Attempt to evaluate a gas price before relaying a call

[forshtat]

I believe this is a safer way to estimate gas price, even though the "web3.eth.getGasPrice" is not reliable in xdai network, the relays will rely on it anyways.
P.S. I did not test this change thoroughly, still having issues just running Burner Wallet.

[drortirosh]

The problem is that if there are to many such relayed calls (compared to normal non-relayed calls) which suggest average1.3 the average will raise...
Need to fix the RelayClient so that it will try to use by default the suggested minGas offered by the relay, up to (say) current1.2.

[riusricardo]

I agree on this. There is an issue caused by 0 Txs avg in gas calculation.

Parity Ethereum #9795

[riusricardo]

@alex-forshtat-tbk @shahafn the latest commit looks to be a misunderstanding in the code.
msg.sender is used to log the fund creator not the claimer which should not be the relay.
Or did I missed something?

It is also important to keep the fund creator here because after the link expires, they'll be the only ones able to claim the link.
Changing "msg.sender" to "get_sender()" since it's RelayRecipient

[drortirosh]

get_sender() helper function returns msg.sender when the transaction is called directly. When called through a relay, it returns the real sender (as the transaction sender is the relay)

…

On Wed, Feb 27, 2019, 19:56 Ricardo Rius ***@***.***> wrote: @alex-forshtat-tbk <https://github.com/alex-forshtat-tbk> @shahafn <https://github.com/shahafn> the latest commit looks to be a misunderstanding in the code. msg.sender is used to log the fund creator not the claimer which should not be the relay. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#105 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AmeOD9WFPxLwFZRDHg2jjNyjZK-jGbhhks5vRsbqgaJpZM4bUdas> .

[riusricardo]

@drortirosh Great! Thanks for clarifying. So it is good to have it. Very useful for sending tokens.

[shahafn]

@riusricardo Another issue that should be noted: RelayRecipient.sol should be on top of the inheritance hierarchy, since if Links.sol calls Vault.sol's functions that might use msg.sender in a relayed call, they should be replaced with get_sender() as well.

[riusricardo]

@shahafn that sounds good to me. I kept Vault as the the most base-like because is the one that handles the value. But if you need to change the order, feel free to do it.
Vault is only used in the Links SC, so you can also change it to use the get_sender() function.