Lib.rs

This crate is the core of the gas metering system of the Aptos blockchain.

More specifically, it

• Is home to the gas meter implementation
• Defines the gas parameters and formulae for instructions
• Defines the gas parameters for transactions
• Sets the initial values for all gas parameters, including the instruction, transaction move-stdlib and aptos-framework ones.
• Defines a bi-directional mapping between the (Rust) gas parameter structs and their corresponding representation on-chain.

The reason why we need two different representations is that they serve different purposes:

• The Rust structs are used for quick (static) lookups by the gas meter and native functions when calculating gas costs.
• The on-chain gas schedule needs to be extensible and unordered so we can upgrate it easily in the future.