public IndexPage GetFreeIndexPage()
{
var freeIndexPage = CacheIndexPage.GetPage(Header.FreeIndexPageID);
// Check if "free page" has no more index to be used
if (freeIndexPage.NodeIndex >= IndexPage.NODES_PER_PAGE - 1)
{
Header.LastPageID++; // Take last page and increase
Header.IsDirty = true;
var newIndexPage = new IndexPage(Header.LastPageID); // Create a new index page
freeIndexPage.NextPageID = newIndexPage.PageID; // Point older page to the new page
Header.FreeIndexPageID = Header.LastPageID; // Update last index page
CacheIndexPage.AddPage(freeIndexPage, true);
return(newIndexPage);
}
else
{
// Has more free index on same index page? return them
freeIndexPage.NodeIndex++; // Reserve space
return(freeIndexPage);
}
}
public EntryInfo[] ListAllFiles()
{
// Get root index page from cache
var pageIndex = CacheIndexPage.GetPage(Header.IndexRootPageID);
bool cont = true;
List <EntryInfo> list = new List <EntryInfo>();
while (cont)
{
for (int i = 0; i <= pageIndex.NodeIndex; i++)
{
// Convert node (if is not logicaly deleted) to Entry
var node = pageIndex.Nodes[i];
if (!node.IsDeleted)
{
list.Add(new EntryInfo(node));
}
}
// Go to the next page
if (pageIndex.NextPageID != uint.MaxValue)
{
pageIndex = CacheIndexPage.GetPage(pageIndex.NextPageID);
}
else
{
cont = false;
}
}
return(list.ToArray());
}
public bool Delete(Guid id)
{
// Search index node from guid
var indexNode = Search(id);
// If null, not found (return false)
if (indexNode == null)
{
return(false);
}
// Delete the index node logicaly
indexNode.IsDeleted = true;
// Add page (from index node) to cache and set as dirty
CacheIndexPage.AddPage(indexNode.IndexPage, true);
// Mark all data blocks (from data pages) as IsEmpty = true
DataFactory.MarkAsEmpty(indexNode.DataPageID, this);
// Set header as Dirty to be saved on dispose
Header.IsDirty = true;
return(true); // Confirma a exclusão
}
public void PersistPages()
{
// Check if header is dirty and save to disk
if (Header.IsDirty)
{
HeaderFactory.WriteToFile(Header, Writer);
Header.IsDirty = false;
}
// Persist all index pages that are dirty
CacheIndexPage.PersistPages();
}
public Engine(FileStream stream)
{
Reader = new BinaryReader(stream);
if (stream.CanWrite)
{
Writer = new BinaryWriter(stream);
Writer.Lock(Header.LOCKER_POS, 1);
}
Header = new Header();
HeaderFactory.ReadFromFile(Header, this.Reader);
CacheIndexPage = new CacheIndexPage(Reader, Writer, Header.IndexRootPageID);
}
public Engine(FileStream stream)
{
Reader = new BinaryReader(stream);
if (stream.CanWrite)
{
Writer = new BinaryWriter(stream);
Writer.Lock(Header.LOCKER_POS, 1);
}
Header = new Header();
HeaderFactory.ReadFromFile(Header, this.Reader);
CacheIndexPage = new CacheIndexPage(Reader, Writer, Header.IndexRootPageID);
}
