs-devel] [PATCH proxmox-backup 10/22] proxmox_client_tools: extract 'key' from client module Stefan Reiter
2021-02-17 9:11 ` Dietmar Maurer
2021-02-16 17:06 ` [pbs-devel] [PATCH proxmox-backup 11/22] file-restore: add binary and basic commands Stefan Reiter
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 12/22] file-restore: allow specifying output-format Stefan Reiter
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 13/22] rest: implement tower service for UnixStream Stefan Reiter
2021-02-17 6:52 ` [pbs-devel] applied: " Dietmar Maurer
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 14/22] client: add VsockClient to connect to virtio-vsock VMs Stefan Reiter
2021-02-17 7:24 ` [pbs-devel] applied: " Dietmar Maurer
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 15/22] file-restore-daemon: add binary with virtio-vsock API server Stefan Reiter
2021-02-17 10:17 ` Dietmar Maurer
2021-02-17 10:25 ` Dietmar Maurer
2021-02-17 10:30 ` Stefan Reiter
2021-02-17 11:13 ` Dietmar Maurer
2021-02-17 11:26 ` Dietmar Maurer
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 16/22] file-restore-daemon: add watchdog module Stefan Reiter
2021-02-17 10:52 ` Wolfgang Bumiller
2021-02-17 11:14 ` Stefan Reiter
2021-02-17 11:29 ` Wolfgang Bumiller
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 17/22] file-restore-daemon: add disk module Stefan Reiter
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 18/22] file-restore: add basic VM/block device support Stefan Reiter
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 19/22] file-restore: improve logging of VM with logrotate Stefan Reiter
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 20/22] debian/client: add postinst hook to rebuild file-restore initramfs Stefan Reiter
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 21/22] file-restore(-daemon): implement list API Stefan Reiter
2021-02-16 17:07 ` [pbs-devel] [PATCH proxmox-backup 22/22] file-restore: add 'extract' command for VM file restore Stefan Reiter
2021-02-16 17:11 ` [pbs-devel] [PATCH 00/22] Single file restore for VM images Stefan Reiter
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