public static KeySchema ReadSchema(byte[] buffer)
{
int offset = 0;
KeySchema SubjectSchema = new KeySchema();
SubjectSchema.KeyName = Encoding.Default.GetString(buffer, offset, 12); offset += 12;
SubjectSchema.KeyLength = BitConverter.ToInt32(buffer, 12); offset += 4;
SubjectSchema.Constraint = buffer[24]; offset += 1;
if (SubjectSchema.CheckConstraint(FOREIGNKEY))
{
Array.Copy(buffer, offset, SubjectSchema.RelatedTableName, 0, 16);
offset += 16;
}
if (SubjectSchema.CheckConstraint(CHECK))
{
Array.Copy(buffer, offset, SubjectSchema.CheckConstraintCondition, 0, 64);
offset += 64;
}
if (SubjectSchema.CheckConstraint(DEFAULT))
{
Array.Copy(buffer, offset, SubjectSchema.DefaultValue, 0, 128);
offset += 128;
}
if (SubjectSchema.CheckConstraint(INDEX))
{
Array.Copy(buffer, offset, SubjectSchema.IndexFileName, 0, 20);
offset += 20;
}
return(SubjectSchema);
}
public static Schema ReadSchemaFile(string FileName)
{
FileStream SchemaReader = new FileStream(DBA.Definitions.Fields.DatabaseLocation + FileName, FileMode.Open);
Schema SubjectSchema = new Schema();
byte[] Buffer = new byte[16];
SchemaReader.Read(Buffer, 0, 16);
SubjectSchema.TableName = Encoding.Default.GetString(Buffer);
Buffer = new byte[24];
SchemaReader.Read(Buffer, 0, 24);
SubjectSchema.LastAccessed = DateTime.FromBinary(BitConverter.ToInt64(Buffer, 0));
SubjectSchema.LastEdited = DateTime.FromBinary(BitConverter.ToInt64(Buffer, 8));
SubjectSchema.LastIndexed = DateTime.FromBinary(BitConverter.ToInt64(Buffer, 16));
Buffer = new byte[8];
SchemaReader.Read(Buffer, 0, 8);
SubjectSchema.recordLength = BitConverter.ToInt32(Buffer, 0);
SubjectSchema.RecordsCount = BitConverter.ToInt32(Buffer, 4);
while (SchemaReader.Position < SchemaReader.Length)
{
Buffer = new byte[256];
SchemaReader.Read(Buffer, 0, 256);
SubjectSchema.Keys.Add(KeySchema.ReadSchema(Buffer));
}
return(SubjectSchema);
}
public static Schema WriteSchemaFile(Schema SubjectSchema)
{
FileStream SchemaWriter = new FileStream(DBA.Definitions.Fields.DatabaseLocation + SubjectSchema.TableName.ComputeSha1Hash() + ".tsf", FileMode.OpenOrCreate);
SchemaWriter.Write(Encoding.Default.GetBytes(SubjectSchema.TableName), 0, Encoding.Default.GetByteCount(SubjectSchema.TableName));
byte[] Buffer = new byte[24];
Array.Copy(BitConverter.GetBytes(SubjectSchema.LastAccessed.ToBinary()), 0, Buffer, 0, 8);
Array.Copy(BitConverter.GetBytes(SubjectSchema.LastEdited.ToBinary()), 0, Buffer, 8, 8);
Array.Copy(BitConverter.GetBytes(SubjectSchema.LastIndexed.ToBinary()), 0, Buffer, 16, 8);
SchemaWriter.Write(Buffer, 0, 24);
SchemaWriter.Write(BitConverter.GetBytes(SubjectSchema.recordLength), 0, 4);
SchemaWriter.Write(BitConverter.GetBytes(SubjectSchema.RecordsCount), 0, 4);
foreach (KeySchema KS in SubjectSchema.Keys)
{
SchemaWriter.Write(KeySchema.WriteSchema(KS), 0, 256);
}
return(SubjectSchema);
}
public static byte[] WriteSchema(KeySchema SubjectSchema)
{
int offset = 0;
byte[] Buffer = new byte[256];
Array.Copy(Encoding.Default.GetBytes(SubjectSchema.KeyName), 0, Buffer, offset, 12); offset += 12;
Array.Copy(BitConverter.GetBytes(SubjectSchema.KeyLength), 0, Buffer, offset, 4); offset += 4;
Buffer[offset++] = SubjectSchema.Constraint;
Array.Copy(SubjectSchema.RelatedTableName, 0, SubjectSchema.RelatedTableName, offset, 16);
offset += 16;
Array.Copy(SubjectSchema.CheckConstraintCondition, 0, Buffer, offset, 64);
offset += 64;
Array.Copy(SubjectSchema.DefaultValue, 0, Buffer, offset, 128);
offset += 128;
Array.Copy(SubjectSchema.IndexFileName, 0, Buffer, offset, 20);
offset += 20;
return(Buffer);
}
