void EmitColumnCode(ColumnDefinition cd)
{
// Ldarg_0 : DbfTableDefinitions
// Ldarg_1 : Byte[]
// Ldarg_2 : DbfRecord
if (cd.mColumnType == ColumnType.DELAYED) return;
string readMethodName;
string writeMethodName;
string dbfType = cd.mColumnType.ToString();
string nativeType;
Type fieldType = cd.mFieldInfo.FieldType;
nativeType = fieldType.Name;
if (fieldType.IsGenericType)
{
if (fieldType.GetGenericTypeDefinition() == typeof(Nullable<>))
{
nativeType = "Nullable" + fieldType.GetGenericArguments()[0].Name;
}
}
else if (fieldType.IsArray)
{
nativeType = fieldType.GetElementType().Name + "Array";
}
else if (fieldType.IsEnum)
{
nativeType = Type.GetTypeCode(fieldType).ToString();
}
readMethodName = "Read_" + dbfType
+ "_" + nativeType;
writeMethodName = "Write_" + nativeType
+ "_" + dbfType;
var writeXXX = this.GetType().GetMethod(
writeMethodName,
BindingFlags.NonPublic | BindingFlags.Static);
if (writeXXX == null)
{
throw new Exception(string.Format("Unknown Method : {0}.", writeMethodName));
}
//void WriteXXX(
mIlWrite.Emit(OpCodes.Ldarg_1); // << 1:Byte[] bytes
mIlWrite.Emit(OpCodes.Ldarg_0); // << 2:dbfTable
mIlWrite.Emit(OpCodes.Ldc_I4, cd.ColumnIndex); // << 3: ColumIndex
mIlWrite.Emit(OpCodes.Ldc_I4, cd.mOffset); // << 4:Offset // for speed
mIlWrite.Emit(OpCodes.Ldc_I4, cd.mWidth); // << 5:Length // for speed
mIlWrite.Emit(OpCodes.Ldarg_2); // < Record
mIlWrite.Emit(OpCodes.Ldfld, cd.mFieldInfo); // >< 5:DateTime/... value
mIlWrite.Emit(OpCodes.Call, writeXXX);
var readXXX = this.GetType().GetMethod(
readMethodName,
BindingFlags.NonPublic | BindingFlags.Static);
if (readXXX == null)
{
throw new Exception(string.Format("Unknown Method : {0}.", readMethodName));
}
//void ReadXXX(
mIlRead.Emit(OpCodes.Ldarg_2); // < Record
mIlRead.Emit(OpCodes.Ldarg_0); // << 2:dbfTable
mIlRead.Emit(OpCodes.Ldarg_1); // << 0:Byte[]
mIlRead.Emit(OpCodes.Ldc_I4, cd.mOffset); // << 1:Offset // for speed
mIlRead.Emit(OpCodes.Ldc_I4, cd.mWidth); // << 2:Length // for speed
mIlRead.Emit(OpCodes.Call, readXXX);
mIlRead.Emit(OpCodes.Stfld, cd.mFieldInfo); // >< 5:DateTime/... value
}
// called when created for indexes
public void Initialize(string columnName, ColumnDefinition originalColumn, bool ascending, int width)
{
this.mColumnName = columnName;
this.mOriginalColumn = originalColumn;
this.mFieldInfo = originalColumn.mFieldInfo;
mColumnType = originalColumn.mColumnType;
mWidth = (width > 0 ? width : mOriginalColumn.mWidth);
mAscending = ascending;
CheckWidthAndDecimals();
}
private void AddColumn(FieldInfo fieldInfo, RecordAttribute recordAttribute)
{
// not sure whether it is more convenient for the user to inherit or not
var atts = fieldInfo.GetCustomAttributes(typeof(ColumnAttribute), true);
ColumnAttribute column = null;
if (atts.Length == 0)
{
var fm = recordAttribute.FieldMapping;
if (fieldInfo.IsPublic)
{
if ((fm & FieldMapping.PublicFields) == 0) return;
}
else
{
if ((fm & FieldMapping.PrivateFields) == 0) return;
}
}
else column = (ColumnAttribute)atts[0];
ColumnDefinition cd = null;
if (mCreateColumns)
{
cd = new ColumnDefinition();
cd.Initialize(mVersion, fieldInfo, column);
mColumns.Add(cd);
}
else if (column != null && column.Type == ColumnType.DELETED_FLAG)
{
cd = new ColumnDefinition();
cd.Initialize(mVersion, fieldInfo, column);
mColumns.Insert(0, cd);
}
else
{
bool found = false;
for (int i = 0; i < mColumns.Count; i++)
{
cd = mColumns[i];
if (fieldInfo.Name == cd.mColumnName)
{
cd.mFieldInfo = fieldInfo;
found = true;
break;
}
}
if (found == false && mIgnoreMissingFields == false)
{
throw new Exception(string.Format("Column {0} was not found in existing DBF file", fieldInfo.Name));
}
}
if (cd.mWidth == 0) mIsFixedRecordWidth = false;
}
