Introduce a gas-based storage limit [MBIP-5]

[ahmadkaouk]

Introduction

This PR implements a new mechanism as detailed in MBIP-5. The aim is to manage the unsustainable storage growth of the state by setting a block storage limit and increasing gas usage when a transaction results in an increase in storage state. Key features include:

• Block Storage Growth Limit: A single block cannot contain transactions that collectively increase the storage state by more than 40 KB.
• Modified Gas Computation Mechanism: Transactions resulting in storage state expansion will be subject to a new, generally higher, required gas to execute.

This feature only enabled on Moonbase.

Example

Given:

• BLOCK_GAS_LIMIT = 15,000,000 (Maximum gas per block)
• BLOCK_STORAGE_LIMIT = 40 * 1024 bytes (40 KB per block)

The ratio between gas and storage is calculated as:

• RATIO = 15,000,000 / (40 * 1024) ≈ 366

Deploying a Smart Contract of 24 kB will cost:

• GAS_COST = 24 * 1024 * 366 = 8,994,816

Executing a transaction that increases the storage by 500 bytes will cost:

• GAS_COST = 500 * 366 = 183,000

Runtime Changes

• GasLimitStorageGrowthRatio: A new parameter in pallet-evm that sets the ratio of gas to storage growth, defaulting to 366.
• Precompile Adaptations: Modifications have been made to precompiles to accommodate the new changes. A new parameter storage_growth: Option<u64> has been added to the try_dispatch function to record the storage increase.

⚠️ Breaking Changes ⚠️

• New Gas Cost: This update introduces key adjustments to how gas fees are calculated, specifically accounting for the increase of the storage state. Transactions may run out of gas even if they meet the initial gasometer requirements. Here are the key points to note:
  • Increased Costs for Contract Deployments: Contract deployments that add to the state will see a noticeable rise in gas costs.
  • Gas increased for Specific Precompiled Contract Calls: Transactions that trigger precompiled contracts, that can possibly create new accounts, will have a minimum gas fee of 54,168.(The result of the storage increase associated with a new account (148 bytes) and the established gas-to-storage ratio of 366).
  • Transactions Impacting Storage Growth: Transactions that lead to the creation of new storage entries will also experience increased gas costs. This includes, but is not limited to, transactions that add new records or key-value pairs to the state.

Despite these changes, gas estimation will continue to function as intended, incorporating the new storage-related gas costs in their calculations.

Relevant PRs:

• EVM: Add support for a gas-based storage limit rust-ethereum/evm#173
• Frontier: Introduce a gas-based Storage limit per tx polkadot-evm/frontier#1142

[github-actions]

Coverage generated "Tue Aug 29 23:23:22 UTC 2023":
https://d3ifz9vhxc2wtb.cloudfront.net/pulls/2452/html/index.html

Master coverage: 87.39%
Pull coverage:

[crystalin]

please wait for a review from @librelois or @notlesh before merging

[notlesh]

Looks good 🎉

Ideally we could see some test coverage that shows this is properly disabled for moonriver and moonbeam (or a test showing that a ratio of 0 does indeed disable the feature). However, I can clearly see here that it should work as intended.

[vanhauser-thc]

typo in function