public void FreeSlot_Insert()
{
using (var e = new LiteEngine())
{
e.BeginTrans();
// get transaction/snapshot "col1"
var t = e.GetTransaction(false, out var isNew);
var s = t.CreateSnapshot(LockMode.Write, "col1", true);
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["n"] = new byte[200]
} }, BsonAutoId.Int32);
// get pages
var colPage = s.CollectionPage;
var dataPage = s.LocalPages.FirstOrDefault(x => x.PageType == PageType.Data);
var indexPage = s.LocalPages.FirstOrDefault(x => x.PageType == PageType.Index);
// test dataPage free space
Assert.AreEqual(7928, dataPage.FreeBytes);
// page sloud be in Slot #0 (7344 - 8160 free bytes)
CollectionAssert.AreEqual(new uint[] { dataPage.PageID, uint.MaxValue, uint.MaxValue, uint.MaxValue, uint.MaxValue },
colPage.FreeDataPageID);
// adding 1 more document into same page
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["n"] = new byte[600]
} }, BsonAutoId.Int32);
Assert.AreEqual(7296, dataPage.FreeBytes);
// page should me moved into Slot #1 (6120 - 7343 free bytes)
CollectionAssert.AreEqual(new uint[] { uint.MaxValue, dataPage.PageID, uint.MaxValue, uint.MaxValue, uint.MaxValue },
colPage.FreeDataPageID);
// adding 1 big document to move this page into last page
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["n"] = new byte[6000]
} }, BsonAutoId.Int32);
Assert.AreEqual(1264, dataPage.FreeBytes);
// now this page should me moved into last Slot (#4) - next document will use another data page (even a very small document)
CollectionAssert.AreEqual(new uint[] { uint.MaxValue, uint.MaxValue, uint.MaxValue, uint.MaxValue, dataPage.PageID },
colPage.FreeDataPageID);
// adding a very small document to test adding new page
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["n"] = new byte[10]
} }, BsonAutoId.Int32);
// no changes in dataPage... but new page as created
Assert.AreEqual(1264, dataPage.FreeBytes);
var dataPage2 = s.LocalPages.FirstOrDefault(x => x.PageType == PageType.Data && x.PageID != dataPage.PageID);
Assert.AreEqual(8118, dataPage2.FreeBytes);
// test slots (#0 for dataPage2 and #4 for dataPage1)
CollectionAssert.AreEqual(new uint[] { dataPage2.PageID, uint.MaxValue, uint.MaxValue, uint.MaxValue, dataPage.PageID },
colPage.FreeDataPageID);
// add another big document into dataPage2 do put both pages in same free Slot (#4)
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["n"] = new byte[7000]
} }, BsonAutoId.Int32);
// now, both pages are linked in same slot #4 (starts with new dataPage2)
CollectionAssert.AreEqual(new uint[] { uint.MaxValue, uint.MaxValue, uint.MaxValue, uint.MaxValue, dataPage2.PageID },
colPage.FreeDataPageID);
// dataPage2 link into dataPage1
Assert.AreEqual(dataPage.PageID, dataPage2.NextPageID);
Assert.AreEqual(dataPage2.PageID, dataPage.PrevPageID);
// and both start/end points to null
Assert.AreEqual(uint.MaxValue, dataPage2.PrevPageID);
Assert.AreEqual(uint.MaxValue, dataPage.NextPageID);
// do ColID tests
Assert.AreEqual(colPage.PageID, dataPage.ColID);
Assert.AreEqual(colPage.PageID, dataPage2.ColID);
Assert.AreEqual(colPage.PageID, indexPage.ColID);
}
}
public void FreeSlot_Delete()
{
using (var e = new LiteEngine())
{
e.BeginTrans();
// get transaction/snapshot "col1"
var t = e.GetTransaction(false, out var isNew);
var s = t.CreateSnapshot(LockMode.Write, "col1", true);
// first page
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["_id"] = 1, ["n"] = new byte[2000]
} }, BsonAutoId.Int32);
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["_id"] = 2, ["n"] = new byte[2000]
} }, BsonAutoId.Int32);
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["_id"] = 3, ["n"] = new byte[2000]
} }, BsonAutoId.Int32);
// second page
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["_id"] = 4, ["n"] = new byte[2000]
} }, BsonAutoId.Int32);
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["_id"] = 5, ["n"] = new byte[2000]
} }, BsonAutoId.Int32);
e.Insert("col1", new BsonDocument[] { new BsonDocument {
["_id"] = 6, ["n"] = new byte[2000]
} }, BsonAutoId.Int32);
// get pages
var colPage = s.CollectionPage;
var indexPage = s.LocalPages.FirstOrDefault(x => x.PageType == PageType.Index);
var dataPage1 = s.LocalPages.FirstOrDefault(x => x.PageType == PageType.Data);
var dataPage2 = s.LocalPages.FirstOrDefault(x => x.PageType == PageType.Data && x.PageID != dataPage1.PageID);
// test dataPage free space
Assert.AreEqual(2064, dataPage1.FreeBytes);
Assert.AreEqual(2064, dataPage2.FreeBytes);
CollectionAssert.AreEqual(new uint[] { uint.MaxValue, uint.MaxValue, uint.MaxValue, uint.MaxValue, dataPage2.PageID },
colPage.FreeDataPageID);
// delete some data
e.Delete("col1", new BsonValue[] { 2 });
// test again dataPage
Assert.AreEqual(4092, dataPage1.FreeBytes);
CollectionAssert.AreEqual(new uint[] { uint.MaxValue, uint.MaxValue, uint.MaxValue, dataPage1.PageID, dataPage2.PageID },
colPage.FreeDataPageID);
// clear first page
e.Delete("col1", new BsonValue[] { 1, 3 });
// page1 must be now a clean page
var emptyPage = s.LocalPages.FirstOrDefault(x => x.PageID == dataPage1.PageID);
Assert.AreEqual(PageType.Empty, emptyPage.PageType);
Assert.AreEqual(0, emptyPage.ItemsCount);
Assert.AreEqual(8160, emptyPage.FreeBytes);
Assert.AreEqual(1, t.Pages.DeletedPages);
Assert.AreEqual(emptyPage.PageID, t.Pages.FirstDeletedPageID);
Assert.AreEqual(emptyPage.PageID, t.Pages.LastDeletedPageID);
}
}
