Tickets are a mechanism to allow for the "out-of-order" execution of
transactions on the XRP Ledger.
This commit, if merged, reworks the existing support for tickets and
introduces support for 'ticket batching', completing the feature set
needed for tickets.
The code is gated under the newly-introduced `TicketBatch` amendment
and the `Tickets` amendment, which is not presently active on the
network, is being removed.
The specification for this change can be found at:
https://github.com/xrp-community/standards-drafts/issues/16
The payment engine restricts payment paths so two steps do not input the
same Currency/Issuer or output the same Currency/Issuer. This check was
skipped when the path started or ended with XRP. An example of a path
that was incorrectly accepted was: XRP -> //USD -> //XRP -> EUR
This patch enables the path loop check for paths that start or end with
XRP.
STAmount::soTime and soTime2 were time based "amendment like"
switches to control small changes in behavior for STAmount.
soTime2, which was the most recent, was dated Feb 27, 2016.
That's over 3 years ago.
The main reason to retain these soTimes would be to replay
old transactions. The likelihood of needing to replay a
transaction from over three years ago is pretty low. So it
makes sense to remove these soTime values.
In Flow_test the testZeroOutputStep() test is removed. That
test started to fail when the STAmount::soTimes were removed.
I checked with the original author of the test. He said
that the code being tested by that unit test has been removed,
so it makes sense to remove the test. That test is removed.
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.
A tiny input amount to a payment step can cause this step to output zero. For
example, if a previous steps outputs a dust amount of 10^-80, and this step is a
IOU -> XRP offer, the offer may output zero drops. In this case, call the strand
dry. Before this patch, an error would be logged, the strand would be called
dry; in debug mode an assert triggered.
Note, this patch is not transaction breaking, as the caller did not user the ter
code. The caller only checked for success or failuer.
This patch addresses github issue issue reported here:
https://github.com/ripple/rippled/issues/2929
At this point all of the jss::* names are defined in the same
file. That file has been named JsonFields.h. That file name
has little to do with either JsonStaticStrings (which is what
jss is short for) or with jss. The file is renamed to jss.h
so the file name better reflects what the file contains.
All includes of that file are fixed. A few include order
issues are tidied up along the way.
The FeeEscalation amendment has been enabled on the XRP Ledger network
since May 19, 2016. The transaction which activated this amendment is:
5B1F1E8E791A9C243DD728680F108FEF1F28F21BA3B202B8F66E7833CA71D3C3.
This change removes all conditional code based around the FeeEscalation
amendment, but leaves the amendment definition itself since removing the
definition would cause nodes to think an unknown amendment was activate
causing them to become amendment blocked.
The commit also removes the redundant precomputed hashes from the
supportedAmendments vector.
Fixes: RIPD-1575. Fix argument passing to runner. Allow multiple unit
test selectors to be passed via --unittest argument. Add optional
integer priority value to test suite list. Fix several failing manual
tests. Update CLI usage message to make it clearer.
The six different ranges of TER codes are broken up into six
different enumerations. A template class allows subsets of
these enumerations to be aggregated. This technique allows
verification at compile time that no TEC codes are returned
before the signature is checked.
Conversion between TER instance and integer is provided by
named functions. This makes accidental conversion almost
impossible and makes type abuse easier to spot in the code
base.
The DepositAuth feature allows an account to require that
it signs for any funds that are deposited to the account.
For the time being this limits the account to accepting
only XRP, although there are plans to allow IOU payments
in the future.
The lsfDepositAuth protections are not extended to offers.
If an account creates an offer it is in effect saying, “I
will accept funds from anyone who takes this offer.”
Therefore, the typical user of the lsfDepositAuth flag
will choose never to create any offers. But they can if
they so choose.
The DepositAuth feature leaves a small gap in its
protections. An XRP payment is allowed to a destination
account with the lsfDepositAuth flag set if:
- The Destination XRP balance is less than or equal to
the base reserve and
- The value of the XRP Payment is less than or equal to
the base reserve.
This exception is intended to make it impossible for an
account to wedge itself by spending all of its XRP on fees
and leave itself unable to pay the fee to get more XRP.
This commit
- adds featureDepositAuth,
- adds the lsfDepositAuth flag,
- adds support for lsfDepositAuth in SetAccount.cpp
- adds support in Payment.cpp for rejecting payments that
don't meet the lsfDepositAuth requirements,
- adds unit tests for Payment transactions to an an account
with lsfDepositAuth set.
- adds Escrow and PayChan support for lsfDepositAuth along
with as unit tests.
* Remove composite helper functions
* Add set difference and Bitset/uint256 operators
* Convert tests to use new feature bitset set difference operator
In order to automatically run unit tests with newly created
amendments, prefer to start with jtx::supported_features() and
then subtract unwanted features.
These changes identified a few bugs that were hiding in
amendments. One of those bugs, in FlowCross, is not yet fixed.
By uncommenting the test in CrossingLimits_test.cpp you can see
failures relating to that bug. Since FlowCross is not yet
enabled on the network we can fix the bug at our convenience.
Both Tickets and SHAMapV2 have been around for a while and don't
look like they will be enabled on the network soon. So they are
removed from the supportedAmendments list. This prevents Env
from automatically testing with Tickets or SHAMapV2 enabled,
although testing with those features can still be explicitly
specified.
Drive-by cleanups:
o supportedAmendments() returns a const reference rather than
a fresh vector on each call.
o supportedAmendments() implementation moved from Amendments.cpp
to Feature.cpp. Amendments.cpp deleted.
o supportedAmendments() declared in Feature.h. All other
declarations deleted.
o preEnabledAmendments() removed, since it was empty and only
used in one place. It will be easy to re-add when it is needed.
o jtx::all_features_except() renamed to
jtx::supported_features_except(), which is more descriptive.
o jtx::all_amendments() renamed to jxt::supported_amendments()
o jtx::with_features() renamed to with_only_features()
o Env_test.cpp adjusted since featureTickets is no longer
automatically enabled for unit tests.
Enable all supported amendments in Env by default. Rename `features()`
to `with_features()` and add `all_features_except()` to support feature
subsets in Env. Refactor internal feature handling based on a bitset.
Replace Taker.cpp with calls to the payment flow() code.
This change required a number of tweaks in the payment flow code.
These tweaks are conditionalized on whether or not offer crossing
is taking place. The flag is explicitly passed as a parameter to
the flow code.
For testing, a class was added that identifies differences in the
contents of two PaymentSandboxes. That code may be reusable in
the future.
None of the Taker offer crossing code is removed. Both versions
of the code are co-resident to support an amendment cut-over.
The code that identifies differences between Taker and Flow offer
crossing is enabled by a feature. That makes it easy to enable
or disable difference logging by changing the config file. This
approach models what was done with the payment flow code. The
differencing code should never be enabled on a production server.
Extensive offer crossing unit tests are added to examine and
verify the behavior of corner cases. The tests are currently
configured to run against both Taker and Flow offer crossing.
This gives us confidence that most cases run identically and
some of the (few) differences in behavior are documented.
`env.fund` requires two transactions: `pay` and `set account`. If there is a
`trust` transaction in the same set of txs, the txs may be reordered so
`pay` -> `trust` -> `set account` so the wrong `no ripple` flag would be used
on the trust line.
Adding a `close` between `env.fund` and `env.trust` resolves this problem.
* Sanity check on newly created strands
* Better loop detection
* Better tests (test every combination of path element pairs)
* Disallow any root issuer (even for xrp)
* Disallow compount element typs in path
* Issue was not reset when currency was XRP
* Add amendment
The deferred credits table can compute a balance that's different from the
ledger balance.
Syntax:
A number written with no decimal means that number exactly. I.e. "12". A number
written with a decimal means that number has a non-zero digit at the lowest
order digit. I.e. "12.XX" means a number like "12.00000000000005"
Consider the following payment:
alice (USD) -> USD/XRP -> (XRP) Bob
Alice initially has 12.XX USD in her account.
The strand is used to debit alice the following amounts:
1) Debit alice 5
2) Debit alice 0.XX
3) Debit alice 3.XX
The next time the strand is explored, alice has a USD/XRP offer on the books,
and her account is credited:
1) Credit alice 20
When the beginning of the strand is reached, consider what happens when alice is
a limiting step. Calculate how much we can get out the step. According to the
deferred credit table this is:
12.XX - (5 + 0.XX + 3.XX)
This is also limited by alice's balance, which is large thanks to the credit she
received in the book step.
Now that the step has calculated how much we can get out, throw out the
sandbox (the one with the credit), and re-execute. However, the following error
occurs. We asked for 12.XX - (5 + 0.XX + 3.XX). However, the ledger has
calculated that alice has:
((12.XX - 5) - 0.XX) - 3.XX
That's a problem, because that number is smaller. Notice that there are two
precision losing operations in the deferred credits table:
1) The 5 + 0.XX step
2) The 12.XX - (total of debits). (Notice total of debits is < 10)
However, there is only one precision losing operation in the ledger calculation:
1) (Subtotal of 12.XX-5) - 0.XX
That means the calculation for the ledger results in a number that's smaller
than the deferred credits. Flow detects this as a re-execution error.
If the mantissas of two non-native amounts differ by less than 10, then
subtracting them leaves a result of zero. This can cause situations
where `a>b`, yet `a-b == 0`.
One consequence of this is unfunded offers were incorrectly left in
order books. The code would check if the offer would be
consumed (`amount in offer > amount needed`), assume it wouldn't be,
yet when `amount needed` was subtracted from `amount in offer` the
result was zero and the offer was unfunded. This unfunded offer
incorrectly remained on the order book.
This patch fixes this bug.
