// Statics //
/// <summary>
/// Dumps any read stream to a path
/// </summary>
/// <param name="Path"></param>
/// <param name="Stream"></param>
public static void Dump(string Path, RecordReader Stream)
{
using (StreamWriter sw = new StreamWriter(Path))
{
sw.WriteLine(Stream.Columns.ToNameString('\t'));
while (Stream.CanAdvance)
{
sw.WriteLine(Stream.ReadNext().ToString('\t'));
}
sw.Flush();
}
}
// Internal debugging //
/// <summary>
/// Dumps the entire table to a flat file
/// </summary>
/// <param name="Path"></param>
internal virtual void Dump(string Path)
{
using (StreamWriter sw = new StreamWriter(Path))
{
sw.WriteLine(this.Columns.ToNameString('\t'));
RecordReader rs = this.OpenReader();
while (rs.CanAdvance)
{
sw.WriteLine(rs.ReadNext().ToString('\t'));
}
sw.Flush();
}
}
/// <summary>
/// Calibrates the index
/// </summary>
public virtual void Calibrate()
{
if (this._Header.RecordCount != 0 || this._Parent.RecordCount == 0)
{
return;
}
RecordReader stream = this._Parent.OpenReader();
while (stream.CanAdvance)
{
RecordKey rk = stream.PositionKey;
Record rec = stream.ReadNext();
this.Insert(rec, rk);
}
}
//public static void ImportLines(Host Host, string Dir, string Alias, string RawPath, int Skip, int LineSize)
//{
// // Create the table //
// Schema q = new Schema();
// q.Add("ROW_ID", CellAffinity.LONG);
// q.Add("RAW_TEXT", CellAffinity.CSTRING, LineSize);
// Table t = Host.CreateTable(Dir, Alias, q);
// // Read in the lines //
// using (RecordWriter rw = t.OpenWriter())
// {
// Import(rw, RawPath, new char[] { }, char.MaxValue, Skip);
// }
//}
public static void Export(RecordReader Reader, string RawPath, bool Headers, char Delim, char Escape)
{
using (FileStream fs = File.Create(RawPath))
{
using (StreamWriter sw = new StreamWriter(fs))
{
if (Headers)
{
sw.WriteLine(Util.StringUtil.ToString(Reader.Columns, Delim, Escape));
}
while (Reader.CanAdvance)
{
string s = Util.StringUtil.ToString(Reader.ReadNext(), Delim, Escape);
sw.WriteLine(s);
}
}
}
}
public static RecordKey CheckSort(Table Element, Key Columns)
{
Record Last = null;
Record Current = null;
RecordReader rr = Element.OpenReader();
Current = rr.ReadNext();
while (rr.CanAdvance)
{
if (Last != null && Record.Compare(Last, Current, Columns) > 0)
{
return(rr.PositionKey);
}
Last = Current;
Current = rr.ReadNext();
}
return(RecordKey.RecordNotFound);
}
// Distinct Support //
public static void Distinct(Table Element, RecordWriter Writer, RecordMatcher Comparer)
{
// Check if the table is a heap //
if (!(Element is HeapTable))
{
throw new Exception("Can only sort a HeapTable");
}
if (Element.Header.IndexHeaders.Count != 0)
{
throw new Exception("Can not sort a table with indexes");
}
// Step 1: sort table //
Sort(Element, Comparer);
// Step 2: create a shell //
//Table t = Element.Host.CreateTempTable(Element.Columns);
// Step 3: open a reader //
RecordReader rr = Element.OpenReader();
// Step 4: write to the shell //
Record lag = null;
while (rr.CanAdvance)
{
Record current = rr.ReadNext();
if (lag == null)
{
Writer.Insert(current);
}
else if (Comparer.Compare(lag, current) != 0)
{
Writer.Insert(current);
}
lag = current;
}
}
