public PageManager(uint defaultPageSize, IPersistedStream persistedStream, IBufferPool bufferPool, ILockManager lockManager, InstrumentationInterface logger)
{
this.pageSize = defaultPageSize;
this.persistedStream = persistedStream;
this.lockManager = lockManager;
this.logger = logger;
this.bufferPool = bufferPool;
this.AllocatationMapPages = new List <BitTrackingPage>();
if (!this.persistedStream.IsInitialized())
{
logger.LogInfo("Initializing the persisted stream.");
using (ITransaction tran = new NotLoggedTransaction())
{
MixedPage allocationMapFirstPage = new MixedPage(pageSize, (ulong)AllocationMapPageId, new [] { new ColumnInfo(ColumnType.Int) }, PageManagerConstants.NullPageId, PageManagerConstants.NullPageId, new byte[4096], 0, tran);
BitTrackingPage.NullifyMixedPage(allocationMapFirstPage, tran);
this.AllocatationMapPages.Add(new BitTrackingPage(allocationMapFirstPage));
this.persistedStream.MarkInitialized();
}
}
else
{
// TODO: Read boot page.
logger.LogInfo("Using already initialized stream.");
ulong position = AllocationMapPageId * this.pageSize;
MixedPage allocationMapFirstPage = (MixedPage)this.persistedStream.SeekAndRead(position, PageType.MixedPage, this.bufferPool, new ColumnInfo[] { new ColumnInfo(ColumnType.Int) }).Result;
this.AllocatationMapPages.Add(new BitTrackingPage(allocationMapFirstPage));
using (ITransaction tran = new NotLoggedTransaction())
{
// TODO: Here we only iterate the first page.
// These pages need to be linked...
foreach (int _ in this.AllocatationMapPages.First().FindAllSet(tran))
{
this.pageCount++;
}
}
}
}
private void AddToAllocationMap(IPage page)
{
// TODO: This needs to be revisited.
// It is not ok to use Not logged transaction here.
// it might be ok to use nested/inner transaction.
// it is fine to leave the page even if user transaction is rolledbacked.
BitTrackingPage AMPage = this.AllocatationMapPages.Last();
int maxFit = AMPage.MaxItemCount();
uint allocationMapPage = (uint)(page.PageId() / (uint)maxFit);
if (allocationMapPage == this.AllocatationMapPages.Count)
{
using (ITransaction gamAllocTran = new NotLoggedTransaction())
{
// TODO: Need to keep the list linked here.
(Memory <byte> memory, ulong token) = this.bufferPool.GetMemory();
MixedPage newAmPage = new MixedPage(
pageSize,
(ulong)AllocationMapPageId + (ulong)(maxFit * this.AllocatationMapPages.Count),
new ColumnInfo[] { new ColumnInfo(ColumnType.Int) },
PageManagerConstants.NullPageId,
PageManagerConstants.NullPageId,
memory,
token,
gamAllocTran);
BitTrackingPage.NullifyMixedPage(newAmPage, gamAllocTran);
this.AllocatationMapPages.Add(new BitTrackingPage(newAmPage));
}
}
using (ITransaction gamUpdateTran = new NotLoggedTransaction())
{
BitTrackingPage gamPage = this.AllocatationMapPages.ElementAt((int)allocationMapPage);
int positionInPage = (int)(page.PageId() % (uint)maxFit);
gamPage.Set(positionInPage, gamUpdateTran);
}
}