private static void LoadColumnOffsetArray(IndexRecord record, int varColStartIndex)
{
var varColCountOffset = record.SlotOffset + record.Page.Header.MinLen + varColStartIndex;
record.VariableLengthColumnCount = BitConverter.ToUInt16(record.Page.PageData, varColCountOffset);
record.Mark("VariableLengthColumnCount", varColCountOffset, sizeof(short));
// Load offset array of 2-byte ints indicating the end offset of each variable length field
record.ColOffsetArray = GetOffsetArray(record.Page.PageData,
record.VariableLengthColumnCount,
record.SlotOffset + record.Page.Header.MinLen + sizeof(short) + varColStartIndex);
record.Mark("ColOffsetArrayDescription", varColCountOffset + sizeof(short), record.VariableLengthColumnCount * sizeof(short));
}
private static void LoadDownPagePointer(IndexRecord record)
{
//Last 6 bytes of the fixed slot
var address = new byte[PageAddress.Size];
var downPagePointerOffset = record.SlotOffset + record.Page.Header.MinLen - PageAddress.Size;
Array.Copy(record.Page.PageData, downPagePointerOffset, address, 0, PageAddress.Size);
record.DownPagePointer = new PageAddress(address);
record.Mark("DownPagePointer", downPagePointerOffset, PageAddress.Size);
}
private static void LoadStatusBits(IndexRecord record)
{
var statusA = record.Page.PageData[record.SlotOffset];
record.StatusBitsA = new BitArray(new byte[] { statusA });
record.Mark("StatusBitsADescription", record.SlotOffset, 1);
record.RecordType = (RecordType)((statusA >> 1) & 7);
record.HasNullBitmap = record.StatusBitsA[4];
record.HasVariableLengthColumns = record.StatusBitsA[5];
}
private static void LoadNullBitmap(IndexRecord record)
{
record.NullBitmapSize = (short)((record.Structure.Columns.Count - 1) / 8 + 1);
var columnCountPosition = record.SlotOffset + record.Page.Header.MinLen;
record.ColumnCount = BitConverter.ToInt16(record.Page.PageData, columnCountPosition);
record.Mark("ColumnCount", columnCountPosition, sizeof(short));
var nullBitmapBytes = new byte[record.NullBitmapSize];
var nullBitmapPosition = record.SlotOffset + record.Page.Header.MinLen + sizeof(short);
Array.Copy(record.Page.PageData,
nullBitmapPosition,
nullBitmapBytes,
0,
record.NullBitmapSize);
record.NullBitmap = new BitArray(nullBitmapBytes);
record.Mark("NullBitmapDescription", nullBitmapPosition, record.NullBitmapSize);
}
private static void LoadRid(IndexRecord record)
{
int ridOffset;
var ridAddress = new byte[8];
if (record.IsIndexType(IndexTypes.Leaf))
{
ridOffset = record.SlotOffset + record.Page.Header.MinLen - 8;
}
else
{
ridOffset = record.SlotOffset + record.Page.Header.MinLen - 14;
}
Array.Copy(record.Page.PageData, ridOffset, ridAddress, 0, RowIdentifier.Size);
record.Rid = new RowIdentifier(ridAddress);
record.Mark("Rid", ridOffset, RowIdentifier.Size);
}
private static void LoadColumnValues(IndexRecord record)
{
RecordField field;
var columnValues = new List <RecordField>();
var index = 0;
foreach (IndexColumn indexCol in (record.Structure as IndexStructure).Columns)
{
var processKeyColumn = !indexCol.Key || (record.IncludeKey && indexCol.Key);
var processIncludesColumn = !indexCol.IncludedColumn || (indexCol.IncludedColumn && record.IsIndexType(IndexTypes.Leaf));
if (processKeyColumn & processIncludesColumn)
{
field = new RecordField(indexCol);
var length = 0;
var offset = 0;
byte[] data = null;
var variableIndex = 0;
if (indexCol.LeafOffset >= 0)
{
// Fixed length field
offset = indexCol.LeafOffset;
length = indexCol.DataLength;
data = new byte[length];
Array.Copy(record.Page.PageData, indexCol.LeafOffset + record.SlotOffset, data, 0, length);
}
else if (record.HasVariableLengthColumns)
{
//Variable length field
variableIndex = (indexCol.LeafOffset * -1) - 1;
if (variableIndex == 0)
{
offset = record.VariableLengthDataOffset;
}
else
{
offset = record.ColOffsetArray[variableIndex - 1];
}
if (variableIndex >= record.ColOffsetArray.Length)
{
length = 0;
}
else
{
length = record.ColOffsetArray[variableIndex] - offset;
}
data = new byte[length];
Array.Copy(record.Page.PageData, offset + record.SlotOffset, data, 0, length);
}
field.Offset = offset;
field.Length = length;
field.Data = data;
field.VariableOffset = variableIndex;
field.Mark("Value", record.SlotOffset + field.Offset, field.Length);
record.Mark("FieldsArray", field.Name, index);
index++;
columnValues.Add(field);
}
}
record.Fields.AddRange(columnValues);
}
