private long WriteSingleVersionInfo(long versionId, NodeId rootNodeId, List <NodeId> deletedRefs)
{
int deletedRefCount = deletedRefs.Count;
// Write the version info and the deleted refs to a new area,
IAreaWriter writer = nodeStore.CreateArea(4 + 4 + 8 + 8 + 8 + 4 + (deletedRefCount * 16));
writer.WriteInt4(0x04EA23);
writer.WriteInt4(1);
writer.WriteInt8(versionId);
writer.WriteInt8(rootNodeId.High);
writer.WriteInt8(rootNodeId.Low);
writer.WriteInt4(deletedRefCount);
foreach (NodeId deletedNode in deletedRefs)
{
writer.WriteInt8(deletedNode.High);
writer.WriteInt8(deletedNode.Low);
}
writer.Finish();
return(writer.Id);
}
public bool Start()
{
lock (lockObject) {
treeSystem = new StoreTreeSystem(store, branchNodeSize, leafNodeSize, heapNodeCacheSize, branchNodeCacheSize);
treeSystem.Create();
treeSystem.CheckPoint();
// The actual database
StoreTreeSystem treeStore;
// Get the header area
IArea headerArea = store.GetArea(-1);
int magicValue = headerArea.ReadInt4();
// If header area magic value is zero, then we assume this is a brand
// new database and initialize it with the configuration information
// given.
if (magicValue == 0)
{
// Create a tree store inside the file store,
treeStore = new StoreTreeSystem(store, branchNodeSize, leafNodeSize, heapNodeCacheSize,
branchNodeCacheSize);
// Create the tree and returns a pointer to the tree,
long treePointer = treeStore.Create();
// Create an area object with state information about the tree
IAreaWriter awriter = store.CreateArea(128);
awriter.WriteInt4(0x0101); // The version value
awriter.WriteInt8(treePointer);
awriter.WriteInt4(branchNodeSize);
awriter.WriteInt4(leafNodeSize);
awriter.Finish();
long dummy = awriter.Id;
IMutableArea harea = store.GetMutableArea(-1);
harea.WriteInt4(0x092BA001); // The magic value
harea.WriteInt8(awriter.Id);
harea.CheckOut();
}
else if (magicValue == 0x092BA001)
{
long apointer = headerArea.ReadInt8();
// The area that contains configuration details,
IArea initArea = store.GetArea(apointer);
int version = initArea.ReadInt4();
if (version != 0x0101)
{
throw new IOException("Unknown version in tree initialization area");
}
// Read the pointer to the tree store
long treePointer = initArea.ReadInt8();
// Read the branch and leaf node sizes as set when the database was
// created.
int ibranchNodeSize = initArea.ReadInt4();
int ileafNodeSize = initArea.ReadInt4();
// Create the tree store
treeStore = new StoreTreeSystem(store, ibranchNodeSize, ileafNodeSize, heapNodeCacheSize,
branchNodeCacheSize);
// Initialize the tree
treeStore.Init(treePointer);
}
else
{
throw new IOException("Data is corrupt, invalid magic value in store");
}
// Set the point of the tree store
treeStore.CheckPoint();
// Set up final internal state and return true
treeSystem = treeStore;
databaseStarted = true;
return(true);
}
}
public IList <NodeId> Persist(TreeWrite write)
{
try {
nodeStore.LockForWrite();
IList <ITreeNode> allBranches = write.BranchNodes;
IList <ITreeNode> allLeafs = write.LeafNodes;
List <ITreeNode> nodes = new List <ITreeNode>(allBranches.Count + allLeafs.Count);
nodes.AddRange(allBranches);
nodes.AddRange(allLeafs);
// The list of nodes to be allocated,
int sz = nodes.Count;
// The list of allocated referenced for the nodes,
NodeId[] refs = new NodeId[sz];
// The list of area writers,
IAreaWriter[] writers = new IAreaWriter[sz];
// Allocate the space first,
for (int i = 0; i < sz; ++i)
{
ITreeNode node = nodes[i];
// Is it a branch node?
if (node is TreeBranch)
{
TreeBranch branch = (TreeBranch)node;
int ndsz = branch.NodeDataSize;
writers[i] = nodeStore.CreateArea(4 + 4 + (ndsz * 8));
}
// Otherwise, it must be a leaf node,
else
{
TreeLeaf leaf = (TreeLeaf)node;
int lfsz = leaf.Length;
writers[i] = nodeStore.CreateArea(12 + lfsz);
}
// Set the reference,
refs[i] = FromInt64StoreAddress(writers[i].Id);
}
// Now write out the data,
for (int i = 0; i < sz; ++i)
{
ITreeNode node = nodes[i];
// Is it a branch node?
if (node is TreeBranch)
{
TreeBranch branch = (TreeBranch)node;
// The number of children
int chsz = branch.ChildCount;
// For each child, if it's a heap node, look up the child id and
// reference map in the sequence and set the reference accordingly,
for (int o = 0; o < chsz; ++o)
{
NodeId childId = branch.GetChild(o);
if (childId.IsInMemory)
{
// The ref is currently on the heap, so adjust accordingly
int refId = write.LookupRef(i, o);
branch.SetChild(refs[refId], o);
}
}
// Write out the branch to the store
long[] nodeData = branch.NodeData;
int ndsz = branch.NodeDataSize;
IAreaWriter writer = writers[i];
writer.WriteInt2(StoreBranchType);
writer.WriteInt2(1); // version
writer.WriteInt4(ndsz);
for (int o = 0; o < ndsz; ++o)
{
writer.WriteInt8(nodeData[o]);
}
writer.Finish();
// Make this into a branch node and add to the cache,
branch = new TreeBranch(refs[i], nodeData, ndsz);
// Put this branch in the cache,
lock (branchCache) {
branchCache.Set(refs[i], branch);
}
}
// Otherwise, it must be a leaf node,
else
{
TreeLeaf leaf = (TreeLeaf)node;
IAreaWriter writer = writers[i];
writer.WriteInt2(StoreLeafType);
writer.WriteInt2(1); // version
writer.WriteInt4(1); // reference count
writer.WriteInt4(leaf.Length);
leaf.WriteTo(writer);
writer.Finish();
}
}
return(refs);
} finally {
nodeStore.UnlockForWrite();
}
}
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);
}
private void DisposeOldVersions()
{
List <object> disposeList = new List <object>();
lock (versions) {
// size - 1 because we don't want to delete the very last version,
int sz = versions.Count - 1;
bool foundLockedEntry = false;
for (int i = 0; i < sz && foundLockedEntry == false; ++i)
{
VersionInfo vinfo = versions[i];
// If this version isn't locked,
if (vinfo.NotLocked)
{
// Add to the dispose list
disposeList.Add(vinfo);
// And delete from the versions list,
versions.RemoveAt(i);
--sz;
--i;
}
else
{
// If it is locked, we exit the loop
foundLockedEntry = true;
}
}
}
// If there are entries to dispose?
if (disposeList.Count > 0)
{
// We synchronize here to ensure the versions list can't be modified by
// a commit operation while we are disposing this.
lock (this) {
// Run within a write lock on the store
try {
nodeStore.LockForWrite();
// First we write out a modified version header minus the versions we
// are to delete,
// Get the current version list
IMutableArea headerArea = nodeStore.GetMutableArea(headerId);
headerArea.Position = 8;
long versionListId = headerArea.ReadInt8();
// Read information from the old version info,
IArea versionListArea = nodeStore.GetArea(versionListId);
versionListArea.ReadInt4(); // The magic
int versionCount = versionListArea.ReadInt4();
int newVersionCount = versionCount - disposeList.Count;
// Create a new list,
IAreaWriter newVersionList = nodeStore.CreateArea(8 + (8 * newVersionCount));
newVersionList.WriteInt4(0x01433);
newVersionList.WriteInt4(newVersionCount);
// Skip the versions we are deleting,
for (int i = 0; i < disposeList.Count; ++i)
{
versionListArea.ReadInt8();
}
// Now copy the list from the new point
for (int i = 0; i < newVersionCount; ++i)
{
newVersionList.WriteInt8(versionListArea.ReadInt8());
}
newVersionList.Finish();
// Write the new area to the header,
headerArea.Position = 8;
headerArea.WriteInt8(newVersionList.Id);
// Delete the old version list Area,
nodeStore.DeleteArea(versionListId);
// Dispose the version info,
int sz = disposeList.Count;
for (int i = 0; i < sz; ++i)
{
VersionInfo vinfo = (VersionInfo)disposeList[i];
long vRef = vinfo.VersionInfoRef;
IArea versionArea = nodeStore.GetArea(vRef);
int magic = versionArea.ReadInt4();
int rev = versionArea.ReadInt4();
// Check the magic,
if (magic != 0x04EA23)
{
throw new ApplicationException("Magic value for version area is incorrect.");
}
long verId = versionArea.ReadInt8();
long nrnHigh = versionArea.ReadInt8();
long nrnLow = versionArea.ReadInt8();
int nodeCount = versionArea.ReadInt4();
// For each node,
for (int n = 0; n < nodeCount; ++n)
{
// Read the next area
long drnHigh = versionArea.ReadInt8();
long drnLow = versionArea.ReadInt8();
NodeId delNodeId = new NodeId(drnHigh, drnLow);
// Cleanly disposes the node
DoDisposeNode(delNodeId);
}
// Delete the node header,
nodeStore.DeleteArea(vRef);
}
} finally {
nodeStore.UnlockForWrite();
}
}
}
}
private long WriteVersionsList(long versionId, TreeSystemTransaction tran)
{
lock (this) {
// Write the version info and the deleted refs to a new area,
NodeId rootNodeId = tran.RootNodeId;
if (rootNodeId.IsInMemory)
{
throw new ApplicationException("Assertion failed, root_node is on heap.");
}
// Get the list of all nodes deleted in the transaction
List <NodeId> deletedRefs = tran.NodeDeletes;
// Sort it
deletedRefs.Sort();
// Check for any duplicate entries (we shouldn't double delete stuff).
for (int i = 1; i < deletedRefs.Count; ++i)
{
if (deletedRefs[i - 1].Equals(deletedRefs[i]))
{
// Oops, duplicated delete
throw new ApplicationException("PRAGMATIC_CHECK failed: duplicate records in delete list.");
}
}
long theVersionId = WriteSingleVersionInfo(versionId, rootNodeId, deletedRefs);
// Now update the version list by copying the list and adding the new ref
// to the end.
// Get the current version list
IMutableArea headerArea = nodeStore.GetMutableArea(headerId);
headerArea.Position = 8;
long versionListId = headerArea.ReadInt8();
// Read information from the old version info,
IArea versionListArea = nodeStore.GetArea(versionListId);
versionListArea.ReadInt4(); // The magic
int versionCount = versionListArea.ReadInt4();
// Create a new list,
IAreaWriter newVersionList = nodeStore.CreateArea(8 + (8 * (versionCount + 1)));
newVersionList.WriteInt4(0x01433);
newVersionList.WriteInt4(versionCount + 1);
for (int i = 0; i < versionCount; ++i)
{
newVersionList.WriteInt8(versionListArea.ReadInt8());
}
newVersionList.WriteInt8(theVersionId);
newVersionList.Finish();
// Write the new area to the header,
headerArea.Position = 8;
headerArea.WriteInt8(newVersionList.Id);
// Delete the old version list Area,
nodeStore.DeleteArea(versionListId);
// Done,
return(theVersionId);
}
}
public bool Start()
{
lock (lockObject) {
// We can't start a database that is already started,
if (databaseStarted || treeSystem != null)
{
return(false);
}
// Make a data.koi file with a single TreeSystem structure mapped into it
const string fileExt = "cdb";
const string dbFileName = "data";
bufferManager = new LoggingBufferManager(path, path, false, maxPageCount, pageSize, fileExt, fileRolloverSize,
logger, true);
bufferManager.Start();
// The backing store
fileStore = new JournalledFileStore(dbFileName, bufferManager, false);
fileStore.Open();
// The actual database
StoreTreeSystem treeStore;
// Get the header area
IArea headerArea = fileStore.GetArea(-1);
int magicValue = headerArea.ReadInt4();
// If header area magic value is zero, then we assume this is a brand
// new database and initialize it with the configuration information
// given.
if (magicValue == 0)
{
// Create a tree store inside the file store,
treeStore = new StoreTreeSystem(fileStore, branchNodeSize, leafNodeSize, heapNodeCacheSize,
branchNodeCacheSize);
// Create the tree and returns a pointer to the tree,
long treePointer = treeStore.Create();
// Create an area object with state information about the tree
IAreaWriter awriter = fileStore.CreateArea(128);
awriter.WriteInt4(0x0101); // The version value
awriter.WriteInt8(treePointer);
awriter.WriteInt4(branchNodeSize);
awriter.WriteInt4(leafNodeSize);
awriter.Finish();
long dummy = awriter.Id;
IMutableArea harea = fileStore.GetMutableArea(-1);
harea.WriteInt4(0x092BA001); // The magic value
harea.WriteInt8(awriter.Id);
harea.CheckOut();
}
else if (magicValue == 0x092BA001)
{
long apointer = headerArea.ReadInt8();
// The area that contains configuration details,
IArea initArea = fileStore.GetArea(apointer);
int version = initArea.ReadInt4();
if (version != 0x0101)
{
throw new IOException("Unknown version in tree initialization area");
}
// Read the pointer to the tree store
long treePointer = initArea.ReadInt8();
// Read the branch and leaf node sizes as set when the database was
// created.
int ibranchNodeSize = initArea.ReadInt4();
int ileafNodeSize = initArea.ReadInt4();
// Create the tree store
treeStore = new StoreTreeSystem(fileStore, ibranchNodeSize, ileafNodeSize, heapNodeCacheSize,
branchNodeCacheSize);
// Initialize the tree
treeStore.Init(treePointer);
}
else
{
throw new IOException("Data is corrupt, invalid magic value in store");
}
// Set the point of the tree store
treeStore.CheckPoint();
// Set up final internal state and return true
treeSystem = treeStore;
databaseStarted = true;
return(true);
}
}