A structure for accepted ledgers that will allow us to do things like traverse the transactions

in applied order and get the affected accounts without rebuilding things several times.

src/cpp/ripple/AcceptedLedger.cpp

@@ -0,0 +1,35 @@
+#include "AcceptedLedger.h"
+
+ALTransaction::ALTransaction(uint32 seq, SerializerIterator& sit)
+{
+	Serializer			txnSer(sit.getVL());
+	SerializerIterator	txnIt(txnSer);
+
+	mTxn =		boost::make_shared<SerializedTransaction>(boost::ref(txnIt));
+	mMeta =		boost::make_shared<TransactionMetaSet>(mTxn->getTransactionID(), seq, sit.getVL());
+	mAffected =	mMeta->getAffectedAccounts();
+}
+
+AcceptedLedger::AcceptedLedger(Ledger::ref ledger) : mLedger(ledger)
+{
+	SHAMap& txSet = *ledger->peekTransactionMap();
+	for (SHAMapItem::pointer item = txSet.peekFirstItem(); !!item; item = txSet.peekNextItem(item->getTag()))
+	{
+		SerializerIterator sit(item->peekSerializer());
+		insert(ALTransaction(ledger->getLedgerSeq(), sit));
+	}
+}
+
+void AcceptedLedger::insert(const ALTransaction& at)
+{
+	assert(mMap.find(at.getIndex()) == mMap.end());
+	mMap.insert(std::make_pair(at.getIndex(), at));
+}
+
+const ALTransaction* AcceptedLedger::getTxn(int i) const
+{
+	map_t::const_iterator it = mMap.find(i);
+	if (it == mMap.end())
+		return NULL;
+	return &it->second;
+}