Min max delegation amounts

[moubctez]

Implements casper-network/ceps#90

Resolves #4860 [Issue created retrospectively]

[wojcik91]

@mpapierski ping

[wojcik91]

@mpapierski We added the forced undelegation process as discussed last week in f1a1400

[mpapierski]

Looking good code-wise. It'd be a good idea to measure how many delegators will be unbonded when 500 CSPR minimum delegation is enforced. Queueing unbonding requests for too many delegators at once may affect the network performance for some time until the queue is cleared.

[casperlabs-bors-ng]

Timed out.

[mpapierski]

bors r+

[casperlabs-bors-ng]

Canceled.

[mpapierski]

bors r+

[casperlabs-bors-ng]

Build failed:

• continuous-integration/drone/push

[casperlabs-bors-ng]

🔒 Permission denied

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[mpapierski]

bors r+

[casperlabs-bors-ng]

Timed out.

[mpapierski]

bors r+

[casperlabs-bors-ng]

Timed out.

[gRoussac]

@moubctez Hi, something is strange here I don't get this function to work as I understood its purpose, not sure if this is on my contract but I get reverted with InvalidArgument passing value, according to the comment (not an Option though)

I would invite to test this function again because according to my test get_named_arg and try_get_named_arg do the exact same thing with Option for get_named_arg, while try_get_named_arg should handle absence of argument (not None) as per code comment.
test calling

        let _ = args.insert("TEST1", None::<u64>);
        let _ = args.insert("TEST2", None::<u64>);
        let _ = args.insert("TEST3", 111_u64);
        let _ = args.insert("TEST4", Some(111_u64));
        let _ = args.insert("TEST5", 111_u64);

contract

    let test1: Option<u64> = get_named_arg("TEST1");
    let test2: Option<u64> = try_get_named_arg("TEST2");

    let test3: u64 = get_named_arg("TEST3");
    let test4: Option<u64> = try_get_named_arg("TEST4");
    
    runtime::print(&format!("{:?}", test1));
    runtime::print(&format!("{:?}", test2));
    runtime::print(&format!("{:?}", test3));
    runtime::print(&format!("{:?}", test4));

    let test5: Option<u64> = try_get_named_arg("TEST5");
    runtime::print(&format!("will revert, never printed{:?}", test5));
        

Regards

[moubctez]

I've re-examined the code and as far as I can recall this is a leftover from my attempt to handle optional arguments that is not used anywhere and can be removed.

[gRoussac]

Hi, I believe try_get_named_arg intention was to handle no-value/value but now it deals with no-value/Some(value) which is not really expected on usage. get_named_arg deals with None/Some(value) which requires the parameter to be given has Option in any case.

There is however a use case thus for an get_optional_named_arg not expecting an Option but I think right now it's indeed better to remove this function as confusing.

#4786