private byte[] GetLargeItemSegment(PageHeaderBase header, IPage page, long startIndex, long endIndex)
{
if (PageFormatter.ReadMultipageItemLength(page) <= endIndex)
{
throw new ArgumentOutOfRangeException(nameof(endIndex));
}
var length = endIndex - startIndex + 1;
var result = new byte[length];
long sourceOffset = 0;
long destOffset = 0;
// navigate through large item
while (true)
{
var readBytes = PageFormatter.ReadMultipageItemBlock(page, Math.Min(_pageManager.PageSize, (int)(endIndex + 1 - sourceOffset)));
sourceOffset += readBytes.Length;
if (sourceOffset > startIndex)
{
var ssi = sourceOffset - startIndex - 1 < readBytes.Length
? startIndex + readBytes.Length - sourceOffset
: 0;
var l = readBytes.Length - Math.Max(0, sourceOffset - endIndex - 1) - ssi;
Array.Copy(readBytes, ssi, result, destOffset, l);
destOffset += l;
if (sourceOffset >= endIndex)
{
return(result);
}
}
var nextPageIndex = ((MultipageItemPageHeader)header).NextPageIndex;
if (nextPageIndex != -1)
{
page = _pageManager.FetchPage(nextPageIndex);
header = PageFormatter.GetPageHeader(page);
}
}
}
private byte[] GetFixedSizeItemSegment(PageHeaderBase header, IPage page, DbItemReference reference, long startIndex, long endIndex)
{
if (!PageFormatter.IsFixedSizeItemAllocated(page, reference.ItemIndex))
{
return new byte[] { }
}
;
var item = PageFormatter.ReadFixedSizeItem(page, reference.ItemIndex);
if (item.RawData.Length >= endIndex)
{
throw new ArgumentOutOfRangeException(nameof(endIndex));
}
var length = endIndex - startIndex + 1;
var result = new byte[length];
Array.Copy(item.RawData, startIndex, result, 0, length);
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);
}
