internal static ICollection<DbaseField> GetFields(DataTable schema, DbaseHeader header)
{
if (schema == null)
{
throw new ArgumentNullException("schema");
}
List<DbaseField> fields = new List<DbaseField>();
DataView schemaView = new DataView(schema, "", ProviderSchemaHelper.ColumnOrdinalColumn, DataViewRowState.CurrentRows);
int offset = 1;
foreach (DataRowView rowView in schemaView)
{
if (String.Compare(rowView[ProviderSchemaHelper.ColumnNameColumn] as string, OidColumnName,
StringComparison.InvariantCultureIgnoreCase) == 0)
{
continue;
}
string colName = rowView[ProviderSchemaHelper.ColumnNameColumn] as string;
Type dataType = (Type)rowView[ProviderSchemaHelper.DataTypeColumn];
Int16 length = Convert.ToInt16(rowView[ProviderSchemaHelper.ColumnSizeColumn]);
Byte decimals = Convert.ToByte(rowView[ProviderSchemaHelper.NumericPrecisionColumn]);
int ordinal = Convert.ToInt32(rowView[ProviderSchemaHelper.ColumnOrdinalColumn]);
DbaseField field = new DbaseField(header, colName, dataType, length, decimals, ordinal, offset);
fields.Add(field);
offset += field.Length;
}
return fields;
}
internal static ICollection <DbaseField> GetFields(DataTable schema, DbaseHeader header)
{
if (schema == null)
{
throw new ArgumentNullException("schema");
}
List <DbaseField> fields = new List <DbaseField>();
DataView schemaView = new DataView(schema, "", ProviderSchemaHelper.ColumnOrdinalColumn, DataViewRowState.CurrentRows);
Int32 offset = 1;
foreach (DataRowView rowView in schemaView)
{
if (String.Compare(rowView[ProviderSchemaHelper.ColumnNameColumn] as String, OidColumnName,
StringComparison.InvariantCultureIgnoreCase) == 0)
{
continue;
}
String colName = rowView[ProviderSchemaHelper.ColumnNameColumn] as String;
Type dataType = (Type)rowView[ProviderSchemaHelper.DataTypeColumn];
Int16 length = Convert.ToInt16(rowView[ProviderSchemaHelper.ColumnSizeColumn]);
Byte decimals = Convert.ToByte(rowView[ProviderSchemaHelper.NumericPrecisionColumn]);
Int32 ordinal = Convert.ToInt32(rowView[ProviderSchemaHelper.ColumnOrdinalColumn]);
DbaseField field = new DbaseField(header, colName, dataType, length, decimals, ordinal, offset);
fields.Add(field);
offset += field.Length;
}
return(fields);
}
internal DbaseField(DbaseHeader header, String name, Type type, Int16 length, Byte decimals, Int32 ordinal, Int32 offset)
{
_header = header;
_columnName = name;
_dataType = type;
_length = length;
_decimals = decimals;
_ordinal = ordinal;
_offset = offset;
}
private void moveToRow(UInt32 row)
{
DbaseHeader header = _dbaseFile.Header;
// Compute the position in the file stream for the requested row
Int64 offset = header.HeaderLength + ((row - 1) * header.RecordLength);
// Seek to the computed offset
_dbaseFile.DataStream.Seek(offset, SeekOrigin.Begin);
}
internal void UpdateHeader(DbaseHeader header)
{
_binaryWriter.Seek(1, SeekOrigin.Begin);
Byte[] dateBytes = new Byte[3]
{
(Byte)(header.LastUpdate.Year - DbaseConstants.DbaseEpoch),
(Byte)header.LastUpdate.Month,
(Byte)header.LastUpdate.Day
};
_binaryWriter.Write(dateBytes);
_binaryWriter.Write(header.RecordCount);
}
internal void WriteFullHeader(DbaseHeader header)
{
_binaryWriter.Seek(0, SeekOrigin.Begin);
_binaryWriter.Write(DbaseConstants.DbfVersionCode);
UpdateHeader(header);
_binaryWriter.Write(header.HeaderLength);
_binaryWriter.Write(header.RecordLength);
_binaryWriter.Write(new Byte[DbaseConstants.EncodingOffset - (Int32)_binaryWriter.BaseStream.Position]);
_binaryWriter.Write(header.LanguageDriver);
_binaryWriter.Write(new Byte[2]);
foreach (DbaseField field in header.Columns)
{
String colName = field.ColumnName + new String('\0', DbaseConstants.FieldNameLength);
Byte[] colNameBytes = Encoding.ASCII.GetBytes(colName.Substring(0, DbaseConstants.FieldNameLength));
_binaryWriter.Write(colNameBytes);
Char fieldTypeCode = DbaseSchema.GetFieldTypeCode(field.DataType);
_binaryWriter.Write(fieldTypeCode);
_binaryWriter.Write(0); // Address field isn't supported
if (fieldTypeCode == 'N' || fieldTypeCode == 'F')
{
_binaryWriter.Write((Byte)field.Length);
_binaryWriter.Write(field.Decimals);
}
else
{
_binaryWriter.Write((Byte)field.Length);
_binaryWriter.Write((Byte)(field.Length >> 8));
}
_binaryWriter.Write(new Byte[14]);
}
_binaryWriter.Write(DbaseConstants.HeaderTerminator);
}
private void parseHeader(Stream dbfStream)
{
_header = DbaseHeader.ParseDbfHeader(new NondisposingStream(dbfStream));
_baseTable = DbaseSchema.GetFeatureTableForFields(_header.Columns, _geoFactory);
_headerIsParsed = true;
}
internal void UpdateHeader(DbaseHeader header)
{
_binaryWriter.Seek(1, SeekOrigin.Begin);
Byte[] dateBytes = new Byte[3]
{
(Byte) (header.LastUpdate.Year - DbaseConstants.DbaseEpoch),
(Byte) header.LastUpdate.Month,
(Byte) header.LastUpdate.Day
};
_binaryWriter.Write(dateBytes);
_binaryWriter.Write(header.RecordCount);
}
internal void WriteFullHeader(DbaseHeader header)
{
_binaryWriter.Seek(0, SeekOrigin.Begin);
_binaryWriter.Write(DbaseConstants.DbfVersionCode);
UpdateHeader(header);
_binaryWriter.Write(header.HeaderLength);
_binaryWriter.Write(header.RecordLength);
_binaryWriter.Write(new Byte[DbaseConstants.EncodingOffset - (Int32)_binaryWriter.BaseStream.Position]);
_binaryWriter.Write(header.LanguageDriver);
_binaryWriter.Write(new Byte[2]);
foreach (DbaseField field in header.Columns)
{
String colName = field.ColumnName + new String('\0', DbaseConstants.FieldNameLength);
Byte[] colNameBytes = Encoding.ASCII.GetBytes(colName.Substring(0, DbaseConstants.FieldNameLength));
_binaryWriter.Write(colNameBytes);
Char fieldTypeCode = DbaseSchema.GetFieldTypeCode(field.DataType);
_binaryWriter.Write(fieldTypeCode);
_binaryWriter.Write(0); // Address field isn't supported
if (fieldTypeCode == 'N' || fieldTypeCode == 'F')
{
_binaryWriter.Write((Byte)field.Length);
_binaryWriter.Write(field.Decimals);
}
else
{
_binaryWriter.Write((Byte)field.Length);
_binaryWriter.Write((Byte)(field.Length >> 8));
}
_binaryWriter.Write(new Byte[14]);
}
_binaryWriter.Write(DbaseConstants.HeaderTerminator);
}
internal static DbaseHeader ParseDbfHeader(Stream dataStream)
{
DbaseHeader header;
using (BinaryReader reader = new BinaryReader(dataStream))
{
if (reader.ReadByte() != DbaseConstants.DbfVersionCode)
{
throw new NotSupportedException("Unsupported DBF Type");
}
DateTime lastUpdate = new DateTime(reader.ReadByte() + DbaseConstants.DbaseEpoch,
reader.ReadByte(), reader.ReadByte()); //Read the last update date
UInt32 recordCount = reader.ReadUInt32(); // read number of records.
Int16 storedHeaderLength = reader.ReadInt16(); // read length of header structure.
Int16 storedRecordLength = reader.ReadInt16(); // read length of a record
reader.BaseStream.Seek(DbaseConstants.EncodingOffset, SeekOrigin.Begin); //Seek to encoding flag
Byte languageDriver = reader.ReadByte(); //Read and parse Language driver
reader.BaseStream.Seek(DbaseConstants.ColumnDescriptionOffset, SeekOrigin.Begin); //Move past the reserved bytes
Int32 numberOfColumns = (storedHeaderLength - DbaseConstants.ColumnDescriptionOffset) /
DbaseConstants.ColumnDescriptionLength; // calculate the number of DataColumns in the header
header = new DbaseHeader(languageDriver, lastUpdate, recordCount);
DbaseField[] columns = new DbaseField[numberOfColumns];
Int32 offset = 1;
for (Int32 i = 0; i < columns.Length; i++)
{
String colName = header.FileEncoding.GetString(
reader.ReadBytes(11)).Replace("\0", "").Trim();
Char fieldtype = reader.ReadChar();
// Unused address data...
reader.ReadInt32();
Int16 fieldLength = reader.ReadByte();
Byte decimals = 0;
if (fieldtype == 'N' || fieldtype == 'F')
{
decimals = reader.ReadByte();
}
else
{
fieldLength += (Int16)(reader.ReadByte() << 8);
}
Type dataType = mapFieldTypeToClrType(fieldtype, decimals, fieldLength);
columns[i] = new DbaseField(header, colName, dataType, fieldLength, decimals, i, offset);
offset += fieldLength;
// Move stream to next field record
reader.BaseStream.Seek(DbaseConstants.BytesFromEndOfDecimalInFieldRecord, SeekOrigin.Current);
}
header.Columns = columns;
if (storedHeaderLength != header.HeaderLength)
{
throw new InvalidDbaseFileException(
"Recorded header length doesn't equal computed header length.");
}
if (storedRecordLength != header.RecordLength)
{
throw new InvalidDbaseFileException(
"Recorded record length doesn't equal computed record length.");
}
}
return(header);
}
/// <summary>
/// Opens the <see cref="DbaseFile"/> on the file name
/// specified in the constructor,
/// with a value determining if the file is locked for
/// exclusive read access or not.
/// </summary>
/// <exception cref="ObjectDisposedException">
/// Thrown when the method is called
/// and object has been disposed.
/// </exception>
internal void Open(bool exclusive)
{
checkState();
// TODO: implement asynchronous access
#if !CFBuild
_dbaseFileStream = new FileStream(_filename, FileMode.OpenOrCreate, FileAccess.ReadWrite,
exclusive ? FileShare.None : FileShare.Read, 4096, FileOptions.None);
#else
_dbaseFileStream = new FileStream(_filename, FileMode.OpenOrCreate, FileAccess.ReadWrite,
exclusive ? FileShare.None : FileShare.Read, 4096);
#endif
_isOpen = true;
if (!_headerIsParsed) //Don't read the header if it's already parsed
{
_header = DbaseHeader.ParseDbfHeader(new BufferingStream(DataStream));
_baseTable = DbaseSchema.GetFeatureTableForFields(_header.Columns);
_headerIsParsed = true;
}
_writer = new DbaseWriter(this);
_reader = new DbaseReader(this);
}
internal static DbaseHeader ParseDbfHeader(Stream dataStream)
{
DbaseHeader header;
using (BinaryReader reader = new BinaryReader(dataStream))
{
if (reader.ReadByte() != DbaseConstants.DbfVersionCode)
{
throw new NotSupportedException("Unsupported DBF Type");
}
DateTime lastUpdate = new DateTime(reader.ReadByte() + DbaseConstants.DbaseEpoch,
reader.ReadByte(), reader.ReadByte()); //Read the last update date
UInt32 recordCount = reader.ReadUInt32(); // read number of records.
Int16 storedHeaderLength = reader.ReadInt16(); // read length of header structure.
Int16 storedRecordLength = reader.ReadInt16(); // read length of a record
reader.BaseStream.Seek(DbaseConstants.EncodingOffset, SeekOrigin.Begin); //Seek to encoding flag
Byte languageDriver = reader.ReadByte(); //Read and parse Language driver
reader.BaseStream.Seek(DbaseConstants.ColumnDescriptionOffset, SeekOrigin.Begin); //Move past the reserved bytes
Int32 numberOfColumns = (storedHeaderLength - DbaseConstants.ColumnDescriptionOffset) /
DbaseConstants.ColumnDescriptionLength; // calculate the number of DataColumns in the header
header = new DbaseHeader(languageDriver, lastUpdate, recordCount);
DbaseField[] columns = new DbaseField[numberOfColumns];
Int32 offset = 1;
for (Int32 i = 0; i < columns.Length; i++)
{
String colName = header.FileEncoding.GetString(
reader.ReadBytes(11)).Replace("\0", "").Trim();
Char fieldtype = reader.ReadChar();
// Unused address data...
reader.ReadInt32();
Int16 fieldLength = reader.ReadByte();
Byte decimals = 0;
if (fieldtype == 'N' || fieldtype == 'F')
{
decimals = reader.ReadByte();
}
else
{
fieldLength += (Int16)(reader.ReadByte() << 8);
}
Type dataType = mapFieldTypeToClrType(fieldtype, decimals, fieldLength);
columns[i] = new DbaseField(header, colName, dataType, fieldLength, decimals, i, offset);
offset += fieldLength;
// Move stream to next field record
reader.BaseStream.Seek(DbaseConstants.BytesFromEndOfDecimalInFieldRecord, SeekOrigin.Current);
}
header.Columns = columns;
if (storedHeaderLength != header.HeaderLength)
{
throw new InvalidDbaseFileException(
"Recorded header length doesn't equal computed header length.");
}
if (storedRecordLength != header.RecordLength)
{
throw new InvalidDbaseFileException(
"Recorded record length doesn't equal computed record length.");
}
}
return header;
}
internal void WriteRow(DataRow row)
{
if (row == null)
{
throw new ArgumentNullException("row");
}
if (row.Table == null)
{
throw new ArgumentException("Row must be associated to a table.");
}
_binaryWriter.Write(DbaseConstants.NotDeletedIndicator);
DbaseHeader header = _dbaseFile.Header;
foreach (DbaseField column in header.Columns)
{
if (!row.Table.Columns.Contains(column.ColumnName) ||
String.Compare(column.ColumnName, DbaseSchema.OidColumnName,
StringComparison.CurrentCultureIgnoreCase) == 0)
{
continue;
}
// TODO: reconsider type checking
//if ((header.Columns[rowColumnIndex].DataType != row.Table.Columns[rowColumnIndex].DataType) || (header.Columns[rowColumnIndex].Length != row.Table.Columns[rowColumnIndex].MaxLength))
// throw new SchemaMismatchException(String.Format("Row doesn't match this DbaseWriter schema at column {0}", i));
switch (Type.GetTypeCode(column.DataType))
{
case TypeCode.Boolean:
if (row[column.ColumnName] == null || row[column.ColumnName] == DBNull.Value)
{
_binaryWriter.Write(DbaseConstants.BooleanNullChar);
}
else
{
writeBoolean((Boolean)row[column.ColumnName]);
}
break;
case TypeCode.DateTime:
if (row[column.ColumnName] == null || row[column.ColumnName] == DBNull.Value)
{
writeNullDateTime();
}
else
{
writeDateTime((DateTime)row[column.ColumnName]);
}
break;
case TypeCode.Single:
case TypeCode.Double:
if (row[column.ColumnName] == null || row[column.ColumnName] == DBNull.Value)
{
writeNullNumber(column.Length);
}
else
{
writeNumber(Convert.ToDouble(row[column.ColumnName]),
column.Length, column.Decimals);
}
break;
case TypeCode.Int16:
case TypeCode.Int32:
case TypeCode.Int64:
if (row[column.ColumnName] == null || row[column.ColumnName] == DBNull.Value)
{
writeNullNumber(column.Length);
}
else
{
writeNumber(Convert.ToInt64(row[column.ColumnName]), column.Length);
}
break;
case TypeCode.String:
if (row[column.ColumnName] == null || row[column.ColumnName] == DBNull.Value)
{
writeNullString(column.Length);
}
else
{
object value = row[column.ColumnName]; //jd: can be a Guid
if (value is string && String.IsNullOrEmpty((string)value))
{
writeNullString(column.Length);
}
else
{
writeString(value is string?(string)value: value.ToString(), column.Length);
}
}
break;
case TypeCode.Char:
case TypeCode.SByte:
case TypeCode.Byte:
case TypeCode.Decimal:
case TypeCode.UInt16:
case TypeCode.UInt32:
case TypeCode.UInt64:
case TypeCode.DBNull:
case TypeCode.Empty:
case TypeCode.Object:
default:
throw new NotSupportedException(String.Format(
"Type not supported: {0}", column.DataType));
}
}
}
private void parseHeader(Stream dbfStream)
{
_header = DbaseHeader.ParseDbfHeader(new NondisposingStream(dbfStream));
_baseTable = DbaseSchema.GetFeatureTableForFields(_header.Columns, _geoFactory);
_headerIsParsed = true;
}
