- Add support for all transaction types and ledger object types to gRPC
implementation of tx and account_tx.
- Create common handlers for tx and account_tx.
- Remove mutex and abort() from gRPC server. JobQueue is stopped before
gRPC server, with all coroutines executed to completion, so no need for
synchronization.
The XRP Ledger utilizes an account model. Unlike systems based on a UTXO
model, XRP Ledger accounts are first-class objects. This design choice
allows the XRP Ledger to offer rich functionality, including the ability
to own objects (offers, escrows, checks, signer lists) as well as other
advanced features, such as key rotation and configurable multi-signing
without needing to change a destination address.
The trade-off is that accounts must be stored on ledger. The XRP Ledger
applies reserve requirements, in XRP, to protect the shared global ledger
from growing excessively large as the result of spam or malicious usage.
Prior to this commit, accounts had been permanent objects; once created,
they could never be deleted.
This commit introduces a new amendment "DeletableAccounts" which, if
enabled, will allow account objects to be deleted by executing the new
"AccountDelete" transaction. Any funds remaining in the account will
be transferred to an account specified in the deletion transaction.
The amendment changes the mechanics of account creation; previously
a new account would have an initial sequence number of 1. Accounts
created after the amendment will have an initial sequence number that
is equal to the ledger in which the account was created.
Accounts can only be deleted if they are not associated with any
obligations (like RippleStates, Escrows, or PayChannels) and if the
current ledger sequence number exceeds the account's sequence number
by at least 256 so that, if recreated, the account can be protected
from transaction replay.
The lsfDepositAuth flag limits the AccountIDs that can deposit into
the account that has the flag set. The original design only
allowed deposits to complete if the account with the flag set also
signed the transaction that caused the deposit.
The DepositPreauth ledger type allows an account with the
lsfDepositAuth flag set to preauthorize additional accounts.
This preauthorization allows them to sign deposits as well. An
account can add DepositPreauth objects to the ledger (and remove
them as well) using the DepositPreauth transaction.
