Re: [pbs-devel] [PATCH v3 proxmox 2/3] compression: Add support for symlinks in zip files

[Filip Schauer <f.schauer@proxmox.com>]

On 20/12/2023 14:20, Wolfgang Bumiller wrote:
> With the link of a symlink being encoded in the contents, I wonder if we
> should just do the same in the code. Not normally what I'd go for in
> rust, but...
>
> On Thu, Dec 14, 2023 at 03:48:21PM +0100, Filip Schauer wrote:
>> Add support for symlinks to ZipEntry. A symlink is encoded by or-ing its
>> attributes with S_IFLNK as seen in the kernel in
>> include/uapi/linux/stat.h
>>
>> Signed-off-by: Filip Schauer<f.schauer@proxmox.com>
>> ---
>>   proxmox-compression/src/zip.rs | 32 +++++++++++++++++++++++++-------
>>   1 file changed, 25 insertions(+), 7 deletions(-)
>>
>> diff --git a/proxmox-compression/src/zip.rs b/proxmox-compression/src/zip.rs
>> index 069e8bc..a3b2346 100644
>> --- a/proxmox-compression/src/zip.rs
>> +++ b/proxmox-compression/src/zip.rs
>> @@ -74,6 +74,7 @@ fn epoch_to_dos(epoch: i64) -> (u16, u16) {
>>   pub enum FileType {
>>       Directory,
>>       Regular,
>> +    Symlink(OsString),
> ... then this enum could be #[repr(u32)] using the values from the hunk
> below as discriminants here directly.
> And without the OsString in there this could be all of `Clone + Copy +
> Eq + PartialEq`, turning all the `matches!()` in this series into
> comparisons with `==`.


Do you want to pass the symlink target as an additional argument to
add_entry? If so, add_entry would take an enum FileType, an Option
content and an Option symlink_target. Depending on the FileType, at
least one of the Options would be None. This approach does not seem very
clean to me.

I just thought of another way:

How about inserting the content into FileType::Regular. This would
eliminate the need to pass None to add_entry. Therefore, it would be
impossible to pass conflicting parameters to the function, such as
FileType::Regular with content = None. This change would not get rid of
the hunk you mentioned, but the code seems cleaner to me this way.