Re: [pbs-devel] [PATCH proxmox-backup] fix #4301: correctly pass rate limit parameters to API

[Stefan Hanreich <s.hanreich@proxmox.com>]

On 10/20/22 15:44, Wolfgang Bumiller wrote:
> On Thu, Oct 20, 2022 at 02:59:46PM +0200, Stefan Hanreich wrote:
>>
>>
>> On 10/20/22 14:48, Wolfgang Bumiller wrote:
>>> On Thu, Oct 20, 2022 at 01:37:31PM +0200, Stefan Hanreich wrote:
>>>> With the old code the rate limit parameters got passed in their own
>>>> dictionary under the limit key, but the API expects the rate-limit
>>>> settings as top-level keys. This commit correctly sets the rate-limit
>>>> parameters so the API actually uses them.
>>>>
>>>> Signed-off-by: Stefan Hanreich <s.hanreich@proxmox.com>
>>>> ---
>>>>    src/bin/proxmox-backup-manager.rs | 14 ++++++++++++--
>>>>    1 file changed, 12 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/src/bin/proxmox-backup-manager.rs b/src/bin/proxmox-backup-manager.rs
>>>> index 58e7e33a..cdd1037d 100644
>>>> --- a/src/bin/proxmox-backup-manager.rs
>>>> +++ b/src/bin/proxmox-backup-manager.rs
>>>> @@ -2,7 +2,7 @@ use std::collections::HashMap;
>>>>    use std::io::{self, Write};
>>>>    use std::str::FromStr;
>>>> -use anyhow::Error;
>>>> +use anyhow::{Error, format_err};
>>>>    use serde_json::{json, Value};
>>>>    use proxmox_router::{cli::*, RpcEnvironment};
>>>> @@ -297,7 +297,6 @@ async fn pull_datastore(
>>>>            "store": store,
>>>>            "remote": remote,
>>>>            "remote-store": remote_store,
>>>> -        "limit": limit,
>>>>        });
>>>>        if remote_ns.is_some() {
>>>> @@ -320,6 +319,17 @@ async fn pull_datastore(
>>>>            args["remove-vanished"] = Value::from(remove_vanished);
>>>>        }
>>>> +    let args_map = args
>>>> +        .as_object_mut()
>>>> +        .ok_or_else(|| format_err!("args is not an Object"))?;
>>>
>>> ^ We create the `args` map only a few lines further up, so it would be
>>> fine to just `.unwrap()` here. And it would be nicer to keep the access
>>> short (iow move the `.as_object_mut()` down to where it's used for `.append()`)
>>>
>>
>> Can replace it with unwrap(), shouldn't be a problem.
>>
>> The reason why I stored it in a variable was that with a subsequent patch I
>> will also append another map to the args, but I could then just call
>> .as_object_mut() twice, what do you think?
> 
> I suppose that's fine. If you already know such things while sending a
> patch without the followups being part of the same series, you can note
> such things after the `---` in the patch mail, that way it won't
> needlessly end up in the commit message, but still be visible to the
> reviewer.
> 
> Come to think of it, there are a lot of `args[key] = value;` assignments
> which could probably benefit from already having the `&mut Map` instead
> of the `Value` enum.
> 
> Maybe should change it like this
> 
>      -    let mut args = json!(...)
>      +    let mut args_value = json(!...);
>      +    let args = args_value.as_object_mut().unwrap();
> 
> right where it is created, this way the unwrap will stay even closer to
> the creation, the remaining assignments already see the object type, and
> you can call append, too.
> Finally, the `Some(args)` would need to be changed to `Some(args_value)`
> in the `post()` call.
>

I will keep that in mind for future patches, thanks for the info!

The problem is when assigning via args[key] = value on a Map, it 
actually panics if the key doesn't exist in the map [1], so I'm afraid 
this isn't a possibility unless I'm missing something.

I was already a bit too overeager and submitted v2, this time without 
the assignment and just using the `args.as_object_mut()`. I think it 
should be fine, I'll just add the variable assignment in the subsequent 
patch series when it is actually needed and not in this patch.

[1] 
https://docs.rs/serde_json/latest/serde_json/struct.Map.html#impl-IndexMut%3C%26%27a%20Q%3E-for-Map%3CString%2C%20Value%3E

>> 
>>>> +
>>>> +    let mut limit_json = json!(limit);
>>>> +    let limit_map = limit_json
>>>> +        .as_object_mut()
>>>> +        .ok_or_else(|| format_err!("limit is not an Object"))?;
>>>> +
>>>> +    args_map.append(limit_map);
>>>> +
>>>>        let result = client.post("api2/json/pull", Some(args)).await?;
>>>>        view_task_result(&client, result, &output_format).await?;
>>>> -- 
>>>> 2.30.2