/// <summary>
/// Unified API for querying user chassis audit logs - both timestamp and maxEntries used as input
/// </summary>
/// <param name="filterStartTime"></param>
/// <param name="filterEndTime"></param>
/// <param name="maxEntries"></param>
/// <returns>Returns list of user log when success else returns null.</returns>
public static List <LogEntry> GetFilteredLogEntries(DateTime filterStartTime, DateTime filterEndTime, int maxEntries)
{
if (Tracer.GetCurrentUserLogFilePath() == null)
{
return(null);
}
try
{
List <LogEntry> timestampFilteredEntries = new List <LogEntry>();
// Parse the log entries from each user log file
// Note that these files could simultaneously be modified (switch primary, delete content etc)
foreach (string filepath in Tracer.GetAllUserLogFilePaths())
{
if (!File.Exists(filepath))
{
Tracer.WriteInfo("UserLogXmllinqHelper.GetFilteredLogEntries(): Skipping file ({0}) since it does not exist.");
continue;
}
using (FileStream fileStream = new FileStream(filepath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
using (BufferedStream bstream = new BufferedStream(fileStream))
using (StreamReader reader = new StreamReader(bstream))
{
int index = 0;
const int count = 2048; // Reading 2K characters at a time to alleviate memory pressure
// Splitting file with arbitrary chunks size may result in chopped 'partial' XML data which is saved in this variable
// This data will be merged with the subsequent (consecutive) XML data
string prevEntry = null;
while (!reader.EndOfStream)
{
char[] localbuffer = new char[count];
reader.Read(localbuffer, index, count);
string myData = new string(localbuffer);
myData = prevEntry + myData;
string[] subStrings = System.Text.RegularExpressions.Regex.Split(myData, @"ApplicationData>");
if (subStrings.Length < 1)
{
break;
}
prevEntry = subStrings[subStrings.Length - 1];
for (int i = 0; i < subStrings.Length - 1; i++)
{
string str = subStrings[i];
if (str.Length > 2 && str.Trim().EndsWith("</"))
{
string currentEntry = (str.Remove(str.Length - 2));
string[] tokens = currentEntry.Trim().Split(new char[] { ',' });
LogEntry timestampFilteredEntry = new LogEntry();
if (DateTime.TryParse(tokens[0], out timestampFilteredEntry.eventTime))
{
timestampFilteredEntry.eventTime = DateTime.ParseExact(tokens[0], "yyyy-MM-dd HH:mm:ss.fff", CultureInfo.InvariantCulture);
timestampFilteredEntry.eventDescription = currentEntry.Replace(tokens[0] + ",", "");
// Add this entry to the list only when the timestamp falls withing the parameter input range
if (timestampFilteredEntry.eventTime >= filterStartTime && timestampFilteredEntry.eventTime <= filterEndTime)
{
timestampFilteredEntries.Add(timestampFilteredEntry);
}
}
else
{
Tracer.WriteWarning("GetFilteredLogEntries(): Reading Chassis user log - ignoring entry '({0})' due to unparse-able date ", tokens[0]);
// Skipping the entry since date is not parse-able
}
}
}
prevEntry = subStrings[subStrings.Length - 1];
}
}
}
timestampFilteredEntries.Reverse();
return(timestampFilteredEntries.Take(maxEntries).ToList());
}
catch (Exception e)
{
Tracer.WriteError("GetFilteredLogEntries(): Reading Chassis user log exception " + e.Message);
return(null);
}
}