fees-analysis tool

[nbaztec]

can be used to perform experiments on fees & generate charts.

for the instructions:

/**
 * This test assumes the following:
 *  + moonbeam
 *    - EVM calls are unfiltered.
 *        NormalFilter - Call::EVM(_) => true
 *    - EVM origin is allowed for all.
 *        type CallOrigin = EnsureAddressAlways;
 *
 *        pub struct EnsureAddressAlways;
 *        impl<OuterOrigin> EnsureAddressOrigin<OuterOrigin> for EnsureAddressAlways {
 *           type Success = ();
 *
 *           fn try_address_origin(
 *                   _address: &H160,
 *                   _origin: OuterOrigin,
 *           ) -> Result<Self::Success, OuterOrigin> {
 *                   Ok(())
 *           }
 *
 *           fn ensure_address_origin(
 *                   _address: &H160,
 *                   _origin: OuterOrigin,
 *           ) -> Result<Self::Success, sp_runtime::traits::BadOrigin> {
 *                   Ok(())
 *           }
 *        }
 *  + frontier
 *    - Baltathar pays no EVM fees and full substrate fees, while Charleth pays the opposite.
 *        let baltathar_addr = H160::from_str("0x3cd0a705a2dc65e5b1e1205896baa2be8a07c6e0").unwrap();
 *        let (validate, payable) = if source == baltathar_addr {
 *                (false, Pays::Yes)
 *        } else {
 *                (true, Pays::No)
 *        };
 *
 * Then start the node with the following command
 ./target/release/moonbeam \
 --execution=Native \
 --wasm-execution=interpreted-i-know-what-i-do \
 --ethapi=txpool \
 --no-hardware-benchmarks \
 --no-telemetry \
 --no-prometheus \
 --force-authoring \
 --rpc-cors=all \
 --alice \
 --chain=moonbase-dev \
 --sealing=manual \
 --in-peers=0 \
 --out-peers=0 -linfo \
 --tmp
 *
 * Examples:
 *  ts-node ./src/tools/fees.ts --name fees --type compute
 *  ts-node ./src/tools/fees.ts --name fees --type compute --multiplier 300000000
 *  ts-node ./src/tools/fees.ts --name fees --type length-small
 *  ts-node ./src/tools/fees.ts --name fees --type length-big
 *
 * The result will open in the browser once done
 */

/**
 * Observations
 * - The first EVM call causes the SmartContract storage to be initialized and costs around 20,000 gas (we avoid this by pre-initializing the storage)
 * - The fees sometime jump abruptly and stay at that level, this is due to nonce going from 1 byte to 2 bytes and so on
 * - The block fill ratio is computed differently by transaction-payment; the multiplier is updated only due to `Normal` weight class (actual / max).
 *   The actual weight also contains some extra weight that doesn't belong to extrinsics (maybe coming from on_initialize/on_finalize)
 */