Ink-log

Ink-log provides pretty log printing for Ink! smart contract，it's implmented by ChainExtension.

Usage

1. Contract Pallet In Substrate Runtime

dependencies

Add this to your Cargo.toml:

runtime-log = { version = "0.1", git = "https://github.com/patractlabs/ink-log", default-features = false }

[features]
std = [
    "runtime-log/std",
]

example

1. If you already have one CustomExt, use runtime_log::logger_ext! to add to your CustomExt.

pub struct CustomExt;

impl ChainExtension for CustomExt {
	fn call<E: Ext>(func_id: u32, env: Environment<E, InitState>) -> Result<RetVal, DispatchError>
	where
		<E::T as SysConfig>::AccountId: UncheckedFrom<<E::T as SysConfig>::Hash> + AsRef<[u8]>,
	{
		// TODO add other libs
        runtime_log::logger_ext!(func_id, env);

		Ok(RetVal::Converging(0))
	}

	fn enabled() -> bool {
		true
	}
}

2. If you don't have any CustomExt, use runtime_log::LoggerExt to set ChainExtension.

impl pallet_contracts::Config for Runtime {
    // ...... 
    type ChainExtension = runtime_log::LoggerExt;
}

2. Ink! contract

dependencies

Add this to your contratc Cargo.toml:

ink_log = { git = "https://github.com/patractlabs/ink-log", branch = "master", default-features = false, features = ["ink-log-chain-extensions"] }

[features]
std = [
    "ink_log/std",
]

Notes: must add feature ink-log-chain-extensions feature, only when the feature is available, the ink-log functions is effective.

example

Use like rust log macro

#![cfg_attr(not(feature = "std"), no_std)]

use ink_lang as ink;

#[ink::contract(env = ink_log::CustomEnvironment)]
pub mod flipper {
    #[ink(storage)]
    pub struct Flipper {
        value: bool,
    }

    impl Flipper {
        #[ink(constructor)]
        pub fn new(init_value: bool) -> Self {
            Self { value: init_value }
        }

        #[ink(message)]
        pub fn flip(&mut self) {
            ink_log::info!(target: "flipper-contract", "latest value is: {}", self.value);
            
            self.value = !self.value;
        }
    }
}

Output:

2020-12-28 17:44:30.274   INFO tokio-runtime-worker flipper-contract:/paritytech/ink/examples/flipper/lib.rs:42:❤️  latest value is: false

3. log extension func_id

0xfeffff00

other func_id refer to https://github.com/patractlabs/PIPs/blob/main/PIPs/pip-100.md