Create_canister u128 vs call_with_payment u64

peterparker · October 12, 2024, 9:24am

Is there a particular reason why the ic-cdk function create_canister accepts an amount of cycles in u128 while the call_with_payment accepts u64?

sea-snake · October 12, 2024, 9:37am

github.com

dfinity/cdk-rs/blob/882fa28116c84887be626a44ce031b739e45e3d5/src/ic-cdk/src/api/management_canister/main/mod.rs#L21


      
          
          mod types;
          pub use types::*;
          
          /// Register a new canister and get its canister id.
          ///
          /// See [IC method `create_canister`](https://internetcomputer.org/docs/current/references/ic-interface-spec/#ic-create_canister).
          ///
          /// This call requires cycles payment. The required cycles varies according to the subnet size (number of nodes).
          /// Check [Gas and cycles cost](https://internetcomputer.org/docs/current/developer-docs/gas-cost) for more details.
          pub async fn create_canister(
              arg: CreateCanisterArgument,
              cycles: u128,
          ) -> CallResult<(CanisterIdRecord,)> {
              let extended_arg = CreateCanisterArgumentExtended {
                  settings: arg.settings,
                  sender_canister_version: Some(canister_version()),
              };
              call_with_payment128(
                  Principal::management_canister(),
                  "create_canister",

Looking at the CDK source, it seems the create_canister method uses the newer call_with_payment128 internally. As far as I can find, u128 cycle support was added back in 2022 after initially it was only u64.

So a call_with_payment equivalent with u128 would be call_with_payment128.

peterparker · October 12, 2024, 9:40am

Thanks a lot! This answer my question and make me improve my code at the same time

Vivienne · October 14, 2024, 8:30am

For context: cycles once were u64 but were changed to u128. There are thoughts of deprecating the u64 APIs eventually (still a looong time out, but still), so I would suggest if you have the choice you stick with the u128 APIs

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Create_canister u128 vs call_with_payment u64

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