Onchain repository for DSS rates
Conv stores all per-second DSS rates for annualized BPSs in a single on-chain repository.
Some parts of the DSS protocol may need rate validation, such as the rate validation of the IAM module. This repository aims to implement that.
Requirements:
- The rates need to have full precision compared to rates currently used in DSS (https://ipfs.io/ipfs/QmVp4mhhbwWGTfbh2BzwQB9eiBrQBKiqcPRZCaAxNUaar6)
- Read cost should be reasonable, allowing other components of the system to use it without too much overhead.
- The contract needs to be deployable efficiently (low priority, one time cost).
In this repo, we explored several ways to store or calculate rates onchain. There are tradeoffs between different approaches as expected:
| Design | Deployment Cost | Contract Size | Precision | Read Cost | Note |
|---|---|---|---|---|---|
| Plain mapping | 20M gas / 1k rates | Small | Full | 2k gas | |
| Calculating onchain (ABDK lib) | low | Small | Lossy (though close) | 20k gas | External lib also used, not usually accepted for DSS modules |
| Calculating onchain (PRB lib) | low | Small | Lossy (though close) | 20k gas | External lib also used, not usually accepted for DSS modules |
| Hardcoded (script generated binary search in Solidity Assembly) | 7M gas / 1k rates | Large (fits up to 800 rates per contract) | Full | 3k gas | |
| Optimized storage | 5.6M / 1k rates | Large (fits up to 5k rates on Ethereum mainnet, rates are hardcoded on the constructor) | Full | 3k gas |
$ forge build$ forge test$ forge snapshotThis code is not production ready. Do not deploy it in prod.