The price-aggregator smart contract keeps track of the price between multiple pairs of tokens. Compared to the other chainlink contracts, it is a simplified and easier to use version.
Arguments:
- staking_token - the token used for staking and slashing
- staking_amount - the minimum staked amount required for a used to be considered a board member
- slash_amount - the amount to be slashed from a board member on a successful slash vote
- slash_quorum - the minimum number of board members required for a vote to be considered successful
- oracles - the list of addresses which are allowed to submit price feed updates
- submission_count - the minimum number of submissions from different oracles which trigger an update of the price feed
The number of decimals for a given token pair can be set by calling setPairDecimals(from, to, decimals). Notes:
- only the owner can configure the number of decimals
- the contract must be paused first
- this method also clears the submissions accumulated so far
- no submissions will be accepted for any given pair unless the number of decimals is configured first
- every oracle must change its configuration to provide submissions with the new number of decimals, as any mismatch will be considered a configuration error and the submission will be rejected
An oracle can submit a price feed update using one of the endpoints:
- submit - submit a single price feed as 5 arguments (from, to, submission_timestamp, price and decimals).
- submitBatch - submit multiple price feeds simultaneously. The number of arguments must be a multiple of 5.
Note: the decimals argument must match the value returned by getPairDecimals for that specific pair, otherwise the submission will be rejected.
Price feeds from multiple oracles are collected. When a certain threshold number of submissions has been reached (given by submission_count), a new round is created.
The price feed recorded in the round is the median value out of all submissions made.
Endpoints:
- latestRoundData takes no arguments and returns all the latest price feeds.
- latestPriceFeed takes a filter (as the from and to token identifiers) and returns a single price feed. The transaction fails if there is no price feed for the given filter.
- latestPriceFeedOptional behaves like latestPriceFeed but it returns an option so that the caller can handle the lack of a price feed.
A price feed contains:
- round_id - the ID of the current round (not related to the blockchain round ID)
- from - the first token
- to - the second token
- price - the price between the two tokens
- decimals - the number of decimals for the price