/// <summary>
/// Reads a user-specified number of lines from the top of the file, displays them to the console,
/// and then exits/
/// </summary>
/// <param name="SplitCols">A Dictionary of column splitting specifiers. The key is a column name, and the
/// value is the value within a field upon which to split. E.g. <"foo",":"> splits the foo column into foo,
/// and foo_descr on the colon character</param>
public static void Preview(Dictionary <string, string> SplitCols)
{
int InRows = 0;
List <ProfileColumn> Cols = ProfileColumn.BuildColumnList(SplitCols);
Dictionary <int, string> SplitOrdinals = SplitOrdinalsToDict(Cols);
Log.InformationMessage("Previewing the file");
using (FileReader Rdr = FileReader.NewFileReader(Cfg.File, Cfg.Prep))
{
List <string> InFields = null;
while ((InFields = Rdr.ReadLine()) != null)
{
if (SplitCols != null)
{
InFields = ProfileColumn.SplitFields(InFields, SplitOrdinals);
}
Log.InformationMessage(string.Join(",", InFields.ToArray()));
if (++InRows >= Cfg.Preview)
{
break;
}
}
}
}
/// <summary>
/// Profiles and pre-processes a file. Pre-processing involves 1) removing headers and footers, 2) skipping lines,
/// 3) un-quoting fields, and 4) splitting fields.
/// </summary>
/// <param name="Cols">A List of ProfileColumn instances to populate with data type information accumulated from the
/// file data</param>
/// <param name="PrepFileFqpn">The fully-qualified path name of the prepped file generated by the method. If the
/// method does not perform prepping, then the output variable will be set to null</param>
/// <param name="ShouldSplit">True if columns splitting should be performed. If true then the Cols arg will have
/// already been split and so the method will split the input lines to align with the Cols list</param>
/// <returns></returns>
private static int ProcessOneFile(List <ProfileColumn> Cols, out string PrepFileFqpn, bool ShouldSplit)
{
int InRows = 0;
int ErrRows = 0;
{
string Msg = "Processing file: {0}";
if (Cfg.Profile && Cfg.Prep)
{
Msg = "Profiling and Prepping file: {0}";
}
else if (Cfg.Profile)
{
Msg = "Profiling file: {0}";
}
else if (Cfg.Prep)
{
Msg = "Prepping file: {0}";
}
Log.InformationMessage(Msg, Cfg.File);
}
bool DoFreqs = !string.IsNullOrEmpty(Cfg.FreqFile);
int SkipLines = Math.Max(Cfg.SkipLines, Cfg.HeaderLine);
DateTime Start = DateTime.Now;
long BytesRead = 0;
decimal FileSize = new FileInfo(Cfg.File).Length;
Dictionary <int, string> SplitOrdinals = SplitOrdinalsToDict(Cols);
using (FileReader Rdr = FileReader.NewFileReader(Cfg.File, Cfg.Prep))
{
List <string> InFields = null;
StreamWriter PrepFileWriter = null;
if ((PrepFileFqpn = Cfg.Prep ? MakePrepFileName(Cfg.File, Cfg.PrepDir) : null) != null)
{
PrepFileWriter = new StreamWriter(PrepFileFqpn);
}
try
{
while ((InFields = Rdr.ReadLine()) != null)
{
if (ShouldSplit)
{
InFields = ProfileColumn.SplitFields(InFields, SplitOrdinals);
}
++InRows;
if (Cols != null && InFields.Count != Cols.Count)
{
// ERROR -- column count mismatch
++ErrRows;
if (!string.IsNullOrEmpty(Cfg.ErrFile))
{
LogErrorRecord(SkipLines + InRows, InFields, Cfg.ErrFile);
}
if (Cfg.MaxErrors >= 0 && ErrRows > Cfg.MaxErrors) // Cfg.MaxErrors value of -1 means ignore all errors
{
throw new LoadException(string.Format("File {0} has a different number of columns than expected on row {1}. Expected: {2} Found: {3}", Cfg.File, SkipLines + InRows, Cols.Count, InFields.Count));
}
else
{
continue;
}
}
if (PrepFileWriter != null)
{
// prepped file is always tab-delimited
PrepFileWriter.WriteLine(string.Join("\t", InFields.ToArray()));
}
if (Cfg.Profile)
{
for (int FldNum = 0; FldNum < InFields.Count; ++FldNum)
{
Cols[FldNum].Profile(InFields[FldNum], DoFreqs, Cfg.Typed);
}
}
if (InRows % 10000 == 0) // && Args.ShowProgress)
{
decimal PctComplete = Rdr.TotBytesRead / FileSize;
Log.InformationMessage("{0} rows ({1:P0})", InRows, PctComplete); // something to look at for large files
}
}
BytesRead = Rdr.TotBytesRead;
}
finally
{
if (PrepFileWriter != null)
{
PrepFileWriter.Close();
}
}
}
if (ErrRows != 0)
{
Log.InformationMessage("{0} error records were written to error file: {1}", ErrRows, Cfg.ErrFile);
}
Log.InformationMessage("Rows read: {0:n0} -- Error rows: {1:n0} -- Bytes read: {2:n0} -- Elapsed time (HH:MM:SS.Milli): {3}", InRows, ErrRows, BytesRead, DateTime.Now - Start);
if (InRows == ErrRows)
{
// something went way wrong
throw new LoadException(string.Format("No records in the input file matched the expected format."));
}
return(InRows);
}