private object[] ReadRowFromBufferMemo(ReadOnlySpan <byte> rowBuf, int index, Stream memofs, short memoBlocksize)
{
var rowData = new object[dbfHeader.Fields.Count];
INullFieldHandler nullFieldHandler = null;
if (nullField != null)
{
rowData[nullField.Index] = nullFieldDataHandler(index, rowBuf.Slice(nullField.Displacement, nullField.Length), nullField, null);
nullFieldHandler = (INullFieldHandler)nullFieldHandlerFactory(index, rowBuf.Slice(nullField.Displacement, nullField.Length), nullField, null);
}
Span <byte> intBuf = stackalloc byte[4];
for (var i = 0; i < rowData.Length; i++)
{
var field = dbfHeader.Fields[i];
if (field == nullField)
{
continue;
}
var hasHandler = DbfTypeMap.TryGetValue(field.Type, out var handler);
if (!hasHandler)
{
continue;
}
var hasNullFlag = false;
if (nullFieldHandler != null && field.CanBeNull)
{
hasNullFlag = nullFieldHandler.IsNull(field.NullFieldIndex);
}
if (field.Type == 'M')
{
if (hasNullFlag)
{
continue;
}
var offset = (int)handler(index, rowBuf.Slice(field.Displacement, field.Length), field, TextEncoding);
if (offset == 0)
{
rowData[i] = "";
continue;
}
var targetPos = 4 + offset * memoBlocksize;
var memoPos = memofs.Position;
if (memoPos < targetPos)
{
memofs.Seek(targetPos - memoPos, SeekOrigin.Current);
}
else
{
memofs.Position = targetPos;
}
var len = memofs.ReadIntBE(intBuf);
if ((field.Flags & DbfFieldFlags.Binary) != 0)
{
var memoBuf = new byte[len];
memofs.Read(memoBuf, 0, len);
rowData[i] = memoBuf;
}
else
{
var memoBuf = bufferPool.Rent(len);
memofs.Read(memoBuf, 0, len);
try
{
rowData[i] = TextEncoding.GetString(memoBuf, 0, len);
}
finally
{
bufferPool.Return(memoBuf);
}
}
}
else if (field.Type == 'V' || field.Type == 'Q')
{
if (hasNullFlag)
{
rowData[i] = null;
}
else if (nullFieldHandler.IsNull(field.VarLengthSizeIndex))
{
var valueLength = rowBuf[field.Displacement + field.Length - 1];
rowData[i] = handler(index, rowBuf.Slice(field.Displacement, valueLength), field, TextEncoding);
}
else
{
rowData[i] = handler(index, rowBuf.Slice(field.Displacement, field.Length), field, TextEncoding);
}
}
else
{
if (hasNullFlag)
{
continue;
}
rowData[i] = handler(index, rowBuf.Slice(field.Displacement, field.Length), field, TextEncoding);
}
}
return(rowData);
}
private object[] ReadRowFromBuffer(ReadOnlySpan <byte> rowBuf, int index)
{
var rowData = new object[dbfHeader.Fields.Count];
INullFieldHandler nullFieldHandler = null;
if (nullField != null)
{
rowData[nullField.Index] = nullFieldDataHandler(index, rowBuf.Slice(nullField.Displacement, nullField.Length), nullField, null);
nullFieldHandler = (INullFieldHandler)nullFieldHandlerFactory(index, rowBuf.Slice(nullField.Displacement, nullField.Length), nullField, null);
}
for (var i = 0; i < rowData.Length; i++)
{
var field = dbfHeader.Fields[i];
if (field == nullField)
{
continue;
}
var hasHandler = DbfTypeMap.TryGetValue(field.Type, out var handler);
if (!hasHandler)
{
continue;
}
var hasNullFlag = false;
if (nullFieldHandler != null && field.CanBeNull)
{
hasNullFlag = nullFieldHandler.IsNull(field.NullFieldIndex);
}
if (field.Type == 'M' || field.Type == 'W' || field.Type == 'G')
{
if (hasNullFlag)
{
continue;
}
var memoPointer = handler(index, rowBuf.Slice(field.Displacement, field.Length), field, TextEncoding);
rowData[i] = $"MEMO@{memoPointer}";
}
else if (field.Type == 'V' || field.Type == 'Q')
{
if (hasNullFlag)
{
rowData[i] = null;
}
else if (nullFieldHandler.IsNull(field.VarLengthSizeIndex))
{
var valueLength = rowBuf[field.Displacement + field.Length - 1];
rowData[i] = handler(index, rowBuf.Slice(field.Displacement, valueLength), field, TextEncoding);
}
else
{
rowData[i] = handler(index, rowBuf.Slice(field.Displacement, field.Length), field, TextEncoding);
}
}
else
{
if (hasNullFlag)
{
continue;
}
rowData[i] = handler(index, rowBuf.Slice(field.Displacement, field.Length), field, TextEncoding);
}
}
return(rowData);
}
