/// <summary>
/// Constructs a new page head. The page head handles page locks and versions
/// </summary>
/// <param name="pageNumber">The page number of the page</param>
/// <param name="page">The current version of the page from storage</param>
public PageHead(ulong pageNumber, IPage page)
{
PageNumber = pageNumber;
Versions = new OwinContainers.LinkedList <PageVersion>();
var pageVersion = new PageVersion(0, page);
pageVersion.Added(this, Versions.Append(pageVersion));
}
/// <summary>
/// Adds a new version of this page
/// </summary>
public PageVersion AddVersion(PageVersion pageVersion)
{
lock (Versions)
{
var nextVersion = Versions.FirstElementOrDefault(v => v.VersionNumber >= pageVersion.VersionNumber);
pageVersion.Added(this, Versions.InsertBefore(nextVersion, pageVersion));
}
return(pageVersion);
}
/// <summary>
/// Appends a page to this database version. This PageVersion will
/// be disposed when the PageVersion is disposed.
/// </summary>
public void AddPage(PageVersion pageVersion)
{
_pageVersions.Append(pageVersion);
}