First part of fetch acceleration changes. Includes a bugfix that I'll push to master.

src/cpp/ripple/SHAMapNodes.cpp

@@ -571,6 +571,95 @@ std::ostream& operator<<(std::ostream& out, const SHAMapMissingNode& mn)
 	return out;
 }
 
+SHAMapIterator::SHAMapIterator(SHAMap& map, bool returnInner, bool returnLeaf) :
+	mMap(map), mInner(returnInner), mLeaf(returnLeaf), mLock(false)
+{
+	mStack.push(stack_t(mMap.root.get(), 0));
+}
 
+SHAMapIterator::~SHAMapIterator()
+{
+	if (mLock)
+	{
+		while (!mStack.empty())
+			mStack.pop();
+		mMap.mLock.unlock();
+	}
+}
+
+bool SHAMapIterator::lock()
+{
+	if (mLock)
+		return false;
+	mMap.mLock.lock();
+	mLock = true;
+	return true;
+}
+
+bool SHAMapIterator::unlock()
+{
+	if (!mLock)
+		return false;
+	mMap.mLock.unlock();
+	mLock = false;
+	return true;
+}
+
+void SHAMapIterator::reset()
+{
+	while (!mStack.empty())
+		mStack.pop();
+	mStack.push(stack_t(mMap.root.get(), 0));
+}
+
+SHAMapTreeNode* SHAMapIterator::getNext()
+{
+	if (mStack.empty())
+		return NULL;
+
+	stack_t& top = mStack.top();
+
+	if (top.first->isLeaf())
+	{ // special case, map has only one leaf
+		SHAMapTreeNode* ret = mLeaf ? top.first : NULL;
+		mStack.pop();
+		return ret;
+	}
+
+	while (1)
+	{
+		while (top.second < 16)
+		{ // continue where we left off
+			if (top.first->isEmptyBranch(top.second))
+				++top.second;
+			else
+			{
+				SHAMapTreeNode* next = mMap.getNodePointer(
+					top.first->getChildNodeID(top.second), top.first->getChildHash(top.second));
+				++top.second;
+				if (next->isLeaf())
+				{
+					if (mLeaf)
+						return next;
+				}
+				else
+				{
+					mStack.push(stack_t(next, 0));
+					top = mStack.top();
+				}
+			}
+		}
+		if (top.second == 16)
+		{ // we ran off the end of an inner node
+			SHAMapTreeNode* ret = top.first;
+			mStack.pop();
+			if (mInner)
+				return ret;
+			if (mStack.empty()) // ran off the end of the root
+				return NULL;
+			top = mStack.top();
+		}
+	}
+}
 
 // vim:ts=4