private DbItemReference AllocateMultiPage(DbItem item)
{
long bytesWritten = 0;
long startPageIndex = -1;
DbItemReference result = null;
IPage page = null;
IPage previousPage = null;
while (bytesWritten < item.RawData.LongLength)
{
page = _pageManager.CreatePage();
if (startPageIndex == -1)
{
startPageIndex = page.Index;
result = new DbItemReference(page.Index, 0);
}
var header = new MultipageItemPageHeader
{
StartPageIndex = startPageIndex,
PreviousPageIndex = previousPage?.Index ?? -1,
NextPageIndex = -1,
SizeRange = SizeRange.MultiPage
};
PageFormatter.InitPage(page, header);
bytesWritten += PageFormatter.WriteMultipageItemBlock(page, item, bytesWritten);
if (previousPage != null)
{
header = (MultipageItemPageHeader)PageFormatter.GetPageHeader(previousPage);
header.NextPageIndex = page.Index;
header.WriteToPage(previousPage);
_pageManager.UpdatePage(previousPage);
}
previousPage = page;
}
if (page != null)
{
_pageManager.UpdatePage(page);
}
return(result);
}
public void CorrectWriteAndReadAllHeaders()
{
int pageSize = 4096;
var dummyPageManager = new FileSystemPageManager(pageSize);
var p = new Page(dummyPageManager, 0, new byte[pageSize]);
var hph = new HeadingPageHeader();
PageFormatter.InitPage(p, hph);
PageHeaderBase phb = PageFormatter.GetPageHeader(p);
Assert.IsInstanceOf <HeadingPageHeader>(phb);
Assert.AreEqual(hph.Length, phb.Length);
Assert.AreEqual(hph.PageType, phb.PageType);
Assert.AreEqual(hph.SizeRange, phb.SizeRange);
var fsiph = new FixedSizeItemsPageHeader();
PageFormatter.InitPage(p, fsiph);
phb = PageFormatter.GetPageHeader(p);
Assert.IsInstanceOf <FixedSizeItemsPageHeader>(phb);
Assert.AreEqual(fsiph.Length, phb.Length);
Assert.AreEqual(fsiph.PageType, phb.PageType);
Assert.AreEqual(fsiph.SizeRange, phb.SizeRange);
var mpph = new MultipageItemPageHeader();
PageFormatter.InitPage(p, mpph);
phb = PageFormatter.GetPageHeader(p);
Assert.IsInstanceOf <MultipageItemPageHeader>(phb);
Assert.AreEqual(mpph.Length, phb.Length);
Assert.AreEqual(mpph.PageType, phb.PageType);
Assert.AreEqual(mpph.SizeRange, phb.SizeRange);
Assert.AreEqual(mpph.StartPageIndex, ((MultipageItemPageHeader)phb).StartPageIndex);
Assert.AreEqual(mpph.PreviousPageIndex, ((MultipageItemPageHeader)phb).PreviousPageIndex);
Assert.AreEqual(mpph.NextPageIndex, ((MultipageItemPageHeader)phb).NextPageIndex);
var fsmph = new FreeSpaceMapPageHeader();
PageFormatter.InitPage(p, fsmph);
phb = PageFormatter.GetPageHeader(p);
Assert.IsInstanceOf <FreeSpaceMapPageHeader>(phb);
Assert.AreEqual(fsmph.Length, phb.Length);
Assert.AreEqual(fsmph.PageType, phb.PageType);
Assert.AreEqual(fsmph.SizeRange, phb.SizeRange);
Assert.AreEqual(fsmph.BasePageIndex, ((FreeSpaceMapPageHeader)phb).BasePageIndex);
var tnph = new BPlusTreeNodePageHeader();
PageFormatter.InitPage(p, tnph);
phb = PageFormatter.GetPageHeader(p);
Assert.IsInstanceOf <BPlusTreeNodePageHeader>(phb);
Assert.AreEqual(tnph.Length, phb.Length);
Assert.AreEqual(tnph.PageType, phb.PageType);
Assert.AreEqual(tnph.SizeRange, phb.SizeRange);
Assert.AreEqual(tnph.ParentPageIndex, ((BPlusTreeNodePageHeader)phb).ParentPageIndex);
Assert.AreEqual(tnph.PreviousPageIndex, ((BPlusTreeNodePageHeader)phb).PreviousPageIndex);
Assert.AreEqual(tnph.NextPageIndex, ((BPlusTreeNodePageHeader)phb).NextPageIndex);
var rtnph = new RadixTreeNodesPageHeader();
PageFormatter.InitPage(p, rtnph);
phb = PageFormatter.GetPageHeader(p);
Assert.IsInstanceOf <RadixTreeNodesPageHeader>(phb);
Assert.AreEqual(rtnph.Length, phb.Length);
Assert.AreEqual(rtnph.PageType, phb.PageType);
Assert.AreEqual(rtnph.SizeRange, phb.SizeRange);
Assert.AreEqual(rtnph.FreeSpace, ((RadixTreeNodesPageHeader)phb).FreeSpace);
}
