Implement native support for Price Oracles.
A Price Oracle is used to bring real-world data, such as market prices,
onto the blockchain, enabling dApps to access and utilize information
that resides outside the blockchain.
Add Price Oracle functionality:
- OracleSet: create or update the Oracle object
- OracleDelete: delete the Oracle object
To support this functionality add:
- New RPC method, `get_aggregate_price`, to calculate aggregate price for a token pair of the specified oracles
- `ltOracle` object
The `ltOracle` object maintains:
- Oracle Owner's account
- Oracle's metadata
- Up to ten token pairs with the scaled price
- The last update time the token pairs were updated
Add Oracle unit-tests
Add `STObject` constructor to explicitly set the inner object template.
This allows certain AMM transactions to apply in the same ledger:
There is no issue if the trading fee is greater than or equal to 0.01%.
If the trading fee is less than 0.01%, then:
- After AMM create, AMM transactions must wait for one ledger to close
(3-5 seconds).
- After one ledger is validated, all AMM transactions succeed, as
appropriate, except for AMMVote.
- The first AMMVote which votes for a 0 trading fee in a ledger will
succeed. Subsequent AMMVote transactions which vote for a 0 trading
fee will wait for the next ledger (3-5 seconds). This behavior repeats
for each ledger.
This has no effect on the ultimate correctness of AMM. This amendment
will allow the transactions described above to succeed as expected, even
if the trading fee is 0 and the transactions are applied within one
ledger (block).
A bridge connects two blockchains: a locking chain and an issuing
chain (also called a mainchain and a sidechain). Both are independent
ledgers, with their own validators and potentially their own custom
transactions. Importantly, there is a way to move assets from the
locking chain to the issuing chain and a way to return those assets from
the issuing chain back to the locking chain: the bridge. This key
operation is called a cross-chain transfer. A cross-chain transfer is
not a single transaction. It happens on two chains, requires multiple
transactions, and involves an additional server type called a "witness".
A bridge does not exchange assets between two ledgers. Instead, it locks
assets on one ledger (the "locking chain") and represents those assets
with wrapped assets on another chain (the "issuing chain"). A good model
to keep in mind is a box with an infinite supply of wrapped assets.
Putting an asset from the locking chain into the box will release a
wrapped asset onto the issuing chain. Putting a wrapped asset from the
issuing chain back into the box will release one of the existing locking
chain assets back onto the locking chain. There is no other way to get
assets into or out of the box. Note that there is no way for the box to
"run out of" wrapped assets - it has an infinite supply.
Co-authored-by: Gregory Popovitch <greg7mdp@gmail.com>
When an AMM account is deleted, the owner directory entries must be
deleted in order to ensure consistent ledger state.
* When deleting AMM account:
* Clean up AMM owner dir, linking AMM account and AMM object
* Delete trust lines to AMM
* Disallow `CheckCreate` to AMM accounts
* AMM cannot cash a check
* Constrain entries in AuthAccounts array to be accounts
* AuthAccounts is an array of objects for the AMMBid transaction
* SetTrust (TrustSet): Allow on AMM only for LP tokens
* If the destination is an AMM account and the trust line doesn't
exist, then:
* If the asset is not the AMM LP token, then fail the tx with
`tecNO_PERMISSION`
* If the AMM is in empty state, then fail the tx with `tecAMM_EMPTY`
* This disallows trustlines to AMM in empty state
* Add AMMID to AMM root account
* Remove lsfAMM flag and use sfAMMID instead
* Remove owner dir entry for ltAMM
* Add `AMMDelete` transaction type to handle amortized deletion
* Limit number of trust lines to delete on final withdraw + AMMDelete
* Put AMM in empty state when LPTokens is 0 upon final withdraw
* Add `tfTwoAssetIfEmpty` deposit option in AMM empty state
* Fail all AMM transactions in AMM empty state except special deposit
* Add `tecINCOMPLETE` to indicate that not all AMM trust lines are
deleted (i.e. partial deletion)
* This is handled in Transactor similar to deleted offers
* Fail AMMDelete with `tecINTERNAL` if AMM root account is nullptr
* Don't validate for invalid asset pair in AMMDelete
* AMMWithdraw deletes AMM trust lines and AMM account/object only if the
number of trust lines is less than max
* Current `maxDeletableAMMTrustLines` = 512
* Check no directory left after AMM trust lines are deleted
* Enable partial trustline deletion in AMMWithdraw
* Add `tecAMM_NOT_EMPTY` to fail any transaction that expects an AMM in
empty state
* Clawback considerations
* Disallow clawback out of AMM account
* Disallow AMM create if issuer can claw back
This patch applies to the AMM implementation in #4294.
Acknowledgements:
Richard Holland and Nik Bougalis for responsibly disclosing this issue.
Bug Bounties and Responsible Disclosures:
We welcome reviews of the project code and urge researchers to
responsibly disclose any issues they may find.
To report a bug, please send a detailed report to:
bugs@xrpl.org
Signed-off-by: Manoj Doshi <mdoshi@ripple.com>
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>
The amendment increases the maximum sign of an account's signer
list from 8 to 32.
Like all new features, the associated amendment is configured with
a default vote of "no" and server operators will have to vote for
it explicitly if they believe it is useful.
Formerly an SOTemplate was default constructed and its elements
added using push_back(). This left open the possibility of a
malformed SOTemplate if adding one of the elements caused a throw.
With this commit the SOTemplate requires an initializer_list of
its elements at construction. Elements may not be added after
construction. With this approach either the SOTemplate is fully
constructed with all of its elements or the constructor throws,
which prevents an invalid SOTemplate from even existing.
This change requires all SOTemplate construction to be adjusted
at the call site. Those changes are also in this commit.
The SOE_Flags enum is also renamed to SOEStyle, which harmonizes
the name with other uses in the code base. SOEStyle elements
are renamed (slightly) to have an "soe" prefix rather than "SOE_".
This heads toward reserving identifiers with all upper case for
macros. The new style also aligns with other prominent enums in
the code base like the collection of TER identifiers.
SOElement is adjusted so it can be stored directly in an STL
container, rather than requiring storage in a unique_ptr.
Correspondingly, unique_ptr usage is removed from both
SOTemplate and KnownFormats.
With this changeset two-level multisigning is removed from the
codebase and replaced with single-level multisigning.
Additionally, SignerLists in the ledger are prepared for the
possibility of multiple SignerLists per account. This was done
by adding a defaulted 32-bit SignerListID to each SignerList.
The SignerListIndex calculation incorporates the SignerListID.
There are three known missing elements:
1. Multisigned transactions should require higher fees than
regular (single-signed) transaction. That's not yet
implemented.
2. It should be possible to disable the master key on an account
if that account is multisign enabled (has a signer list).
That's not yet implemented.
3. Documentation about multisigning needs to be improved.
Multisigning is still compiled out of the code base. To enable
multisigning for a stand-alone rippled, change the
RIPPLE_ENABLE_MULTI_SIGN macro (in BeastConfig.h) to "1" and
rebuild.
This commit also addresses:
o RIPD-912: Remove multisign APIs from STObject, and
o RIPD-944: Replace common_transactor with jtx at call sites.
This commit provides support for 2-level multi-signing of
transactions. The ability is usually compiled out, since other
aspects of multi-signing are not yet complete.
Here are the missing parts:
o Full support for Tickets in transactions.
o Variable fees based on the number of signers,
o Multiple SignerLists with access control flags on accounts,
o Enable / disable operations based on access control flags,
o Enable / disable all of multi-signing based on an amendment,
o Integration tests, and
o Documentation.
Add support for the SignerListSet transaction as a step toward
multi-sign support.
As part of the SignerListSet implementation, add InnerObjectFormat
templates (similar to TxFormats and LedgerFormats) and enforce them
in STObject, STArray, and STParsedJSON.
