/// <summary>
/// Fetches the page by index.
/// </summary>
/// <param name="pageIndex">An index of page</param>
/// <returns>The fetched page</returns>
public IPage FetchPage(long pageIndex)
{
CheckDisposed();
Lock();
try
{
CheckStorage();
if (_deferredUpdatesMode)
{
if (_recoveryFile.IsPageUpdated(pageIndex))
{
return(new Page(this, pageIndex, _recoveryFile.GetUpdatedPageContent(pageIndex)));
}
if (_recoveryFile.DeletedPageIndexes.Contains(pageIndex))
{
throw new PageMapException($"Page {pageIndex} is removed");
}
}
long pageAllocation = _pagemap.GetPageAllocation(pageIndex);
if (pageAllocation == -1)
{
throw new PageMapException("Page is removed");
}
CheckRemovalMarker(pageIndex);
_storageStream.Seek(pageAllocation, SeekOrigin.Begin);
var pageContent = new byte[_pageSize];
_storageStream.BlockingRead(pageContent);
return(new Page(this, pageIndex, pageContent));
}
finally
{
Unlock();
}
}
