The oracle program is responsible for several tasks:
- 1.Maintaining the set of price feeds.
- 2.Storing the contributions of data providers to each price feed.
- 3.Combining the individual data providers' prices into a single aggregate price and confidence interval.
- 4.Performing any additional stateful computations on the resulting price series, such as computing moving averages.
The oracle solves these problems by maintaining a collection of Solana accounts to represent the set of price feeds. Each feed has two accounts: a product account to store metadata and a price account. The price account stores a list of authorized data providers for this specific price feed, and allocates storage space for each data provider's price. The oracle program exposes an instruction called
upd_pricethat enables an authorized data provider to update the price account with their current estimate of the price and confidence interval. Additionally, the first time that
upd_priceis called in a slot, it will aggregate the individual data provider's prices into an aggregate price and confidence interval. Only the aggregate price and confidence are made available for use in downstream applications; the individual data providers prices are internal state of the oracle program. Finally, the oracle program computes an exponentially-weighted moving average of the oracle price.