[pve-devel] applied: [PATCH v2 http-server 2/2] AnyEvent: Fix #3990 - make small files uploadable

[Thomas Lamprecht <t.lamprecht@proxmox.com>]

Am 13/05/2022 um 15:49 schrieb Matthias Heiserer:
> == The problem
> Upload of files smaller than ~16kb failed.
> This was because the code assumed that it would be called
> several times, and each time would do a certain action.
> When the whole file was in the buffer, this failed because
> the function would try parssing the first part in the payload and
> then return, instead of parsing the rest of the available data.
> 
> == Why not just modifying the current code a bit?
> The code had a lot of nested control statements and a
> non-intuitive control flow (phase 0->2->1->1->1 and so on).
> 
> The way the phases and buffer content were checked made it
> rather difficult to just fix a few lines.
> 
> == What was changed
> * Part headers are parsed with a single regex line each,
>  which improves code readability.
> 
> * Parsing the content is done in order, so even if the whole data is in the buffer,
>  it can be read in one go. Files of arbitrary sizes can be uploaded.
> 
> == Tested with
> * Uploaded 0B, 1B, 14KB, 16KB, 1GB, 10GB, 20GB files
> 
> * Tested with all checksums and without
> 
> * Tested on firefox, chromium, and pvesh
> 
> I didn't do any fuzzing or automated upload testing.
> 
> == Drawbacks & Potential issues
> * Part headers are hardcoded, adding new ones requries modifying this file
> 
> == does not fix
> * upload can still time out
> 
> Signed-off-by: Matthias Heiserer <m.heiserer@proxmox.com>
> ---
> 
> Note:
> Regarding trim, I forgot to answer the mail.
> Trim is imo a good name, as several languagues (e.g. rust, javascript)
> use trim to mean mean "remove all whitespace, including newlines and such".
> I can send a v3 if that's a problem.
> 
> Changes from v1:
> * fix whitespace in separate patch
> * move trim into inline closure
> * correctly call trim
> * replace [^\S] with \S in regexes
> * improve trim regex: don't replace string
> * check for phase 1 once
> * remove regex comment
> 
>  src/PVE/APIServer/AnyEvent.pm | 146 ++++++++++++++++++----------------
>  1 file changed, 76 insertions(+), 70 deletions(-)
> 
>

applied, with slightly reworking the commit messages subject and Daniel's T-b tag,
thanks to both!

Note that I made some follow ups trying to improve a few things of your change and the
existing code. E.g.: $string in trim wasn't used anywhere, same for $eof in phase 2.
The content-disposition extraction could be factored in a small closure to reduce code
size and (IMO) legibility, and some other smaller style/formatting stuff.

None of that was a blocker, and due to the age of this series (sorry for that!) I
really did not want to bother for a v3 and applied changes myself. I re-tested it
with various sizes and functionality (checksum), but an additional pair of eyes
would be appreciated to ensure no regression snuck in.