This implements the tracking of when an amendment achieved a majority
in the ledger, ensuring that there's always network-wide agreement
on which amendments have achieved a majority and how long they've
held it.
* New fields
* Change transactor changes
* AmendmentTable API and implementation changes
* Update amendment enabled status on validated ledgers
* Reinstate support for ledger sequence in fee transactions
* Remove dependence on boost::iterator_facade.
* Rename iterator to const_iterator.
* Change value_type from shared_ptr<SHAMapItem const> to SHAMapItem.
* Install a stack-path to the current SHAMapItem in the const_iterator.
The View hierarchy of classes is reorganized to include new
classes with member functions moved and renamed, to solve
defects in the original design:
OpenView accumulates raw state and tx changes and
can be applied to the base. ApplyView accumulates changes
for a single transaction, including metadata, and can be
applied to an OpenView. The Sandbox allows changes with
the option to apply or throw them out. The PaymentSandbox
provides a sandbox with account credit deferral.
Call sites are changed to use the class appropriate for
the task.
The OpenLedger class encapsulates the functionality of
maintaining the open ledger. It uses an OpenView with the
last closed ledger as its base. Routines are provided to
modify the open ledger to add new transactions, and to
accept a new last closed ledger. Business logic for
performing transaction retries is rewritten to fit this
framework and used in the implementation of accept.
When the RIPPLE_OPEN_LEDGER macro is set to 1 (BeastConfig.h),
the global Application OpenLedger singleton maintains
its open ledger in parallel by applying new transactions
and accepting new last closed ledgers. In the current
implementation this does not affect transaction processing
but logs any differences in the results as compared to
the original code.
Logging shows an occasional mismatch in what the OpenLedger
builds versus the original code, usually an OfferCreate
which gets a terINSUF_RESERVE instead of tesSUCCESS.
Many functions and classes that used a Ledger now use a BasicView.
Calls to cachedRead are changed to call member read on the view,
note that this bypasses the SLECache optimization. To restore the
optimization, the BasicView passed at the top of call stacks
should be wrapped with a caching view, coming in future commits.
When the last closed ledger jumps, transactions from the
old open ledger and local transactions need to be applied
to the new open ledger or else transactions could get lost
locally (but still relayed, and therefore make it into a ledger).
A harmful effect is that rippled will report that the transaction
was not applied even when it was, making robust transaction
submission malfunction.
