private string GetIndexData()
{
// with the backward reader we can quickly locate the origin of the <indexOffset>
string line = null;
StreamBackwardReader s = new StreamBackwardReader(filename);
// look for the closing tag of the mzXML structure
bool foundSlashMzXml = false;
while (!foundSlashMzXml)
{
line = s.ReadLine();
if (line.Contains("</mzXML>"))
{
foundSlashMzXml = true;
}
}
if (!foundSlashMzXml)
{
throw new Exception("Invalid mz-xml File; couldn't locate the ending </mzXML> tag.");
}
// look for the index offset so we can read forward again
// TODO this is not the most elegant way to do this.
while (!line.Contains("</indexOffset>"))
{
line = s.ReadLine();
}
while (!line.Contains("<indexOffset>"))
{
line += s.ReadLine();
}
s.Close();
long indexOffset = Parser.Uint(regexInteger.Match(line).Groups[1].ToString());
// load the offset table
StreamReader stream = new StreamReader(filename);
stream.BaseStream.Seek(indexOffset, SeekOrigin.Begin);
stream.DiscardBufferedData();
//_stream.BaseStream.Seek(indexOffset, SeekOrigin.Begin);
//_stream.DiscardBufferedData();
StringBuilder indexData = new StringBuilder();
do
{
line = stream.ReadLine();
indexData.Append(line);
indexData.Append("\n");
} while (!line.Contains("</index>"));
stream.Close();
string index = indexData.ToString();
int indexStart = index.IndexOf("<index", StringComparison.InvariantCulture);
return(index.Substring(indexStart, (index.IndexOf("</index>", StringComparison.InvariantCulture) + 8) - indexStart));
}
public void TestReadingBackwards()
{
var text = "these\nare\nsome\nlines";
var linesBackwards = new List <string>();
using (var memory = new MemoryStream(Encoding.UTF8.GetBytes(text)))
using (var reader = new StreamBackwardReader(memory))
{
linesBackwards.AddRange(reader.ReadLines());
}
linesBackwards.Reverse();
var actual = string.Join("\n", linesBackwards);
Assert.AreEqual(text, actual);
}
