public void InsertLeaf(Key newLeafKey, TreeLeaf newLeaf, bool before)
{
int leafSize = newLeaf.Length;
if (leafSize <= 0)
{
throw new ArgumentException("size <= 0");
}
// The current absolute position and key
Key newKey = newLeafKey;
// The frame at the end of the stack,
StackFrame frame = StackEnd(0);
object[] info;
object[] rInfo = new object[5];
Key leftKey;
long curAbsolutePos;
// If we are inserting the new leaf after,
if (!before)
{
info = new object[] {
currentLeaf.Id,
(long)currentLeaf.Length,
newLeafKey,
newLeaf.Id,
(long)newLeaf.Length
};
leftKey = null;
curAbsolutePos = frame.Offset + currentLeaf.Length;
}
// Otherwise we are inserting the new leaf before,
else
{
// If before and current_leaf key is different than new_leaf key, we
// generate an error
if (!currentLeafKey.Equals(newLeafKey))
{
throw new InvalidOperationException("Can't insert different new key before.");
}
info = new Object[] {
newLeaf.Id,
(long)newLeaf.Length,
currentLeafKey,
currentLeaf.Id,
(long)currentLeaf.Length
};
leftKey = newLeafKey;
curAbsolutePos = frame.Offset - 1;
}
bool insertTwoNodes = true;
int sz = FrameCount;
// Walk the stack from the end
for (int i = 1; i < sz; ++i)
{
// child_i is the previous frame's child_i
int childIndex = frame.ChildIndex;
frame = StackEnd(i);
// The child ref of this stack element
NodeId childId = frame.NodeId;
// Fetch it
TreeBranch branch = (TreeBranch)UnfreezeNode(FetchNode(childId));
// Do we have two nodes to insert into the branch?
if (insertTwoNodes)
{
TreeBranch insertBranch;
int insertIndex = childIndex;
// If the branch is full,
if (branch.IsFull)
{
// Create a new node,
TreeBranch leftBranch = branch;
TreeBranch rightBranch = CreateBranch();
// Split the branch,
Key midpointKey = leftBranch.MidPointKey;
// And move half of this branch into the new branch
leftBranch.MoveLastHalfInto(rightBranch);
// We split so we need to return a split flag,
rInfo[0] = leftBranch.Id;
rInfo[1] = leftBranch.LeafElementCount;
rInfo[2] = midpointKey;
rInfo[3] = rightBranch.Id;
rInfo[4] = rightBranch.LeafElementCount;
// Adjust insert_n and insert_branch
if (insertIndex >= leftBranch.ChildCount)
{
insertIndex -= leftBranch.ChildCount;
insertBranch = rightBranch;
rInfo[4] = (long)rInfo[4] + newLeaf.Length;
// If insert_n == 0, we change the midpoint value to the left
// key value,
if (insertIndex == 0 && leftKey != null)
{
rInfo[2] = leftKey;
leftKey = null;
}
}
else
{
insertBranch = leftBranch;
rInfo[1] = (long)rInfo[1] + newLeaf.Length;
}
}
// If it's not full,
else
{
insertBranch = branch;
rInfo[0] = insertBranch.Id;
insertTwoNodes = false;
}
// Insert the two children nodes
insertBranch.Insert((NodeId)info[0], (long)info[1],
(Key)info[2],
(NodeId)info[3], (long)info[4],
insertIndex);
// Copy r_nfo to nfo
for (int p = 0; p < rInfo.Length; ++p)
{
info[p] = rInfo[p];
}
// Adjust the left key reference if necessary
if (leftKey != null && insertIndex > 0)
{
insertBranch.SetKeyToLeft(leftKey, insertIndex);
leftKey = null;
}
}
else
{
branch.SetChild((NodeId)info[0], childIndex);
info[0] = branch.Id;
branch.SetChildLeafElementCount(
branch.GetChildLeafElementCount(childIndex) + leafSize, childIndex);
// Adjust the left key reference if necessary
if (leftKey != null && childIndex > 0)
{
branch.SetKeyToLeft(leftKey, childIndex);
leftKey = null;
}
}
} // For all elements in the stack,
// At the end, if we still have a split then we make a new root and
// adjust the stack accordingly
if (insertTwoNodes)
{
TreeBranch newRoot = CreateBranch();
newRoot.Set((NodeId)info[0], (long)info[1],
(Key)info[2],
(NodeId)info[3], (long)info[4]);
RootNodeId = newRoot.Id;
if (TreeHeight != -1)
{
TreeHeight = TreeHeight + 1;
}
}
else
{
RootNodeId = (NodeId)info[0];
}
// Now reset the position,
Reset();
SetupForPosition(newKey, curAbsolutePos);
}
public long Create()
{
if (initialized)
{
throw new InvalidOperationException("This tree store is already initialized.");
}
// Temporary node heap for creating a starting database
TreeNodeHeap nodeHeap = new TreeNodeHeap(17, 4 * 1024 * 1024);
// Write a root node to the store,
// Create an empty head node
TreeLeaf headLeaf = nodeHeap.CreateLeaf(null, Key.Head, 256);
// Insert a tree identification pattern
headLeaf.Write(0, new byte[] { 1, 1, 1, 1 }, 0, 4);
// Create an empty tail node
TreeLeaf tailLeaf = nodeHeap.CreateLeaf(null, Key.Tail, 256);
// Insert a tree identification pattern
tailLeaf.Write(0, new byte[] { 1, 1, 1, 1 }, 0, 4);
// The write sequence,
TreeWrite seq = new TreeWrite();
seq.NodeWrite(headLeaf);
seq.NodeWrite(tailLeaf);
IList <NodeId> refs = Persist(seq);
// Create a branch,
TreeBranch rootBranch = nodeHeap.CreateBranch(null, MaxBranchSize);
rootBranch.Set(refs[0], 4, Key.Tail, refs[1], 4);
seq = new TreeWrite();
seq.NodeWrite(rootBranch);
refs = Persist(seq);
// The written root node reference,
NodeId rootId = refs[0];
// Delete the head and tail leaf, and the root branch
nodeHeap.Delete(headLeaf.Id);
nodeHeap.Delete(tailLeaf.Id);
nodeHeap.Delete(rootBranch.Id);
// Write this version info to the store,
long versionId = WriteSingleVersionInfo(1, rootId, new List <NodeId>(0));
// Make a first version
VersionInfo versionInfo = new VersionInfo(1, rootId, versionId);
versions.Add(versionInfo);
// Flush this to the version list
IAreaWriter versionList = nodeStore.CreateArea(64);
versionList.WriteInt4(0x01433);
versionList.WriteInt4(1);
versionList.WriteInt8(versionId);
versionList.Finish();
// Get the versions id
long versionListId = versionList.Id;
// The final header
IAreaWriter header = nodeStore.CreateArea(64);
header.WriteInt4(0x09391); // The magic value,
header.WriteInt4(1); // The version
header.WriteInt8(versionListId);
header.Finish();
// Set up the internal variables,
headerId = header.Id;
initialized = true;
// And return the header reference
return(headerId);
}