Files
rippled/include/xrpl/protocol
Ed Hennis 33f4c92b61 Expand Number to support the full integer range (#6025)
- Refactor Number internals away from int64 to uint64 & a sign flag
  - ctors and accessors use `rep`. Very few things expose
    `internalrep`.
  - An exception is "unchecked" and the new "normalized", which explicitly
    take an internalrep. But with those special control flags, it's easier
    to distinguish and control when they are used.

- For now, skip the larger mantissas in AMM transactions and tests

- Remove trailing zeros from scientific notation Number strings
  - Update tests. This has the happy side effect of making some of the string
    representations _more_ consistent between the small and large
    mantissa ranges.

- Add semi-automatic rounding of STNumbers based on Asset types
  - Create a new SField metadata enum, sMD_NeedsAsset, which indicates
    the field should be associated with an Asset so it can be rounded.
  - Add a new STTakesAsset intermediate class to handle the Asset
    association to a derived ST class. Currently only used in STNumber,
    but could be used by other types in the future.
  - Add "associateAsset" which takes an SLE and an Asset, finds the
    sMD_NeedsAsset fields, and associates the Asset to them. In the case
    of STNumber, that both stores the Asset, and rounds the value
    immediately.
  - Transactors only need to add a call to associateAsset _after_ all of
    the STNumbers have been set. Unfortunately, the inner workings of
    STObject do not do the association correctly with uninitialized
    fields.
  - When serializing an STNumber that has an Asset, round it before
    serializing.
  - Add an override of roundToAsset, which rounds a Number value in place
    to an Asset, but without any additional scale.
  - Update and fix a bunch of Loan-related tests to accommodate the
    expanded Number class.

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Co-authored-by: Vito <5780819+Tapanito@users.noreply.github.com>
2026-01-13 21:01:11 +00:00
..

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 the rippled codebase.
    • 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.

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.