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using System;
using System.IO;
using System.Reflection;
using System.Reflection.Emit;
namespace DbfDotNet.Core
{
public class ColumnDefinition
{
public FieldInfo mFieldInfo;
internal int mOffset;
internal TypeCode NativeTypeCode;
internal bool IsNullable;
internal int ColumnIndex;
internal string mColumnName;
internal int mWidth;
internal int mDecimals;
internal ColumnType mColumnType;
internal ColumnDefinition mOriginalColumn;
internal bool mAscending = true;
internal DbfVersion mVersion;
public ColumnDefinition()
{
}
// called when created from existing DBF file
public void Initialize(DbfVersion version, FieldInfo fieldinfo, ColumnAttribute columnAttribute)
{
this.mFieldInfo = fieldinfo;
this.mVersion = version;
if (columnAttribute == null) columnAttribute = new ColumnAttribute();
Type fieldType = mFieldInfo.FieldType;
if (fieldType.IsGenericType && fieldType.GetGenericTypeDefinition() == typeof(Nullable<>))
{
IsNullable=true;
NativeTypeCode= Type.GetTypeCode(fieldType.GetGenericArguments()[0]);
}
else this.NativeTypeCode = Type.GetTypeCode(fieldType);
mColumnName = (columnAttribute.ColumnName == null || columnAttribute.ColumnName.Length == 0 ?
fieldinfo.Name : columnAttribute.ColumnName);
mColumnType = columnAttribute.Type;
mWidth = columnAttribute.Width;
mDecimals = columnAttribute.Decimals;
int defaultWidth, defaultDecimals;
if (mColumnType == ColumnType.UNKNOWN)
{
if (NativeTypeCode == TypeCode.Object)
{
GetDefaultColumnType(fieldType, mVersion, out mColumnType, out defaultWidth, out defaultDecimals);
}
else
{
GetDefaultColumnType(NativeTypeCode, IsNullable, mVersion, out mColumnType, out defaultWidth, out defaultDecimals);
}
if (mWidth == -1) mWidth = defaultWidth;
if (mDecimals == -1) mDecimals = defaultDecimals;
}
CheckWidthAndDecimals();
}
// called when created from fieldinfo
public void Initialize(string name, char type, int width, int decimals)
{
mColumnName = name;
switch (type)
{
case 'C':
mColumnType = ColumnType.CHARACTER;
break;
case 'N':
mColumnType = ColumnType.NUMERICAL;
break;
case 'L':
mColumnType = ColumnType.LOGICAL;
break;
case 'M':
mColumnType = ColumnType.MEMO;
break;
case 'D':
mColumnType = ColumnType.DATE_YYYYMMDD;
break;
default:
throw new Exception(string.Format("Invalid column datatype :'{0}'", type));
}
mWidth = width;
mDecimals = decimals;
}
// 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();
}
public static void GetDefaultColumnType(TypeCode nativeTypeCode, bool nullable, DbfVersion version, out ColumnType type, out int defaultWidth, out int defaultDecimals)
{
defaultDecimals = 0; // default
if (version == DbfVersion.DbfDotNet)
{
switch (nativeTypeCode)
{
case TypeCode.Boolean:
type = ColumnType.LOGICAL;
defaultWidth = 1;
break;
case TypeCode.Byte:
type = ColumnType.BYTE;
defaultWidth = 1;
break;
case TypeCode.SByte:
type = ColumnType.SBYTE;
defaultWidth = 1;
break;
case TypeCode.Int16:
type = ColumnType.INT16;
defaultWidth = 2;
break;
case TypeCode.UInt16:
type = ColumnType.UINT16;
defaultWidth = 2;
break;
case TypeCode.Int32:
type = ColumnType.INT32;
defaultWidth = 4;
break;
case TypeCode.UInt32:
type = ColumnType.UINT32;
defaultWidth = 4;
break;
case TypeCode.Single:
type = ColumnType.SINGLE;
defaultWidth = 4;
break;
case TypeCode.Int64:
type = ColumnType.INT64;
defaultWidth = 8;
break;
case TypeCode.UInt64:
type = ColumnType.UINT64;
defaultWidth = 8;
break;
case TypeCode.Double:
type = ColumnType.DOUBLE;
defaultWidth = 8;
break;
case TypeCode.Decimal:
type = ColumnType.DECIMAL;
defaultWidth = 13;// 96 bits + 0..28 (4 bits exponent) + sign = 101 bits minimum
break;
case TypeCode.DateTime:
type = ColumnType.DATETIME;
defaultWidth = 8; // 64 bits
break;
case TypeCode.String:
type = ColumnType.CHARACTER;
defaultWidth = 20; // unknown
break;
case TypeCode.Char:
// TODO depend on the encoding
type = ColumnType.CHARW;
defaultWidth = 2;
break;
default:
throw new InvalidColumnException(nativeTypeCode.ToString(), null);
}
}
else
{
switch (nativeTypeCode)
{
case TypeCode.Boolean:
type = ColumnType.LOGICAL;
defaultWidth = 1; // T or F
break;
case TypeCode.Byte:
type = ColumnType.NUMERICAL;
defaultWidth = 3; // 255
break;
case TypeCode.SByte:
type = ColumnType.NUMERICAL;
defaultWidth = 4; // -128
break;
case TypeCode.Int16:
type = ColumnType.NUMERICAL;
defaultWidth = 6; // -32768
break;
case TypeCode.UInt16:
type = ColumnType.NUMERICAL;
defaultWidth = 5; // 65535
break;
case TypeCode.Int32:
type = ColumnType.NUMERICAL;
defaultWidth = 11; // -2147483648
break;
case TypeCode.UInt32:
type = ColumnType.NUMERICAL;
defaultWidth = 10; // 4294967295
break;
case TypeCode.Single:
type = ColumnType.NUMERICAL;
defaultWidth = 9 + 1; // 7..9 decimals digits of decimals + the DOT
defaultDecimals = 2;
break;
case TypeCode.Int64:
type = ColumnType.NUMERICAL;
defaultWidth = 20; // Int64.MinValue "-9223372036854775808"
break;
case TypeCode.UInt64:
type = ColumnType.NUMERICAL;
defaultWidth = 19; // UInt64.MaxValue "18446744073709551615"
break;
case TypeCode.Double:
type = ColumnType.NUMERICAL;
defaultWidth = 17 + 1; // 15..17 decimal digits of decimals + the DOT
defaultDecimals = 2;
break;
case TypeCode.Decimal:
type = ColumnType.NUMERICAL;
defaultWidth = 30 + 1; // Decimal.MinValue "-79228162514264337593543950335" + the DOT
defaultDecimals = 4;
break;
case TypeCode.DateTime:
type = ColumnType.DATE_YYYYMMDD;
defaultWidth = 8;
break;
case TypeCode.String:
type = ColumnType.CHARACTER;
defaultWidth = 20; // unknown really
break;
case TypeCode.Char:
// TODO depend on the encoding
type = ColumnType.CHARACTER;
defaultWidth = 1;
break;
default:
throw new InvalidColumnException(nativeTypeCode.ToString(), null);
}
}
}
public static void GetDefaultColumnType(Type objectType, DbfVersion version, out ColumnType type, out int defaultWidth, out int defaultDecimals)
{
defaultDecimals = 0;
if (objectType == typeof(byte[]))
{
type = ColumnType.BYTES;
defaultWidth = 0;
}
else throw new InvalidColumnException(objectType, null);
}
private void CheckWidthAndDecimals()
{
int minWidth = 1;
int maxWidth = 255;
int minDecimals = 0;
int maxDecimals = 0;
int fixedwidth = -1;
int defaultWidth = -1;
int defaultDecimals = 0;
switch (mColumnType)
{
case ColumnType.BOOL:
case ColumnType.LOGICAL:
fixedwidth = 1; // T or F
break;
//case ColumnType.INTEGER:
// maxWidth = 20; // Int64.MinValue "-9223372036854775808"
// break;
case ColumnType.NUMERICAL:
defaultWidth = 30 + 1; // Decimal.MinValue "-79228162514264337593543950335" + the DOT
maxDecimals = 255;
break;
case ColumnType.DATE_YMD:
fixedwidth = 3;
break;
case ColumnType.DELAYED:
maxDecimals = 255;
break;
case ColumnType.DELETED_FLAG:
fixedwidth = 1;
break;
case ColumnType.BYTES:
maxWidth = int.MaxValue; // we assume you know what you do on this type
break;
case ColumnType.CHARACTER:
break;
case ColumnType.BYTE:
case ColumnType.SBYTE:
case ColumnType.CHAR:
fixedwidth = 1;
break;
case ColumnType.INT16:
case ColumnType.UINT16:
case ColumnType.CHARW:
fixedwidth = 2;
break;
case ColumnType.INT32:
case ColumnType.UINT32:
case ColumnType.SINGLE:
fixedwidth = 4;
break;
case ColumnType.INT64:
case ColumnType.UINT64:
case ColumnType.DOUBLE:
case ColumnType.DATE_YYYYMMDD:
fixedwidth = 8;
break;
case ColumnType.DECIMAL:
fixedwidth = 13;// 96 bits + 0..28 (4 bits exponent) + sign = 101 bits minimum
break;
case ColumnType.DATETIME:
fixedwidth = 8; // 64 bits
break;
default:
throw new InvalidColumnException(mColumnType.ToString(), null);
}
if (fixedwidth >= 0)
{
minWidth = fixedwidth;
maxWidth = fixedwidth;
defaultWidth = fixedwidth;
}
if (mWidth == -1) mWidth = defaultWidth;
if (mDecimals == -1) mDecimals = defaultDecimals;
if (mWidth < minWidth || mWidth > maxWidth)
{
throw new InvalidColumnException(mColumnName,
(minWidth == maxWidth ?
string.Format("Width must be {0}.", minWidth) :
string.Format("Width must be between {0} and {1}.", minWidth, maxWidth))
);
}
if (mDecimals < minDecimals || mDecimals > maxDecimals)
{
throw new InvalidColumnException(mColumnName,
(minWidth == maxWidth ?
string.Format("Decimals must be {0}.", minDecimals) :
string.Format("Decimals must be between {0} and {1}.", minDecimals, maxDecimals))
);
}
}
internal char DbfColumnType
{
get {
switch(mColumnType)
{
case ColumnType.CHARACTER:
return 'C';
case ColumnType.NUMERICAL:
return 'N';
case ColumnType.DATE_YYYYMMDD:
return 'D';
case ColumnType.LOGICAL:
return 'L';
default:
throw new Exception("Invalid column type");
}
}
}
}
}
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These days I spend most of my time with the .NET framework, JavaScript and html.
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