/// <summary>
/// Write entries directory to pages. If pages not enough for new directory - additional pages will allocated.
/// Also write header and pageAllocator state
/// </summary>
public void Write(Stream stm, PagedContainerHeader header, PageAllocator pageAllocator)
{
var targetPages = pages;
var buff = entries.WriteEntries(header.DataHandler);
var requiredPages = header.GetRequiredPages(buff.Length);
if (requiredPages > targetPages.Length) // need to allocate additional pages?
{
targetPages = targetPages.Concat(pageAllocator.AllocatePages(requiredPages - targetPages.Length)).ToArray();
}
else if (requiredPages < targetPages.Length) // can free unused pages?
{
var mustBeFreePages = targetPages.Skip(requiredPages).ToArray();
targetPages = targetPages.Take(requiredPages).ToArray();
pageAllocator.FreePages(mustBeFreePages);
}
stm.WriteIntoPages(header, buff, 0, targetPages);
header.DirectoryFirstPage = targetPages[0];
header.Write(stm);
pageAllocator.Write(stm);
pages = targetPages;
}
protected PagedContainerAbstract(Stream stm, PersistentContainerSettings?settings = null)
{
Stream = stm;
settings ??= new PersistentContainerSettings();
try
{
if (stm.Length == 0) // new file
{
Header = new PagedContainerHeader(settings);
Header.Write(stm);
pageAllocator = new PageAllocator(Header);
pageAllocator.Write(stm);
}
else
{
Header = new PagedContainerHeader(stm, settings.encryptorDecryptor);
pageAllocator = new PageAllocator(Header, stm);
}
entries = Header.DirectoryFirstPage == 0
? new PagedContainerEntryCollection()
: new PagedContainerEntryCollection(Header, stm.ReadWithPageSequence(Header, Header.DirectoryFirstPage));
}
catch
{
Dispose();
throw;
}
}