/// <summary>
/// Seek to the specified date. Will throw if date not found.
/// </summary>
/// <param name="Date"></param>
public void SeekToDate(DateTime Date)
{
int NumRowsToSkip = (Date - _FirstDate).Days;
In.Seek(FirstLinePosition, SeekOrigin.Begin);
while (!In.EndOfStream && NumRowsToSkip > 0)
{
In.ReadLine();
NumRowsToSkip--;
}
int SavedPosition = In.Position;
StringCollection Words = new StringCollection();
if (GetNextLine(In, ref Words))
{
// Make sure we found the date.
object[] Values = ConvertWordsToObjects(Words, ColumnTypes);
DateTime RowDate = GetDateFromValues(Values);
if (RowDate != Date)
{
throw new Exception("Non consecutive dates found in file: " + _FileName);
}
}
else
{
throw new Exception("End of file reached while trying to find date " + Date.ToShortDateString() +
" in file " + _FileName);
}
// All ok - restore position.
In.Seek(SavedPosition, SeekOrigin.Begin);
}
/// <summary>
/// Open the file ready for reading.
/// </summary>
public void Open(string FileName)
{
if (FileName == "")
{
return;
}
if (!File.Exists(FileName))
{
throw new Exception("Cannot find file: " + FileName);
}
_FileName = FileName;
CSV = Path.GetExtension(FileName).ToLower() == ".csv";
_Constants.Clear();
In = new StreamReaderRandomAccess(_FileName);
ReadApsimHeader(In);
FirstLinePosition = In.Position;
// Read in first line.
StringCollection Words = new StringCollection();
GetNextLine(In, ref Words);
ColumnTypes = DetermineColumnTypes(In, Words);
// Get first date.
object[] Values = ConvertWordsToObjects(Words, ColumnTypes);
_FirstDate = GetDateFromValues(Values);
// Now we need to seek to the end of file and find the last full line in the file.
In.Seek(0, SeekOrigin.End);
if (In.Position >= 1000 && In.Position - 1000 > FirstLinePosition)
{
In.Seek(-1000, SeekOrigin.End);
In.ReadLine(); // throw away partial line.
}
else
{
In.Seek(FirstLinePosition, SeekOrigin.Begin);
}
while (GetNextLine(In, ref Words))
{
}
In.Seek(FirstLinePosition, SeekOrigin.Begin);
// Get the date from the last line.
if (Words.Count == 0)
{
throw new Exception("Cannot find last row of file: " + FileName);
}
Values = ConvertWordsToObjects(Words, ColumnTypes);
_LastDate = GetDateFromValues(Values);
}
public void TestBomParsing(string inputFile)
{
string[] expected = new string[4]
{
"x,y",
"0,1",
"1,2",
"2,4"
};
long[] endOfLinePositions = new long[expected.Length];
using (Stream stream = GetResourceStream(inputFile))
{
StreamReaderRandomAccess reader = new StreamReaderRandomAccess(stream);
for (int i = 0; i < expected.Length; i++)
{
string line = reader.ReadLine();
Assert.AreEqual(expected[i], line);
endOfLinePositions[i] = reader.Position;
}
// Seek to the end of each line, and read a line, and ensure
// that we get the expected result. This should probably be a
// separate test.
for (int i = 1; i < expected.Length - 1; i++)
{
reader.Seek(endOfLinePositions[i], SeekOrigin.Begin);
string input = reader.ReadLine();
Assert.AreEqual(expected[i + 1], input);
}
}
}
public void TestPositionAfterSeek(string input, int seekPosition, SeekOrigin origin, int expectedPosition)
{
using (Stream stream = CreateStream(input))
{
StreamReaderRandomAccess reader = new StreamReaderRandomAccess(stream);
reader.Seek(seekPosition, SeekOrigin.Begin);
Assert.AreEqual(expectedPosition, reader.Position);
}
}
public void TestSeek(string input, int position, SeekOrigin origin, string expectedOutput)
{
using (Stream stream = CreateStream(input))
{
StreamReaderRandomAccess reader = new StreamReaderRandomAccess(stream);
reader.Seek(position, origin);
string actualOutput = reader.ReadLine();
Assert.AreEqual(expectedOutput, actualOutput);
}
}