public void Write(T model)
{
var fieldList = FixedLengthFieldHelper.GetFixedLengthFieldList <T>(true);
foreach (var field in fieldList)
{
var value = field.GetValue(model);
if (value == null)
{
throw new InvalidDataException($"The value of {field.TypeString} '{field.Name}' cannot be null.");
}
var length = FixedLengthFieldHelper.GetFieldLength(field);
var buffer = FixedLengthFieldHelper.ValueToBytes(value, field);
if (length < buffer.Length)
{
throw new InvalidDataException($"The value size of {field.TypeString} '{field.Name}' exceeds " +
$"the specific {field.TypeString} length: {length}.");
}
_fileStream.Write(buffer, 0, buffer.Length);
if (length > buffer.Length)
{
Debug.WriteLine($"The value size of {field.TypeString} '{field.Name}' is smaller than " +
$"the specific {field.TypeString} length {length}. Written bytes will be padded.");
// pad with '\0'
buffer = new byte[length - buffer.Length];
_fileStream.Write(buffer, 0, buffer.Length);
}
}
}
public T Read()
{
bool isValueType = typeof(T).IsValueType;
var rawModel = new T();
object model = rawModel;
var fieldList = FixedLengthFieldHelper.GetFixedLengthFieldList <T>();
if (isValueType)
{
model = rawModel as ValueType;
}
var basePos = _fileStream.Position;
var lastPos = _fileStream.Position;
foreach (var field in fieldList)
{
var offset = field.Offset;
if (offset == -1)
{
if (_fileStream.Position != lastPos)
{
_fileStream.Seek(lastPos, SeekOrigin.Begin);
}
}
else
{
_fileStream.Seek(basePos + offset, SeekOrigin.Begin);
}
var length = FixedLengthFieldHelper.GetFieldLength(field);
if (_buffer.Length < length)
{
_buffer = new byte[length];
}
_fileStream.Read(_buffer, 0, length);
if (offset == -1)
{
lastPos = _fileStream.Position;
}
var val = FixedLengthFieldHelper.BytesToValue(_buffer, field);
if (val == null)
{
throw new InvalidDataException($"The value of {field.TypeString} '{field.Name}' cannot be null.");
}
field.SetValue(model, val);
}
_fileStream.Seek(lastPos, SeekOrigin.Begin);
if (isValueType)
{
rawModel = (T)model;
}
return(rawModel);
}
