public async Task <bool> Exists(ColumnCreateDefinition def, ITransaction tran)
{
await foreach (RowHolder rh in pageListCollection.Iterate(tran))
{
int tableId = rh.GetField <int>(MetadataColumn.TableIdColumnPos);
if (tableId == def.TableId)
{
PagePointerOffsetPair stringPointer = rh.GetField <PagePointerOffsetPair>(MetadataColumn.ColumnNameColumnPos);
if (def.ColumnName == new string(await stringHeap.Fetch(stringPointer, tran)))
{
return(true);
}
}
}
return(false);
}
public async Task <int> CreateObject(ColumnCreateDefinition def, ITransaction tran)
{
if (await this.Exists(def, tran))
{
throw new ElementWithSameNameExistsException();
}
RowHolder rh = new RowHolder(columnDefinitions);
PagePointerOffsetPair namePointer = await this.stringHeap.Add(def.ColumnName.ToCharArray(), tran);
rh.SetField <int>(0, def.ColumnId);
rh.SetField <int>(1, def.TableId);
rh.SetField <PagePointerOffsetPair>(2, namePointer);
rh.SetField <int>(3, (int)def.ColumnType.ColumnType);
rh.SetField <int>(4, def.ColumnType.RepCount);
await pageListCollection.Add(rh, tran);
return(def.ColumnId);
}
public async Task <int> CreateObject(TableCreateDefinition def, ITransaction tran)
{
if (await this.Exists(def, tran))
{
throw new ElementWithSameNameExistsException();
}
if (def.ColumnNames.Length != def.ColumnTypes.Length)
{
throw new ArgumentException();
}
int id = 1;
if (!(await pageListCollection.IsEmpty(tran)))
{
int maxId = await pageListCollection.Max <int>(rh => rh.GetField <int>(0), startMin : 0, tran);
id = maxId + 1;
}
MixedPage rootPage = await this.pageAllocator.AllocateMixedPage(def.ColumnTypes, PageManagerConstants.NullPageId, PageManagerConstants.NullPageId, tran);
RowHolder rh = new RowHolder(columnDefinitions);
PagePointerOffsetPair namePointer = await this.stringHeap.Add(def.TableName.ToCharArray(), tran);
rh.SetField <int>(0, id);
rh.SetField <PagePointerOffsetPair>(1, namePointer);
rh.SetField <long>(2, (long)rootPage.PageId());
await pageListCollection.Add(rh, tran);
for (int i = 0; i < def.ColumnNames.Length; i++)
{
ColumnCreateDefinition ccd = new ColumnCreateDefinition(id, def.ColumnNames[i], def.ColumnTypes[i], i);
await columnManager.CreateObject(ccd, tran);
}
return(id);
}
