public async Task Add(RowHolder item, ITransaction tran)
{
MixedPage currPage = null;
for (ulong currPageId = this.lastPageId; currPageId != PageManagerConstants.NullPageId; currPageId = currPage.NextPageId())
{
using Releaser lck = await tran.AcquireLock(currPageId, LockManager.LockTypeEnum.Shared).ConfigureAwait(false);
currPage = await pageAllocator.GetMixedPage(currPageId, tran, this.columnTypes).ConfigureAwait(false);
if (currPage.CanFit(item, tran))
{
lck.Dispose();
using Releaser writeLock = await tran.AcquireLock(currPageId, LockManager.LockTypeEnum.Exclusive).ConfigureAwait(false);
// Need to check can fit one more time.
if (currPage.CanFit(item, tran))
{
currPage.Insert(item, tran);
return;
}
}
}
{
using Releaser prevPageLck = await tran.AcquireLock(currPage.PageId(), LockManager.LockTypeEnum.Exclusive).ConfigureAwait(false);
if (currPage.NextPageId() != PageManagerConstants.NullPageId)
{
// TODO: it would be good if caller had ability to control this lock.
// This dispose doesn't mean anything in current implementation of read committed.
prevPageLck.Dispose();
await Add(item, tran).ConfigureAwait(false);
}
else
{
currPage = await this.pageAllocator.AllocateMixedPage(this.columnTypes, currPage.PageId(), PageManagerConstants.NullPageId, tran).ConfigureAwait(false);
using Releaser currPageLck = await tran.AcquireLock(currPage.PageId(), LockManager.LockTypeEnum.Exclusive).ConfigureAwait(false);
this.lastPageId = currPage.PageId();
currPage.Insert(item, tran);
}
}
}
public static void NullifyMixedPage(MixedPage page, ITransaction tran)
{
for (int i = 0; i < page.MaxRowCount(); i++)
{
RowHolder rhf = new RowHolder(new ColumnType[] { ColumnType.Int });
rhf.SetField <int>(0, 0);
page.Insert(rhf, tran);
}
}