xrpl::ValidVault Class Reference

Invariants: Vault object and MPTokenIssuance for vault shares. More...

#include <VaultInvariant.h>

Collaboration diagram for xrpl::ValidVault:

Classes
struct	Vault
struct	Shares
struct	DeltaInfo

Public Member Functions
void	visitEntry (bool, SLE::const_ref, SLE::const_ref)
bool	finalize (STTx const &, TER const, XRPAmount const, ReadView const &, beast::Journal const &)

Static Public Member Functions
static std::int32_t	computeCoarsestScale (std::vector< DeltaInfo > const &numbers)

Private Member Functions
std::int32_t	computeVaultMinScale (DeltaInfo const &vaultDelta, Rules const &rules) const
	Compute the minimum STAmount scale for rounding invariant calculations.
std::optional< DeltaInfo >	deltaAssets (AccountID const &id) const
	Return the vault-asset balance-change delta for an account.
std::optional< DeltaInfo >	deltaAssetsTxAccount (STTx const &tx, XRPAmount fee) const
	Return the vault-asset delta for the transaction's sending account, adjusted for the fee.
std::optional< DeltaInfo >	deltaShares (AccountID const &id) const
	Return the vault-share balance-change delta for an account.
bool	finalizeLoanSet (ReadView const &view, beast::Journal const &j) const
	Invariant check for ttLOAN_SET.

Static Private Member Functions
static bool	isVaultEmpty (Vault const &vault)
	Check whether a vault holds no assets.

Private Attributes
std::vector< Vault >	afterVault_
std::vector< Shares >	afterMPTs_
std::vector< Vault >	beforeVault_
std::vector< Shares >	beforeMPTs_
std::unordered_map< uint256, DeltaInfo >	deltas_

Static Private Attributes
static constexpr Number	kZero {}

Detailed Description

Invariants: Vault object and MPTokenIssuance for vault shares.

• vault deleted and vault created is empty
• vault created must be linked to pseudo-account for shares and assets
• vault must have MPTokenIssuance for shares
• vault without shares outstanding must have no shares
• loss unrealized does not exceed the difference between assets total and assets available
• assets available do not exceed assets total
• vault deposit increases assets and share issuance, and adds to: total assets, assets available, shares outstanding
• vault withdrawal and clawback reduce assets and share issuance, and subtracts from: total assets, assets available, shares outstanding
• vault set must not alter the vault assets or shares balance
• no vault transaction can change loss unrealized (it's updated by loan transactions)
• a created closed-ended vault must satisfy MIN_INVESTMENT_PERIOD <= RedemptionDate - SubscriptionDate < MAX_INVESTMENT_PERIOD
• vault deposit may only succeed when the vault phase is NoPhase or Subscription
• vault withdrawal may not succeed when the vault phase is Investment
• closed-ended loan origination (ttLOAN_SET) may only succeed when the vault phase is Investment

Immutability of VaultKind, SubscriptionDate and RedemptionDate is enforced by NoModifiedUnmodifiableFields (see InvariantCheck.cpp).

Definition at line 53 of file VaultInvariant.h.

Member Function Documentation

computeVaultMinScale()

std::int32_t xrpl::ValidVault::computeVaultMinScale ( DeltaInfo const & vaultDelta, Rules const & rules ) const

nodiscardprivate

Compute the minimum STAmount scale for rounding invariant calculations.

Post-amendment (fixCleanup3_2_0) this is simply the posterior assetsTotal scale. Pre-amendment it is the coarsest scale across vaultDelta and both asset-field deltas.

Parameters

vaultDelta	Delta of the vault's asset balance for this transaction.
rules	Active ledger rules (used to check the amendment).

Returns

The minimum scale to apply when rounding vault-related amounts.

Definition at line 309 of file VaultInvariant.cpp.

deltaAssets()

std::optional< ValidVault::DeltaInfo > xrpl::ValidVault::deltaAssets ( AccountID const & id ) const

nodiscardprivate

Return the vault-asset balance-change delta for an account.

Looks up the ledger-entry delta recorded during visitEntry for the account entry (XRP), trust line (IOU), or MPToken (MPT) that corresponds to the vault asset held by id.

Parameters

id	Account whose asset delta is requested.

Returns

The delta, or std::nullopt if the entry was not touched.

Definition at line 206 of file VaultInvariant.cpp.

deltaAssetsTxAccount()

std::optional< ValidVault::DeltaInfo > xrpl::ValidVault::deltaAssetsTxAccount ( STTx const & tx, XRPAmount fee ) const

nodiscardprivate

Return the vault-asset delta for the transaction's sending account, adjusted for the fee.

Calls deltaAssets for tx[sfAccount] and, for non-delegated XRP transactions, adds the consumed fee back so the invariant sees the net asset movement rather than the fee-reduced balance change.

Parameters

tx	The transaction being applied.
fee	Fee charged by this transaction.

Returns

The fee-adjusted delta, or std::nullopt if the net delta is zero or the account entry was not touched.

Definition at line 238 of file VaultInvariant.cpp.

deltaShares()

std::optional< ValidVault::DeltaInfo > xrpl::ValidVault::deltaShares ( AccountID const & id ) const

nodiscardprivate

Return the vault-share balance-change delta for an account.

For the vault's pseudo-account the MPTokenIssuance outstanding-amount delta is returned; for all other accounts the MPToken delta is returned.

Parameters

id	Account whose share delta is requested.

Returns

The delta, or std::nullopt if the entry was not touched.

Definition at line 259 of file VaultInvariant.cpp.

isVaultEmpty()

bool xrpl::ValidVault::isVaultEmpty ( Vault const & vault )

staticnodiscardprivate

Check whether a vault holds no assets.

Parameters

vault

Snapshot of the vault to test.

Returns

true when both assetsAvailable and assetsTotal are zero.

Definition at line 272 of file VaultInvariant.cpp.

finalizeLoanSet()

bool xrpl::ValidVault::finalizeLoanSet ( ReadView const & view, beast::Journal const & j ) const

nodiscardprivate

Invariant check for ttLOAN_SET.

For a closed-ended vault, a loan may only be originated while the vault is in the Investment phase (strictly past SubscriptionDate and before RedemptionDate). Open-ended vaults (NoPhase) are unaffected. The complementary maturity bound (final payment strictly precedes RedemptionDate) is enforced by ValidLoan.

Definition at line 278 of file VaultInvariant.cpp.

computeCoarsestScale()

std::int32_t xrpl::ValidVault::computeCoarsestScale ( std::vector< DeltaInfo > const & numbers )

staticnodiscard

Definition at line 1191 of file VaultInvariant.cpp.

visitEntry()

void xrpl::ValidVault::visitEntry	(	bool	isDelete,
		SLE::const_ref	before,
		SLE::const_ref	after )

Definition at line 85 of file VaultInvariant.cpp.

finalize()

bool xrpl::ValidVault::finalize	(	STTx const &	tx,
		TER const	ret,
		XRPAmount const	fee,
		ReadView const &	view,
		beast::Journal const &	j )

Definition at line 335 of file VaultInvariant.cpp.

Member Data Documentation

kZero

Number xrpl::ValidVault::kZero {}

staticconstexprprivate

Definition at line 55 of file VaultInvariant.h.

afterVault_

std::vector<Vault> xrpl::ValidVault::afterVault_

private

Definition at line 96 of file VaultInvariant.h.

afterMPTs_

std::vector<Shares> xrpl::ValidVault::afterMPTs_

private

Definition at line 97 of file VaultInvariant.h.

beforeVault_

std::vector<Vault> xrpl::ValidVault::beforeVault_

private

Definition at line 98 of file VaultInvariant.h.

beforeMPTs_

std::vector<Shares> xrpl::ValidVault::beforeMPTs_

private

Definition at line 99 of file VaultInvariant.h.

deltas_

std::unordered_map<uint256, DeltaInfo> xrpl::ValidVault::deltas_

private

Definition at line 100 of file VaultInvariant.h.