mirror of
https://github.com/XRPLF/rippled.git
synced 2025-11-20 02:55:50 +00:00
621df422a7
* Add AMM bid/create/deposit/swap/withdraw/vote invariants:
- Deposit, Withdrawal invariants: `sqrt(asset1Balance * asset2Balance) >= LPTokens`.
- Bid: `sqrt(asset1Balance * asset2Balance) > LPTokens` and the pool balances don't change.
- Create: `sqrt(asset1Balance * assetBalance2) == LPTokens`.
- Swap: `asset1BalanceAfter * asset2BalanceAfter >= asset1BalanceBefore * asset2BalanceBefore`
and `LPTokens` don't change.
- Vote: `LPTokens` and pool balances don't change.
- All AMM and swap transactions: amounts and tokens are greater than zero, except on withdrawal if all tokens
are withdrawn.
* Add AMM deposit and withdraw rounding to ensure AMM invariant:
- On deposit, tokens out are rounded downward and deposit amount is rounded upward.
- On withdrawal, tokens in are rounded upward and withdrawal amount is rounded downward.
* Add Order Book Offer invariant to verify consumed amounts. Consumed amounts are less than the offer.
* Fix Bid validation. `AuthAccount` can't have duplicate accounts or the submitter account.
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.