Add AMM functionality: - InstanceCreate - Deposit - Withdraw - Governance - Auctioning - payment engine integration To support this functionality, add: - New RPC method, `amm_info`, to fetch pool and LPT balances - AMM Root Account - trust line for each IOU AMM token - trust line to track Liquidity Provider Tokens (LPT) - `ltAMM` object The `ltAMM` object tracks: - fee votes - auction slot bids - AMM tokens pair - total outstanding tokens balance - `AMMID` to AMM `RootAccountID` mapping Add new classes to facilitate AMM integration into the payment engine. `BookStep` uses these classes to infer if AMM liquidity can be consumed. The AMM formula implementation uses the new Number class added in #4192. IOUAmount and STAmount use Number arithmetic. Add AMM unit tests for all features. AMM requires the following amendments: - featureAMM - fixUniversalNumber - featureFlowCross Notes: - Current trading fee threshold is 1% - AMM currency is generated by: 0x03 + 152 bits of sha256{cur1, cur2} - Current max AMM Offers is 30 --------- Co-authored-by: Howard Hinnant <howard.hinnant@gmail.com>
protocol
Classes and functions for handling data and values associated with the XRP Ledger protocol.
Serialized Objects
Objects transmitted over the network must be serialized into a canonical format. The prefix "ST" refers to classes that deal with the serialized format.
The term "Tx" or "tx" is an abbreviation for "Transaction", a commonly occurring object type.
Optional Fields
Our serialized fields have some "type magic" to make optional fields easier to read:
- The operation
x[sfFoo]means "return the value of 'Foo' if it exists, or the default value if it doesn't." - The operation
x[~sfFoo]means "return the value of 'Foo' if it exists, or nothing if it doesn't." This usage of the tilde/bitwise NOT operator is not standard outside of therippledcodebase.- As a consequence of this,
x[~sfFoo] = y[~sfFoo]assigns the value of Foo from y to x, including omitting Foo from x if it doesn't exist in y.
- As a consequence of this,
Typically, for things that are guaranteed to exist, you use
x[sfFoo] and avoid having to deal with a container that may
or may not hold a value. For things not guaranteed to exist,
you use x[~sfFoo] because you want such a container. It
avoids having to look something up twice, once just to see if
it exists and a second time to get/set its value.
(Real example)
The source of this "type magic" is in SField.h.