/// <summary>
/// split the leaf into two, leave left half in current leaf, and move right half into right node
/// </summary>
/// <param name="newKey"></param>
/// <param name="median">the middle key is popped up</param>
/// <param name="right"></param>
public void SplitAtLeaf(IKey newKey, int pos, ref IKey median, ref BNode right)
{
Debug.Assert(this.m_leaf);
Debug.Assert(this.IsFull);
right.SetOrder(this.m_order);
right.m_leaf = this.m_leaf;
int mid = m_order >> 1;
//copy current keys into a bigger array
IKey[] temp = new IKey[m_order];
Array.Copy(m_keys, 0, temp, 0, m_order - 1);
//insert the newKey into the pos location
//shift later keys to the right
for (int i = this.m_keyNums; i > pos; i--)
{
temp[i] = temp[i - 1];
}
temp[pos] = newKey;
median = temp[mid];
//copy left half to current leaf
for (int i = 0; i < mid; i++)
{
m_keys[i] = temp[i];
}
//copy right half to right leaf
for (int i = mid + 1; i < temp.Length; i++)
{
right.m_keys[i - mid - 1] = temp[i];
}
m_keyNums = (short)mid;
right.m_keyNums = (short)(m_order - 1 - mid);
this.m_dirty = true;
right.m_dirty = true;
}
/// <summary>
/// Create the internal storage for the dbFile.
/// Note:
/// 1. a helper file for segment managment b-tree is also created if this database file
/// does not exist.
/// </summary>
/// <param name="dbFile"></param>
public ObjectStore(string dbFileName)
{
m_dbFile = new DiskFile(dbFileName);
m_indexFile = new DiskFile(dbFileName+".idx");
m_indexPageManager = new memSegmentManager(m_indexFile);
if (m_indexPageManager.Header.InitializeNeeded)
{
m_indexPageManager.Header.NextSegmentId = 0;
m_indexPageManager.Header.NextObjectId = 0;
m_indexPageManager.Header.NextClassId = 0;
//initialize the segment b-tree's top node id
OOD.Imp.Storage.BNode segTreeTop = new OOD.Imp.Storage.BNode();
m_indexPageManager.GetNewSegment(segTreeTop);
segTreeTop.SetOrder(m_segTreeNodeOrder);
segTreeTop.Leaf = true;
m_indexPageManager.Header.SegmentTreeTopNodeSId = segTreeTop.SegmentID;
//initialize the space b-tree's top node id
BNode spaceTreeTop = new BNode();
m_indexPageManager.GetNewSegment(spaceTreeTop);
spaceTreeTop.SetOrder(m_spaceTreeNodeOrder);
spaceTreeTop.Leaf = true;
m_indexPageManager.Header.FreeSpaceTreeTopNodeSId = spaceTreeTop.SegmentID;
}
m_segmentIndexTree = new SegTree(m_indexPageManager.Header.SegmentTreeTopNodeSId, m_indexPageManager);
m_spaceIndexTree = new SpaceTree(m_indexPageManager.Header.FreeSpaceTreeTopNodeSId, m_indexPageManager, m_dbFile);
m_dbSegmentManager = new dbSegmentManager(
m_indexPageManager.Header.NextSegmentId,
m_segmentIndexTree,
m_spaceIndexTree,
m_dbFile);
if (m_indexPageManager.Header.InitializeNeeded)
{
BNode catalogTop = new BNode();
m_dbSegmentManager.GetNewSegment(catalogTop);
catalogTop.SetOrder(m_catalogTreeNodeOrder);
catalogTop.Leaf = true;
m_indexPageManager.Header.CatalogTreeTopNodeSId = catalogTop.SegmentID;
}
m_catalogTree = new CatalogTree(
m_indexPageManager.Header.CatalogTreeTopNodeSId,
m_dbSegmentManager,
m_indexPageManager.Header.NextClassId);
m_classCache = new LRUHashtable(m_cache_size, m_classCacheLimit);
m_objectTreeCache = new LRUHashtable(m_cache_size, m_objectTreeCacheLimit);
//bring top node's segment tree, space tree, catalog tree into cache, they will be needed anyway
if (!m_indexPageManager.Header.InitializeNeeded)
{
m_indexPageManager.GetSegment(m_segmentIndexTree.TopNodSegId, new BNode(), new KSegId());
m_indexPageManager.GetSegment(m_spaceIndexTree.TopNodeSId, new BNode(), new KOffset());
m_dbSegmentManager.GetSegment(m_catalogTree.TopNodeSId, new BNode(), new KCatalog());
}
}
/* operations regarding class information, scheme */
public bool InsertClassIno(string className, string[] fieldNames, ref uint assignedCId, ref uint topNodeSId)
{
if (m_catalogTree.Search(className) != null)
return false;
//reserve a segment id for this class clustering's top node
BNode classTopSid = new BNode();
m_dbSegmentManager.GetNewSegment(classTopSid);
classTopSid.SetOrder(m_classTreeNodeOrder);
classTopSid.Leaf = true;
topNodeSId = classTopSid.SegmentID;
if (m_catalogTree.Insert(className, fieldNames, classTopSid.SegmentID, ref assignedCId) == false)
throw new OOD.Exception.ProgramLogicError(
this,
"Inserting class information failed.");
return true;
}
/// <summary>
/// Insert the newKey into this B-tree,
/// </summary>
/// <param name="newKey"></param>
/// <returns></returns>
public bool Insert(IKey newKey)
{
//find the leaf where the newKey should be in
BNode n = m_top;
System.Collections.Stack visited = new System.Collections.Stack();
int pos = -1;
while (!n.Leaf)
{
IKey temp = n.SearchKey(newKey, ref pos);
if (temp == null)
{
uint nextNodeId = n.GetChildAt(pos);
visited.Push(n);
n = (BNode)m_sgManager.GetSegment(nextNodeId, m_nodeFactory, m_keyFactory);
}
else
return false;
}
//now BNode n is the leaf where insert should happen
IKey t_temp = n.SearchKey(newKey, ref pos);
if (t_temp == null)
{
//not exists, go ahead to insert the new key
if (!n.IsFull)
{
n.InsertAtLeaf(newKey, pos);
return true;
}
else
{
//split needed for this node
BNode right = new BNode();
m_sgManager.GetNewSegment(right);
IKey median = null;
n.SplitAtLeaf(newKey, pos, ref median, ref right); //this split is at leaf
bool finished = false;
//now n holds the left half of the items,
//right holds the right half items, median is the middle key
while (!finished)
{
//parent is node middle key will be inserted
BNode parent = (visited.Count >0 ? (BNode)visited.Pop() : null);
if (parent == null)
{
//new top node is needed
BNode new_top = new BNode();
m_sgManager.GetNewSegment(new_top);
new_top.SetOrder(m_top.Order);
new_top.Leaf = false;
new_top.InsertFirstKey(median, n.SegmentID, right.SegmentID);
this.m_top_sid = new_top.SegmentID;
return true;
}
else
{
IKey tt = parent.SearchKey(median, ref pos);
if (tt != null)
return false;
if (!parent.IsFull)
{
parent.InsertAtInternal(median, pos, right.SegmentID);
return true;
}
else
{
//parent is full again
BNode newRight = new BNode();
m_sgManager.GetNewSegment(newRight);
newRight.SetOrder(parent.Order);
newRight.Leaf = parent.Leaf;
//this split will insert median into the parent, then split and new middle key is newMedian
IKey newMedian;
parent.SplitAtInternal(median, pos, right.SegmentID, out newMedian, newRight);
n = parent;
median = newMedian;
right = newRight;
}
}
}
}
}
else
return false;
return false;
}
/// <summary>
/// split the leaf into two, leave left half in current leaf, and move right half into right node
/// </summary>
/// <param name="newKey"></param>
/// <param name="median">the middle key is popped up</param>
/// <param name="right"></param>
public void SplitAtLeaf(IKey newKey, int pos, ref IKey median, ref BNode right)
{
Debug.Assert(this.m_leaf);
Debug.Assert(this.IsFull);
right.SetOrder(this.m_order);
right.m_leaf = this.m_leaf;
int mid = m_order >> 1;
//copy current keys into a bigger array
IKey[] temp = new IKey[m_order];
Array.Copy(m_keys,0,temp,0,m_order - 1);
//insert the newKey into the pos location
//shift later keys to the right
for (int i=this.m_keyNums; i>pos; i--)
{
temp[i] = temp[i-1];
}
temp[pos] = newKey;
median = temp[mid];
//copy left half to current leaf
for (int i=0; i<mid; i++)
{
m_keys[i] = temp[i];
}
//copy right half to right leaf
for (int i=mid+1; i<temp.Length; i++)
{
right.m_keys[i-mid-1] = temp[i];
}
m_keyNums = (short)mid;
right.m_keyNums = (short)(m_order - 1 - mid);
this.m_dirty = true;
right.m_dirty = true;
}
/// <summary>
/// Create the internal storage for the dbFile.
/// Note:
/// 1. a helper file for segment managment b-tree is also created if this database file
/// does not exist.
/// </summary>
/// <param name="dbFile"></param>
public ObjectStore(string dbFileName)
{
m_dbFile = new DiskFile(dbFileName);
m_indexFile = new DiskFile(dbFileName + ".idx");
m_indexPageManager = new memSegmentManager(m_indexFile);
if (m_indexPageManager.Header.InitializeNeeded)
{
m_indexPageManager.Header.NextSegmentId = 0;
m_indexPageManager.Header.NextObjectId = 0;
m_indexPageManager.Header.NextClassId = 0;
//initialize the segment b-tree's top node id
OOD.Imp.Storage.BNode segTreeTop = new OOD.Imp.Storage.BNode();
m_indexPageManager.GetNewSegment(segTreeTop);
segTreeTop.SetOrder(m_segTreeNodeOrder);
segTreeTop.Leaf = true;
m_indexPageManager.Header.SegmentTreeTopNodeSId = segTreeTop.SegmentID;
//initialize the space b-tree's top node id
BNode spaceTreeTop = new BNode();
m_indexPageManager.GetNewSegment(spaceTreeTop);
spaceTreeTop.SetOrder(m_spaceTreeNodeOrder);
spaceTreeTop.Leaf = true;
m_indexPageManager.Header.FreeSpaceTreeTopNodeSId = spaceTreeTop.SegmentID;
}
m_segmentIndexTree = new SegTree(m_indexPageManager.Header.SegmentTreeTopNodeSId, m_indexPageManager);
m_spaceIndexTree = new SpaceTree(m_indexPageManager.Header.FreeSpaceTreeTopNodeSId, m_indexPageManager, m_dbFile);
m_dbSegmentManager = new dbSegmentManager(
m_indexPageManager.Header.NextSegmentId,
m_segmentIndexTree,
m_spaceIndexTree,
m_dbFile);
if (m_indexPageManager.Header.InitializeNeeded)
{
BNode catalogTop = new BNode();
m_dbSegmentManager.GetNewSegment(catalogTop);
catalogTop.SetOrder(m_catalogTreeNodeOrder);
catalogTop.Leaf = true;
m_indexPageManager.Header.CatalogTreeTopNodeSId = catalogTop.SegmentID;
}
m_catalogTree = new CatalogTree(
m_indexPageManager.Header.CatalogTreeTopNodeSId,
m_dbSegmentManager,
m_indexPageManager.Header.NextClassId);
m_classCache = new LRUHashtable(m_cache_size, m_classCacheLimit);
m_objectTreeCache = new LRUHashtable(m_cache_size, m_objectTreeCacheLimit);
//bring top node's segment tree, space tree, catalog tree into cache, they will be needed anyway
if (!m_indexPageManager.Header.InitializeNeeded)
{
m_indexPageManager.GetSegment(m_segmentIndexTree.TopNodSegId, new BNode(), new KSegId());
m_indexPageManager.GetSegment(m_spaceIndexTree.TopNodeSId, new BNode(), new KOffset());
m_dbSegmentManager.GetSegment(m_catalogTree.TopNodeSId, new BNode(), new KCatalog());
}
}
/// <summary>
/// Insert the newKey into this B-tree,
/// </summary>
/// <param name="newKey"></param>
/// <returns></returns>
public bool Insert(IKey newKey)
{
//find the leaf where the newKey should be in
BNode n = m_top;
System.Collections.Stack visited = new System.Collections.Stack();
int pos = -1;
while (!n.Leaf)
{
IKey temp = n.SearchKey(newKey, ref pos);
if (temp == null)
{
uint nextNodeId = n.GetChildAt(pos);
visited.Push(n);
n = (BNode)m_sgManager.GetSegment(nextNodeId, m_nodeFactory, m_keyFactory);
}
else
{
return(false);
}
}
//now BNode n is the leaf where insert should happen
IKey t_temp = n.SearchKey(newKey, ref pos);
if (t_temp == null)
{
//not exists, go ahead to insert the new key
if (!n.IsFull)
{
n.InsertAtLeaf(newKey, pos);
return(true);
}
else
{
//split needed for this node
BNode right = new BNode();
m_sgManager.GetNewSegment(right);
IKey median = null;
n.SplitAtLeaf(newKey, pos, ref median, ref right); //this split is at leaf
bool finished = false;
//now n holds the left half of the items,
//right holds the right half items, median is the middle key
while (!finished)
{
//parent is node middle key will be inserted
BNode parent = (visited.Count > 0 ? (BNode)visited.Pop() : null);
if (parent == null)
{
//new top node is needed
BNode new_top = new BNode();
m_sgManager.GetNewSegment(new_top);
new_top.SetOrder(m_top.Order);
new_top.Leaf = false;
new_top.InsertFirstKey(median, n.SegmentID, right.SegmentID);
this.m_top_sid = new_top.SegmentID;
return(true);
}
else
{
IKey tt = parent.SearchKey(median, ref pos);
if (tt != null)
{
return(false);
}
if (!parent.IsFull)
{
parent.InsertAtInternal(median, pos, right.SegmentID);
return(true);
}
else
{
//parent is full again
BNode newRight = new BNode();
m_sgManager.GetNewSegment(newRight);
newRight.SetOrder(parent.Order);
newRight.Leaf = parent.Leaf;
//this split will insert median into the parent, then split and new middle key is newMedian
IKey newMedian;
parent.SplitAtInternal(median, pos, right.SegmentID, out newMedian, newRight);
n = parent;
median = newMedian;
right = newRight;
}
}
}
}
}
else
{
return(false);
}
return(false);
}
